99-26795. Control of Emissions of Air Pollution From 2004 and Later Model Year Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty Truck Definition  

  • [Federal Register Volume 64, Number 209 (Friday, October 29, 1999)]
    [Proposed Rules]
    [Pages 58472-58566]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 99-26795]
    
    
    
    [[Page 58471]]
    
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    Part II
    
    
    
    
    
    Environmental Protection Agency
    
    
    
    
    
    _______________________________________________________________________
    
    
    
    40 CFR Parts 85 and 86
    
    
    
    Control of Emissions of Air Pollution From 2004 and Later Model Year 
    Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty Truck 
    Definition; Proposed Rule
    
    Federal Register / Vol. 64, No. 209 / Friday, October 29, 1999 / 
    Proposed Rules
    
    [[Page 58472]]
    
    
    
    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Parts 85 and 86
    
    [AMS-FRL-6456-3]
    RIN 2060-AI12, 2060-AI23
    
    
    Control of Emissions of Air Pollution From 2004 and Later Model 
    Year Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty 
    Truck Definition
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Notice of proposed rulemaking (NPRM).
    
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    SUMMARY: We are proposing to take several actions relating to emission 
    standards and test procedures for heavy-duty engines and vehicles 
    intended for operation on roads and highways. The proposed provisions 
    are for the 2004 and later model years. First, we are proposing new 
    more stringent emissions standards and related provisions for all 
    heavy-duty Otto-cycle (e.g., gasoline-fueled) engines and vehicles. 
    Vehicles in this category include large full size pick-up trucks, full 
    size cargo and passenger vans, and the largest sport utility vehicles. 
    For heavy-duty Otto-cycle engines and vehicles, today's proposal would 
    reduce the standards for oxides of nitrogen and hydrocarbons by 
    approximately 75 percent from current standards. Second, we propose to 
    reaffirm that the NMHC+NOX standard promulgated in October, 
    1997 for diesel heavy-duty engines is both necessary and feasible. This 
    standard represents about a 50 percent reduction in emissions of 
    nitrogen oxides, as well as reductions in hydrocarbons, from diesel 
    trucks and buses. Third, we are proposing to require on-board 
    diagnostics systems for all heavy-duty vehicles and engines at or below 
    14,000 lbs gross vehicle weight rating (GVWR), and to revise the on-
    board diagnostics requirements for diesel light-duty vehicles and 
    trucks. These systems will identify the failure of components of the 
    emissions control system. Fourth, we are proposing the addition of new 
    test procedures and associated standards for heavy-duty diesel engines 
    and vehicles. Fifth, we are proposing to include heavy models of 
    gasoline and diesel-fueled sport-utility vehicles and similar heavy-
    duty vehicles used primarily for personal transportation in the Tier 2 
    program that EPA proposed earlier this year. Today's proposal would 
    result in lower emissions of oxides of nitrogen and hydrocarbons, as 
    well as lower particulate matter due to reductions in secondary 
    particulate formation (secondary particulate matter is not emitted 
    directly from the engine, but is formed when emissions of oxides of 
    nitrogen react with ammonia in the atmosphere to produce ammonium 
    nitrate particulates), and would assist states and regions facing ozone 
    air quality problems that are causing a range of adverse health 
    effects, particularly respiratory impairment and related illnesses.
    
    DATES: We must receive your comments on this NPRM by December 2, 1999. 
    A public hearing will be held on November 2, 1999 (EPA has published 
    notice of this hearing on October 22, 1999 (64 FR 56985).). EPA 
    requests that parties who want to testify notify the contact person 
    listed in the ADDRESSES section of this document one week before the 
    date of the hearing. More information about commenting on this action 
    and on the public hearing may be found in section XI What are the 
    Opportunities for Public Participation?
    
    ADDRESSES: Written comments should be submitted (in duplicate, if 
    possible) to: EPA Air and Radiation Docket, Attn: Docket No. A-98-32, 
    Room M-1500 (Mail Code 6102), 401 M Street SW, Washington, DC 20460. 
    EPA requests that a copy of the comments also be sent to the contact 
    person listed below. Materials relevant to this proposal have been 
    placed in Docket Nos. A-98-32 and A-95-27 and may be viewed in Room M-
    1500 between 8:00 a.m. and 5:30 p.m., Monday through Friday. The 
    telephone number is (202) 260-7548 and the facsimile number is (202) 
    260-4400. A reasonable fee may be charged by EPA for copying docket 
    materials.
        The public hearing will be held at Top of the Tower, 1717 Arch 
    Street, 51st Floor, Philadelphia, PA 19103, telephone: 215-567-8787, 
    fax: 215-557-5171.
    
    FOR FURTHER INFORMATION CONTACT: Margaret Borushko, U.S. Environmental 
    Protection Agency, Engine Programs and Compliance Division, 2000 
    Traverwood Drive, Ann Arbor, MI 48105-2498. Telephone (734) 214-4334; 
    Fax (734) 214-4816; e-mail borushko.margaret@epa.gov.
    
    SUPPLEMENTARY INFORMATION:
    
    Regulated Entities
    
        Entities potentially regulated by this action are those that 
    manufacture and sell new heavy-duty motor vehicles, new heavy-duty 
    engines, and new diesel light-duty motor vehicles in the United States. 
    Regulated categories and entities include:
    
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                    Category                 Examples of regulated  entities
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    Industry...............................  Manufacturers of new heavy-duty
                                              motor vehicles and engines.
                                             Manufacturers of new diesel
                                              light-duty motor vehicles and
                                              engines.
    ------------------------------------------------------------------------
    
        This table is not intended to be exhaustive, but rather provides a 
    guide for readers regarding entities likely to be regulated by this 
    action. This table lists the types of entities that EPA is now aware 
    could potentially be regulated by this action. Other types of entities 
    not listed in the table could also be regulated. To determine whether 
    your activities are regulated by this action, you should carefully 
    examine the applicability criteria in Secs. 86.001-1 and 86.1801-01. If 
    you have questions regarding the applicability of this action to a 
    particular entity, consult the person listed in the preceding FOR 
    FURTHER INFORMATION CONTACT section.
    
    Obtaining Rulemaking Documents Through the Internet
    
        The preamble, regulatory language, regulatory impact analysis, and 
    other related documents are also available electronically from the EPA 
    Internet Web site. This service is free of charge, except for any cost 
    you already incur for Internet connectivity. The electronic version is 
    made available on the day of publication on the primary Web site listed 
    below. The EPA Office of Mobile Sources also publishes Federal Register 
    notices and related documents on the secondary Web site listed below.
    
    1. http://www.epa.gov/docs/fedrgstr/EPA-AIR/ (either select desired 
    date or use Search feature)
    2. http://www.epa.gov/OMSWWW/ (Look in What's New or under the specific 
    rulemaking topic)
    
        Please note that due to differences between the software used to 
    develop the document and the software into which the document may be 
    downloaded, changes in format, page length, etc. may occur.
    
                       Table of Acronyms and Abbreviations
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    ABT                      Averaging, Banking, and Trading
    AECD                     Auxiliary Emission Control Device
    ALVW                     Adjusted Loaded Vehicle Weight
    ANPRM                    Advance Notice of Proposed Rulemaking
    BSFC                     Brake-Specific Fuel Consumption
    CAA                      Clean Air Act
    CAP 2000                 Compliance Assurance Program for the 2000 and
                              later model years
    CARB                     California Air Resources Board
    
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    CASAC                    Clean Air Scientific Advisory Committee
    CFF                      Clean Fuel Fleet
    CO                       Carbon Monoxide
    DF                       Deterioration Factor
    DOC                      Diesel Oxidation Catalyst
    DRI                      Desert Research Institute
    EGR                      Exhaust Gas Recirculation
    EMA                      Engine Manufacturers Association
    EPA                      Environmental Protection Agency
    FEL                      Family Emission Limit
    g/bhp-hr                 grams per brake-horsepower hour
    g/mi                     grams per mile
    GVWR                     Gross Vehicle Weight Rating
    HC                       Hydrocarbons
    HD                       Heavy-Duty
    HDDE                     Heavy-Duty Diesel Engine
    HDE                      Heavy-Duty Engine
    HDEWG                    Heavy-Duty Engine Working Group
    HDV                      Heavy-Duty Vehicle
    HEUI                     Hydraulically Actuated Electronic Unit
                              Injection
    HLDT                     Heavy Light-Duty Truck
    LDT                      Light-Duty Truck
    LDV                      Light-Duty Vehicle
    LEV                      Low Emission Vehicle
    LLDT                     Light Light-Duty Truck
    LRT                      Load Response Test
    MDV                      Medium-Duty Vehicle
    MEUI                     Mechanically Actuated Electronic Unit Injection
    MIL                      Malfunction Indicator Light
    MY                       Model Year
    NAAQS                    National Ambient Air Quality Standards
    NCP                      Non-Conformance Penalty
    NMHC                     Non-Methane Hydrocarbon
    NMOG                     Non-Methane Organic Gas
    NOX                      Nitrogen Oxides
    NPRM                     Notice of Proposed Rulemaking
    OBD                      On-Board Diagnostics
    OEM                      Original Equipment Manufacturer
    ORVR                     Onboard Refueling Vapor Recovery
    PM                       Particulate Matter
    PM10                     Particulate Matter of 10 microns or less in
                              diameter
    PM2.5                    Particulate Matter of 2.5 microns or less in
                              diameter
    RIA                      Regulatory Impact Analysis
    SIP                      State Implementation Plan
    SOP                      Statement of Principles
    TW                       Test Weight
    UDDS                     Urban Dynamometer Driving Schedule
    ULEV                     Ultra Low Emission Vehicle
    VGT                      Variable Geometry Turbocharger
    VMT                      Vehicle Miles Traveled
    VNT                      Variable Nozzle Turbocharger
    VOC                      Volatile Organic Compound
    ------------------------------------------------------------------------
    
    Table of Contents
    
    I. What is EPA Proposing to Do?
    
    A. Changes to the Engine-Based Program
    B. Expanding the Otto-cycle Vehicle-based Program to Certain Heavy-
    duty Vehicles
    C. Additional Changes Affecting Heavy-duty Vehicle and Heavy-duty 
    Engine Programs
    D. Heavy-duty Lead Time Issues and Voluntary Federal Standards
    
    II. What is the Environmental Need for this Proposal?
    
    A. Need for Additional NOX and NMHC Reductions
        1. Health and Welfare Effects from NMHC and NOX
        2. Current Compliance with the Ozone NAAQS
        3. Future Compliance with the Ozone NAAQS
        4. Contribution of HD Diesel and Gasoline Engines to Total VOC 
    and NOX Inventories
    B. Need for Additional PM Reductions
        1. Health and Welfare Effects from PM
        2. Current and Future Compliance with the PM10 NAAQS
        3. Contribution of HD Diesel and Gasoline Vehicles to PM 
    Inventories
        a. Contribution to National PM10 Inventories
        b. Source-apportionment Studies for Diesel PM
    C. Air Toxics from HD Engines and Vehicles
    
    III. What is the Important Background Information for this Proposal?
    
    A. Statement of Principles and Rulemaking History
    B. 1999 Review of Heavy-duty Diesel Engine NMHC+NOX 
    Standards
    C. Proposal for Heavy-duty Gasoline Engine Standards
        1. Summary of Comments on 1996 NPRM
        2. Analysis Leading to Decision to not Finalize Otto-cycle 
    Standards
    D. Consent Decrees with Heavy-duty Diesel Engine Manufacturers
    
    IV. What are the Details of this Proposal?
    
    A. Reaffirmation of 2004 NMHC + NOX Standard for Heavy-
    duty Diesel Engines
    B. Are Changes in Diesel Fuel Quality Necessary to Meet the 2004 
    Standards?
    C. Otto-cycle Engine-based Program
        1. Engine Exhaust Emissions Standards
        2. Averaging, Banking, and Trading for Otto-Cycle Engines
    D. Supplemental Exhaust Emission Standards and Test Procedures for 
    HD Diesel Engines
        1. Introduction/Background
        2. Proposed Supplemental Test Procedures and Standards
        a. Supplemental Steady-State Test
        b. Not-To-Exceed Limits
        c. Diesel Supplemental Load Response Test
        d. Ambient Conditions, Temperature and Humidity, Laboratory and 
    In-use Testing
        3. Access to On-board Computer Information
    E. Otto-cycle Vehicle-based Program
        1. Moving to a Vehicle-based Test Procedure and Standards
        2. Vehicle Exhaust Emissions Standards
        3. Heavy-duty Vehicle Averaging, Banking and Trading
        a. Background
        b. Proposal
        c. Credit exchanges between the engine and chassis-based 
    programs
        4. Evaporative standards/onboard refueling vapor recovery
        a. Enhanced evaporative emissions
        b. Onboard refueling vapor recovery
        5. Compliance Assurance Program
        a. CAP 2000 for HDVs
        b. Proposed Modifications to the CAP 2000 Program For Chassis-
    Based HDVs
        6. Useful Life
        7. Aftermarket Alternative Fuels Conversions
    F. Proposal to Revise the Definition of Light-duty Truck
        1. Background
        2. Proposal
        3. Integration into Proposed Tier 2 Program
        a. Tier 2 Standards for New HLDTs
        b. Interim Standards for New HLDTs
        c. Technological Feasibility of Tier 2 Standards for New HLDTs
    G. On-Board Diagnostics
        1. Background on OBD
        2. CARB OBDII Requirements
        3. Proposed Federal OBD Requirements
        4. Federal OBD Malfunction Thresholds and Monitoring 
    Requirements
        5. Proposed Standardization Requirements
        6. Deficiency Provisions
        7. Applicability and Waivers
        8. Certification Provisions
    H. Durability Procedures
    I. Non-Conformance Penalties
    
    V. Additional Heavy-Duty Engine Provisions Under Consideration
    
    A. Revision to the Definition of Rated Speed
    B. A Manufacturer-based In-use Testing Program for Heavy-duty 
    Engines
    C. On-board Diagnostics for Heavy-duty Engines and Vehicles Above 
    14,000 Pounds GVWR
    D. Applying the Not-to-Exceed Approach and Emission Limits to Heavy-
    duty Otto-cycle Engines
    
    VI. Are the Proposed Requirements Technologically Feasible?
    
    A. 2004 Emission Standards for Heavy-duty Diesel Engines
        1. Probable Emission Control Strategies
        2. Feasibility of 2004 HD Diesel Standards
    B. 2004 Emission Standards for Heavy-duty Otto-cycle Vehicles and 
    Engines
        1. Current Technologies
        2. Chassis-based standards
        3. Engine-based standards
        4. Onboard Refueling Vapor Recovery
    C. On-Board Diagnostics
    
    VII. What are the Environmental Benefits of this Proposal?
    
    A. 2004 Emission Standards for Heavy-Duty Diesel Engines
    B. 2004 Emission Standards for Heavy-duty Otto-cycle Vehicles and 
    Engines
    C. Benefits of the Supplemental Standards and In-Use Control 
    Measures of Today's Proposal
    
    VIII. What are the Economic Impacts of the Proposal?
    
    A. 2004 Emission Standards for Heavy-duty Diesel Engines
        1. Expected Technologies
        2. Per Engine Costs
        3. Aggregate Costs to Society
    B. 2004 Emission Standards for Heavy-duty Otto-cycle Vehicles and 
    Engines
        1. Expected Technologies
        2. Per Vehicle Costs
        3. Aggregate Cost to Society
    
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    IX. What is the Cost-Effectiveness of the Proposal?
    
    A. 2004 Emission Standards for Heavy-duty Diesel Engines
    B. 2004 Emission Standards for Heavy-duty Otto-cycle Vehicles and 
    Engines
    
    X. Are Future Reductions in HD Emissions Possible?
    
    A. Potential Future Standards for Heavy-duty Diesel Vehicles and 
    Engines
        1. Potential Future Reductions in Heavy-duty Diesel 
    NOX and NMHC
        2. Potential Future Reductions in Heavy-duty Diesel Engine PM
        3. Potential Structure of Future Diesel Emission Standards
    B. Potential Future Standards for Heavy-duty Otto-cycle Vehicles
        1. Exhaust Emission Standards
        2. Evaporative standards
    
    XI. What are the Opportunities for Public Participation?
    
    A. Comments and the Public Docket
    B. Public Hearing
    
    XII. What Administrative Requirements Apply to this Proposal?
    
    A. Compliance with Executive Order 12866
    B. Impact on Small Entities
    C. Unfunded Mandates Reform Act
    D. Reporting and Recordkeeping Requirements
    E. Compliance with Executive Order 13045
    F. Enhancing Intergovernmental Partnerships
    G. Consultation and Coordination with Indian Tribal Governments
    H. National Technology Transfer and Advancement Act
    I. Compliance with Executive Order on Federalism
    
    XIII. What is EPA's Statutory Authority for this Proposal?
    
    I. What Is EPA Proposing To Do?
    
        EPA (or, ``the Agency'') is proposing to take several actions 
    relating to emission standards and test procedures for heavy-duty 
    engines (HDEs) and heavy-duty vehicles (HDVs) intended for highway 
    operation.\1\ The proposed provisions would become effective starting 
    with the 2004 model year (MY). These actions supplement a June 1996 
    proposed rule (61 FR 33421, June 27, 1996), in which we proposed new 
    emission standards for heavy-duty diesel engines (HDDE) and heavy-duty 
    Otto-cycle engines and vehicles, and a subsequent October 1997 final 
    rule (62 FR 54694, October 21, 1997), in which we finalized new 
    emission standards for heavy-duty diesel engines.\2\
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        \1\ Light-duty vehicles and light-duty trucks are defined as 
    vehicles with a gross vehicle weight rating (GVWR) below 8,500 
    pounds. Heavy-duty vehicles are vehicles with a GVWR greater than or 
    equal to 8,500 pounds. Heavy-duty engines are engines used in heavy-
    duty vehicles.
        \2\ The terms ``diesel'' and ``Otto-cycle'' generally refer to 
    the type of combustion cycle employed by an engine. In a diesel-
    cycle engine combustion is brought about by the compression of the 
    fuel mixture (compression ignition), whereas in an Otto-cycle engine 
    combustion is achieved by providing a spark to the fuel mixture 
    (spark ignition). Although a generalization for which there are 
    exceptions, diesel-cycle vehicles are generally fueled with diesel 
    fuel and Otto-cycle vehicles are generally fueled with standard 
    gasoline.
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        Currently, EPA has a chassis-based regulatory program for light-
    duty vehicles (LDVs) and light-duty trucks (LDTs), meaning that the 
    vehicle itself is subject to emission standards and testing. For all 
    heavy-duty vehicles the engine alone is tested and must currently meet 
    engine-based standards.\3\ Engine testing currently applies to all 
    diesel-cycle and Otto-cycle heavy-duty vehicles. One of the key 
    elements of today's action is a proposal to begin regulating a subset 
    of heavy-duty vehicles using chassis-based requirements. The heavy-duty 
    vehicles that are proposed to be subject to chassis-based requirements 
    are complete Otto-cycle heavy-duty vehicles with a gross vehicle weight 
    rating (GVWR) below 14,000 pounds.4,5 In addition, some 
    complete gasoline and diesel-fueled heavy-duty vehicles between 8,500 
    and 10,000 pounds GVWR are proposed to be incorporated into the Tier 2 
    program proposed by EPA earlier this year (64 FR 26004, May 13, 1999). 
    Today's proposal can generally be separated into those elements 
    relating to the new chassis-based requirements and those elements that 
    affect the engine-based requirements. The proposals listed below are 
    explained in greater detail in the remainder of this document.
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        \3\ Engine-based standards are expressed in terms of emissions 
    per unit of work, whereas chassis-based (or vehicle-based) standards 
    are expressed in terms of amount of emissions per mile driven by the 
    vehicle.
        \4\ ``Complete'' vehicles are those that are manufactured with 
    their primary cargo carrying container or device attached, whereas 
    ``incomplete'' vehicles are those that are manufactured without the 
    primary cargo carrying container or device attached. Incomplete 
    vehicles (basically the engine plus a chassis) are then manufactured 
    into a variety of vehicles, such as recreational vehicles, panel 
    trucks, dump trucks, fire trucks, and tow trucks.
        \5\ Gross Vehicle Weight Rating (GVWR) is defined by federal 
    regulation in 40 CFR 86.082-2 as ``The value specified by the 
    manufacturer as the maximum design loaded weight of a single 
    vehicle.'' In other words, it is the weight of the vehicle 
    completely loaded with the maximum load that the manufacturer states 
    the vehicle is capable of carrying.
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        Some of these proposals would harmonize EPA's regulatory programs 
    with California's current medium-duty vehicle (MDV) program (e.g., 
    vehicle-based standards for complete Otto-cycle heavy-duty vehicles 
    below 14,000 pounds GVWR), while others may differ from California's 
    current requirements. These similarities and differences are outlined 
    in the detailed discussion that follows. We request comments on the 
    proposals described below, and encourage commenters to supply relevant 
    data that would help us further assess the proposals.6
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        \6\ The current federal standards for Clean Fuel Vehicles are 
    less stringent than the proposed Otto-cycle standards and the 
    existing diesel standards for the 2004 and later model years. See 40 
    CFR 88.105-94. The 2004 and later model year standards proposed 
    today would supercede the current Clean Fuel Vehicle standards, and, 
    if EPA adopts the Otto-cycle standards proposed today and maintains 
    the diesel standards for the 2004 and later model years, the Agency 
    intends to undertake a rulemaking to revise the Clean Fuel Vehicle 
    standards accordingly.
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    A. Changes to the Engine-Based Program
    
        The first sections of this proposal describe the proposed revisions 
    to the engine-based program. Some of these proposals would apply to 
    both diesel and Otto-cycle engines, and others would apply uniquely to 
    either diesel or Otto-cycle engines. Proposed requirements that affect 
    the engine-based program include:
         Reaffirmation of the existing 2004 and later model year 
    NMHC+NOx standard for heavy-duty diesel engines.
         New more stringent emission standards for 2004 and later 
    model year Otto-cycle heavy-duty engines.
         A revised averaging, banking, and trading (ABT) program 
    for Otto-cycle heavy-duty engines.
         Revised deterioration factor (DF) requirements for heavy-
    duty engines.
         New emission standards for heavy-duty diesel engines to 
    improve the assurance that vehicles are emitting low levels of 
    pollutants over a wide range of operation experienced in actual use.
         New supplemental test procedures for heavy-duty diesel 
    engines associated with the proposed new emission 
    standards.7
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        \7\ We believe that our compliance program is fundamentally 
    incomplete until a similar form of additional assurance that Otto-
    cycle engines will meet applicable emission standards in-use can be 
    added to the compliance requirements, but such provisions are not 
    specifically proposed today. Section V of today's proposal describes 
    several important compliance program elements that are not included 
    in today's proposal, but that we intend to finalize such that they 
    can take effect in conjunction with those elements in today's 
    proposal. See section V for more information.
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    B. Expanding the Otto-Cycle Vehicle-Based Program to Certain Heavy-Duty 
    Vehicles
    
        Additional sections of this proposal describe the proposed chassis-
    based (or vehicle-based) program for certain heavy-duty vehicles. Many 
    of these proposals result in harmonization with the California Air 
    Resources Board (CARB) Medium-duty Vehicle (MDV)
    
    [[Page 58475]]
    
    Program. For the vehicle-based program, we are proposing the following 
    elements:
         New standards for 2004 and later model year complete Otto-
    cycle heavy-duty vehicles with a GVWR below 14,000 pounds.
         The incorporation of certain complete Otto-cycle and 
    diesel vehicles between 8,500 and 10,000 pounds GVWR into the Tier 2 
    light-duty program. These provisions would be limited to those vehicles 
    designed primarily for personal transportation.
         Vehicle-based testing of all complete heavy-duty Otto-
    cycle vehicles below 14,000 pounds GVWR for these new standards.
         An averaging, banking, and trading program.
         On-board refueling vapor recovery (ORVR) requirements.
         CAP 2000 provisions.8
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        \8\ The new compliance assurance program for light-duty vehicles 
    and light-duty trucks, known as CAP 2000 (since manufacturers may 
    opt-in for model year 2000), streamlines the existing vehicle 
    certification program, enabling manufacturers to save significant 
    time and money. In addition, it requires manufacturers to test 
    customer-owned in-use vehicles for model year 2001 and beyond. The 
    CAP 2000 program was proposed on July 23, 1998 (63 FR 36954), and 
    finalized on May 4, 1999 (64 FR 23906).
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         Revised useful life requirements.
    
    C. Additional Changes Affecting Heavy-Duty Vehicle and Heavy-Duty 
    Engine Programs
    
        Additional sections describe provisions or issues that apply to 
    both heavy-duty vehicle and engine programs. These proposals include:
         On-board Diagnostics (OBD) requirements for heavy-duty 
    diesel and Otto-cycle vehicles and engines up to 14,000 pounds GVWR.
         Non-Conformance Penalties (NCPs).
    
    D. Heavy-Duty Lead Time Issues and Voluntary Federal Standards
    
        One of the important concepts contained in the rulemaking record, 
    is the need for harmonized, 50-state emission standards for the heavy-
    duty industry. Consistent national standards provide the states with 
    the emission reductions they need, while providing manufacturers with 
    the knowledge they can design and market one engine design regardless 
    of what state the engine is sold to. Our proposal today would implement 
    nationwide standards which would harmonize with California for the 
    majority HD engines and vehicle in 2004 ( the exception being 
    incomplete HD Otto-cycle engines.)
        Since the finalization of the 1997 rule for 2004 HD diesels, state 
    and local air quality agencies have been counting on the emission 
    reductions from the 2004 standards in order to meet their long-term air 
    quality needs. In addition, as discussed previously in this proposal, 
    the 2004 standards for HD Otto-cycle engines and vehicles will also 
    provide state and local air quality agencies additional needed emission 
    reductions. However, Section 202 of the Clean Air Act requires EPA to 
    provide manufacturers of heavy-duty engines and vehicles four years of 
    lead time between standards. This would require EPA to issue a final 
    rule by the end of 1999 in order to implement new standards in 2004. We 
    are concerned due to the short amount of time between today's proposal 
    and the end of the calendar year that the final rule for today's 
    proposal may not be final until after December 31, 1999, which may 
    prevent a model year 2004 implementation of the standards proposed 
    today. This concern does not apply for the 2004 model year heavy-duty 
    diesel engine standards which were promulgated in 1997 and meet the 
    lead time requirements.
        This four year lead time issue for the 2004 standards contained in 
    today's proposal reflects a statutory requirement, not a technological 
    feasibility issue. As demonstrated elsewhere in this proposal, 
    technology is clearly available which will allow manufacturers to meet 
    the proposed HD diesel and HD gasoline standards by 2004.
        The lack of more stringent federal 49-state HD standards in 2004 
    may lead some states with incentive to exercise their rights under 
    Section 177 of the Clean Air Act to adopt the California HD diesel and 
    Otto-cycle standards in order to realize the emission reductions 
    associated with covering vehicles produced in 2004. This could result 
    in a patchwork of emission standards across the country and could 
    present the manufacturers with significant difficulties.
        In the event the Agency is unable to finalize the new standards 
    contained in today's proposal by the end of calendar year 1999, we 
    request comment on the appropriateness of EPA's efforts to manage the 
    implementation of these standards and in particular, of establishing a 
    program for those manufacturers willing to cooperate in meeting the 
    requirements in today's proposal. We would expect that manufacturers 
    participating in this program would merely certify their 2004 model 
    year engines to meet all of the emission standards and requirements 
    included in today's proposal. If the proposed standards are not 
    finalized by the end of 1999, mandatory federal standards would apply 
    in model year 2005, with the goal of putting in place all requirements 
    contained in today's proposal. We request comment on whether 
    manufacturers would need to opt-in to such a program, and how such opt-
    in would take place. In addition, EPA requests comment on incentives to 
    encourage manufacturers to opt into the voluntary program.
    
    II. What Is the Environmental Need for This Proposal?
    
        This section presents information on the negative health and 
    environmental impacts from air pollution from heavy-duty (HD) engines 
    and vehicles, as well as EPA's assessment of the need for additional 
    emission reductions from HD engines and vehicles in order to meet the 
    air quality needs of the U.S. A detailed analysis and explanation of 
    the health impacts and air quality needs was presented in the advanced 
    notice of proposed rulemaking, as well as the preamble and the 
    Regulatory Impact Analysis (RIA) for the proposal and final rule of the 
    1997 rulemaking for the 2004 standards.9 The reader should 
    refer to those documents for additional information on this topic.
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        \9\ See ``Control of Air Pollution for Heavy-Duty Engines, 
    Advanced Notice of Proposed Rulemaking'', Available in EPA Air 
    Docket A-95-27, Docket Item # AMS-FRL, and ``Draft Regulatory Impact 
    Analysis: Control of Emissions of Air Pollution from Highway Heavy-
    Duty Engines'', available in EPA Air Docket A-95-27, Docket Item # 
    III-B-01, and ``Control of Emissions of Air Pollution from Highway 
    Heavy-Duty Engines; Notice of Proposed Rulemaking'' available in EPA 
    Air Docket A-95-27, Docket Item # III-A-01, and ``Final Regulatory 
    Impact Analysis: Control of Emissions of Air Pollution from Highway 
    Heavy-Duty Engines'', available in EPA Air Docket A-95-27, Docket 
    Item # V-B-01, and ``Control of Emissions of Air Pollution from 
    Highway Heavy-Duty Engines; Final Rule,'' available in EPA Air 
    Docket A-95-27, Docket Item # V-A-01.
    ---------------------------------------------------------------------------
    
    A. Need for Additional NOx and NMHC Reductions
    
    1. Health and Welfare Effects From NMHC and NOx
        Oxides of Nitrogen (NOx) and volatile organic compounds 
    (VOC) are precursors in the photochemical reaction which forms 
    tropospheric ozone. VOC emissions from mobile sources consist mostly of 
    nonmethane hydrocarbons (NMHC). There is a large body of evidence 
    showing that ozone can cause harmful respiratory effects including 
    chest pain, coughing, and shortness of breath, affecting people with 
    compromised respiratory systems and children most severely. In 
    addition, NOx itself can directly harm human health. Beyond 
    their human health effects, other negative environmental effects are 
    also associated with ozone
    
    [[Page 58476]]
    
    and NOx. Ozone has been shown to injure plants and 
    materials; NOx contributes to the secondary formation of 
    particulate matter (PM) (nitrates), acid deposition, and the overgrowth 
    of algae in coastal estuaries. These environmental effects, as well as 
    the health effects noted above, are described in the Regulatory Impact 
    Analysis, and additional information may be found in EPA's ``staff 
    papers'' and ``air quality criteria'' documents for ozone and nitrogen 
    oxides.10, 11, 12, 13
    ---------------------------------------------------------------------------
    
        \10\ U.S. EPA, 1996, Review of National Ambient Air Quality 
    Standards for Ozone, Assessment of Scientific and Technical 
    Information, OAQPS Staff Paper, EPA-452/R-96-007.
        \11\ U.S.EPA, 1996, Air Quality Criteria for Ozone and Related 
    Photochemical Oxidants, EPA/600/P-93/004aF.
        \12\ U.S. EPA, 1995, Review of National Ambient Air Quality 
    Standards for Nitrogen Dioxide, Assessment of Scientific and 
    Technical Information, OAQPS Staff Paper, EPA-452/R-95-005.
        \13\ U.S.EPA, 1993, Air Quality Criteria for Oxides of Nitrogen, 
    EPA/600/8-91/049aF.
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    2. Current Compliance With the Ozone NAAQS
        Today, many states are finding it difficult to show how they can 
    meet or maintain compliance with the current National Ambient Air 
    Quality Standard (NAAQS) for ozone by the deadlines established in the 
    Clean Air Act (CAA, or ``the Act'').14 As of August, 1998, 
    72 million people outside of California lived in 36 metropolitan areas 
    and two counties designated nonattainment under the 1-hour ozone NAAQS.
    ---------------------------------------------------------------------------
    
        \14\ See 42 U.S.C. 7401 et seq.
    ---------------------------------------------------------------------------
    
        In July 1997, EPA established a new 8-hour ozone NAAQS to better 
    protect against longer exposure periods at lower concentrations than 
    the current 1-hour standard. Under the July 1997 rule, the 1-hour NAAQS 
    would still be applicable in certain areas during the transition to the 
    8-hour standard (62 FR 38856; July 17, 1997). EPA reviewed ambient 
    ozone monitoring data for the period 1993 through 1995 to determine 
    which counties violated either the 1-hour or 8-hour NAAQS for ozone 
    during this time period.15, 16 Eighty-four counties violated 
    the 1-hour NAAQS during this 3-year period, while 248 counties violated 
    the 8-hour NAAQS. The 84 counties had a 1990 population of 47 million, 
    while the 248 counties had a 1990 population of 83 million. EPA is 
    reviewing more recent air quality data for 1996 and 1997. A preliminary 
    assessment of 1994 through 1996 ozone monitoring data reveals only 
    marginal changes in the number of counties experiencing a nonattainment 
    problem with the 8-hour NAAQS, and essentially no change in the 
    population levels impacted by nonattainment.
    ---------------------------------------------------------------------------
    
        \15\ This use of the term ``nonattainment'' in reference to a 
    specific area is not meant as an official designation or future 
    determination as to the attainment status of the area.
        \16\ See 63 FR 57356, October 27, 1998, ``Finding of Significant 
    Contribution and Rulemaking for Certain States in the Ozone 
    Transport Assessment Group Region for Purposes of Reducing Regional 
    Transport of Ozone.''
    ---------------------------------------------------------------------------
    
        On May 14, 1999, a panel of the U.S. Court of Appeals for the 
    District of Columbia Circuit found, by a 2-1 vote, that Clean Air Act 
    sections 108 and 109, as interpreted by EPA in establishing the 8-hour 
    ozone NAAQS (as well as the new NAAQS for PM2.5 and 
    PM10), effect an unconstitutional delegation of 
    Congressional power. American Trucking Ass'ns, Inc., et al., v. 
    Environmental Protection Agency, Nos. 97-1440, 1441 (D.C. Cir. May 14, 
    1999). The Court remanded the record to EPA. One judge dissented, 
    finding that the majority's opinion ``ignores the last half-century of 
    Supreme Court nondelegation jurisprudence.'' Id., slip op. at 31. The 
    Court also ruled, regarding the 8-hour ozone NAAQS, that the statute 
    permits EPA to promulgate a revised ozone NAAQS and to designate the 
    attainment status of areas. However, the Court curtailed EPA's ability 
    to require states to comply with the revised ozone NAAQS. Further the 
    Court directed the Agency to determine whether tropospheric ozone has a 
    beneficent effect, and if so, assess ozone's net adverse health effect. 
    In general, the Court did not find fault with the scientific basis for 
    EPA's determinations regarding adverse health effects from ozone. On 
    June 28, 1999, EPA filed a petition for rehearing and petition for 
    rehearing en banc seeking review of the panel's decision.
        The Court's decision does not address the provisions of section 
    202(a), and does not change EPA's belief that the standards in today's 
    proposal are lawful and appropriate under these criteria. We believe 
    that the information provided in this proposal and the draft Regulatory 
    Impact Analysis, as well as the information that EPA relied on in 
    setting the NAAQS for ozone, support a conclusion that ozone can be 
    reasonably anticipated to endanger the public health or welfare. EPA's 
    belief that it is appropriate to seek reductions of NOX and 
    NMHCs from heavy duty vehicles and engines to protect public health or 
    welfare is not changed by the decision of the court.
    3. Future Compliance With the Ozone NAAQS
        Local, state and federal organizations charged with delivering 
    cleaner air have mounted significant efforts in recent years to reduce 
    air quality problems associated with ground-level ozone, and there are 
    signs of partial success. NOX and VOCs appear to have been 
    reduced, and average levels of ozone seem to have begun gradually 
    decreasing. However, this progress is in jeopardy. EPA projects that 
    reductions in ozone precursors that will result from the full 
    implementation of current emission control programs will fall far short 
    of what would be needed to offset the normal emission increases that 
    accompany economic expansion. By the middle of the next decade, the 
    Agency expects that the downward trends will have reversed, primarily 
    due to increasing numbers of emission sources. By around 2020, EPA 
    expects that NOX levels will have returned to current levels 
    in the absence of significant new reductions.17 To the 
    extent that some areas are seeing a gradual decrease in ozone levels in 
    recent years, EPA believes that the expected increase in NOX 
    will likely result in an increase in ozone problems in the future.
    ---------------------------------------------------------------------------
    
        \17\ See Chapter 2 of the draft Regulatory Impact Analysis for 
    this proposal.
    ---------------------------------------------------------------------------
    
        The Agency has recently finalized a rulemaking requiring 22 States 
    and the District of Columbia to submit State Implementation Plan (SIP) 
    revisions to reduce specified amounts of emissions of NOX 
    for the purpose of reducing NOX and ozone transport across 
    State boundaries in the eastern half of the United States.18 
    The specified NOX reduction for each State varies. In making 
    this decision EPA relied upon, among other items, ozone modeling 
    studies for the eastern U.S. In the baseline scenario for these 
    modeling runs EPA included the emission reductions expected from the 
    2004 HDDE standards. These modeling runs concluded that significant 
    additional NOX reductions beyond the baseline case were 
    necessary from 22 eastern States in order to meet the ozone NAAQS 
    standards. The NOX emission reductions from the 2004 HDDE 
    standards are assumed by these models to be part of the reductions that 
    will be needed to meet the ozone NAAQS in these areas. The Agency did 
    not analyze the specified reductions that would be required by the rule 
    if the baseline did not include the 2004 HDDE standards.
    ---------------------------------------------------------------------------
    
        \18\ See 63 FR 57356, October 27, 1998, ``Finding of Significant 
    Contribution and Rulemaking for Certain States in the Ozone 
    Transport Assessment Group Region for Purposes of Reducing Regional 
    Transport of Ozone.''
    ---------------------------------------------------------------------------
    
        The deadline for submission of SIPs was recently stayed by a panel 
    of the Court of Appeals for the D.C. Circuit pending further review. 
    EPA believes that the October 27, 1998 rule is fully consistent with 
    the Clean Air Act and
    
    [[Page 58477]]
    
    should be upheld. However, it should be noted that if the emission 
    reductions sought by the SIP call are not achieved, it would be more 
    difficult to attain the NAAQS for ozone.
        In addition, many states (including western states) have also 
    included the emission reductions projected from the 2004 HDDE standards 
    in their State Implementation Plans. This demonstrates that these 
    states are relying on these emission reductions to meet the ozone 
    NAAQS.
    4. Contribution of HD Diesel and Gasoline Engines to Total VOC and 
    NOX Inventories
        HD engines and vehicles are important contributors to the national 
    inventories of NOX emissions, and they contribute moderately 
    to national VOC pollution. The draft RIA for this proposal describes in 
    detail recent emission inventory modeling completed by EPA for this 
    proposal. Table 1 summarizes EPA's current estimates for national 
    NOX and VOC contributions from major source categories.
    
                                      Table 1.--2000 National NOX and VOC Emissions
                                             [thousand short tons per year]
    ----------------------------------------------------------------------------------------------------------------
                           Emission source                            NOX         NOX %         VOC         VOC %
    ----------------------------------------------------------------------------------------------------------------
    Light-Duty Vehicles.........................................        4,420           19        4,098           25
    Heavy-Duty Diesel Vehicles..................................        2,274           10          246            1
    Heavy-Duty Gasoline Vehicles................................          318            1          198            1
    Nonroad Engines and Vehicles................................        5,343           23        2,485           15
    Other (Stationary Point and Area Sources)...................       10,656           47        9,567           58
                                                                 ---------------------------------------------------
            Total Nationwide Emissions..........................       22,831  ...........       16,594  ...........
    ----------------------------------------------------------------------------------------------------------------
    
        It should be noted that Table 1 does not include estimated 
    NOX emission impacts associated with the previously produced 
    HD diesel engines at issue in the recent enforcement action involving 
    the government and several HD diesel engine manufacturers. The 
    relationship of these consent decrees to today's proposed rule is 
    described in section III.D. The excess NOX emissions from 
    these engines are substantial, and would significantly increase the 
    estimated contribution from HD diesel vehicles presented in Table 1. 
    However, as discussed in section VI.A of this preamble, we did not 
    update our emission inventory model to include the impact on these 
    previously produced engines for this proposal.
        Notwithstanding these excess emissions, Table 1 indicates that HD 
    gasoline and diesel vehicles will represent approximately 11 percent of 
    national NOX emissions and two percent of national VOC 
    emissions in the year 2000. The Regulatory Impact Analysis document for 
    this proposal contains updated emission inventory modeling for HD 
    vehicles. The results show that without additional HD NOX 
    control beyond the 1998 standards, national NOX emissions 
    from HD vehicles would decline between 2000 and 2005, but this trend 
    would stop in 2005. After 2005, NOX emissions from the HD 
    vehicle fleet would increase as a result of future growth in the HD 
    vehicle market without additional emission controls. A similar trend is 
    seen for national NMHC emissions from HD vehicles; however, NMHC 
    emissions are projected to decrease until approximately 2010, after 
    which changes in the make-up of the fleet result in an increase in the 
    NMHC emissions from HD vehicles (see Chapter 5 of the draft RIA).
        We estimate that the HD diesel and gasoline standards contained in 
    this proposal will result in a combined reduction by the year 2020 of 
    1,629,000 tons of NOX per year and 54,000 tons of 
    hydrocarbons (HC) per year. Section VI of this preamble (``What are the 
    Environmental Benefits of this Proposal?'') as well as the draft RIA 
    for this proposal contain more detailed information on the Agency's 
    projected benefits from today's proposal.
    
    B. Need for Additional PM Reductions
    
    1. Health and Welfare Effects From PM
        Particulate matter is the general term for the mixture of solid 
    particles and liquid droplets found in the air. Particulate matter 
    includes dust, dirt, soot, smoke, and liquid droplets that are directly 
    emitted into the air from natural and manmade sources, such as 
    windblown dust, motor vehicles, construction sites, factories, and 
    fires. Particles are also formed in the atmosphere by condensation or 
    the transformation of emitted gases such as sulfur dioxide, nitrogen 
    oxides, and volatile organic compounds. Particulate matter, like ozone, 
    has been linked to a range of serious respiratory health problems. 
    Scientific studies suggest a likely causal role of ambient particulate 
    matter in contributing to a series of health effects. The key health 
    effects categories associated with particulate matter include premature 
    mortality, aggravation of respiratory and cardiovascular disease (as 
    indicated by increased hospital admissions and emergency room visits, 
    school absences, work loss days, and restricted activity days), changes 
    in lung function and increased respiratory symptoms, changes to lung 
    tissues and structure, and altered respiratory defense mechanisms. PM 
    also causes damage to materials and soiling. It is a major cause of 
    substantial visibility impairment in many parts of the U.S.
        Motor vehicle particle emissions and the particles formed by the 
    transformation of motor vehicle gaseous emissions (secondary 
    particulates) tend to be in the fine particle range. Fine particles 
    (those less than 2.5 micrometers in diameter) are a health concern 
    because they easily reach the deepest recesses of the lungs. Scientific 
    studies have linked fine particles (alone or in combination with other 
    air pollutants), with a series of significant health problems, 
    including premature death; respiratory related hospital admissions and 
    emergency room visits; aggravated asthma; acute respiratory symptoms, 
    including aggravated coughing and difficult or painful breathing; 
    chronic bronchitis; and decreased lung function that can be experienced 
    as shortness of breath.
        These effects are discussed further in the RIA for this proposal, 
    as well as the RIA for the 1997 final rule for the 2004 standards, and 
    additional information may be found in EPA's ``staff paper'' and ``air 
    quality criteria document'' for particulate matter.19
    ---------------------------------------------------------------------------
    
        \19\ U.S. EPA, 1996, Air Quality Criteria for Particulate 
    Matter, EPA/600/P-95/001aF.
    ---------------------------------------------------------------------------
    
    2. Current and Future Compliance With the PM10 NAAQS
        The first NAAQS for particulate matter regulated total suspended
    
    [[Page 58478]]
    
    particulate in the atmosphere. In 1987, EPA replaced that standard with 
    one for inhalable PM (PM10--particles less than ten microns 
    in size), because the smaller particles, due to their ability to reach 
    the lower regions of the respiratory tract, are more likely responsible 
    for the adverse health effects. The major source of PM10 is 
    fugitive emissions from agricultural tilling, construction, fires, and 
    unpaved roads. Some revisions to the PM10 standards were 
    made in 1997. EPA has also recently added new fine particle standards 
    for particles less than 2.5 microns in size (PM2.5). Most of 
    the particulate due to motor vehicles falls in the fine particle 
    category. These standards have both an annual and a daily component. 
    The annual component is set to protect against long-term exposures, 
    while the daily component protects against more extreme short-term 
    events.
        As noted above, on May 14, 1999, a panel of the U.S. Court of 
    Appeals for the District of Columbia Circuit found, by a 2-1 vote, that 
    Clean Air Act sections 108 and 109, as interpreted by EPA in 
    establishing the new NAAQS for PM2.5 and PM10, 
    effect an unconstitutional delegation of Congressional power. American 
    Trucking Ass'ns, Inc., et al., v. Environmental Protection Agency, Nos. 
    97-1440, 1441 (D.C. Cir. May 14, 1999). The Court remanded the record 
    to EPA. The court vacated the new PM10 standard, but has not 
    vacated the PM2.5 standard. See American Trucking Ass'ns, 
    Inc., et al., v. Environmental Protection Agency, No. 97-1440 (D.C. 
    Cir. June 18, 1999).
        Compliance with the current PM10 standard continues to 
    be a problem. According to the 1996 EPA Air Quality and Emissions 
    Trends report, there were 7 million people living in 15 counties across 
    the U.S. which exceeded the PM10 NAAQS in 1996.20
    ---------------------------------------------------------------------------
    
        \20\ U.S. EPA, January 1998, ``National Air Quality and 
    Emissions Trends Report, 1996'', EPA 454/R-97-0013.
    ---------------------------------------------------------------------------
    
        EPA recently projected ambient PM10 levels and the 
    number of U.S. counties expected to be in violation of the revised 
    PM10 NAAQS in 2010.21 Based on the 1990 census, 
    about 10 million people live in the 11 counties projected to be in 
    nonattainment of the revised PM10 NAAQS.
    ---------------------------------------------------------------------------
    
        \21\ Regulatory Impact Analyses for the Particulate Matter and 
    Ozone National Ambient Air Quality Standards and Proposed Regional 
    Haze Rule, Innovative Strategies and Economics Group, Office of Air 
    Quality Planning and Standards, U.S. Environmental Protection 
    Agency, Research Triangle Park, N.C., July 16, 1997.
    ---------------------------------------------------------------------------
    
    3. Contribution of HD Diesel and Gasoline Vehicles to PM Inventories
    a. Contribution to National PM10 Inventories
        The national inventory of PM10 is dominated by natural 
    sources (wind erosion) and so-called miscellaneous sources, which 
    include paved and unpaved road dust, agricultural crops, fugitive dust, 
    and dust from construction activities. Together natural and 
    miscellaneous sources represented approximately 90 percent of national 
    PM10 emissions in 1996. Since these sources are not readily 
    amenable to regulatory standards and controls, it is appropriate to 
    focus on more traditional ``controllable'' portions of the particulate 
    pollution problem when considering the need for PM controls. Excluding 
    natural and miscellaneous sources, HD vehicles (gasoline and diesel) 
    represent approximately five percent of the remaining man-made sources 
    of PM10 in 1996, virtually all (95 percent) of which is from 
    diesel vehicles.22
    ---------------------------------------------------------------------------
    
        \22\ U.S. EPA, December 1997, ``National Air Pollutant Emission 
    Trends, 1900-1996'', EPA-454/R-97-011.
    ---------------------------------------------------------------------------
    
        In the proposal for the 1997 final rule for the 2004 standards, EPA 
    presented data on future projections of mobile and stationary source 
    PM10 national emission inventories out to the year 2010, as 
    well as a break-down of mobile sources into on-highway light-duty, on-
    highway heavy-duty, and nonroad categories (see 61 FR 33432-33440, June 
    27, 1996). These projections showed that without additional future 
    controls on PM or NOX emissions, annual PM emissions (tons/
    year) for all mobile sources would begin to rise after the year 2000. 
    The Regulatory Impact Analysis document for this proposal presents the 
    results of updated emission modeling specifically for HD vehicles. 
    These results show that the annual national PM10 emissions 
    from HD vehicles (tons/year) are expected to decline between now and 
    approximately the year 2010, after which increases in the size of the 
    fleet will result in a steady increase into the future (see Chapter 5 
    of the draft RIA).
    b. Source-apportionment Studies for Diesel PM
        Discussion of PM inventories from HD vehicles, and in particular HD 
    diesel vehicles which represent the vast majority of the HD PM 
    emissions, can be discussed in terms other than just contributions to 
    national yearly emission inventories. In recent years several research 
    groups have been looking at the contribution of diesel PM in selected 
    urban and rural areas. In several cases these studies indicate that the 
    contribution from diesels in certain urban areas to PM emissions is 
    much larger than is indicated by national PM inventories. Several 
    studies have been performed in the past several years which have 
    attempted to apportion particulate matter collected at specific sites 
    to individual source categories, i.e., source apportionment studies. 
    These studies collect particulate matter samples in the ambient air 
    which are subsequently analyzed using various chemical techniques in 
    order to estimate what sources contributed to the sample.
        There have been a number of source apportionment studies for mobile 
    source particulate emissions. Among the most recent and thorough are 
    studies by the state of Colorado (the Northern Front Range Air Quality 
    Study [NFRAQS]) for the Denver area and the California Institute of 
    Technology for the Los Angeles area. These studies emphasize 
    particulate smaller than 2.5 microns. Also, EPA has a cooperative 
    agreement with the Desert Research Institute (DRI); under this 
    agreement, DRI is completing a detailed report on mobile source 
    particulates; a major portion of this report summarizes source 
    apportionment studies for particulates that include those from mobile 
    sources.23
    ---------------------------------------------------------------------------
    
        \23\ Draft report for EPA from the Desert Research Institute, 
    June 30, 1998, Available in EPA Air Docket A-98-32, Item # 
    --01.
    ---------------------------------------------------------------------------
    
        Source apportionment work involves collecting and analyzing a 
    number of ambient particulate samples from a number of specific sources 
    such as gasoline and diesel vehicles. Some samples of high molecular 
    weight hydrocarbons are frequently also collected and analyzed, these 
    hydrocarbons can be transformed to particulates in the ambient air; 
    such compounds include polycyclic organic matter. These samples are 
    analyzed in detail to determine what specific compounds are present 
    including those in trace amounts that are more common from one source 
    type than from others, these traces are called source signatures. From 
    these analyses, a number of source signatures are developed including 
    those for gasoline and diesel vehicles. Source apportionment work also 
    involves collecting and analyzing a larger number of ambient 
    particulate and, frequently, high molecular weight hydrocarbon. The 
    compounds found in these samples can be compared to the source 
    signatures to determine what and how much individual sources contribute 
    to the ambient particulate.
    
    [[Page 58479]]
    
    Source apportionment work is subject to complications and uncertainty. 
    Thus, no single study should be considered definitive. Additional 
    information on source apportionment techniques, and the uncertainties 
    associated with the techniques, can be found in Chapter 2 of the RIA 
    for this proposal.
        The NFRAQS study analyzed ambient particulate samples in the 
    Colorado area including Denver using data it collected on the chemical 
    speciation from specific source types to determine how much various 
    mobile and stationary source types contribute to PM2.5. 
    Authorized by Colorado state legislation, the total study was funded by 
    37 government, industry, and trade association groups. The many outputs 
    and conclusions from the NFRAQS will not be discussed here, only source 
    apportionment results for diesel engines are summarized. Complete 
    copies of the NFRAQS are available from the following World Wide Web 
    site, http://charon.cira.colostate.edu/. The NFRAQS included several 
    time periods and several locations in and around Denver. Two locations, 
    Brighton and Welby, during the winter of 1997 included the most 
    detailed sampling and analysis, which allowed the researchers to 
    estimate very detailed source specific contributions, including the 
    contributions to PM2.5 from diesel exhaust (all diesel, 
    nonroad and on-highway sources were not differentiated). Based on this 
    work, it was estimated that diesel exhaust sources contributed 10 
    percent of the total mass of PM2.5 in the areas of Brighton 
    and Welby in the winter of 1997.
        Similar work has been done for the Los Angeles area by a group of 
    researchers at the California Institute of Technology. This work 
    concluded that direct emissions from diesel exhaust represented 
    approximately 30 percent of fine PM mass on an annual basis in downtown 
    Los Angeles in 1982.24 In follow-on work looking at the city 
    of Claremont, California in 1987, direct diesel exhaust was found to 
    represent approximately 13 percent of PM2.5 mass, and 9 
    percent of PM10 mass.25
    ---------------------------------------------------------------------------
    
        \24\ ``Source Apportionment of Airborne Particulate Matter Using 
    Organic Compounds as Tracers'', J.J. Schauer, W.F. Rogge, L.M. 
    Hildemann, M.A. Mazurek, and G.R. Cass, Atmospheric Environment, 
    Vol. 30, No. 22, 1996.
        \25\ ``Source Contributions to the Size and Composition 
    Distribution of Urban Particulate Air Pollution'', M.J. Kleeman and 
    G.R. Cass, Atmospheric Environment, Vol. 32, No. 16, 1998.
    ---------------------------------------------------------------------------
    
        The California Institute of Technology has also collected ambient 
    particulate in the Boston, MA and Rochester, NY areas. These samples, 
    especially those for Boston, show that carbonaceous particulate is the 
    largest single constituent in PM2.5 for these areas. Mobile 
    source particulate, including diesels, is an important contributor to 
    carbonaceous particulate. The Boston and Rochester samples have not yet 
    been used for source apportionment work.
        Other ambient samples collected in the eastern U.S. such as 
    Washington, DC show carbonaceous particulate to be an important 
    constituent of PM2.5, although sulfates is a somewhat larger 
    constituent and nitrates a much smaller constituent. Particulate 
    samples collected in the western U.S. such as in Spokane, WA, Phoenix, 
    AZ and the San Joaquin Valley of California show that carbonaceous 
    particulate is the major constituent with sulfates/nitrates being 
    lesser constituents although nitrates are more important in southern 
    California than elsewhere in the United States. This work is summarized 
    in the EPA report ``National Air Pollutant Emission Trends, 1900-
    1996.'' 26
    ---------------------------------------------------------------------------
    
        \26\ ``National Air Pollutant Emission Trends, 1900-1996'', EPA 
    Report 454/R-97-011, December 1997.
    ---------------------------------------------------------------------------
    
        The reports on source apportionment summarized in this section 
    indicate that the contribution of diesel engines to PM inventories in 
    several local areas around the U.S. are much higher than what would be 
    assumed from looking only at the estimates presented in national PM 
    emission inventories. One possible explanation for this is the 
    concentrated use of diesel engines in certain local or regional areas 
    which is not well represented by the national, yearly average presented 
    in national PM emission inventories.
    
    C. Air Toxics From HD Engines and Vehicles
    
        In addition to contributing to the health and welfare problems 
    associated with exceedances of the National Ambient Air Quality 
    Standards for ozone and PM10, emissions from HD diesel and 
    Otto-cycle vehicles include a number of air pollutants that increase 
    the risk of cancer or have other negative health effects. These air 
    pollutants include benzene, formaldehyde, acetaldehyde, 1,3-butadiene, 
    and diesel particulate matter. For several of these pollutants, motor 
    vehicle emissions are believed to account for a significant proportion 
    of total nation-wide emissions. All of these compounds are products of 
    combustion; benzene is also found in nonexhaust emissions from 
    gasoline-fueled vehicles. These reductions in hydrocarbon emissions 
    from HD vehicles resulting from today's proposal will further reduce 
    the potential cancer risk and other health risks from these air toxics 
    (other than diesel PM) because many of these pollutants are themselves 
    VOCs. Diesel engine particulate matter is also a potential concern 
    because of its possible carcinogenic and mutagenic effects on people. 
    Diesel PM is made of hundreds of chemical species, including many 
    organic and metallic compounds. Researchers have been investigating the 
    potential health hazards associated with exposure to diesel PM for many 
    years.27 EPA's Office of Research and Development is 
    currently updating the EPA's diesel emission health assessment 
    document. However, the document has only been released as a preliminary 
    draft, and is currently undergoing review by the Clean Air Scientific 
    Advisory Committee. A final version is not expected to be available 
    until late 1999.28
    ---------------------------------------------------------------------------
    
        \27\ ``Diesel Exhaust: A Critical Analysis of Emissions, 
    Exposure, and Health Effects'', Health Effects Institute, April, 
    1995.
        \28\ ``Preliminary Draft--Health Assessment Document for Diesel 
    Emissions'', U.S. EPA, February 1998, EPA 600/8-90/057C.
    ---------------------------------------------------------------------------
    
        The California Air Resources Board and the California Office of 
    Environmental Health Hazard Assessment (COEHHA) have undertaken an 
    assessment of the cancer and non-cancer effects from exposure to diesel 
    exhaust, including the particulate matter component of diesel exhaust, 
    to determine whether diesel exhaust should be classified as a Toxic Air 
    Contaminant (TAC) under California law. The evaluation of diesel 
    exhaust by CARB and COEHHA began in 1989, in June of 1998 a Staff 
    Report was published which recommended that diesel exhaust be 
    classified as a TAC.29 In a CARB Board hearing held in 
    August, the Board decided to identify diesel exhaust particulate matter 
    as a TAC.30
    ---------------------------------------------------------------------------
    
        \29\ California Air Resources Board--Staff Report--``Proposed 
    Identification of Diesel Exhaust as a Toxic Air Contaminant'', June 
    1998.
        \30\ California Air Resources Board, Resolution 98-35, August 
    27, 1998.
    ---------------------------------------------------------------------------
    
        EPA will be addressing the issues raised by air toxics from motor 
    vehicles and their fuels in a separate rulemaking that EPA is 
    initiating in the near future under section 202(l)(2) of the Act. That 
    rulemaking will address the emissions of hazardous air pollutants from 
    motor vehicles and fuels, and the appropriate level of control of 
    hazardous air pollutants from these sources.
    
    III. What Is the Important Background Information for This 
    Proposal?
    
        Under EPA's classification system, heavy-duty vehicles are those 
    with a
    
    [[Page 58480]]
    
    GVWR of 8,500 pounds or more.\31\ The State of California classifies 
    the lighter end of this class--up to 14,000 pounds GVWR--as ``medium-
    duty vehicles.'' Heavy-duty engines are engines used in heavy-duty 
    vehicles. Heavy-duty engines and vehicles are used in a wide range of 
    applications, from large full size pick-up trucks to the largest 
    commercial trucks. Because one type of heavy-duty engine may be used in 
    many different applications, EPA emission standards for the heavy-duty 
    class of vehicles have historically been based on the emissions 
    performance of the engine (and any associated aftertreatment devices) 
    as tested separately from the vehicle chassis.
    ---------------------------------------------------------------------------
    
        \31\ The Clean Air Act defines heavy-duty vehicles as those with 
    a GVWR of 6,000 pounds. However, EPA has classified vehicles between 
    6,000 and 8,500 pounds GVWR as light-duty vehicles, while treating 
    them as heavy-duty for statutory purposes. Vehicles weighing between 
    6,000 and 8,500 pounds GVWR are not addressed generally in this 
    proposed rulemaking.
    ---------------------------------------------------------------------------
    
        Highway HDEs are categorized into diesel-cycle (compression-
    ignited) and Otto-cycle (spark-ignited) engines. Most diesel-cycle 
    engines are fueled by diesel fuel, but heavy-duty diesel-cycle engines 
    can also be fueled by methanol or natural gas. The heavy-duty diesel 
    engine class is further subdivided by EPA into three subclassifications 
    or ``primary intended service classes''; light, medium, and heavy HDDEs 
    (see 40 CFR 86.090-2). HDDEs are categorized into one of the three 
    subclasses depending on the GVWR of the vehicles for which they are 
    intended, the usage of the vehicles, the engine horsepower rating, and 
    other factors. The subclassifications allow EPA to more effectively set 
    requirements that are appropriate for the wide range of sizes and uses 
    of HDDEs.
        Most highway heavy-duty Otto-cycle vehicles and engines are 
    gasoline-fueled, but may also be fueled with alternative fuels 
    including methanol and gaseous fuels such as natural gas. Heavy-duty 
    Otto-cycle vehicles and engines include large full size pick-up trucks, 
    full size cargo and passenger vans, and the largest sport utility 
    vehicles. Approximately 75 percent of heavy-duty Otto-cycle vehicles 
    are in the 8,500-10,000 pound GVWR range, and the vast majority of 
    these are sold as ``complete'' vehicles. The majority of heavy-duty 
    Otto-cycle vehicles above 10,000 pounds GVWR are sold as ``incomplete'' 
    vehicles, meaning that they are manufactured without their primary 
    cargo carrying container or device attached. These incomplete vehicles 
    (basically the engine plus a chassis) are then manufactured into a 
    variety of vehicles, including recreational vehicles, panel trucks, tow 
    trucks, and dump trucks.
        EPA's NOX standard for 1998 and later model year diesel 
    and Otto-cycle heavy-duty engines is 4.0 grams per brake horsepower-
    hour (g/bhp-hr). The hydrocarbon standards for 1998 and later model 
    year Otto-cycle engines are 1.1 g/bhp-hr for engines used in lighter 
    vehicles (8500 to 14,000 pounds GVWR) and 1.9 g/bhp-hr for engines used 
    in heavier vehicles (greater than 14,000 pounds GVWR), and the 1998 and 
    later model year hydrocarbon standard for HDDEs is 1.3 g/bhp-hr. EPA 
    currently requires testing of the engine (with emissions control 
    systems in place) rather than the entire vehicle. Thus, the standards 
    are in units of g/bhp-hr (i.e., grams of emissions per unit of work the 
    engine performs over the test cycle), rather than the grams-per-mile 
    unit currently used for testing passenger cars and light-duty trucks.
        This proposed rulemaking is the continuation of a rulemaking 
    process for heavy-duty engines which began in 1995 with an Advanced 
    Notice of Proposed Rulemaking (ANPRM) (60 FR 45580, August 31, 1995). 
    As discussed below, a 1996 Notice of Proposed Rulemaking proposed the 
    same NMHC+NOX standards for both Otto-cycle and diesel 
    engines (61 FR 33421, June 27, 1996). However, EPA did not finalize the 
    proposed NMHC+NOX standard for Otto-cycle engines in the 
    final rule published in October 1997 (62 FR 54694, October 21, 1997). 
    EPA did finalize a new NMHC+NOX emission standard for HDDEs, 
    starting with the 2004 model year, but committed to review the 
    appropriateness of this standard in 1999. This NPRM thus addresses two 
    broad issues that remain from earlier rulemaking efforts--a review of 
    the NMHC+NOX standard for diesel engines and a supplemental 
    proposal addressing new NMHC+NOX standards for heavy-duty 
    Otto-cycle engines and vehicles. The previous rulemaking documents, and 
    the documents referenced therein (see EPA Air Docket No. A-95-27), 
    contain extensive background on the engines and vehicles, the affected 
    industry, and the need for lower emissions standards.
    
    A. Statement of Principles and Rulemaking History
    
        In July of 1995, EPA, the California Air Resources Board, and 
    heavy-duty engine manufacturers representing over 90 percent of annual 
    nationwide engine sales signed a Statement of Principles (SOP) that 
    established a framework for a proposed rulemaking to address concerns 
    regarding the growing contribution of heavy-duty engines to air 
    pollution problems. The SOP contained levels for a new proposed 
    standard for NMHC+NOX that would become effective in model 
    year 2004. The SOP also contained several key provisions in addition to 
    the standards. The SOP discusses the need to review in 1999 the 
    technological feasibility of the NMHC+NOX standard and its 
    appropriateness under the Clean Air Act. Also, the SOP outlines a plan 
    for developing technology with the goal of reducing NOX 
    emissions to 1.0 g/bhp-hr and particulate matter to 0.05 g/bhp-hr while 
    maintaining performance, reliability, and efficiency of the engines. 
    EPA sought early comment on the general regulatory framework laid out 
    in the SOP in an ANPRM on August 31, 1995 (60 FR 45580), then 
    subsequently issued an NPRM on June 27, 1996 (61 FR 33421).
        On October 21, 1997, EPA issued a final rule (62 FR 54694). The 
    centerpiece of the final rule was the new NOX + NMHC 
    standard of 2.4 g/bhp-hr (or 2.5 g/bhp-hr with a 0.5 g/bhp-hr NMHC cap) 
    for 2004 and later model year heavy-duty diesel-cycle engines. The rule 
    also adopted other related compliance provisions for diesel-cycle 
    heavy-duty engines beginning with the 2004 model year, as well as 
    revisions to the useful life for the heavy heavy-duty diesel engine 
    service class. As explained in the following section, no new standards 
    were finalized for on-highway heavy-duty Otto-cycle engines.
        The final rule also contained modified ABT provisions for heavy-
    duty diesel engines, allowing EPA to finalize a more stringent engine 
    standard than might otherwise be appropriate under the CAA, since ABT 
    reduces the cost and improves the technological feasibility of 
    achieving the NMHC+NOX standard. The changes to the ABT 
    program provide the manufacturers with additional product planning 
    flexibility and the opportunity for a more cost-effective introduction 
    of product lines meeting the new standard. We also believe that the ABT 
    program can create an incentive for the early introduction of new 
    emission control technology. EPA did not finalize new ABT provisions 
    for Otto-cycle engines because EPA did not take action at that time on 
    new standards for those engines. In summary, engine manufacturers will 
    be able to generate credits under the new program beginning with the 
    1998 model year for use only in 2004 and later model years. The credits 
    in the modified program will have unlimited life, as opposed to the 
    three year credit life contained in the current HD program. Also, 
    engines
    
    [[Page 58481]]
    
    with certification levels at or below a certain cut point are able to 
    generate undiscounted credits. Credits generated by engine families 
    certified above the specified cut point are discounted by 10 percent 
    for purposes of banking and trading. The pre-existing ABT program was 
    retained for engine families using credits before 2004, and for Otto-
    cycle engines which cannot earn credits in the modified program, as 
    noted above. In 2004, the certification level cut-point is adjusted to 
    reflect the implementation of the new standard.
        EPA also finalized several provisions to help ensure in-use 
    durability. First, EPA increased the useful life period for heavy 
    heavy-duty diesel engines to 435,000 miles. This new useful life 
    represents a 50 percent increase and is more representative of the 
    durability of current and future heavy heavy-duty diesel engines. In 
    addition, longer allowable maintenance intervals were finalized for 
    some critical emission-control components, including exhaust gas 
    recirculation (EGR) systems, catalysts, and other add-on emissions 
    control components. Generally, the maintenance intervals for the 
    components are set at 100,000 miles for light heavy-duty diesel engines 
    and 150,000 miles for medium and heavy heavy-duty diesel engines. 
    Warranty regulations were also revised to better reflect current 
    industry practices.
        Other provisions of the October, 1997 final rule address the period 
    after the manufacturer's responsibility for emission control ends, 
    including engine rebuilding. One of those provisions requires engine 
    manufacturers to establish a section in the owner's manual for add-on 
    components that includes recommendations for maintenance and diagnosing 
    malfunction. In addition, all on-board monitoring used to satisfy the 
    engine's allowable maintenance must not be designed to turn off after 
    the end of the useful life. Finally, EPA established provisions to 
    address engine rebuilding which specify what actions are needed to 
    ensure proper operation of emissions control components and ensure that 
    rebuilding does not result in loss of emissions control. Removal or 
    disabling of emissions related components, resulting in a higher 
    emitting vehicle, are considered tampering.
    
    B. 1999 Review of Heavy-Duty Diesel Engine NMHC+NOX 
    Standards
    
        In addition to the elements of the final rule described above, EPA 
    finalized a regulatory provision providing for a 1999 review of the new 
    NMHC+NOX emission standard for HDDEs. EPA committed to 
    ``reassess the appropriateness of the standards under the Clean Air 
    Act, including the need for and technical and economic feasibility of 
    the standards based on information available in 1999'' (See 62 FR 
    54699, October 21, 1997). This provision was put in place because the 
    technologies required to meet the 2004 NMHC+NOX standard for 
    HDDEs were, at the time the standard was finalized, not yet fully 
    developed and proven. This commitment was spelled out in regulatory 
    language in the final rule in 40 CFR 86.004-11, paragraph (a)(1)(i)(E), 
    which reads:
    
        No later than December 31, 1999, the Administrator shall review 
    the emissions standards set forth in paragraph (a)(1)(i) of this 
    section and determine whether these standards continue to be 
    appropriate under the Act.
    
        In the preamble to the 1997 final rule EPA outlined the three 
    potential outcomes of the 1999 review: further tightening of the 
    NMHC+NOX standard, no change to the standard, or a 
    relaxation of the standard. The preamble noted that if EPA determined 
    through the 1999 review process that a tighter standard was feasible 
    and appropriate under the Clean Air Act, such tighter standard would be 
    proposed. Conversely, if EPA's 1999 review process concluded that the 
    2004 NMHC+NOX standard was not technologically feasible, the 
    1997 preamble outlined alternative less stringent sets of standards 
    that EPA would propose. These alternative less stringent standards 
    would depend on EPA's conclusions regarding the necessity for diesel 
    fuel changes and, if changes were found to be needed, whether or not 
    EPA took action to require such changes. Specifically, the preamble 
    stated that if EPA finds through the 1999 review process that the 
    existing 2004 NMHC+NOX standard is not feasible, a standard 
    no higher than 2.9 g/bhp-hr NMHC+NOX (or 3.0 g/bhp-hr 
    NMHC+NOX with a limit of 0.6 g/bhp-hr NMHC) would be 
    proposed. If EPA were to find that changes to diesel fuel would be 
    necessary to meet the 2004 NMHC+NOX standards, and if EPA 
    did not engage in a rulemaking to make such changes, then standards no 
    higher than 3.4 g/bhp-hr NMHC+NOX (or 3.5 g/bhp-hr 
    NMHC+NOX with a limit of 0.6 g/bhp-hr NMHC) would be 
    proposed.
        While the specific regulatory provision is limited to the 
    NMHC+NOX standard for review in 1999, in the preamble to the 
    final rule EPA committed to investigating or seeking comment on several 
    other issues in the context of the 1999 review. These additional issues 
    include:
         An evaluation of whether the appropriateness and technical 
    feasibility of the 2004 standards depend upon changes to diesel fuel.
         A reassessment of the appropriateness of the 2004 
    NMHC+NOX standard in the context of the current PM standard.
         Non-conformance penalty provisions for the 2004 HDDE 
    standards.
    
    C. Proposal for Heavy-Duty Gasoline Engine Standards
    
    1. Summary of Comments on 1996 NPRM
        As was noted above, EPA proposed the same NMHC+NOX 
    standard for diesel and Otto-cycle heavy-duty engines in the 1996 NPRM. 
    In the comment period following the NPRM, several commenters urged the 
    Agency to reconsider its proposal for Otto-cycle engines. The 
    commenters argued that the proposal ignored the true low emissions 
    capability of gasoline-powered vehicles equipped with advanced three 
    way catalysts. Environmental groups provided comments highlighting 
    manufacturers' certification data for the 1996 model year, which 
    included some engine families with emission levels considerably below 
    the standards proposed for the 2004 model year. One commenter 
    recommended that the proposed standard be phased in earlier than 2004 
    for Otto-cycle engines since the emissions control technology capable 
    of meeting the NMHC+NOX standard was more advanced for Otto-
    cycle engines than for diesel engines.
        Manufacturers commented that the proposed standard was appropriate 
    for Otto-cycle engines and that EPA should not use certification data 
    as a basis for determining the feasibility of a lower standard. 
    Manufacturers noted that due to the potential for in-use deterioration 
    of catalysts and oxygen sensors, they must design to emissions targets 
    and certification levels well below the standards. Catalysts experience 
    wide variations in exhaust temperature due to the wide and varied usage 
    of vehicles in the field. Some vehicles may experience more severe in-
    use operation than is represented by the durability testing conducted 
    for engine certification. Manufacturers argued that this variation in 
    in-use operation has an impact on emission system durability not 
    represented by engine certification data and deterioration factors. 
    They argued that it is necessary to certify engines to levels well 
    below the standards to ensure in-use compliance of all engines. One 
    manufacturer presented light-duty
    
    [[Page 58482]]
    
    vehicle and light-duty truck data to demonstrate that certification 
    levels were about half the standard while some vehicles' in-use 
    emissions levels were higher although not above the standard.\32\
    ---------------------------------------------------------------------------
    
        \32\ Comments from Kelly Brown, Ford Motor Company, to Margo 
    Oge, Director OMS, U.S. EPA, September 9, 1996, Docket A-95-27, IV-
    D-26.
    ---------------------------------------------------------------------------
    
    2. Analysis Leading to Decision To Not Finalize Otto-Cycle Standards
        EPA, in deciding whether to finalize the NMHC+NOX 
    standard as originally proposed, had to determine if the proposed 
    standards met the requirements of section 202(a)(3)(A) of the Clean Air 
    Act.\33\ For Otto-cycle engines, EPA examined 1997 model year 
    certification data and found some engines certified to very low 
    emissions levels. The certification data for 1997 showed a large number 
    of engine families emitting at or below the 2004 levels as they were 
    proposed, with some engines certified at emission levels only ten to 
    twenty percent of the proposed 2004 emission standards. Examples of 
    these engines are listed in Table 2.\34\
    ---------------------------------------------------------------------------
    
        \33\ Section 202(a)(3)(A) of the Clean Air Act specifies that 
    regulations ``shall contain standards which reflect the greatest 
    degree of emission reduction achievable through the application of 
    technology which the Administrator determines will be available for 
    the model year to which such standards apply, giving appropriate 
    consideration to cost, energy, and safety factors associated with 
    the application of such technology.''
        \34\ Note that the text here is a brief assessment of the 
    information EPA had available at the time a decision was made to 
    refrain from finalizing heavy-duty Otto-cycle standards. However, 
    today's proposal, and the accompanying analysis of feasibility in 
    the RIA, uses more recent data.
    
                            Table 2.--1997 MY Heavy-Duty Otto-Cycle Engine Certification Data
    ----------------------------------------------------------------------------------------------------------------
                                                                       NOX        HC certification
                        Engine size (liter)                       certification     level (g/bhp-   NOX + HC  (g/bhp-
                                                                level (g/bhp-hr)         hr)               hr)
    ----------------------------------------------------------------------------------------------------------------
    4.3.......................................................               1.2               0.3               1.5
    5.4.......................................................               0.2               0.1               0.4
    5.7.......................................................               1.4               0.1               1.5
    6.8.......................................................               0.1               0.1               0.2
    7.4.......................................................               1.2               0.4               1.6
    8.0.......................................................               2.2               0.1               2.3
    Emission Standards........................................               5.0              *1.3               N/A
    ----------------------------------------------------------------------------------------------------------------
    *(1.9 above 14,000 pounds GVWR)
    
        EPA also examined certification data for California vehicles. 
    California's MDV program requires all complete heavy-duty vehicles 
    (i.e., all vehicles that exit the manufacturer's assembly line with 
    their cargo carrying device or container attached) up to 14,000 pounds 
    GVWR to be certified on the chassis-based (vehicle) federal test 
    procedure (EPA currently requires engine-based testing of vehicles in 
    this class). Table 3 lists examples of model year 1997 California 
    vehicle certification results for vehicles above 8,500 pounds GVWR.\35\ 
    These vehicles were required to meet the California Tier 1 standards 
    which are listed on the table. Starting with the 1998 MY, California is 
    requiring manufacturers to begin phase-in of vehicles meeting more 
    stringent Low Emission Vehicle (LEV) standards which are also listed in 
    Table 3 for these vehicles.
    ---------------------------------------------------------------------------
    
        \35\ All of the vehicles and standards listed are categorized 
    MDV3 in the medium duty vehicle program which includes vehicles with 
    test weights between 5,751-8,500. Test weight is the average of the 
    curb weight and gross vehicle weight.
    
                           Table 3.--1997 MY California Medium-Duty Vehicle Certification Data
                                                     [120,000 mile]
    ----------------------------------------------------------------------------------------------------------------
                                                                      NOX level  (g/   HC level  (g/    NOX+HC (g/
                           Engine size (liter)                             mile)           mile)           mile)
    ----------------------------------------------------------------------------------------------------------------
    5.4.............................................................            0.20           0.220            0.42
    5.7.............................................................            0.88           0.160            1.04
    6.8.............................................................            0.42           0.300            0.72
    7.4.............................................................            0.48           0.210            0.69
    7.5.............................................................            0.24           0.190            0.43
    8.0.............................................................            0.51           0.234            0.74
    Tier 1 standards................................................            1.53           0.560             N/A
    LEV standards...................................................            0.90           0.280             N/A
    ----------------------------------------------------------------------------------------------------------------
    
        EPA understands that manufacturers have established certification 
    levels which represent typical vehicle usage and that manufacturers 
    have given themselves a significant margin between the certification 
    levels and the standards to account for variability including more 
    severe usage and deterioration. However, EPA found that some 1997 model 
    year engines were certified to very low levels even taking the need for 
    a compliance margin into consideration. At the time, however, EPA did 
    not believe it was appropriate, given the lack of a full opportunity 
    for notice and comment, and the need for more thorough data and 
    analyses, to proceed directly to finalizing standards tighter than 
    those originally proposed for heavy-duty Otto-cycle engines. For these 
    reasons, EPA did not finalize the proposed standards for Otto-cycle 
    engines and asserted that more stringent standards might be reasonably 
    achievable in the 2004 model year time frame. With the lead time 
    available for the 2004 time frame and in the context of EPA's emission 
    control program at the time, EPA concluded in 1997 that final action 
    establishing an appropriate standard for Otto-cycle heavy-duty engines 
    should be the subject of a future action that more thoroughly assessed
    
    [[Page 58483]]
    
    whether a more stringent standard might be achievable and appropriate 
    for some or all categories of Otto-cycle heavy-duty engines.
    
    D. Consent Decrees With Heavy-Duty Diesel Engine Manufacturers
    
        The Department of Justice and EPA recently filed proposed consent 
    decrees with seven of the largest heavy-duty diesel engine 
    manufacturers in the U.S. in order to resolve the problems uncovered 
    from current and past heavy-duty diesel engines which the government 
    does not believe meet existing standards and defeat device rules. (See 
    63 FR 59330-59334; November 3, 1998). In these consent decrees with the 
    Federal Government these manufacturers have agreed, among other things, 
    to meet a 2.5g/bhp-hr limit on NMHC+NOX no later than 
    October 1, 2002. The majority of these engine manufacturers have also 
    agreed to produce engines by October 1, 2002 which meet a 1.25 not-to-
    exceed limit, a 1.0 Euro III limit (on which the Agency's proposed 
    supplemental steady-state cycle is based), and to test engines over and 
    eventually comply with a load response test and limit. \36\ The fact 
    that these engine manufacturers have agreed to meet the 2004 standards 
    in 2002 gives the Agency additional confidence that the 
    NMHC+NOX standard being reaffirmed in today's proposal is 
    appropriate for the 2004 model year. Other elements of these consent 
    decrees that are carried over to today's proposed rule include the 
    addition of a new steady state certification test and a new ``not-to-
    exceed'' (NTE) approach to in-use testing. In addition, under the 
    consent decrees the manufacturers are required to invest considerable 
    resources to evaluate instrumentation and methodologies for on-road 
    testing, providing an additional basis for EPA's expectations regarding 
    the advancement of technology in this area.
    ---------------------------------------------------------------------------
    
        \36\ The Consent Decrees establish target limits for a load 
    response test of 1.3 times the federal test procedure (FTP) standard 
    for NMHC+NOX and 1.7 times the FTP standard for PM. These 
    limits would take effect for affected manufacturers after October 1, 
    2002. However, the Consent Decrees establish a process to determine 
    whether these limits should be modified to ensure that they are the 
    lowest achievable given the technology available at the time. Under 
    this process, manufacturers would submit load response test data 
    with their certification applications starting with the 1999 model 
    year, and by October 1, 2000, the parties to the Consent Decrees 
    would review these data to determine appropriate emission limits.
    ---------------------------------------------------------------------------
    
        The Agency believes these consent decrees will partially address 
    the emission problems from these previously produced engines. However, 
    we do not believe that relying on the current compliance program and 
    the use of enforcement actions in the future is the most appropriate 
    method to assure in-use compliance of heavy-duty engines under all 
    operating conditions. We estimate that the more than 1,000,000 engines 
    at issue in these consent decrees produced since 1988 will have 
    resulted in excess NOX emissions of more than 15 million 
    tons over the lifetime of the engines, with an estimated 1.3 million 
    excess tons of NOX being emitted in 1998 alone. This level 
    of NOX emissions is enormous. To put this in perspective, 
    the Agency's National Air Pollutant Emission Trends report for 1900-
    1996 estimates the total U.S. emission inventory for annual 
    NOX emissions was 23.3 million tons. These estimates do not 
    include the previously unknown excess NOX emissions from on-
    highway heavy-duty diesels. Assuming the total 1998 national 
    NOX emissions are similar to 1996, the 1.3 million tons 
    excess NOX emissions from heavy-duty diesels in 1998 
    represent approximately five percent of the national total. We believe 
    the new compliance requirements proposed in this NPRM must be put in 
    place in order to assure that the public's health and welfare are 
    protected from these types of excess emissions in the future.
    
    IV. What Are the Details of This Proposal?
    
    A. Reaffirmation of 2004 NMHC + NOX Standard for Heavy-Duty 
    Diesel Engines
    
        In today's proposal, the Agency is reaffirming the technological 
    feasibility, cost-effectiveness, and appropriateness under the Clean 
    Air Act of the 2004 NMHC+NOX standard for HDDEs, including 
    the appropriateness of the current 0.1g/bhp-hr PM standard. In 1997, 
    the Agency finalized on-highway heavy-duty diesel standards for model 
    year 2004 of:
    
    2.4 g/bhp-hr NMHC + NOX
    
        or
    
    2.5 g/bhp NMHC + NOX with a limit of 0.5 g/bhp-hr on NMHC
    
        For today's proposal, the Agency has conducted a thorough analysis 
    of information and data which has become available since the 
    finalization of these standards in October of 1997. As discussed 
    elsewhere in this preamble and in the RIA for this proposal, 
    manufacturers have made significant progress toward meeting the 2004 
    standards, and in fact, the Agency believes a large number of 
    manufacturers will be meeting the 2004 model year standards by the end 
    of 2002. Manufacturers have made significant progress in several key 
    technologies for HD diesels which will allow them to meet the 2004 
    NMHC+NOX standards. These areas included advanced fuel 
    injection systems, EGR, advanced turbocharger systems, and advanced 
    electronic controls. In the relatively short time frame since the 
    finalization of the 1997 rule, manufacturers have either announced or 
    begun to introduce second generation electronically controlled fuel 
    injection systems, such as the Cummins Accumulator Pump system (CAPS), 
    and the Navistar/Caterpillar second generation hydraulicly actuated 
    electronic unit injections (HEUI) and mechanically actuated electronic 
    unit injection (MEUI) systems.\37\ \38\ \39\ \40\ \41\ These newer 
    systems provide manufacturers with enormous capabilities to tailor-fit 
    engine injection pressures, injection rate shaping, and pilot injection 
    (or multiple pilot injections) to lower NOX emissions while 
    still complying with the current PM standard, and maintaining or 
    improving upon the fuel efficiency, performance, and durability 
    expected by HDDE users. These advanced fuel systems will be coupled 
    with new, sophisticated EGR systems. As discussed in the RIA, 
    considerable research has been done in the last few years on the 
    application of EGR to heavy-duty diesels in order to meet the 2004 
    standards. Based on this relatively recent information, it now appears 
    manufacturers will use a combination of hot and cooled EGR, sometimes 
    at relatively high EGR flow rates, on the order of 40-50 percent under 
    certain operating conditions, to achieve the 2004 NMHC+NOX 
    standards. The Agency believes EGR is perhaps the single most 
    significant advance in emission control technology for HD diesels which 
    will enable the approximately 50 percent reduction in NOX 
    emissions required by the 2004 standards. As discussed in the draft 
    RIA, cooled EGR is very effective at reducing NOX emissions. 
    Laboratory studies have shown that EGR can reduce NOX 
    emissions by up to 90 percent at
    
    [[Page 58484]]
    
    light load and up to 60 percent at full load near rated 
    speed.42 Other studies have shown similar reductions at 
    other speeds and loads.43 In addition to fuel system changes 
    and EGR, turbocharger manufacturers and engine manufacturers are in the 
    process of developing new variable nozzle turbochargers (VNT, sometimes 
    referred to as variable geometry turbochargers), as well as more 
    advanced, electronically controlled wastegated turbochargers, for both 
    performance and emission reasons. The new VNT systems will allow 
    manufacturers more flexibility in how they design their EGR systems, 
    and provide improved performance for engine users. Finally, engine 
    manufacturers continue to develop and introduce highly sophisticated 
    electronic control management systems based on the latest 
    microprocessor technology available.\44\ These next generation control 
    systems integrate the complete engine/powertrain system, including the 
    injection system, EGR, and turbocharger, which allows the manufacturer 
    to maximize the engine performance as well as emission control system. 
    The RIA for this proposal provides additional detail on these 
    technologies, as well as the Agency's cost analysis for the combination 
    of technologies which EPA expects will be used to meet the 2004 
    NMHC+NOX standards. Based on the most recent information 
    available, the Agency is confident that engine manufacturers are making 
    sufficient progress in the development of technologies which will allow 
    them to meet the 2004 NMHC+NOX standards. As discussed 
    below, the Agency does not believe changes in diesel fuel quality are 
    needed for engines to meet these standards.
    ---------------------------------------------------------------------------
    
        \37\ SAE paper 973182, ``Advanced Technology Fuel System for 
    Heavy-duty Diesel Engines''.
        \38\ Diesel Progress, August 1998, ``CAT Gears Up Next 
    Generation Fuel Systems'', available in EPA Air Docket A-98-32, 
    Docket Item #II-D-03.
        \39\ Diesel Progress, August 1998, ``Next Generation MEUI-B to 
    Debut in 2001'', available in EPA Air Docket A-98-32, Docket Item 
    #II-D-03.
        \40\ Diesel Progress, October 1998, ``No Mistaking New Cummins 
    ISL Engine'', available in EPA Air Docket A-98-32, Docket Item #II-
    D-04.
        \41\ ``Cummins New Midrange Fuel System'', presented by John 
    Youngblood, Cummins Engine Company, at the SAE Diesel Technology 
    TOPTEC, April 22, 1998, available in EPA Air Docket A-98-32, Docket 
    Item #II-D-01.
        \42\ Dickey D.W., T.W. Ryan III, A.C. Matheaus: ``NOX 
    Control in Heavy-Duty Engines-What is the Limit?'', SAE paper 
    980174, 1998. Dickey; and, Zelenka P., H. Aufinger, W. Reczek, W. 
    Cartellieri: ``Cooled EGR-A Key Technology for Future Efficient HD 
    Diesels,'' SAE paper 980190, 1998.
        \43\ Kohketsu S., K. Mori, K. Sakai, T. Hakozaki: EGR 
    Technologies for a Turbocharged and Intercooled Heavy-Duty Diesel 
    Engine,'' SAE paper 970340, 1997; Baert R., D.E. Beckman, A.W.M.J. 
    Veen: ``EGR Technology for Lowest Emissions,'' SAE paper 964112, 
    1996; and, Heavy-duty Engine Working Group, Mobile Source Technical 
    Advisory Subcommittee of the Clean Air Act Advisory Committee, 
    ``Phase 2 of the EPA HDEWG Program--Summary Document'', available in 
    EPA Air Docket A-98-32.
        \44\ See for example SAE paper 981035, ``The Cummins Signature 
    600 Heavy-Duty Diesel Engine'' T.R. Stover, D.H. Reichenbach, and 
    E.K. Lifferth, Cummins Engine Co., Inc., Feb., 1998.
    ---------------------------------------------------------------------------
    
        In addition, as noted in section III.D, the fact that several 
    heavy-duty diesel engine manufacturers have agreed to meet the 2004 
    standards in 2002 gives the Agency additional confidence that the 
    NMHC+NOX standard being reaffirmed in today's proposal is 
    appropriate for the 2004 model year.
        As discussed in section IX, and in the draft RIA, EPA does not 
    believe more stringent standards for the 2004 model year are 
    technologically feasible, giving appropriate consideration to cost, 
    energy, and safety factors. Technologies which could reduce emissions 
    significantly below the 2004 standards, such as NOX absorber 
    catalysts, are still in the research and development stage, and do not 
    appear to be ready for the 2004 model year. The Agency has also 
    examined technologies to reduce PM from HD diesel engines, including 
    diesel oxidation catalysts and particulate traps. As discussed in the 
    draft RIA, we believe the current PM standard of 0.1 g/bhp-hr (0.05 for 
    urban buses) continues to be the appropriate standard for the 2004 time 
    frame. However, in section X of today's proposal we discuss the 
    possible feasibility of more stringent standards in later model years, 
    although no specific proposals are made today.
    
    B. Are Changes in Diesel Fuel Quality Necessary To Meet the 2004 
    Standards?
    
        The purpose of this section is to assess the current understanding 
    of the role diesel fuel quality plays in the ability of diesel engines 
    to meet the 2004 NMHC+NOX emission standards and to 
    determine whether these standards can be met using currently available 
    fuel. It has long been realized that diesel engine technology alone is 
    not the only mechanism to lower NOX emissions. Diesel fuel 
    quality also plays an important role in emission formation, as well as 
    engine performance. In addition, diesel fuel quality can play a role in 
    the effectiveness of certain emission control technologies, and in some 
    cases can be considered a technology enabler, i.e., some emission 
    control devices may not function because of certain diesel fuel 
    properties, such as sulfur content. In EPA's 1997 final rulemaking for 
    the 2004 standards, we stated that we believed the 2004 standards were 
    appropriate and technologically feasible through diesel engine 
    technology modifications alone, without changes to diesel fuel quality 
    (see 62 FR 54700, Oct. 21, 1997). However, we also stated that this 
    issue would be revisited in the 1999 technology review rulemaking. 
    ``EPA will evaluate in light of any new information whether diesel fuel 
    improvements are needed for the standards to be appropriate for 2004.'' 
    (See 62 FR 54700, Oct. 21, 1997).
        Section V.A. of this preamble (``2004 Emission Standards for Heavy-
    duty Diesel Engines'') and Chapter 3 of the draft RIA for this proposal 
    (``Technological Feasibility of HD Diesel and Otto-cycle Standards'') 
    discuss in detail the technologies we believe will enable HD diesel 
    engines to meet the 2004 standards, on existing U.S. HD diesel fuel. 
    These technologies include cooled EGR, advanced fuel injection systems 
    with rate-shaping ability, advanced turbocharger designs (such as 
    variable nozzle turbochargers), and electronic engine management. These 
    technologies have been demonstrated to produce significant emission 
    reduction, independent of changes in current U.S. diesel fuel quality. 
    Based on the information discussed in section V.A. of this preamble and 
    Chapter 3 of the draft RIA, and based on the fact that these emission 
    control technologies can produce substantial emission reductions using 
    current diesel fuel, we conclude no change in diesel fuel quality is 
    necessary to meet the 2004 NMHC+NOX standard. We request 
    comment on this conclusion, and encourage commenters to supply any data 
    and information that may support their comments.
        Engine manufacturers have recently raised concerns to EPA regarding 
    the potential negative effects of current diesel fuel sulfur levels on 
    engine durability for 2004 technology engines for the full useful life 
    of the engines. As discussed in Chapter 3 of the draft RIA for this 
    rule, the use of cooled EGR systems to meet the 2004 standards can give 
    rise to potentially significant concentrations of sulfuric acid 
    formation in the recirculated exhaust if the EGR system cools the 
    exhaust below the water vapor dew point. In addition, some HD diesel 
    engine manufacturers have expressed specific concern regarding the 
    extended useful life for the heavy-heavy duty diesel service class 
    which goes into effect in 2004. In the 1997 final rulemaking for on-
    highway heavy-duty diesel engines, EPA revised and extended the useful 
    life for the heavy-heavy service class from 290,000 miles to 435,000 
    miles (see 62 FR 54700, October 21, 1997). Several manufacturers have 
    suggested EPA should reconsider this useful life extension due to their 
    concerns with engine durability, diesel fuel sulfur, and cooled EGR 
    systems. These manufacturers have suggested EPA implement the extended 
    useful life contingent upon federal diesel fuel standards meeting some 
    threshold maximum fuel sulfur content. However, the Agency believes 
    manufacturers will design cooled EGR systems to limit sulfuric acid 
    formation and to prevent in-use durability problems. As
    
    [[Page 58485]]
    
    discussed in the RIA (section 3.II.B), EPA expects engine manufacturers 
    to maintain EGR cooler systems slightly above the water vapor dew 
    point, particularly at high load. In addition, EPA expects 
    manufacturers to utilize EGR systems made of sulfuric acid corrosive 
    resistant materials (such as specially treated stainless steel) to 
    prevent deterioration of the EGR system. We request additional 
    information and supporting data on the manufacturers' concerns 
    regarding durability issues associated with the 2004 standards. We 
    request specific comment and supporting data on the manufacturers' 
    concerns, including any in-use or laboratory durability data, and any 
    data which would support or refute the manufacturers' contentions 
    regarding the need for a shorter useful life for the heavy-heavy 
    service class.
        In the remainder of this section, we review the new information 
    which has become available since the 1997 rulemaking through a study 
    performed by the Heavy-duty Engine Working Group.
        In anticipation of the need for new information regarding the 
    influence of diesel fuel quality on future emission technologies and 
    achievable levels, in December of 1995 a new Working Group called the 
    Heavy-duty Engine Working Group (HDEWG) was formed under the Mobile 
    Source Technical Advisory Subcommittee of the Clean Air Act Advisory 
    Committee. The HDEWG consists of approximately 30 members, including 
    representatives from EPA, heavy-duty engine original equipment 
    manufacturers (OEMs), the oil industry, state air quality agencies, 
    private consultants and members of academic institutions. The HDEWG 
    formed a steering committee which consisted of representatives from 
    EPA, Cummins, Caterpillar, Navistar, Ford, British Petroleum, Equilon, 
    Mobil Oil, Phillips, the Engine Manufacturers Association, the American 
    Petroleum Institute, and the National Petroleum Refinery Association. 
    The HDEWG set as their research objective to contribute to EPA's 1999 
    technology review of the NMHC+NOX emission standards for 
    model year 2004 heavy-duty diesel engines by assessing relative merits 
    of achieving 2.5 g/bhp-hr NMHC+NOX level either through 
    engine system modifications alone, or a combination of engine system 
    and fuel modifications.
        The HDEWG established a three phase process in order to meet their 
    objective. In Phase 1, the goal was to determine whether the combined 
    effects of diesel fuel properties on exhaust emissions of ``black 
    box'',45 advanced prototype engines being developed by 
    engine manufacturers were large enough to warrant a Phase 2. However, 
    the details of each black box engine would not be shared with the 
    HDEWG. In addition, the HDEWG agreed to use one ``transparent'' engine 
    at an independent test facility, Southwest Research Institute (SwRI). 
    During Phase 1, testing was to be performed on the transparent engine 
    at SwRI, as well as the black box engines at manufacturers' own testing 
    facilities, to determine if the transparent engine was representative 
    of the black box engines with respect to diesel fuel effects on 
    NOX emissions. Phase 2 of the program, which would occur 
    upon successful completion of Phase 1, would be used to test a range of 
    relevant fuel properties on the transparent engine at SwRI, in order to 
    determine the effects of various fuel properties on emissions. Finally, 
    Phase 3 of the test program would determine whether or not the results 
    seen during Phase 2 on the transparent engine was in fact 
    representative of black box engines, i.e., advanced prototype engines 
    being developed by engine manufacturers to meet the 2004 standards. 
    Phase 3 would be performed at engine manufacturers' laboratories using 
    a subset of the fuel matrix from Phase 2.
    ---------------------------------------------------------------------------
    
        \45\ ``Black box'' engines are advanced engines being designed 
    by engine manufacturers to meet the 2004 standards.
    ---------------------------------------------------------------------------
    
        At the time of the publication of this proposal, Phase 1 and Phase 
    2 of the program have been completed. Phase 3 is expected to be 
    completed by the end of 1999. The RIA for this proposal contains a 
    detailed discussion of the Phase 1 and Phase 2 portions of the HDEWG 
    test program. The reader should see Chapter 3 of the draft RIA for this 
    proposal for a detailed description.
        The HDEWG's primary focus was on the effects of diesel fuel 
    properties on HC and NOX emissions, not on PM emissions, and 
    therefore fuel sulfur level was not investigated. A significant amount 
    of data exists on the effects of diesel fuel sulfur on engine 
    emissions, and in fact this data was summarized recently in a paper 
    published by members of the HDEWG.46 Existing data on recent 
    model year HD engines indicates diesel fuel sulfur level does have a 
    statistically significant effect on PM emissions, but no statistically 
    significant effect on HC, carbon monoxide (CO), or NOX 
    emissions for engines with no exhaust aftertreatment. For this reason, 
    and because of the focus on NMHC and NOX emissions, as well 
    as the limitations of the prototype SwRI transparent engine, the HDEWG 
    did not include fuel sulfur level as a variable in Phase 1, 2 or 3 of 
    their test program, nor were PM emissions measured during Phase 1 or 2. 
    The Phase 3 test program, done at individual engine manufacturers' 
    facilities, will include PM measurement.
    ---------------------------------------------------------------------------
    
        \46\ See Lee, R., Pedley, J., and Hobbs, C., ``Fuel Quality 
    Impact On Heavy-Duty Diesel Emissions:--A Literature Review'', 
    Society of Automotive Engineers paper number 982649, 1998.
    ---------------------------------------------------------------------------
    
        The HDEWG concluded two points based on the results of the Phase 1 
    testing. First, initial testing on a limited set of diesel fuel 
    formulations (fuel batches with high cetane number and low aromatics) 
    on advanced prototype engines by the engine manufacturers showed a 
    change in NOX emissions which warranted additional testing 
    under Phase 2. Second, the ``transparent'' engine at SwRI performed in 
    a way that was representative of engine manufacturers' advanced 
    prototypes, and was therefore an adequate test engine for Phase 2.
        The purpose of the Phase 2 component of the test program was to 
    test a range of relevant fuel properties on the transparent engine at 
    SwRI in order to determine the effects of various fuel properties on 
    emissions. All testing during Phase 2 of the test program was done at 
    SwRI on the transparent engine. Based on the results of the Phase 1 
    testing, as well as the literature review performed under Phase 1, the 
    HDEWG selected four fuel properties for investigation under Phase 2: 
    density, cetane (natural and ``boosted'' 47), monoaromatic 
    content and polyaromatic content. As mentioned previously, fuel sulfur 
    level was not investigated. A test matrix was designed to decouple 
    these fuel properties from each other. The design matrix included two 
    levels of density, monoaromatic hydrocarbons, polyaromatic 
    hydrocarbons, and three levels of cetane, with duplicate test points 
    for both natural and ``boosted'' cetane. The final matrix included 
    eighteen test fuels, with density varying from 830 to 860 kg/m\3\, 
    cetane numbers from 42 to 48 to 53, monoaromatic content from 10 to 25 
    percent, and polyaromatic content from 2.5 to 10 percent. The test 
    cycle used by SwRI was the AVL 8-mode test. This steady-state test 
    cycle, with associated weighting factors, has been shown in the past to 
    correlate very well with NOX emissions measured over the 
    U.S. heavy-duty federal test procedure (FTP). All emission tests were 
    performed at least in duplicate. The transparent engine used a SwRI is 
    a modern, heavy-heavy duty diesel engine with
    
    [[Page 58486]]
    
    electronically controlled unit injectors capable of meeting the U.S. 
    1998 model year emission standards. This engine was modified by SwRI 
    with the addition of a prototype, low-pressure loop, cooled EGR system 
    with manual control of EGR flow rates. For the Phase 2 test program, 
    SwRI selected EGR rates necessary to approach an AVL 8-mode composite 
    NOX level of 2.5g/hp-hr.
    ---------------------------------------------------------------------------
    
        \47\ Boosted cetane is achieved by the addition of a fuel 
    additive, in this case ethylhexyl nitrate.
    ---------------------------------------------------------------------------
    
        The large quantity of test data generated by the test program was 
    evaluated using statistical techniques in order to develop exhaust 
    emission and fuel consumption prediction models based on the four fuel 
    properties. All properties were evaluated using a significance level of 
    five percent. The data generated during Phase 2 indicates that for 
    engines utilizing advanced fuel injection and a cooled EGR system 
    operating at emissions levels near the 2004 standards the effects of 
    large changes in individual fuel properties on HC+NOX 
    emissions are rather small, and for cetane number not statistically 
    significant. A large decrease in fuel density, from 860 to 830 kg/
    m3, or in monoaromatic content, from 25 to 10 percent, is 
    predicted to result in a 4.3 percent decrease in HC+NOX 
    emissions. A large decrease in polyaromatics content, from 10 to 2.5 
    percent, is predicted to result in a 2.3 percent decrease in 
    HC+NOX emissions.
        The Phase 2 data was also analyzed to predict the combined effects 
    from diesel fuel changes on emissions, not just single property 
    changes. The Phase 2 model was used to predict the effect of fuel 
    modifications from current, average U.S. on-highway diesel fuel to a 
    ``cleaner'', reformulated diesel fuel, one with low density (830 kg/
    m3), high cetane (52), low monoaromatics (10 percent), and 
    low polyaromatics (2.5 percent). The Phase 2 model predicts this 
    significant change in U.S. diesel fuel formulation would result in a 
    8.4 percent decrease in HC+NOX emissions.
        The Phase 3 results are currently not available. However, based on 
    what has been seen in the Phase 1 and Phase 2 portions of this test 
    program, we do not believe a change in diesel fuel formulation is 
    required to make the 2004 model year NMHC+NOX standards 
    technologically feasible and appropriate under the CAA. The data from 
    the Phase 1 and 2 portions of the HDEWG does indicate that a change in 
    diesel fuel formulation could provide for a small reduction in 
    HC+NOX emissions from HD diesels, on the order of an 8 
    percent reduction. An assessment of the appropriateness of such a 
    diesel fuel reformulation, beyond the 2004 standards with existing HD 
    diesel fuel, is outside the scope of this rulemaking.
    
    C. Otto-Cycle Engine-Based Program
    
        We are proposing an NMHC+NOX standard for Otto-cycle 
    engines for 2004 and later model years, but are limiting the 
    applicability of this new standard to engines used in vehicles over 
    14,000 pounds GVWR and in incomplete vehicles. 48 (We are 
    also proposing new vehicle standards for the remaining engines, as 
    discussed in later sections.) We are not proposing to apply the vehicle 
    standards to these engines at this time. Engines used in incomplete 
    vehicles are manufactured for use in many different kinds of heavy-duty 
    vehicles by many different manufacturers. Vehicles in the weight 
    categories above 14,000 pounds GVWR tend to be quite large and varied 
    compared to pick-up trucks and full-size vans, and most dynamometer 
    test facilities are currently not equipped to accommodate vehicles in 
    this size range. Additionally, this approach is consistent with 
    California which allows engine-based testing for these vehicles in its 
    Medium-duty Vehicle program.
    ---------------------------------------------------------------------------
    
        \48\ Incomplete vehicles less than 14,000 lbs GVWR could 
    optionally certify to the proposed new vehicle standards, as 
    discussed in a later section.
    ---------------------------------------------------------------------------
    
    1. Engine Exhaust Emissions Standards
        We propose a NMHC+NOX standard of 1.0 g/bhp-hr for MY 
    2004 and later for those Otto-cycle engines in the engine-based 
    program. The proposed standard represents a reduction in the 
    NOX and HC standards of over 75 percent. EPA believes that 
    this standard represents the most stringent standard reasonably 
    achievable for these engines, in keeping with the requirements of the 
    CAA. EPA's analysis of the technological feasibility of a 1.0 g/bhp-hr 
    NMHC+NOX standard is contained in Technological Feasibility 
    section below. We also believe that the ABT program proposed for 
    engines provides manufacturers with the needed flexibility to meet the 
    new standard as their product lines become subject to the new engine 
    standards. The ABT provisions are also described below. In their 
    assessment of the feasibility of new engine-based standards, engine 
    manufacturers recommended a standard of 2.0 g/bhp-hr 
    NMHC+NOX. The Technological Feasibility section also 
    contains a discussion of the manufacturer's recommendations. EPA 
    requests specific comment on a range of possible standards, from the 
    proposed standard of 1.0 g/bhp-hr to 1.5 g/bhp-hr, and on the standard 
    of 2.0 g/bhp-hr proposed by engine manufacturers.
    2. Averaging, Banking, and Trading for Otto-Cycle Engines
        As part of proposing more stringent engine-based standards, EPA is 
    proposing a modified ABT program for these engines. The program is 
    similar in design to the program adopted for diesel engines. EPA is 
    proposing ABT modifications to allow more flexibility within the ABT 
    framework to help meet the more stringent standards. ABT credits can 
    help manufacturers with engine configurations that are more difficult 
    to modify, where more time would help reduce costs. Credits can also 
    allow manufacturers to continue with product plans that might call for 
    the retirement of an engine family at some point shortly after 2004. By 
    banking credits manufacturers can also reduce their uncertainty or risk 
    associated with the new standards. In the Summary and Analysis of 
    Comments for the Diesel Final Rule, EPA explained why the modified ABT 
    program adopted in that rulemaking will not decrease emissions 
    reductions associated with the new standards. 49 Similarly, 
    EPA believes that the modified ABT program proposed in this rulemaking 
    also will not decrease emissions reductions associated with the new 
    standards.
    ---------------------------------------------------------------------------
    
        \49\ See EPA Air Docket No. A-95-27.
    ---------------------------------------------------------------------------
    
        The ABT program has been used for only one Otto-cycle engine family 
    to meet the current 4.0 g/bhp-hr NOX standard which went 
    into effect in the 1998 model year. In other cases, advances in 
    catalyst technology and engine/fuel system improvements have allowed 
    manufacturers to meet the standard across their product line. Most 
    engine families have certification levels of less than half the 
    standard. However, with the proposed standard for 2004, EPA expects ABT 
    to become a more important tool for Otto-cycle engine manufacturers.
        An ABT program allows the Agency to propose and finalize a more 
    stringent engine standard than might otherwise be appropriate under the 
    CAA, since ABT reduces the cost and improves the technological 
    feasibility of achieving the standard. EPA is proposing changes to the 
    ABT program with the intent that the changes would enhance the 
    technological feasibility and cost-effectiveness of the new standard, 
    and thereby help to ensure the new standard would be attainable earlier 
    than would otherwise be possible. The changes would provide 
    manufacturers with additional product planning flexibility and the 
    opportunity for a more cost effective introduction of product lines
    
    [[Page 58487]]
    
    meeting the new standard. Also, EPA believes that ABT creates an 
    incentive for early introduction of new technology which allows certain 
    engine families to act as trail blazers for new technology. This can 
    help provide valuable information to manufacturers on the technology 
    prior to manufacturers needing to apply the technology throughout their 
    product line. This further improves the feasibility of achieving the 
    standard. This early introduction can also provide valuable information 
    for use in other regulatory programs that may benefit from similar 
    technologies (e.g., nonroad programs). EPA views the effect of the ABT 
    program itself as environmentally neutral because the use of credits by 
    some engines is offset by the generation of credits by other engines. 
    However, when coupled with the new standards, the ABT program would be 
    environmentally beneficial because it would allow the new standards to 
    be implemented earlier than would otherwise be appropriate under the 
    Act.
        EPA proposes the following provisions for the modified ABT program 
    for Otto-cycle engines:
         Manufacturers could bank NOX credits beginning 
    in MY 2000 for MYs 2004 and later.
         Credits would be earned up to a NOX level of 
    2.0 g/bhp-hr.
         Credits would be discounted by 10 percent for engine 
    families with FELs above the 1.0 g/bhp-hr NMHC+NOX level 
    (i.e., the proposed standard) and undiscounted for engine families with 
    FELs at or below the 1.0 g cut point.
         For model year 2004 and later, engine families with FELs 
    above 0.5
    g/bhp-hr NMHC+NOX (i.e., one-half of the proposed standard) 
    would be discounted by 10 percent. Engine families with FELs at or 
    below 0.5
    g/bhp-hr would earn undiscounted credits.
         As with the diesel program, NOX credits banked 
    prior to 2004 would be used to meet the combined NMHC+NOX 
    standard in 2004 and later.
         Credits banked under the modified program would have 
    unlimited credit life.
         Engine families using credits after MY 2004 may not exceed 
    the previous NOX standard of 4.0 g/bhp-hr.
         Engine families generating credits prior to 2004 must meet 
    the revised requirements for deterioration factors noted above.
        Prior to 2004, manufacturers could continue to use the current ABT 
    program. EPA proposes that the current program would end in 2004 and 
    the modified program would remain. Only credits banked under the 
    modified program could be used in 2004 and later. EPA is proposing to 
    end the current program with the 2003 model year because of concern 
    that manufacturers could generate enough credits under the current 
    program to significantly delay the 2004 standards. The current program 
    allows manufacturers to earn credits up to the current NOX 
    standard of 4.0 g/bhp-hr. With most engines currently certified with 
    NOX levels below 2.0 g/bhp-hr, there is potential for 
    substantial credit generation without the application of improved 
    technology under the current ABT program. If manufacturers were to bank 
    these credits, they could potentially use them to delay the 
    introduction of engines meeting the 2004 standards for a large majority 
    of their sales for up to three years. The proposed 2.0 g/bhp-hr ceiling 
    for credit generation in the modified program provides opportunity for 
    manufacturers to earn credits through the use of emissions controls 
    that are superior to the average controls currently being used. EPA 
    believes this approach is consistent with the goals of ABT. EPA 
    requests comment on the proposed 2.0 g/bhp-hr ceiling and on other 
    alternatives for transitioning from the current 4.0 g/bhp-hr 
    NOX standard to the 1.0 g/bhp-hr NOX standard 
    proposed for 2004. One such alternative could be a phase down of the 
    credit generation trigger value during the model years prior to 2004, 
    rather than a single trigger point of 2.0 g/bhp-hr.
        The changes to credit life and discounting being proposed for Otto-
    cycle engines are conceptually consistent with the modifications 
    finalized for diesel engines. EPA is proposing to discount credits by 
    10 percent if the engine has an FEL above a certain value or cut-point. 
    EPA adopted cut points in the diesel program in order to identify the 
    introduction of new technology as opposed to recalibrating or enhancing 
    existing technology. EPA believes that adoption of cutpoints in the HD 
    Otto-cycle engine program will provide similar technology forcing 
    incentives. EPA selected cut-point levels which represent a clear step 
    in emissions control rather than a marginal emissions reduction. The 10 
    percent discount selected for the HD Otto-cycle engine ABT program is 
    consistent with the program finalized for diesel engines. In that final 
    rule, EPA noted that a 10 percent discount strikes a balance between 
    zero (which significantly reduces the incentive to develop and 
    implement significantly cleaner technology) and 20 percent (which 
    manufacturers indicated in comments was far too large and would create 
    a disincentive for the introduction of cleaner technology). (See 62 FR 
    54708, October 21, 1997.) EPA requests comment on the selected levels 
    of the cut-points and discount adjustment, including comments on 
    whether a phased-in approach with a decreasing cut-point would be 
    appropriate for this category of engines.
        For diesels, EPA removed the three year credit life limit which 
    allows manufacturers to earn credits to be used in 2004 and later as 
    early as the 1998 model year. For Otto-cycle engines, MY 2000 will be 
    the earliest model year in which the rule would be effective due to the 
    timing of the rulemaking. Removing the credit life limit will provide 
    an additional year of potential credit banking and allows manufacturers 
    to retain credits after 2004 rather than having them expire after a 
    certain year. We believe that having credits expire would simply 
    encourage manufacturers to use the credits rather than save them; thus, 
    removing the credit life limit should provide a net environmental 
    benefit.50
    ---------------------------------------------------------------------------
    
        \50\ EPA presented a detailed analysis of its ABT program in the 
    Summary and Analysis of Comments for the Diesel Final Rule, Docket 
    A-95-27, document No. V-C-01.
    ---------------------------------------------------------------------------
    
        We believe that our proposals detailed above for a modified ABT 
    program will encourage the early use of cleaner technologies and 
    provide manufacturers with valuable flexibility in transitioning to 
    more stringent standards. EPA is proposing the modification to the ABT 
    program in conjunction with the 1.0
    g/bhp-hr NMHC+NOX engine-based standards to provide the 
    flexibility necessary to enable manufacturers to meet the standard 
    across their product line. This flexibility may not be necessary in the 
    context of a less stringent standard, in which case the proposed 
    modifications to the ABT program might not be supportable. EPA requests 
    comments on all aspects of the proposed ABT program.
    
    D. Supplemental Exhaust Emission Standards and Test Procedures for HD 
    Diesel Engines
    
    1. Introduction/Background
        EPA's goal is to ensure real-world emissions control over the broad 
    range of in-use speed and load combinations that can occur, rather than 
    just controlling emissions under certain laboratory conditions. EPA's 
    1997 HD diesel rule was based on the expectation that this would be the 
    case. The 1997 rule's projected emissions benefit, expected control 
    technology, cost, and cost-effectiveness were derived with the
    
    [[Page 58488]]
    
    belief that the engines would be meeting the standards in-use under 
    typical operating conditions. The supplemental provisions we are 
    proposing today for HD diesel engines are intended to help ensure this 
    is the case. Today's proposal includes a new set of supplemental 
    emission standards and associated test procedures to more closely 
    represent the range of real world driving conditions.
        EPA believes that an important tool for achieving an effective 
    compliance program is an in-use program with an objective standard and 
    easily implemented test procedure. Today's action does not include a 
    proposal for a manufacturer in-use testing program for HD diesels and 
    HD Otto-cycle engines. However, as discussed in section V, EPA believes 
    a manufacturer in-use testing program is a critical component of a 
    comprehensive compliance program, and EPA intends to work with 
    interested parties towards the development of a proposal for an in-use 
    testing program in the near future. We believe that the combination of 
    supplemental standards and an effective in-use testing program will 
    ensure that the environmental benefits resulting from the emission 
    standards for model year 2004 and beyond will be achieved in-use.
        Historically, EPA's approach to emission standard setting has been 
    to set a numerical emission standard on a specified test procedure and 
    rely on the prohibition of defeat devices to ensure in-use control over 
    the range of operation not included in the test procedure. No single 
    test procedure can cover all real world operation or conditions, 
    particularly where certification is an engine-based test procedure 
    rather than a vehicle-based procedure (i.e., heavy-duty diesel engines, 
    heavy-duty Otto-cycle engines used in incomplete vehicles, and heavy-
    duty Otto-cycle engines used in vehicles with a GVWR greater than 
    14,000 pounds). For example, the same engine used in both a 9,000 pound 
    and a 15,000 pound vehicle would likely see much higher speeds and 
    loads, on average, in the 15,000 pound vehicle. The defeat device 
    prohibition is designed to ensure that emissions controls are employed 
    during real world operation and not just under laboratory or test 
    procedure conditions. However, the defeat device prohibition is not a 
    quantified numerical standard and does not have an associated test 
    procedure. As a result, the current focus on a standardized test 
    procedure makes it harder to ensure that engines will operate with the 
    same level of control in the real world as in the test cell. To ensure 
    that emission standards are providing the intended benefits in use, the 
    Agency must have a reasonable expectation that emissions under real 
    world conditions reflect those measured on the test procedure. The 
    supplemental exhaust emission standards and test procedures for HD 
    diesel engines are designed to supplement the current FTP standards and 
    defeat device prohibition, and help ensure that the standards are 
    providing the intended benefits in actual use.
        The Agency also believes a supplemental standard and test procedure 
    or an alternative mechanism is needed for HD Otto-cycle engines used in 
    incomplete vehicles, and heavy-duty Otto-cycle engines used in vehicles 
    with a GVWR greater than 14,000 pounds, in order to assure in-use 
    compliance over a broad range of operating conditions. Today's proposal 
    does not include supplemental standards for test procedures for this 
    class of engines because more information is needed to allow 
    determination of appropriate emission levels and resolution of other 
    specific technical issues. As discussed in section V, the Agency 
    intends to gather further information related to the appropriate levels 
    and scope of such standards over the next several months and to release 
    a subsequent proposal within the next year which would include 
    supplemental standards and test procedures for HD Otto-cycle engines.
        In the Statement of Principles,51 signed by EPA, the 
    California Air Resources Board and engine manufacturers, the 
    signatories agreed to develop appropriate measures which ensure that 
    emission controls are maintained throughout the engine's life. During 
    the public comment period for the proposed 2004 standards for diesel 
    heavy duty engines, several state and environmental organizations 
    advocated establishing an in-use compliance program. (See 62 FR 54707-
    54708; October 21, 1997). Commenters urged EPA to develop an effective 
    in-use compliance program to ensure that heavy-duty engines comply with 
    emission standards over their useful lives. We also received comment 
    that the current federal test procedure (FTP) does not reflect 
    realistic driving conditions (for example, high speeds and loads), and 
    that a more representative test cycle is needed. We acknowledged that 
    it was essential to further understand in-use emissions and establish a 
    comprehensive in-use compliance presence.
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        \51\ For more background on the Statement of Principles, see 
    section III.A. of this preamble.
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        In the October 1997 final rule, EPA adopted a number of measures 
    designed to improve in-use compliance for heavy-duty diesel engines. 
    (See 62 FR 54700-54702; October 21, 1997). In summary, these measures 
    included: (1) Extending the engines' useful life; (2) increasing the 
    maintenance intervals for emissions-related components; (3) 
    strengthening the warranty provisions for emissions defects and 
    emission performance; (4) requiring that manufacturers provide owners 
    with guidance on maintenance for emissions-related components and on 
    responding to emission-related codes from on-board diagnostic systems; 
    and (5) strengthening ``anti-tampering'' requirements for engine 
    rebuilding. We also committed to further review and revise the 
    compliance programs if needed to ensure that the emission reductions 
    from more stringent standards are realized in-use. Since then, we have 
    learned that many heavy-duty engines currently are not meeting emission 
    standards in-use. EPA recently issued enforcement policy guidance to 
    partially address this problem.52
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        \52\ Available in the public docket for review.
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    2. Proposed Supplemental Test Procedures and Standards
        We propose to add two supplemental sets of standards and test 
    requirements for HD diesel engines: (1) A supplemental steady-state 
    test and accompanying standards; and (2) Not-To-Exceed Limits. Like 
    current standards, these new standards would apply to certification, 
    production line testing, and vehicles in actual use. All existing 
    provisions regarding standards (e.g., warranty, certification, recall) 
    would be applicable to these new standards as well. The steady-state 
    test is proposed because it represents a significant portion of in-use 
    operation of heavy-duty diesel engines that is not adequately 
    represented by the FTP. In addition, we are proposing a third 
    supplemental test procedure for heavy-duty diesel engines--a Load 
    Response Test--as a data submittal requirement only; we do not propose 
    emission limits for this test procedure at this time. The proposed Load 
    Response Test also represents operation not adequately represented by 
    the current FTP (harder accelerations), and could eventually be used to 
    ensure effective control of NOX and PM during this type of 
    operation. The combination of these supplemental test requirements and 
    emission standards would provide assurance that engine emissions are 
    designed to achieve the expected level of in-use emissions control over 
    all expected operating regimes in-use. These test procedures and 
    emission limits are
    
    [[Page 58489]]
    
    described in greater detail in the following sections.
        We believe that to ensure that emission standards actually achieve 
    their intended environmental benefits, the emissions measured during 
    engine test procedures must be indicative of emissions released during 
    real world operation. Recent advances in engine technology have created 
    the opportunity for a broader gap to exist between typical real world 
    operating conditions and those conditions represented by the current 
    EPA test cycle. The inconsistencies between lab and real world 
    emissions reduce the certainty that emission standards will achieve 
    their intended benefits. One approach to address this is enforcing 
    compliance with the current regulations, including the defeat device 
    prohibition, on a case-by-case basis. However, as discussed previously, 
    given the potential magnitude of the emission impact, we believe it is 
    more appropriate to address this concern through expanding the test 
    procedures and related emission standards.
        As discussed in more detail in the following sections, each of 
    these supplemental proposed emission standards is expressed as a 
    multiple of the existing FTP emission standards, or Family Emission 
    Limit (FEL) if the engine is certified under the ABT program, whichever 
    is applicable. For example, the diesel engine NTE limit for 
    NOX + NMHC is 1.25 times the current FTP emission standard, 
    or 1.25 times the applicable FEL. When certifying engines under the ABT 
    program, manufacturers must ensure that the FEL is set sufficiently 
    high so that all of the new proposed emission standards will be met in-
    use. For example, there may be cases where the FTP and supplemental 
    steady-state emission result is well below the standard, but setting 
    the FEL is constrained by the Not-To-Exceed emission result.
        For purposes of certification, actual test data for the steady 
    state test and the Load Response Test would have to be submitted as 
    part of the certification application (although only the steady state 
    test data would require comparison to proposed emission limits). The 
    Not-to-Exceed test limits would require only a statement of compliance 
    at certification (with supporting details). The compliance statement 
    would need to state explicitly that the engine will comply with the 
    applicable NTE limits when operated under all conditions which may 
    reasonably be expected to be encountered in normal vehicle operation 
    and use. However, this statement must be founded upon emission test 
    data, additional technical information, and good engineering judgement. 
    The manufacturer's basis for making the compliance statement would be 
    explained within the certificate application documentation, and the 
    supporting information would be available for review by the Agency.
    a. Supplemental Steady-State Test
        We propose to add a steady-state test cycle to the current Federal 
    test procedures for HD diesel engines. The proposed steady-state test 
    cycle is consistent with the test cycle found in the European's ``EURO 
    III ESC Test''; however not all aspects of the proposed supplemental 
    steady-state test are identical to the EURO III ESC Test.53 
    Manufacturers would be required to meet the standards under this test 
    cycle as well as continuing to meet the standards using the current 
    test procedure (including the current transient test cycle) in 40 CFR 
    part 86, subpart N.54 The proposed supplemental steady-state 
    test cycle is needed so that the FTP reflects a greater range of 
    driving conditions experienced on the road. The current FTP does not 
    fully represent the driving patterns of today's heavy-duty diesel 
    vehicles, nor does it fully take into account the increased use of 
    electronic engine management systems. These electronic systems have the 
    ability to optimize fuel economy during real-world driving, but often 
    at the expense of emissions. The proposed steady-state test cycle 
    represents an important type of modern engine operation, in power and 
    speed ranges that are typically used in practice. The mid-speeds and 
    mid-to-high loads represented by the proposed steady-state test are the 
    speeds and loads that these engines are designed to operate at for 
    maximum efficiency and durability. Specifically, highway cruise speeds 
    and loads fall into the operation represented by the proposed steady-
    state test.
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        \53\ ``Draft Proposal for a Directive of the European Parliament 
    and the Council Amending Directive 88/77/EEC of 3 December 1987 on 
    the Approximation of the Laws of the Member States Relating to the 
    Measures to be Taken Against the Emission of Gaseous and Particulate 
    Pollutants from Diesel Engines for Use in Vehicles'', a proposal 
    adopted by the Commission of the European Union on 3 December 1997, 
    for presentation to the European Council and Parliament.
        \54\ These requirements are consistent with those in the Consent 
    Decrees recently signed with several heavy-duty diesel engine 
    manufacturers. (See 63 FR 59330-59334; November 3, 1998).
    ---------------------------------------------------------------------------
    
        The proposed supplemental steady-state test cycle consists of 13 
    modes of speed and power, covering the typical operating range of 
    heavy-duty diesel engines. The cycle concentrates on the engine speed 
    range bounded by 50 percent and 70 percent of rated power, which is the 
    range most utilized by heavy-duty diesel engines. This speed range is 
    then divided into bands (engine speeds A, B and C, as defined in 
    proposed Sec. 86.1360-2004(c)). The ``control area'' is defined by the 
    area between engine speeds A and C, and between 25 to 100 percent load. 
    During the test cycle, the engine is initially run at idle speed, then 
    through a defined sequence of 12 modes at various speeds and engine 
    loads of 25, 50, 75 and 100 percent. Each mode (except idle) is run for 
    two minutes. During each mode of operation, the concentration of the 
    gaseous pollutants is measured and weighted (according to the weighting 
    factors in proposed Sec. 86.1360-2004(b)(1)). The weighted average 
    emissions for each pollutant, as calculated according to this steady-
    state test procedure, must not be greater than 1.0 times the applicable 
    2004 emission standards. (See proposed Sec. 86.004-11(a)(3).)
        Manufacturers would perform the supplemental steady-state test in 
    the laboratory following all applicable test procedures in 40 CFR part 
    86, subpart N (e.g., procedures for engine warm-up and exhaust 
    emissions measurement). The test must be conducted with all emission-
    related engine control variables in the maximum NOX 
    producing condition which could be encountered for a 30 second or 
    longer averaging period at the given test point.
        In addition to the 13 modes of the test cycle, EPA would have the 
    opportunity to select an additional three test points as a check to 
    ensure the effectiveness of the engine's emission controls within the 
    control area (e.g., ensuring that emissions do not ``peak'' outside of 
    the 13-mode test points). This requirement would ensure that an engine 
    achieves emissions control throughout the typical operating range. EPA 
    would notify the manufacturer of these three additional test points 
    prior to the test. During the test, the regulated pollutants would be 
    measured at each of these EPA-selected test points. The manufacturer 
    also would determine an interpolated value of pollutant emissions at 
    each EPA-selected test point, using the measured emissions of the 
    closest four adjacent test points. See the illustration in Figure 2 of 
    proposed Sec. 86.1360-2004(g). EPA proposes a four-point linear 
    interpolation procedure that is consistent with that of the European's 
    ``EURO III'', referenced above. (See proposed Sec. 86.1360-2004(g)(2).) 
    The measured emissions value would then be compared to the interpolated 
    emissions value. The measured pollutant value must not exceed the
    
    [[Page 58490]]
    
    interpolated pollutant value by more than five percent. We request 
    comment on the proposed interpolation methodology and on whether five 
    percent is the appropriate value to use for comparison of interpolated 
    values and measured emissions.
        The emission levels at the 12 non-idle test points and the 
    calculated emissions values from the four-point interpolation procedure 
    for intermediate test points would establish an emissions ``surface'' 
    of Maximum Allowable Emission Limits (MAELs), as illustrated in Figure 
    1 of proposed Sec. 86.1360-2004(f). This surface would limit emissions 
    levels during all normal operations, including transient operation, 
    that occur within the control area defined above. Each point on this 
    surface will have a MAEL associated with it for all engines in that 
    engine family.55 The MAEL for each point is calculated using 
    the same four-point linear interpolation procedure used to determine 
    the emission value for the EPA test points discussed above. For 
    certification, production line and in-use engines, emissions generated 
    within the control area may not exceed the MAEL for the corresponding 
    speed and load point over a thirty second averaging period.
    ---------------------------------------------------------------------------
    
        \55\ The emissions surface would include all points in the 
    Supplemental Steady-State control area, as defined above.
    ---------------------------------------------------------------------------
    
        At certification, manufacturers would be responsible for testing 
    the MAELs by performing the ``check'' described above for the three 
    EPA-selected test points. Under its authorities in the Act, EPA could 
    determine compliance with the MAELs under any conditions that may 
    reasonably be expected to be encountered in normal vehicle operation 
    and use, either in the laboratory or in actual use (``on-road''), under 
    steady-state or transient conditions, and under varying ambient 
    conditions. (See section IV.D.3 for a discussion of on-road testing). 
    To determine compliance, test results from operation within the control 
    area must comply with the MAEL established for that engine family at 
    the same engine speed and load.
    b. Not-To-Exceed Limits
        To help ensure that heavy-duty engine emissions are controlled over 
    the full range of speed and load combinations commonly experienced in-
    use, EPA is proposing to apply Not-To-Exceed (NTE) limits to HDDEs. The 
    NTE approach establishes an area (the ``NTE zone'') under the torque 
    curve of an engine where emissions must not exceed a specified value 
    for any of the regulated pollutants.56 The NTE standard 
    would apply under any conditions that could reasonably be expected to 
    be seen by that engine in normal vehicle operation and use. In 
    addition, we propose that the whole range of real ambient conditions be 
    included in NTE testing. The proposed NTE zones, limits, and ambient 
    conditions and test procedures for HDDEs and HDGEs are described below. 
    These requirements would take effect starting in the 2004 model year 
    and would apply to new engines as well as in use throughout the useful 
    life of the engine. We request comment on expanding the range of 
    ambient conditions in this manner and on whether this expanded range is 
    appropriate to begin with the 2004 model year, or whether a phased in 
    approach is more appropriate.
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        \56\ Torque is a measure of rotational force. The torque curve 
    for an engine is determined by an engine ``mapping'' procedure 
    specified in the Code of Federal Regulations. The intent of the 
    mapping procedure is to determine the maximum available torque at 
    all engine speeds. The torque curve is merely a graphical 
    representation of the maximum torque across all engine speeds.
    ---------------------------------------------------------------------------
    
        In addition to helping to ensure emission benefits over the full 
    range of in-use operating conditions, the NTE requirements are also 
    expected to be an effective element of an in-use testing program. At 
    the time of certification manufacturers would have to submit a 
    statement that its engines will comply with these requirements under 
    all conditions which may reasonably be expected to occur in normal 
    vehicle operation and use. The manufacturer must provide a detailed 
    description of all testing, engineering analysis, and other information 
    that forms the basis for the statement. This certification statement 
    must be based on testing and/or research reasonably necessary to 
    support such a statement and on good engineering judgement. This 
    supporting information would have to be submitted to EPA at 
    certification upon request; manufacturers would not necessarily be 
    required to submit NTE test data for compliance during certification.
        EPA believes that there are significant advantages to taking this 
    sort of approach for heavy-duty engines. The test procedure is very 
    flexible so it can represent most in-use operation and ambient 
    conditions. Therefore, the NTE approach takes all of the benefits of a 
    numerical standard and test procedure and expands it to cover a broad 
    range of conditions. Also, with the NTE approach, in-use testing and 
    compliance become much easier since emissions may be sampled during 
    normal vehicle use. A standard that relies on laboratory testing over a 
    very specific driving schedule makes it harder to perform in-use 
    testing, especially for engines, since the engines would have to be 
    removed from the vehicle. Testing during normal vehicle use, using an 
    objective numerical standard, makes enforcement easier and provides 
    more certainty of what is occurring in use versus a fixed laboratory 
    procedure.
        Even with NTE requirements, EPA believes that it is still important 
    to retain standards based on the current heavy-duty engine test 
    procedure. This is the standard that EPA expects the certified engines 
    to meet on average in use. The NTE testing is more focused on maximum 
    limits on emissions for segments of operation or engines used in 
    certain applications or geographic regions and should not require 
    additional technology beyond what is used to meet the applicable FTP 
    standards. EPA believes that basing the emissions standards on a 
    distinct cycle and using the NTE zone to help ensure in-use control 
    creates a comprehensive program. The existing duty cycle includes low 
    speed and low torque operation that are not included in the NTE zone. 
    In addition, the standardized test cycle gives a basis for calculating 
    credits for use in the averaging, banking, and trading program.
        The NTE requirements for heavy-duty diesel engines are proposed to 
    include other provisions including ambient temperature and humidity 
    ranges and corrections (discussed below). Start up conditions are 
    excluded from NTE testing because start-up is sufficiently covered by 
    the cold start in the FTP and would be expected to be significantly 
    higher than the proposed NTE limits for a short period of time.
        The NTE test procedure could be run in a vehicle on the road or in 
    an emissions testing laboratory using an appropriate 
    dynamometer.57 The test itself does not involve a specific 
    driving cycle of any specific length (mileage or time), rather it 
    involves driving of any type that could occur within the bounds of the 
    NTE control area. The vehicle (or engine) would be operated under 
    conditions that may reasonably be expected to be encountered in normal 
    vehicle operation and use, including operation under steady-state or 
    transient conditions and under varying ambient conditions. Emissions 
    would be averaged over a minimum time of thirty seconds and then 
    compared to the applicable NTE emission limits. The
    
    [[Page 58491]]
    
    applicable ambient conditions and the methodology for correcting 
    emissions results for temperature and/or humidity are described in the 
    following section. The proposed test procedure can be found in 
    Sec. 86.1370-2004 of the proposed regulations. We request comment on 
    this test procedure and its applicability to HD diesel engines, 
    particularly with respect to whether 30 seconds is an appropriate time 
    over which to average emissions for comparison to the emission limits 
    for HD diesel engines.
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        \57\ Likewise, testing to determine compliance with the Maximum 
    Allowable Emission Limits could be conducted in the laboratory or in 
    a vehicle on the road.
    ---------------------------------------------------------------------------
    
        The definition of defeat device is being modified slightly to 
    account for the NTE limits. Under the previous definition of defeat 
    device, an auxiliary emission control device would not be considered a 
    defeat device if it reduced the effectiveness of the emission control 
    system under conditions that are substantially included in the federal 
    test procedure.
        This definition is less appropriate for the NTE requirements. The 
    potential testing surface for the NTE encompasses much of the operating 
    range of the vehicle. Therefore, a definition of defeat device that 
    would exclude this testing surface would leave little area in which a 
    defeat device could be found. This, however, is not the intent of the 
    NTE. The NTE is not intended to be the primary emission limit on an 
    engine, but is intended instead as a ``no worse than this'' requirement 
    that puts an absolute high limit on emissions under most operating 
    conditions. It is not supposed to supplant the continuing obligation of 
    manufacturers to design their engines without defeat devices. Nor is it 
    supposed to provide a cushion for manufacturers to meet a less 
    stringent standard off the testing cycles. Therefore, EPA has revised 
    the definition of defeat device such that substantial inclusion in the 
    federal test procedure does not extend to the NTE zone.
        The proposed NTE zone is illustrated in Figures 1 and 2. With the 
    exception of two limited regions under the torque curve (described 
    below), the NTE zone for diesels includes all engine operation at or 
    above 30 percent of the maximum torque value of the engine and all 
    engine operation at or above a specific engine speed calculated based 
    on the maximum power of the engine.58 This zone covers the 
    areas of operation that are of most concern to the Agency from an 
    environmental perspective. Because engines do not operate frequently at 
    speeds that occur below the maximum torque peak (heavy-duty diesel 
    engines generally operate at speeds near or above their maximum 
    torque), the emissions generated from operation at lower speeds are 
    relatively insignificant. The same is generally true of operation at 
    below 30 percent of maximum torque--heavy-duty diesel engines do not 
    spend much time in this region and the emissions generated in this 
    region of operation tend to be less of a concern for the Agency. 
    Manufacturers are still forbidden from using defeat devices both inside 
    and outside the NTE zone, however.
    ---------------------------------------------------------------------------
    
        \58\ The maximum torque value and maximum power of the engine 
    are derived as part of the engine mapping procedures specified in 40 
    CFR 86.1332.
    ---------------------------------------------------------------------------
    
        For the reasons described below, two small regions are excluded (or 
    ``carved out'') from the NTE zone defined above. First, we propose to 
    exclude from the NTE zone the area under the torque curve that falls 
    below the curve representing 30 percent of the maximum power value of 
    the engine (as distinguished from maximum torque). This excluded region 
    contains low engine speed and torque operation for which we believe 
    current heavy-duty engines spend an insignificant portion of their 
    operating lives. In addition, at low loads and low-to-mid speeds (low 
    total power), the measurement of grams per brake-horsepower emissions 
    tends to balloon, even while emissions go down. This region is proposed 
    to be carved out for all pollutants.
        Second, a PM-specific region is ``carved out'' of the NTE control 
    area. The PM-specific area of exclusion is generally in the area under 
    the torque curve where engine speeds are high and engine torque is low, 
    and can vary in shape depending upon several speed-related criteria and 
    calculations detailed in the regulations. Controlling PM in this range 
    of operation presents fundamental technical challenges which we believe 
    cannot be overcome in the 2004 time frame. Specifically, the cylinder 
    pressures created under these high speed and low load conditions are 
    often insufficient to prevent lube oil from being ingested into the 
    combustion chamber. High levels of PM emissions are the result. 
    Furthermore, we do not believe that these engines spend a significant 
    portion of their operating time in this limited speed and torque range.
        The definition of the proposed NTE zone and the carve-out areas 
    strives to place an effective cap on emissions over a broad area of in-
    use operation that includes the types of operation that are of the 
    greatest environmental concern. The definition of the control area, the 
    carve-outs, and the emissions limit must all be balanced to achieve the 
    Agency's goals. We believe that the combination of the proposed zone 
    and the proposed emission limits within the zone effectively accomplish 
    the Agency's goals of ensuring that emissions are controlled over a 
    wide range of in-use operation. We request comment on the proposed zone 
    and emission limits.
        Examples of the NTE zone, including the areas excluded from the 
    zone, are shown below in Figures 1 and 2. The A, B, and C engine speeds 
    are the same as those defined for the advanced steady state test and 
    described above and in the proposed regulations. Note that there are 
    two possible constructions of the PM ``carve-out'' detailed in the 
    draft regulatory language. The example in Figure 1 shows the PM carve-
    out as it would look if the C speed is below 2400 revolutions per 
    minute (rpm), while Figure 2 shows the construct of the PM carve-out if 
    the C speed is above 2400 rpm.
    BILLING CODE 6560-50-P
    
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        Within the NTE zone, EPA proposes that emissions of each of the 
    regulated pollutants (NMHC+NOX, CO, PM), when averaged over 
    a minimum time of 30 seconds, must not exceed 1.25 times the applicable 
    FTP standards (or FEL if ABT is used). A minimum 30 second average is 
    proposed to ensure that a short transient does not produce high 
    results. This 30 second sampling period should be long enough to allow 
    an emissions spike to be averaged out while still retaining a short 
    enough period to look at a specific type of operation. In addition, EPA 
    proposes that within the NTE zone smoke and opacity must not exceed 
    either a filter smoke limit of 1.0 (on the Bosch smoke number scale) or 
    a thirty second average smoke opacity of four percent for a five inch 
    path for transient testing and a ten second average smoke opacity of 
    four percent for a five inch path for steady state testing.
    c. Diesel Supplemental Load Response Test
        Today we are also proposing a Supplemental Load Response Test (LRT) 
    for heavy-duty diesel engines. This supplemental test is intended to 
    represent a specific type of engine operation--rapid transient 
    acceleration--that is not adequately represented in the current 
    transient test procedure. Although the current transient test cycle 
    does contain numerous transient operations, these transients are 
    limited to the engine operating range exercised during the current FTP, 
    not the broader range of operation which is covered by the Supplemental 
    Load Response Test. Specifically, the Supplemental Load Response Test 
    is intended to address diesel engine emissions performance during rapid 
    transient accelerations from any speed within the NTE zone. As 
    proposed, the test focuses on quantifying PM and NOX 
    emissions during the portion of a truck's operation where it 
    accelerates rapidly and where certain engine emission controls can be 
    inadequate. In addition, this type of operation can often produce 
    visible smoke, which is frequently noticed by the public and can 
    influence their opinions about the cleanliness of diesel engines.
        We are not proposing specific emission limits for this test 
    procedure at this time. Rather, we are proposing that manufacturers of 
    heavy-duty diesel engines submit test results as part of their 
    application for EPA certification. The test results to be submitted at 
    certification would include testing, at a minimum, at a several engine 
    speeds specified in the proposed regulations. As noted in section 
    III.D, the Consent Decrees with most of the heavy-duty diesel engine 
    manufacturers establish target limits for the Load Response Test of 1.3 
    times the FTP standard for NMHC+NOX and 1.7 times the FTP 
    standard for PM. We believe that these limits may be appropriate and 
    technologically feasible, but we also recognize that under the Consent 
    Decrees there is a process of data collection and evaluation that could 
    result in modifications to these limits sometime in the latter half of 
    the year 2000. The data submittal requirements proposed today are 
    consistent with the requirements in the Consent Decrees.
        We believe that establishing a future Load Response Test with 
    appropriate emission limits may be a valuable addition to EPA's 
    compliance program, particularly for in-use on-road testing using the 
    equipment specified in a later section of this document, and when the 
    process of evaluating the available data is complete we intend to 
    evaluate the addition of specific Load Response Test emission limits to 
    EPA's compliance program in a future supplemental proposal. The 
    proposed data submittal requirement would enable a better understanding 
    of the emissions that occur under this type of operation and would 
    ensure that EPA establishes robust standards in a future action. Such a 
    future action would consider including a requirement that manufacturers 
    submit a statement of compliance at certification (similar to the 
    approach proposed today for the NTE emission limits). We request 
    comment on the proposed approach to a Load Response Test, as well as on 
    the possibility of adding appropriate emission limits and certification 
    requirements with a later action.
        The test procedure as proposed is relatively straightforward. The 
    engine fuel control is moved rapidly to the full fuel position and held 
    at that point for a minimum of two seconds. As proposed, this sequence 
    would be carried out in a laboratory environment at a constant speed 
    setting, but in the future testing could be conducted using on-road 
    equipment specified in a following section, in which case the vehicle 
    speed would depend upon the characteristics and response of the vehicle 
    being tested. The proposed regulations specify six different speeds, 
    ranging from the lowest speed in the NTE control area to a high speed 
    defined according to a calculation specified in the proposed 
    regulations. The test sequence could be repeated if necessary to obtain 
    an adequate sample for analysis (e.g., in the event that one cycle is 
    inadequate for collecting enough particulate mass for gravimetric 
    analysis). Although this could conceivably be carried out in several 
    different ways, we encourage the use of methodologies that adequately 
    represent the transient operation that is the true emphasis of this 
    test procedure. The proposed test procedure can be found in proposed 
    Sec. 86.1380-2004.
    d. Ambient Conditions, Temperature and Humidity, Laboratory and In-Use 
    Testing
        As stated above, our goal is to create a program that will ensure 
    emission control over a wide range of in-use conditions, including 
    ambient temperature and humidity. The FTP and Supplemental Steady State 
    tests are laboratory-based test procedures that would be conducted 
    under standard laboratory ambient conditions defined in the 
    regulations, with emission results corrected according to existing 
    regulations regarding laboratory testing procedures.59 The 
    NTE and verification of compliance with the Maximum Allowable Emission 
    Limits could be conducted in the laboratory or during on-the-road 
    driving, and the standards associated with these tests, where 
    applicable, are proposed to apply under any ambient conditions. Within 
    proposed temperature and humidity ranges, emissions from heavy-duty 
    diesel engines must meet the requirements described above, without 
    corrections for temperature and humidity. For situations in which the 
    ambient conditions are outside these ranges, EPA proposes that 
    NOX be corrected for humidity and both NOX and PM 
    be corrected for temperature. Corrections would be to the end of the 
    specified temperature or humidity range nearest the actual ambient 
    conditions. We request comment on applying this expanded range of 
    ambient conditions to the new supplemental test procedures, and on 
    whether implementation of an expanded range should apply starting with 
    the 2004 model year or some later model year.
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        \59\ The acceptable temperature range for FTP testing is defined 
    by regulation as 68-86 degrees Fahrenheit. There is no specified 
    humidity range, but NOX emission results are to be 
    corrected to 75 grains of water per pound of dry air.
    ---------------------------------------------------------------------------
    
        For emission results to be compared to the NTE emission limits, we 
    propose that the temperature range be from 55 to 95 degrees Fahrenheit 
    (12.8 to 35.0 degrees Celsius) and that the humidity range be from 50 
    to 75 grains of water per pound of dry air (7.14 to 10.71 grams of 
    water per kilogram of dry air). The proposed temperature range 
    encompasses the conditions exhibited by most days on which an 
    exceedance
    
    [[Page 58495]]
    
    of the ozone NAAQS is observed. 60 In addition, EPA analyses 
    pertaining to a recent rulemaking effort concluded that the ``typical'' 
    ozone nonattainment day exhibits a maximum temperature between 90 and 
    95 degrees Fahrenheit. (See 61 FR 54852, October 22, 1996). The 
    relative humidity range being proposed today reflects the current 
    understanding of humidity corrections, in that higher humidity 
    typically results in lower NOX levels. Therefore, 
    NOX test results from a truly hot and humid day (e.g., a 
    ``typical'' ozone exceedance day where the maximum temperature is in 
    the 90's and the humidity is about 100 grains of water per pound of dry 
    air, or 40 percent relative humidity) would be adjusted upward by the 
    correction factor when correcting back to the drier conditions of the 
    specified range, thus providing environmental protection during hot and 
    humid conditions typical of ozone exceedance days. For emission results 
    to be compared to the Maximum Allowable Emission Limits we propose that 
    NOX emissions be corrected to a standard level of 75 grains 
    of water per pound of dry air and that NO X and PM emissions 
    be corrected to the nearest endpoint of the range from 68 to 86 degrees 
    fahrenheit if tested outside this range. The proposed corrections for 
    verifying compliance with the Maximum Allowable Emission Limits would 
    correct emission results to standard laboratory conditions used for FTP 
    testing because these emission limits are derived from testing under 
    the standard laboratory conditions. We request comment on these 
    proposed ranges.
    ---------------------------------------------------------------------------
    
        \60\ Memorandum, Mark Wolcott, EPA, to Charles L. Gray, EPA, 
    ``Ambient Temperatures Associated With High Ozone Concentrations,'' 
    September 6, 1984. Available in the public docket for review.
    ---------------------------------------------------------------------------
    
        At this time, EPA is working with HD diesel engine manufacturers on 
    developing humidity and temperature correction factors. In the future, 
    it is EPA's intent to adopt the correction factors that are developed 
    through this effort. Because the correction factors are not yet 
    developed, EPA proposes only that good engineering judgement be used 
    when correcting for humidity and temperature outside of the proposed 
    ranges.
    3. Access to On-Board Computer Information
        Modern HD diesel and gasoline engines make extensive use of 
    electronics for engine control and management. HD engines make 
    extensive use of on-board computers for fuel system control, and other 
    emission-related component control, which in the future will likely 
    include cooled EGR systems on HD diesel engines. Many of these newer 
    systems make use of Controller Area Networks as a means of 
    communicating information from the on-board electronic control module 
    (ECM) to other on-board sensors and control devices (such as fuel 
    injectors, rail pressure for common rail systems, boost-pressure 
    sensors, coolant level sensors, coolant temperature sensors). These on-
    board systems control many aspects of emission related components, 
    including fuel and air management components. EPA is concerned that 
    electronic controls (or any other Auxiliary Emission Control Devices) 
    not be used in such a way as to result in higher emissions from HD 
    engines in use than would be seen during certification or laboratory 
    testing. Therefore, EPA must have access to this information. We are 
    proposing that, upon request from EPA, engine manufacturers must 
    provide to EPA hardware and/or documentation necessary to read and 
    easily interpret (in engineering units if applicable) any information 
    broadcast by on-board computers and ECM's which relate in anyway to 
    emission control devices and auxiliary emission control devices (AECD). 
    This proposed requirement includes access to proprietary code 
    information which could not otherwise be interpreted by parties other 
    than the engine manufacturer, EPA would retain any legitimate 
    confidential business information as such. This requirement could 
    include the delivery, upon request from EPA, from the manufacturer to 
    EPA the most up to date scantool hardware used by the engine 
    manufacturer for monitoring, interpreting, and recording all emission 
    related electronic input and output data broadcast on an engine's on-
    board controller network. The requirement could also include access to 
    passwords which would enable a generic scan tool or personal computer 
    to read and interpret proprietary codes, if such passwords exist. EPA 
    requests comment on these requirements.
    
    E. Otto-Cycle Vehicle-Based Program
    
        Heavy-duty Otto-cycle vehicles can be split into two groupings, 
    complete and incomplete vehicles. Complete vehicles are those that are 
    manufactured with their cargo carrying container attached. Complete 
    vehicles consist almost entirely of pick-up trucks, vans, and sport 
    utility vehicles and account for about 75 percent of all Otto-cycle 
    heavy-duty vehicle sales. All complete vehicles are currently below 
    14,000 pounds GVWR. Incomplete vehicles are those chassis that are 
    manufactured without their cargo carrying container attached. These 
    chassis may or may not have a cab attached. The incomplete chassis are 
    then manufactured into a variety of vehicles such as recreational 
    vehicles, tow trucks, dump trucks, and delivery vehicles. Currently, 
    there are three original equipment manufacturers (GM, Ford, and Daimler 
    Chrysler) of heavy-duty Otto-cycle engines and they also manufacturer 
    all of the complete vehicles in which those engines are 
    used.61 These manufacturers also manufacture most incomplete 
    chassis equipped with Otto-cycle engines.
    ---------------------------------------------------------------------------
    
        \61\ There are also aftermarket alternative fuels conversion 
    manufacturers, as discussed in section E.7, below.
    ---------------------------------------------------------------------------
    
        Currently, EPA requires heavy-duty engines to be tested to engine-
    based standards. Light-duty vehicles and light-duty trucks are required 
    to be tested over a vehicle-based test commonly known as the light-duty 
    federal test procedure, or FTP. Heavy-duty vehicle manufacturers have 
    the option of testing heavy-duty vehicles up to 14,000 pounds GVWR over 
    the light-duty FTP to light-duty truck standards (EPA ``heavy-as-
    light'' testing provisions), rather than to EPA engine-based standards.
        As part of their medium-duty vehicle program, California requires 
    complete Otto-cycle vehicles between 8,500 and 14,000 pounds to be 
    certified to vehicle-based standards rather than engine-based 
    standards. Manufacturers test the vehicles in essentially the same 
    manner light-duty trucks are tested. California has established Low 
    Emission Vehicle (LEV and LEV-II) standards for these vehicles. In the 
    MDV program, engines used in incomplete vehicles and vehicles above 
    14,000 pounds may be certified to engine-based standards rather than 
    vehicle standards. Diesel powered vehicles are also allowed to be 
    certified to engine-based standards as an alternative to the vehicle 
    standards, and in fact, most if not all manufacturers choose the 
    engine-based standards for their diesels.
        Today's proposal recognizes that manufacturers have found the 
    option to certify diesel vehicles to the California chassis-based 
    standards not particularly useful, and as a result the ability to 
    certify diesels to the chassis-based standards proposed below is not 
    included in the proposal. However, we request comment on this issue, 
    and if this option is indeed a desirable one, we would add the 
    California MDV PM standard of 0.12 grams/mile to the regulations for 
    manufacturers that select this option. In addition, we request comment 
    on the possibility of requiring
    
    [[Page 58496]]
    
    complete diesel heavy-duty vehicles under 14,000 pounds GVWR to be 
    subject to chassis-based standards, and if so, whether the standards 
    proposed for complete Otto-cycle vehicles or some other set of 
    standards (perhaps the proposed Otto-cycle standards adjusted by an 
    appropriate factor) would be appropriate for chassis-certified heavy-
    duty diesel vehicles.
    1. Moving to a Vehicle-Based Test Procedure and Standards
        EPA proposes to adopt vehicle-based standards and test procedures 
    for complete Otto-cycle vehicles between 8,500 and 14,000 pounds GVWR. 
    As in the California MDV program, these complete vehicles would be 
    tested on the federal light-duty vehicle and light-duty truck test 
    procedure.62 EPA believes this approach is reasonable and 
    offers several advantages over engine-based testing. In addition, EPA 
    is proposing to refine the program further by incorporating some 
    complete Otto-cycle vehicles between 8,500 and 10,000 pounds GVWR into 
    the Tier 2 program proposed earlier this year (see Section IV.F for 
    details regarding this aspect of the proposal). Many of the full size 
    pick-up trucks, vans, and sport-utility vehicles which have a GVWR 
    above 8,500 pounds are often used by owners for personal 
    transportation, and a chassis-based test procedure incorporating the 
    light-duty FTP cycle is representative of this type of transportation 
    and operation. The harmonization of test procedures with California 
    allows for certification data to be used for both federal and 
    California certification requirements, reducing the testing burden for 
    manufacturers. In addition, because vehicle testing is less resource 
    intensive than engine testing, EPA and manufacturers will be better 
    able to conduct in-use testing to verify emissions compliance.
    ---------------------------------------------------------------------------
    
        \62\ Test procedures contained in 40 CFR Part 86 subpart B, 
    excluding the Supplemental FTP.
    ---------------------------------------------------------------------------
    
        In developing the proposal, EPA met with a number of stakeholders 
    and during these discussions several stakeholders supported EPA's 
    consideration of a chassis-based program, similar to California's MDV 
    program.63 Manufacturers presented EPA with a proposal for a 
    chassis-based program after EPA expressed its substantial interest in 
    moving to chassis-based testing. Manufacturers expressed interest in 
    EPA's adoption of a program that would allow them to use one set of 
    certification information for both California and EPA. Other 
    stakeholders were also supportive of the move to a chassis-based 
    requirement due to the benefits noted above.
    ---------------------------------------------------------------------------
    
        \63\ Stakeholders involved in these discussions included 
    representatives from states, environmental groups, emission control 
    equipment manufacturers, and engine manufacturers. See Docket A-95-
    27, IV-E, for more information on these discussions.
    ---------------------------------------------------------------------------
    
    2. Vehicle Exhaust Emissions Standards
        EPA proposes to adopt the chassis-based standards contained in 
    Table 4 below for model years 2004 and later. The numeric levels were 
    selected to match the full life emissions standards in place for 
    California's MDV program for LEV vehicles above 8,500 pounds GVWR. The 
    standards would apply to complete vehicles in the weight categories 
    shown. The standards are for emissions over the FTP and vehicles would 
    be tested at adjusted loaded vehicle weight (ALVW), also known as test 
    weight (TW).64
    ---------------------------------------------------------------------------
    
        \64\ ALVW or TW is the actual weight of the vehicle, known as 
    curb weight, plus half pay load. Its also the average of the curb 
    weight and GVWR, which is curb weight plus full pay load.
    
                     Table 4.--EPA Proposed Full-Life Emission Standards Model Years 2004 and Later
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                                                                        Nonmethane
                     Vehicle weight category (GVWR)                     organic gas         NOX             CO
                                                                          (NMOG)
    ----------------------------------------------------------------------------------------------------------------
    8,500-10,000 lbs*...............................................            0.28             0.9             7.3
    10,001-14,000 lbs...............................................            0.33             1.0             8.1
    ----------------------------------------------------------------------------------------------------------------
    *Excluding those vehicles covered by the proposed Tier 2 program, as described in Section IV.F of this proposal.
    
        We believe that these proposed standards reflect the most stringent 
    standards achievable for the 2004 model year, considering cost and 
    other appropriate factors, and are therefore consistent with the 
    requirements of the CAA. As discussed in the Technological Feasibility 
    section below, LEV technologies are being required in California 
    beginning in 1998 and will be fully phased in beginning in 2004. By 
    harmonizing the federal and California standards, this proposal would 
    allow manufacturers to take advantage of the research and development 
    that they have undertaken to meet the California requirements. While it 
    is true that a small percentage of vehicles that have not been offered 
    for sale in California would, under the proposal, be required to meet 
    lower vehicle standard, EPA believes that the decision not to market 
    such vehicles in California was typically related more to their very 
    small sales volumes rather than for technological reasons. 
    Manufacturers would have some flexibility in meeting the standards, and 
    therefore some capability to deal with issues such as this, by today's 
    proposal to apply an ABT program to heavy-duty Otto-cycle vehicles.
        In a recent NPRM, we proposed to reduce the sulfur in federal test 
    fuel to reflect the reductions in sulfur we proposed for commercial 
    gasoline.65 Currently, federal test gasoline is subject to a 
    limit of 0.10 percent sulfur by weight. We proposed to amend that to an 
    allowable range of 30 to 80 ppm (0.003 to 0.008 percent by weight). We 
    also proposed that vehicles be certified and in-use tested using 
    federal test fuel. However, where vehicles are certified for 50 state 
    sale, and where other testing issues do not arise, we proposed to 
    accept for purposes of certification the results of testing done for 
    California certification on California Phase II fuel, but we would 
    reserve the right to perform or require in-use testing on federal fuel. 
    Where vehicles are only certified for non-California sale, we proposed 
    to require certification and in-use testing on federal fuel. These 
    provisions, if finalized as proposed, would apply to heavy-duty 
    vehicles certified to the chassis-based provisions in this proposal.
    ---------------------------------------------------------------------------
    
        \65\ 64 FR 26003, May 13, 1999, ``Control of Air Pollution From 
    New Motor Vehicles: Proposed Tier 2 Motor Vehicle Emissions 
    Standards and Gasoline Sulfur Control Requirements''.
    ---------------------------------------------------------------------------
    
        EPA is proposing a hydrocarbon standard in the form of nonmethane 
    organic gas (NMOG) in order to be consistent with California's MDV 
    standards. EPA proposes to also accept hydrocarbon emissions in the 
    form of NMHC or total hydrocarbons (THC) in
    
    [[Page 58497]]
    
    lieu of NMOG, These are forms of hydrocarbon standards which are the 
    standards typically used by EPA under the heavy-duty Otto-cycle control 
    program. Accepting emissions in these various forms provides 
    manufacturers with additional flexibility since establishing NMOG 
    levels can be more complex than NMHC or total hydrocarbon levels. 
    Manufacturers submitting California certification data would submit 
    NMOG emissions data due to California requirements.
        The vehicle manufacturer would be responsible for determining 
    whether a vehicle is a complete vehicle and subject to the vehicle-
    based standards or an incomplete vehicle and subject to engine-based 
    standards. The manufacturer would make this determination based on the 
    definition of incomplete vehicle described above. The vehicle 
    manufacturer may request a determination from EPA when the status of a 
    specific vehicle model is unclear. Manufacturers of complete vehicles 
    are responsible for vehicle emissions certification, as is the case 
    currently in EPA light-duty vehicle programs. More details on vehicle 
    compliance are provided in section E.5 below. Although currently 
    uncommon in this segment of the market, a vehicle manufacturer may 
    purchase engines from another manufacturer to place in incomplete 
    vehicles. In such cases, the vehicle manufacturer would be responsible 
    for ensuring that the engines they purchase have been emissions 
    certified to EPA's engine-based standards by the engine manufacturer. 
    The engine manufacturer would be responsible for the engine 
    certification and emissions performance of the engines, as is the case 
    currently in EPA's engine programs.
        The approach EPA is proposing is based on the technological 
    feasibility of extending the use of LEV technologies from California to 
    nationwide use in the 2004 MY time frame. The standards selected are 
    based on the capabilities of technologies designed to meet the LEV 
    standards. The approach of allowing the option of using California 
    certification data is intended to avoid duplication of effort for the 
    manufacturers. EPA requests comments on the proposed approach for 
    chassis-based testing and the proposed standards.
    3. Heavy-Duty Vehicle Averaging, Banking and Trading
    a. Background
        Averaging, Banking, and Trading is a long-established mechanism 
    allowing the Agency to propose and finalize a more stringent standard 
    than might otherwise be appropriate under the CAA, since ABT reduces 
    the cost and improves the technological feasibility of achieving the 
    standard. Manufacturers are able to bank credits by certifying some 
    engine families to emissions levels lower than applicable standards. 
    The credits may be banked and then used to certify other engine 
    families to levels higher than the emissions standards. For HD Otto-
    cycle engines, ABT is available for meeting NOX standards. 
    Under the current ABT program, banked credits are discounted by 20 
    percent and have a three year life, after which they 
    expire.66
    ---------------------------------------------------------------------------
    
        \66\ With ABT, manufacturers are able to establish a Family 
    Emissions Limit (FEL) for an engine family which becomes the 
    standard for that family. Manufacturers earn or use credits based on 
    the difference between the FEL and the applicable standard. A full 
    overview of the ABT program is contained in EPA's 1996 NPRM, 61 FR 
    33451.
    ---------------------------------------------------------------------------
    
        In the final rule for diesel engine standards for MY 2004 and 
    later, EPA modified the ABT program for diesel engines with the intent 
    that the changes would enhance the technological feasibility and cost-
    effectiveness of the new standard, and thereby to help to ensure that 
    the new standard would be attainable earlier than would otherwise be 
    possible.67 EPA reduced the discount rate to 10 percent and 
    established a cut point under which an engine family would earn 
    undiscounted credits. Also, EPA removed the three year credit life 
    limit which allows manufacturers to earn credits to be used in 2004 and 
    later as early as the 1998 model year. EPA modified the HD diesel ABT 
    program, among other reasons, because the Agency believes that the 2004 
    and later standards are stringent technology-forcing standards and the 
    additional flexibility would improve the manufacturer's ability to 
    comply with the standards cost effectively and in a manner that would 
    not disrupt product planning.68 EPA did not adopt the 
    modified program for Otto-cycle engines at that time, however, because 
    the Agency did not finalize the proposed standards for Otto-cycle 
    engines.
    ---------------------------------------------------------------------------
    
        \67\ 62 FR 54694, October 21, 1997.
        \68\ For a more complete discussion of the ABT provisions 
    relating to the 2004 model year heavy- duty diesel engine standards, 
    see Summary and Analysis of Comments: Control of Emissions of Air 
    Pollution from Highway Heavy-Duty Engines, September 16, 1997, EPA 
    Air Docket A-95-27, Doc. No. V-C-01.
    ---------------------------------------------------------------------------
    
        The CAA requires that EPA set emission standards with appropriate 
    consideration to feasibility and cost. We believe that the ABT programs 
    in today's proposal are appropriate in the context of the technical 
    feasibility and the cost of the proposed emission standards. For all of 
    these reasons, we are proposing an ABT program for the vehicle-based 
    standards.
    b. Proposal
        EPA is proposing separate averaging, banking, and trading programs 
    for vehicles certified to the vehicle-based standards and engines 
    certified to the engine-based standards. This section addresses the 
    proposed ABT program for the vehicle-based standards. The proposed 
    engine-based ABT program is discussed above in section IV.C. EPA is 
    also requesting comment on the possibility of allowing credit exchanges 
    between the engine and vehicle ABT programs. This issue is discussed 
    below in the following section.
        For vehicles, EPA proposes an ABT program structured similar to the 
    modified ABT program described above for engines. EPA proposes the 
    following provisions:
         Beginning in 2000, manufacturers could bank vehicle-based 
    credits by choosing to certify vehicles rather than engines
         Manufacturers would earn NOX credits up to the 
    applicable 2004 NOX standard by establishing an FEL below 
    the 2004 standard
         Vehicles with FELs at or below 0.6 g/mile NOX 
    would earn undiscounted credits, engines with FELs above 0.6 g/mile 
    would earn credits discounted by 10 percent
         2004 and later model year vehicles using credits may not 
    exceed a NOX level 1.53 g/mile
         Heavy-duty Otto-cycle vehicles would be a single grouping 
    or averaging set.
        EPA recognizes that manufacturers would be required to achieve 
    NOX levels lower than the proposed 2004 NOX 
    standards in order to generate credits prior to 2004, and that this 
    aspect of the program differs from the proposed program for engines. 
    Based on current vehicle certification data from the California LEV 
    program, some vehicle models have demonstrated the potential for very 
    low NOX emissions in the 0.2 to 0.5 g/mi range. We believe 
    there would be the potential for credit generation in the proposed 
    program if similar technologies were used nationwide prior to 2004. In 
    addition, manufacturers are required to meet the proposed standards in 
    California prior to 2004 and therefore will be well on their way to 
    transitioning to the standards. They are already designing vehicles to 
    meet the standards in California. Therefore, the importance of banked 
    credits is likely to be diminished for vehicles compared to engines.
    
    [[Page 58498]]
    
        The ABT program can help manufacturers certify especially difficult 
    or low volume applications and help manufacturers comply across their 
    full product line without having to restrict vehicle offerings. The 
    Agency believes the proposed program offers sufficient flexibility in 
    light of the technology and cost requirements associated with the 
    proposed standards. Based on current certification data and 
    technological capabilities we believe manufacturers will have 
    opportunities to generate credits to help with meeting the proposed 
    2004 standards. Moreover, because these standards are required in 
    California for several model years prior to 2004, EPA does not expect 
    feasibility issues with the vast majority of vehicle models.
    c. Credit Exchanges Between the Engine and Chassis-Based Programs
        We believe that credit exchanges between the separate engine and 
    chassis-based ABT programs might be appropriate, as well as desirable 
    for manufacturers, but unresolved concerns and issues (described below) 
    prevent a proposal to allow such exchanges at this time. If these 
    concerns can be addressed prior to the final rulemaking we will 
    consider finalizing provisions allowing credit exchanges between the 
    two ABT programs. Specific concerns include derivation of engine and 
    vehicle-specific conversion factors, the possibility of large 
    quantities of credits effectively delaying the introduction of cleaner 
    vehicles and/or engines, and the method for exchanging vehicle-based 
    NOX credits with engine-based NMHC+NOX credits 
    (or vice versa), and whether the emissions standards would continue to 
    be appropriate if such a broader credit exchange program was allowed.
        The chassis-based ABT program is based on emissions in units of 
    grams per mile (g/mi) and the engine ABT program is based on emissions 
    in units of grams per brake horsepower-hour (g/bhp-hr). Consequently, 
    trading credits between the two programs would require a conversion 
    factor. Although the Agency uses conversion factors to estimate g/mi 
    emissions based on g/bhp-hr emissions rates for purposes of emissions 
    inventory modeling, these conversion factors are estimates of a fleet 
    average, not an engine- or vehicle-specific conversion factor. There is 
    considerable variation in the conversion factors from vehicle to 
    vehicle. Also, conversion factors that have been previously derived 
    don't necessarily predict emissions over the specific test cycles. Both 
    the emission standards and the ABT credits are based on emissions over 
    specific test cycles. Conversion factors developed for specific engines 
    and vehicles on specific test cycles could vary widely from an 
    ``average'' conversion factor. EPA believes that vehicle and engine 
    test cycle specific conversion factors would be needed in order to 
    allow transfers of credits between the two Otto-cycle ABT programs.
        In general, EPA believes that provisions allowing the exchange of 
    credits between the two Otto-cycle ABT programs should include a 
    conversion factor for each engine family for which the manufacturer 
    intends to develop transferable credits. Each conversion factor would 
    likely have to be based upon a number of engine and vehicle tests, and 
    would have to be approved by EPA prior to use. To ensure adequate 
    emissions control, EPA would consider requiring the conversion factors 
    to be developed by testing engines and vehicles expected to generate 
    ``worst-case'' emissions. EPA requests comment on how to structure a 
    program that manufacturers would be required to use to develop 
    appropriate conversion factors for each engine family.
        The ability to trade credits between the engine and chassis-based 
    ABT programs is not needed prior to the 2004 model year and would 
    unnecessarily complicate the ABT programs, for the following reasons. 
    Prior to the 2004 model year, EPA emission standards for heavy-duty 
    Otto-cycle vehicles are engine-based standards. Absent any credit 
    exchange provisions, manufacturers could still generate vehicle-based 
    credits by voluntarily certifying engines to the vehicle-based program. 
    These provisions already provide the flexibility for manufacturers to 
    decide how many engine-based and vehicle-based credits to generate.
        Manufacturers will have the opportunity to generate Otto-cycle 
    engine-based credits prior to the 2004 model year due to the structure 
    of the proposed Otto-cycle engine-based ABT program. These engine 
    credits could be used by manufacturers to facilitate meeting the 
    proposed engine standard. However, EPA is concerned that significant 
    quantities of engine-based credits could flow to the chassis-based 
    program, thus potentially having the effect of significantly postponing 
    the introduction of vehicles with emission levels below the proposed 
    vehicle standards. EPA would likely want to structure provisions for 
    exchanging credits such that the exchanges would be limited for use in 
    averaging and trading within a given model year, but banked credits 
    could not be exchanged. EPA requests comment on structuring credit 
    exchanges in this manner.
        For the 2004 and later model years, the proposal would require 
    manufacturers to certify a large portion of their Otto-cycle heavy-duty 
    vehicles to the vehicle-based provisions (via chassis testing), thus 
    reducing the opportunity to generate Otto-cycle engine-based credits. 
    In addition, the proposed engine-based emission standards would be 
    significantly more stringent starting with the 2004 model year, thus 
    making generation of engine-based credits more difficult. For these 
    reasons, exchanging credits earned starting in the 2004 model year 
    between the chassis-based and engine-based ABT programs may be a 
    desirable option for manufacturers.
        Another issue for credit exchanges in 2004 and later model years is 
    that vehicle credits would be based on NOX only emissions 
    and the engine credits would be based on NMHC+NOX emissions. 
    EPA believes that the NMHC portion of engine emissions compared to 
    NOX emissions is about 15 percent of total emissions, or 
    between 0.1 and 0.2 g/bhp-hr. EPA requests comment on allowing credit 
    exchanges without regard to this difference in the standards, or 
    alternatively, requiring the use of an appropriate factor (e.g., the 15 
    percent factor noted above) to apply to exchanges of NOX-
    only and NMHC+NOX credits.
        To summarize, EPA is not proposing allowing exchanges between the 
    two Otto-cycle ABT programs at this time, but will consider finalizing 
    provisions that would allow such exchanges if our concerns can be 
    addressed. Specifically, EPA requests comments on the following issues:
         Allowing manufacturers to transfer credits between the 
    Otto-cycle engine and vehicle ABT programs;
         Restricting the transfers of credits between the two ABT 
    programs to credits earned in the 2004 and later model years;
         The derivation of conversion factors that would make 
    transfers of credits appropriate, including the test methodology and 
    appropriate engine and vehicle parameters used to derive the factors 
    (horsepower, vehicle weight, etc.);
         Ensuring that credit exchanges do not effectively delay 
    introduction of cleaner vehicles;
         How to address exchanging NMHC credits with 
    NMHC+NOX credits and vice versa;
         Limiting the exchange of credits to engines and vehicles 
    below 14,000 pounds GVWR because engines rated for vehicles above this 
    would not have any
    
    [[Page 58499]]
    
    counterparts certified to chassis-based provisions.
         Limiting the exchanges between the two Otto-cycle ABT 
    programs to averaging and trading only.
         What impact the broader exchange program would have on the 
    degree of the emission reduction of the standards and the 
    appropriateness of such an approach.
    4. Evaporative Standards/Onboard Refueling Vapor Recovery
        Consistent with the proposal to move all complete vehicles 8,500 to 
    14,000 lbs GVWR from the current engine-based program to a chassis-
    based program, EPA is proposing that such vehicles also be certified 
    according to the chassis-based enhanced evaporative test procedures. In 
    addition, the Agency is proposing to require complete HDVs to meet an 
    ORVR standard in a manner similar to that required of heavy light-duty 
    trucks. Each of these provisions is discussed in depth in the following 
    sections. The Agency is not proposing any changes to the current 
    evaporative emission standards or test procedures for the engine-based 
    program at this time.
    a. Enhanced Evaporative Emissions
        In 1993, EPA adopted enhanced evaporative test procedures for LDVs, 
    LDTs and HDVs to be phased in beginning with the 1996 model year, with 
    full compliance required by the 1999 model year (see 55 FR 16002, March 
    24, 1993). Under the enhanced evaporative requirements adopted in 1993 
    the provisions for LDVs and LDTs are essentially the same as those for 
    HDVs with two main differences. The first difference is that the actual 
    levels of the emission limits are higher for HDVs due to their 
    typically larger fuel tanks. EPA is not proposing any changes to the 
    HDV numerical evaporative limits in this proposed rule. The second 
    difference is in the driving cycles used in the test sequence, as 
    described in the next paragraph.
        The urban dynamometer driving schedule (UDDS) used for HDVs is 
    somewhat shorter than that used for light-duty, both in terms of 
    mileage covered and minutes. What this means in practical terms is 
    that, while the light-duty and heavy-duty procedures generally parallel 
    each other, under the heavy-duty procedure there is considerably less 
    driving time than under the light-duty procedure. This results in 
    considerably less time for canister purge under the heavy-duty 
    procedure than under the light-duty procedure.
        EPA recognizes this discrepancy between its light-duty and heavy-
    duty programs, and has routinely provided waivers under the enhanced 
    evaporative program which allow the use of the light-duty procedures 
    for heavy-duty certification testing. The Agency does not believe that 
    this approach impacts the stringency of the standards. Further, it is 
    consistent with CARB's treatment of medium-duty vehicles. EPA is 
    proposing that this approach be formally adopted for all complete 
    vehicles which are certified according to the provisions of the 
    chassis-based program discussed elsewhere in this notice. The Agency 
    requests comment on this approach to evaporative emissions testing for 
    complete HDVs, and also requests comment on whether it should be 
    extended to those HDVs which will remain in the engine-based program.
    b. Onboard Refueling Vapor Recovery
        Onboard refueling vapor recovery systems prevent the fuel vapors 
    which are displaced from a vehicle's fuel tank during refueling from 
    entering the atmosphere. Typically, the displaced fuel vapors are 
    routed to a charcoal canister where they are subsequently routed to the 
    engine to be burned as fuel. EPA adopted ORVR requirements applicable 
    to light-duty vehicles and light-duty trucks (see 59 FR 16262, April 6, 
    1994). These requirements are being phased in beginning with the 1998 
    model year for LDVs, the 2001 model year for light LDTs (6,000 lb and 
    under GVWR), and 2004 for heavy LDTs (6,001 through 8,500 lb GVWR).
        During the original ORVR rulemaking, EPA chose not to apply ORVR to 
    HDVs for several reasons. First, a sizeable percentage of HDVs are sold 
    as incomplete vehicles. In such cases EPA is concerned that secondary 
    manufacturers may improperly modify or incorrectly complete the vehicle 
    fuel system (which is usually not fully installed for incomplete 
    vehicles). In such cases the primary manufacturer may have legal 
    liability for potential problems. Second, the application of ORVR to 
    HDVs could be more difficult than to LDVs and LDTs. This is because HDV 
    fuel systems are sometimes configured differently than their LDV/LDT 
    counterparts. This is especially true of the larger HDVs which tend to 
    have large fuel tanks with short or almost nonexistent fillnecks. 
    Finally, under the current HDV regulatory scheme, the engine would be 
    certified separately from the ORVR system. This would result in 
    additional challenges in matching the canister purge provided by the 
    engine with the needs of each ORVR system.
        EPA still believes that the above mentioned concerns are valid for 
    some HDVs. However, the Agency also believes that, in light of the 
    proposal to move to a chassis-based compliance program for complete 
    vehicles, they are only valid for the larger, incomplete vehicles. The 
    majority of HDVs are simply heavy-duty configurations of LDTs, with 
    fuel systems similar to or the same as their light-duty counterparts. 
    With this in mind EPA is proposing to require ORVR controls on all 
    complete HDVs up to 10,000 GVWR in the same manner and on the same 
    schedule as heavy LDTs. Thus, complete HDVs will be required to meet a 
    refueling emission standard of 0.20 grams per gallon of fuel dispensed. 
    For purposes of ORVR applicability, EPA is proposing that complete 
    vehicle means a vehicle that leaves the primary manufacturer's control 
    with its primary load carrying device or container attached.
        The proposed ORVR standard would be phased in with 40 percent 
    compliance required in the 2004 model year, 80 percent compliance in 
    the 2005 model year, and 100 percent compliance in the 2006 model year. 
    This phase-in is the same as that currently in place for heavy LDTs. 
    EPA believes that using the same phase in schedule for heavy LDTs and 
    HDVs will allow for a lower cost and easier phase in, since many HDVs 
    are simply heavy duty versions of light duty configurations. Further, 
    EPA is proposing that heavy LDTs and HDVs be considered a single 
    category for the purposes of the phase in. In other words, the percent 
    compliance requirements for a given model year would apply to heavy 
    LDTs and HDVs as a single group, rather than to each group separately. 
    EPA recognizes that combining these two categories into one may have 
    the effect of modifying the stringency of the existing LDT 
    requirements. However, EPA believes that this is appropriate because it 
    will allow for additional flexibility in the implementation of ORVR 
    systems that may be the same for heavy LDTs and HDVs. Also, given the 
    proposed phase-in requirements, if less than the required percentage of 
    heavy LDTs are certified to the ORVR requirement, it follows that 
    greater than the required percentage of the heavy-duty vehicles would 
    have to be certified to the ORVR requirements.
        As was previously mentioned, EPA is proposing to phase in ORVR to 
    HDVs in the same way as it is being phased in for heavy LDTs. This is 
    because most covered HDVs are simply heavy-duty versions of light-duty 
    configurations,
    
    [[Page 58500]]
    
    and the ORVR systems developed for the light-duty configurations can be 
    readily applied to their heavy-duty counterparts. However, EPA is aware 
    that not all covered HDVs have light-duty counterparts. Given the 
    number of other emission requirements taking effect in 2004, EPA 
    believes that the manufacturers' development resources may be spread 
    thin prior to 2004, making development of ORVR systems for HDVs which 
    do not have a light-duty counterpart excessively burdensome in that 
    time frame. Thus, EPA is considering alternative timing options for the 
    application of ORVR to HDVs that do not have light-duty counterparts. 
    One alternative is to simply require ORVR on these vehicles (those that 
    do not have light-duty counterparts) in 2006, with no phase in prior to 
    2006. EPA requests comment on this option, as well as other 
    alternatives. EPA also requests comment on how to best define which 
    HDVs do not have light-duty counterparts for the purposes of 
    determining which vehicles may be subject to the alternative 
    implementation date. Finally, EPA requests comment on whether such a 
    delay of ORVR for HDVs without light-duty counterparts is appropriate 
    or needed.
        EPA is proposing to limit the application of ORVR to HDVs of 10,000 
    lb GVWR and under because the vast majority of HDVs which have light-
    duty counterparts fall into this category. For the most part 
    application to HDVs of 10,000 lbs GVWR and under should not present any 
    new technological challenges. The technology applied for light-duty 
    configurations should be readily transferrable to their heavy-duty 
    counterparts. The Agency does not believe that limiting the ORVR 
    provisions to vehicles 10,000 lbs and under results in any significant 
    compromise in environmental benefits since almost all HD Otto-cycle 
    complete vehicle sales are of vehicles 10,000 lb or less GVWR.
        Currently, in the review of certification applications for ORVR-
    equipped LDVs and LDTs, EPA studies the design of the vehicle's ORVR 
    system, its on-vehicle configuration and operation, and consults 
    directly with the National Highway Traffic Safety Administration on 
    these applications. EPA expects to extend this practice of consulting 
    with NHTSA in the review of certification applications for ORVR-
    equipped HDVs as well.
        EPA requests comment on all aspects of today's ORVR proposal. 
    Specifically, the Agency requests comment on whether the proposed 
    definition of complete vehicle for ORVR purposes adequately covers 
    those vehicles for which ORVR application will present no substantial 
    new challenges, while exempting those vehicles for which concerns 
    expressed by EPA in the original ORVR rulemaking remain valid.
    5. Compliance Assurance Program
        On July 23, 1998, EPA proposed a new compliance assurance program 
    for light-duty vehicles and light-duty trucks known as ``CAP 2000'' 
    (see 63 FR 36954, July 23, 1998). The light-duty CAP 2000 program final 
    rule was published on May 4, 1999 (see 64 FR 23906, May 4, 1999), with 
    only minor changes from the proposed program. In brief, as compared 
    with EPA's traditional chassis-based compliance program, CAP 2000 is 
    designed to redirect manufacturer and Agency efforts towards in-use 
    compliance and give manufacturers more control of certification timing, 
    and yet maintain the integrity of the compliance assurance program. 
    Aspects of the CAP 2000 program include streamlined certification, 
    manufacturer in-use testing.
        In today's action, EPA proposes that the CAP 2000 program would be 
    the compliance assurance program for heavy-duty vehicles certified to 
    chassis-based standards (hereafter referred to as ``chassis-based 
    HDVs'').69 EPA has proposed modifications to Part 86, 
    Subpart S, that would extend the applicability of CAP 2000 to chassis-
    based HDVs. Key aspects of the proposed CAP 2000 program as it would 
    apply to chassis-based HDVs are described below, followed by a 
    discussion of issues and possible modifications to the light-duty CAP 
    2000 program considered by the Agency in the development of the 
    proposal to extend the CAP 2000 program to chassis-based HDVs.
    ---------------------------------------------------------------------------
    
        \69\ The compliance assurance program for heavy-duty engines 
    subject to engine-based standards is discussed in section II.C.2 of 
    this preamble.
    ---------------------------------------------------------------------------
    
        EPA believes that it is appropriate to extend the CAP 2000 program 
    to chassis-based HDVs for the following reasons. First, CAP 2000 for 
    HDVs would provide pre-production certification flexibilities, while 
    providing an emphasis on checking real in-use emissions, as compared 
    with the traditional light-duty chassis-based compliance program. As 
    with light-duty vehicles, EPA believes that it is appropriate to 
    improve pre-production compliance procedures, to reduce the 
    manufacturer's certification burden, and to shift the focus of 
    compliance assessment towards in-use testing, which is expected to 
    generate significant amounts of in-use data that are currently not 
    available. Second, applying CAP 2000 to chassis-based HDVs would align 
    EPA's chassis-based compliance programs for light-duty vehicles, light-
    duty trucks, and heavy-duty vehicles. Third, EPA's proposal to extend 
    CAP 2000 to chassis-based HDVs would further harmonize the EPA and ARB 
    programs for this industry. The California Air Resources Board is 
    adopting the CAP 2000 program for chassis-certified medium-duty 
    vehicles in the 8,500 to 10,000 gross vehicle weight range, beginning 
    in the 2001 model year.
    a. CAP 2000 for HDVs
        For the certification process, manufacturers would divide their 
    product lines into new units called ``durability groups'', determined 
    according to common emission deterioration elements. A vehicle with the 
    ``worst case'' durability would be chosen from the durability group to 
    establish the rate of emission deterioration expected from that group. 
    The procedures used to determine durability would be developed by the 
    manufacturer, with EPA approval. Durability groups would then be 
    subdivided into ``test groups'', and a vehicle representative of each 
    test group would be tested to show emission compliance. Once compliance 
    has been demonstrated, certification could proceed. The CAP 2000 
    program provisions for information collection are streamlined from the 
    traditional light-duty chassis-based compliance regulations. The timing 
    of information submittal has been optimized to provide some flexibility 
    for manufacturers, and the amount of information has been reduced, 
    without compromising the Agency's information needs for future 
    compliance or enforcement issues.
        A second element of the proposed chassis-based HDV CAP 2000 
     requirements is manufacturer in-use testing. There are two 
    parts to the program. Part one requires manufacturers to perform in-use 
    emission testing on privately owned vehicles in an ``as-received'' 
    state. This ``in-use verification testing'' would occur on low mileage 
    and high mileage test fleets. The size of the low and high mileage 
    fleets would be dictated by sales categories. Small volume 
    manufacturers and small volume test groups would have little or no 
    testing, depending on sales limits. In-use verification testing data 
    would be used by the manufacturer to improve the predictive quality of 
    its durability program, and by the Agency to target vehicle testing for 
    a recall program. Part
    
    [[Page 58501]]
    
    two requires manufacturers to conduct additional testing of a test 
    group when the in-use verification program data for the test group 
    equals or exceeds a mean of 1.3 times the standard, with a 50 percent 
    or greater failure rate for the test group sample at either the low or 
    high mileage test point. The second level of in-use testing, known as 
    ``in-use confirmatory testing'', would be performed on ``properly 
    maintained and used'' vehicles and could be used to determine the need 
    for recall. The preambles of the July 23, 1998, CAP 2000 proposed rule 
    and the May 4, 1999, CAP 2000 final rule provide further discussion of 
    these and other aspects of the CAP 2000 program.
    b. Proposed Modifications to the CAP 2000 Program for Chassis-Based 
    HDVs
        In the development of the CAP 2000 proposal for chassis-based HDVs, 
    EPA considered several issues and possible modifications to the light-
    duty vehicle CAP 2000 program. These issues are discussed below.
        First, EPA proposes that the ``heavy-as-light'' provision in the 
    current regulations (see 40 CFR 86.001-01(b) and 40 CFR 86.1801(c)(1)) 
    would be available through the 2003 model year; starting with the 2004 
    model year, the ``heavy-as-light'' provision would no longer be 
    available. EPA's ``heavy-as-light'' provision permits a manufacturer to 
    certify a HDV of 14,000 pounds GVWR or less in accordance with the 
    light-duty truck provisions. In effect, this provision allows 
    manufacturers to certify these HDVs on a chassis dynamometer rather 
    than on an engine dynamometer, as long as the HDVs comply with the more 
    stringent light-duty truck standards. Today's action obviates the 
    ``heavy-as-light'' provision after the 2003 model year. EPA is also 
    proposing new provisions that would allow manufacturers flexibilities 
    in grouping vehicles into test groups, as well as provisions allowing 
    manufacturers to certify incomplete HDVs under the chassis-based HDV 
    program.
        Second, manufacturers have requested the ability to group vehicles 
    from different test weight categories into the same test group for 
    compliance purposes. For example, manufacturers would like the 
    flexibility to group HDVs with LDT3s or LDT4s, or to group HDVs above 
    and below 10,000 pounds GVWR together, for compliance purposes. In the 
    light-duty CAP 2000 program, vehicles must be subject to the same 
    emission standards to be grouped into the same test group (see 40 CFR 
    86.1827(a)(5)). However, EPA believes it is reasonable to allow 
    manufacturers to voluntarily certify to more stringent standards. EPA 
    is today proposing to allow manufacturers to request that vehicles from 
    different weight categories be grouped together in the same test group, 
    as long as the vehicles are then subject to the most stringent 
    standards that would be applicable to any vehicles within that 
    grouping. Voluntary certification to the more stringent emission 
    standards means that the manufacturer would be subject to enforcement 
    against the more stringent standards. EPA requests comment on the 
    proposal to remove the ``heavy-as-light'' provision after the 2003 
    model year, the proposal to allow manufacturers to request to certify 
    incomplete HDVs under the chassis-based HDV program, and the proposal 
    that manufacturers be allowed to request that vehicles from different 
    weight categories, which might be subject to different standards, be 
    grouped together in one test group meeting the most stringent set of 
    standards.
        Third, in discussions about the application of CAP 2000 to chassis-
    based HDVs, manufacturers have questioned whether the light-duty 
    ``AMA'' cycle would be allowed for durability testing.70 In 
    response, EPA is proposing that the AMA cycle would not be available as 
    a durability procedure for chassis-based HDVs. (The CAP 2000 program 
    likewise disallows the AMA durability procedure, but does allow for the 
    carryover of AMA-based deterioration factors.) This proposal differs 
    from the light-duty CAP 2000 program, in which under certain conditions 
    the AMA cycle would be accepted during a transition period of three 
    years, until the 2004 model year.71 This transition period 
    is reasonable for the light-duty CAP 2000 program, given that the 
    light-duty compliance program had traditionally rested on use of the 
    AMA cycle for durability demonstrations, and also that the use of the 
    AMA cycle data is limited to the use of existing data generated for a 
    2000 model year or earlier certification (CAP 2000 requires that all 
    new exhaust durability data be generated according to a manufacturer 
    durability procedure approved by EPA). Manufacturers have long 
    identified the AMA durability process as very costly and requiring 
    extensive lead time for completion. EPA has been concerned about the 
    ability of any fixed cycle, including the AMA cycle, to accurately 
    predict in-use deterioration for all vehicles. In fact, EPA has 
    particular concerns that the AMA does not represent the driving 
    patterns of today and does not appropriately age current design 
    vehicles. As a result, EPA believes that the AMA may have become 
    outdated.72
    ---------------------------------------------------------------------------
    
        \70\ See Item # IV-E-24 in EPA Air Docket #A-95-27. The ``AMA 
    cycle'' is a part of EPA's standard light-duty durability process 
    prior to CAP 2000, which requires manufacturers to accumulate 
    mileage on a pre-production vehicle over a prescribed mileage 
    accumulation driving cycle, specified in 40 CFR Part 86 (commonly 
    referred to as the ``AMA cycle''), for 100,000 miles to simulate 
    deterioration over the useful life of the vehicle.
        \71\ This is limited to only those products which qualify for 
    carryover. New engine designs may not use the AMA carryover option.
        \72\ See the CAP 2000 NPRM (63 FR 39659, July 23, 1998) and 
    Final Rule (64 FR 23913).
    ---------------------------------------------------------------------------
    
        Based on these concerns and also the fact that today's proposal 
    includes provisions for averaging, banking and trading credits across 
    test groups (in which FELs would be set based on durability procedures 
    that would need to be comparable across test groups), EPA is proposing 
    that the AMA cycle would not be automatically available as a durability 
    procedure for chassis-based HDVs, unless a manufacturer were able to 
    obtain approval for it. As in the light-duty CAP 2000 program, to 
    obtain approval for a durability process, EPA is proposing to require 
    that manufacturers provide data showing that the aging procedures would 
    predict the deterioration of the significant majority of in-use 
    vehicles over the breadth of their product line which would ultimately 
    be covered by this procedure. This demonstration would be more than 
    simply matching the average in-use deterioration; manufacturers would 
    need to demonstrate to EPA's satisfaction that their durability 
    processes would result in the same or more deterioration than is 
    reflected by the in-use data for a significant majority of their 
    vehicles. This approval process is the same as that already established 
    for EPA's first phase of the light-duty revised durability program 
    (RDP-I).73 EPA requests comment on the proposal to not 
    automatically allow the use of the AMA cycle for chassis-based HDVs.
    ---------------------------------------------------------------------------
    
        \73\ In RDP-I manufacturers have typically shown that their 
    durability programs cover ninety percent or higher of the 
    distribution of deterioration rates experienced by vehicles in 
    actual use. See EPA's guidance letter CD-94-13 dated July 29, 1994, 
    available for review in the public docket.
    ---------------------------------------------------------------------------
    
        Fourth, manufacturers have expressed several concerns about in-use 
    testing for chassis-based HDVs, including potential difficulties in 
    procuring vehicles for testing given the commercial use of many of 
    these vehicles, and the appropriateness of in-use confirmatory testing 
    for HDVs.74 EPA believes that the provisions of the light-
    duty CAP 2000 program, when extended to chassis-
    
    [[Page 58502]]
    
    based HDVs, are sufficient to address manufacturer concerns about 
    possible difficulties in procuring vehicles for in-use testing. If a 
    manufacturer or a manufacturer's test group qualifies for in-use 
    testing under a small volume sampling plan, there may be no in-use 
    testing requirements (for volumes up to 5000), or as few as two tests 
    per test group (for volumes up to 15,000); also, vehicles for testing 
    may be owned by or under the control of the manufacturer (as opposed to 
    being procured form customers) (see 40 CFR 86.1838-01(c)). In addition, 
    if any manufacturer believes it is unable to procure the test vehicles 
    necessary to test the required number of vehicles in a test group, the 
    manufacturer may request a smaller sample size for any test group, 
    subject to advance EPA approval (see 40 CFR 86.1845-01(c)(3)). EPA 
    requests comment on the proposed provisions of the HDV CAP 2000 program 
    regarding procuring vehicles for in-use testing.
    ---------------------------------------------------------------------------
    
        \74\ See Item #IV-E-24 in EPA Air Docket #A-95-27.
    ---------------------------------------------------------------------------
    
        Manufacturers have also suggested that it would be desirable to 
    have a transition to the in-use confirmatory testing requirements over 
    a period of years, as was available in the light-duty vehicle CAP 2000 
    program, rather than requiring this testing in the same year that the 
    chassis-based certification and in-use verification testing 
    requirements go into effect.75 EPA is proposing that in-use 
    confirmatory testing would be required for chassis-based HDVs. However, 
    EPA believes that a delay in the in-use confirmatory testing 
    requirements is appropriate in order to allow manufacturers to gain 
    experience with chassis-based certification and in-use verification 
    testing for chassis-based HDVs. Thus, EPA is proposing that the in-use 
    confirmatory requirements would be applicable to vehicles produced 
    starting with the 2007 model year. While manufacturers would not be 
    required to conduct in-use confirmatory testing for vehicles produced 
    prior to the 2007 model year, EPA would be fully prepared to 
    investigate any high emissions indicated through manufacturer in-use 
    verification testing or any other means. EPA requests comment on this 
    proposal to require in-use confirmatory testing starting with the 2007 
    model year.
    ---------------------------------------------------------------------------
    
        \75\ See Item # IV-E-24 in EPA Air Docket #A-95-27. On the 
    light-duty side, some manufacturers had experience with in-use 
    testing through the RDP-I in-use verification testing, starting as 
    early as the 1994 model year.
    ---------------------------------------------------------------------------
    
        Finally, certain aspects of the light-duty CAP 2000 program, as 
    contained in 40 CFR part 86, subpart S, would not apply to chassis-
    based HDVs, since EPA is not proposing requirements for HDVs in these 
    areas at this time. These areas include provisions relating to 
    intermediate useful lives, certification short test, cold temperature 
    CO requirements, fuel economy programs, and supplemental FTP 
    requirements.
        In summary, EPA is proposing to extend the light-duty CAP 2000 
    program to chassis-based HDVs, with the following minor modifications. 
    First, the option to certify HDVs under ``heavy-as-light'' provisions 
    would no longer be available after the 2003 model year; instead, 
    manufacturers could request to certify incomplete HDVs under the 
    chassis-based HDV program. Second, manufacturers could request to group 
    vehicles from different weight categories or subject to different 
    standards into the same test group, provided that they meet the most 
    stringent standards applicable to vehicles within that test group. 
    Third, the AMA cycle would not automatically be available for HDVs as a 
    durability procedure. Fourth, the in-use confirmatory testing 
    requirement would be delayed for HDVs until the 2007 model year. Fifth, 
    certain elements of the CAP 2000 program would not apply to chassis-
    based HDVs.
        EPA requests comment on all aspects of this proposal for a chassis-
    based HDV compliance assurance program.
    6. Useful Life
        Currently, the useful life mileage interval for Otto-cycle HD 
    engines is 8 years or 110,000 miles, whichever occurs first. The useful 
    life for these vehicles in the California MDV program is 120,000 miles, 
    which is also the useful life of heavy light-duty trucks. EPA proposes 
    to adopt the useful life mileage interval of 120,000 miles for the HD 
    Otto-cycle vehicles program. This approach allows consistency across 
    the programs and is consistent with the use of the vehicles.
    7. Aftermarket Alternative Fuels Conversions
        There are companies that convert heavy-duty engines originally 
    designed to run on conventional fuel to run on an alternative fuel. 
    These engines are subject to EPA standards and the conversion 
    manufacturers certify the converted engines. It is possible that some 
    of these vehicles could be considered incomplete by the original 
    manufacturer and certified to engine-based standards. However, when 
    they reach the aftermarket conversion manufacturer, they may have the 
    cargo carrying container attached and could be considered complete 
    vehicles. In discussions with the conversion manufacturers they 
    expressed a general preference for vehicle-based testing due to the 
    greater availability of test facilities and lower costs. However, the 
    conversion manufacturers raised concerns that it may be infeasible or 
    unreasonable for them to test very large vehicles, those well over 
    10,000 pounds GVWR, on a chassis dynamometer due to lack of available 
    test facilities designed to handle these very large vehicles.
        EPA proposes the following two provisions for vehicles over 10,000 
    pounds GVWR. EPA proposes that aftermarket conversion manufacturers can 
    choose to test vehicles that are originally designed and considered by 
    the original manufacturer to be incomplete vehicles to either the 
    engine or vehicle-based standards. In addition, aftermarket conversion 
    manufacturers may certify complete vehicles to the engine-based 
    standards due to the lack of available test facilities upon pre-
    approval from EPA. EPA requests comments on these proposed provisions.
    
    F. Proposal To Revise the Definition of Light-Duty Truck
    
    1. Background
        In May of 1999, EPA proposed stringent new Tier 2 standards for 
    passenger cars and light-duty trucks beginning in the 2004 model year 
    (64 FR 26004, May 13, 1999). We are now in the process of analyzing the 
    many public comments we received on the Tier 2 proposal. The proposed 
    Tier 2 program would require all passenger cars and light-duty trucks 
    to meet the same Tier 2 exhaust emissions standards by model year 2009. 
    The phase-in of the standards would begin in 2004 with passenger cars 
    and lighter light-duty trucks and end in 2009 when all light-duty 
    trucks would be required to meet the standards. We proposed the same 
    emissions standards for both cars and light-duty trucks because of the 
    increased use of light-duty trucks primarily for personal 
    transportation. The Tier 2 proposal did not contain any specific 
    regulatory proposals for heavy-duty vehicles. We did, however, request 
    comment on several options discussed in the proposal to prevent 
    manufacturers from redesigning LDT4s so that they would fall into the 
    heavy-duty vehicle category in order to avoid Tier 2 
    standards.76
    ---------------------------------------------------------------------------
    
        \76\ The LDT4 category contains the largest of the LDTs. The 
    category includes LDTs with a gross vehicle weight greater than 
    6,000 pounds and an adjusted loaded vehicle weight of greater than 
    5,750 pounds.
    ---------------------------------------------------------------------------
    
        We received several comments strongly supporting including all 
    passenger vehicles in the Tier 2
    
    [[Page 58503]]
    
    program, regardless of vehicle weight. These commenters were very 
    concerned that the Tier 2 standards would not apply to any vehicles 
    above 8,500 pounds GVWR. Commenters believe that a number of these 
    vehicles categorized by EPA as heavy-duty are primarily used as 
    personal transportation much like their light-duty counterparts. Many 
    commenters cited the new Ford Excursion sport-utility vehicle (SUV) as 
    an example of a vehicle designed primarily for passenger transportation 
    that would currently be classified as heavy-duty. Commenters also 
    expressed concern that a significant difference in the standards for 
    light-duty trucks and heavy-duty vehicles would encourage manufacturers 
    to redesign vehicles to make them fit the definition of heavy-duty 
    vehicles.
        EPA also received comment stating that no heavy-duty vehicles 
    should be included in the Tier 2 program. The Alliance of Automobile 
    Manufacturers commented that full product line manufacturers currently 
    offer light-duty and heavy-duty versions of vehicles such as pickups 
    and vans and would not want to create a product void in the LDT4 market 
    segment. They further commented that manufacturers would refrain from 
    changing their vehicles in ways that would increase cost and decrease 
    performance and marketability. Commenters also noted that heavy-duty 
    vehicles are designed for a broad range of purposes. They are designed 
    to be heavier, stronger, and more durable and it would be impossible 
    for such vehicles to meet light-duty emissions standards, claimed some 
    commenters.
        After carefully considering all of the comments, we believe both 
    general perspectives have merit depending on the type of vehicle being 
    considered. A small minority of sales in the complete heavy-duty 
    vehicle category consist of vehicles that are more clearly designed for 
    personal use, such as SUVs and passenger vans. All of these vehicles 
    are below 10,000 pounds GVWR. In addition, we are concerned that there 
    will be an increase in new vehicle offerings marketed primarily for 
    passenger transportation in this market segment in the future. As 
    personal use passenger vehicles, they would be more likely to be used 
    as personal transportation and operated under lightly loaded conditions 
    more of the time. We propose that these passenger vehicles (both 
    gasoline and diesel fueled) be included in the Tier 2 program, tested 
    as light-duty trucks, and held to Tier 2 standards. The following 
    sections provide our detailed proposal to capture these vehicles in the 
    Tier 2 framework and provides an overview of the Tier 2 emissions 
    standards that would apply.
        For the remaining vehicles in the heavy-duty category (primarily 
    traditional large pickup trucks, cargo vans, and incomplete vehicles), 
    we continue to believe the heavy-duty standards and test procedures 
    proposed in this rulemaking are most appropriate. Heavy-duty vehicles 
    would be tested under more heavily loaded conditions compared with 
    light-duty trucks in Tier 2. Considering this difference in test 
    conditions, we believe that the heavy-duty vehicle standards we are 
    proposing in this rule for 2004 would be similar in stringency to the 
    Tier 2 standards that have been proposed for light-duty trucks in this 
    time frame.
        In addition, we are considering the need for more stringent heavy-
    duty vehicle standards for 2007 and later model years, as discussed in 
    section X.C of this preamble.
    2. Proposal
        As noted above, we believe it is appropriate to consider including 
    certain vehicles currently classified as heavy-duty vehicles in the 
    proposed light-duty Tier 2 program. In order to accomplish this 
    objective, the proposed regulations include a revised definition of 
    ``light-duty truck'' designed to bring large models of SUVs and 
    passenger vans into the proposed Tier 2 program. The proposed 
    regulations also contain a parallel revision to the definition of 
    ``heavy-duty vehicle'' in order to prevent an overlap in the vehicles 
    covered by the two definitions.
        Specifically, the proposed definition of light-duty trucks seeks to 
    include the targeted vehicles by stating that a light-duty truck, in 
    addition to those vehicles that meet the current definition, is also 
    any complete vehicle between 8,500 and 10,000 pounds GVWR that is 
    designed primarily for personal transportation and has a capacity of up 
    to 12 persons. We expect that the proposed definition would exclude 
    vehicles that have been designed for a legitimate work function as 
    their primary use, such as the largest pick-up truck, the largest 
    passenger vans, and cargo vans; these vehicles would continue to be 
    categorized as heavy-duty and would be subject to applicable heavy-duty 
    standards. However, we request comment on whether the proposed 
    definition adequately excludes these vehicles, or whether additional 
    criteria may be needed. If additional criteria are believed to be 
    needed, we request comment on how such criteria might be used (i.e., 
    what are appropriate cut points). For example, the definition could 
    include the use of factors such as whether the vehicle's body is fully 
    or almost fully enclosed (i.e., there is no significant exterior cargo 
    space such as there is on a pick-up truck), the portion of the total 
    payload that might be consumed by vehicle passengers, the portion of 
    available chassis space consumed by passenger seating, the percent of 
    the total GVWR comprised of the vehicle's curb weight, or other 
    relevant factors. We believe that this definition will capture SUVs, 
    such as the Chevrolet Suburban and the Ford Excursion, and bring them 
    into the proposed Tier 2 program. Table 5 identifies the currently 
    produced vehicles that we believe would be subject to the Tier 2 
    program according to the revised definition of light-duty truck.
    
        Table 5.--Passenger Vehicles Between 8,500 and 10,000 Pounds GVWR
    ------------------------------------------------------------------------
               Vehicle               Vehicle type          Manufacturer
    ------------------------------------------------------------------------
    Suburban.....................  SUV.............  GM.
    Excursion....................  SUV.............  Ford.
    Express Wagon (G2500 and       Passenger van...  GM.
     G3500).
    Dodge Ram Wagon 3500.........  Passenger van...  Daimler Chrysler.
    Econoline Super-duty Wagon     Passenger van...  Ford.
     (E250 and E350).
    ------------------------------------------------------------------------
    
        Vehicles meeting the proposed additional element to the light-duty 
    truck definition would be classified as heavy light-duty trucks (HLDTs) 
    according to definitions that already exist in the regulations, and 
    therefore would be subject to the standards in EPA's proposed Tier 2 
    program.77 The
    
    [[Page 58504]]
    
    specifics of how these vehicles would be folded into the Tier 2 program 
    are described below.
    ---------------------------------------------------------------------------
    
        \77\ LDT3 and LDT4s are considered heavy light-duty trucks 
    (HLDTs).
    ---------------------------------------------------------------------------
    
    3. Integration Into Proposed Tier 2 Program
    a. Tier 2 Standards for New HLDTs
        We propose that for 8,500-10,000 pound GVWR vehicles covered under 
    the revised definition of light-duty trucks discussed above, these 
    vehicles would meet the same standards as the LDT3 and LDT4 vehicles in 
    Tier 2, that is, this new category of vehicles would be part of the 
    Tier 2 heavy-light duty truck program. That program is discussed in 
    detail in the Tier 2 proposal, and will only be summarized here. The 
    reader should review the entire Tier 2 proposal to gain a full 
    understanding of the Tier 2 program for HLDTs. The new HLDTs covered by 
    the proposed change in definition would be averaged in with a 
    manufacturers' LDT3s and LDT4s so that 50 percent of the HLDTs would 
    meet Tier 2 standards in 2008, and 100 percent would have to meet Tier 
    2 standards in 2009. As Tier 2 vehicles, these large SUVs and passenger 
    vans would be included with other HLDTs in meeting the 0.07 g/mi 
    average NOX standard in 2008. In 2009, they would be 
    included with all Tier 2 LDVs and LDTs in meeting the 0.07 g/mi 
    NOX average standard (see Table 6).
    
    BILLING CODE 6560-50-P
    
    [[Page 58505]]
    
    Table 6.--Tier 2 and Interim Non-Tier 2 Phase-in and Exhaust 
    Averaging Sets (Bold lines around shaded areas indicate averaging 
    sets)
    [GRAPHIC] [TIFF OMITTED] TP29OC99.002
    
    
    BILLING CODE 6560-50-C
    
        a 0.60 NOX cap applies to balance of 
    vehicles during the 2004-2006 phase-in years.
        b Alternative phase-in provisions permit 
    manufacturers to deviate from the 25/50/75% 2004-2006 and 50% 2008 
    phase-in requirements and provide credit for phasing in some 
    vehicles during one or more of these model years.
        c HLDT vehicles between 8,500 and 10,000 pound GVWR 
    will be meeting the 1998 Heavy-duty standards during this time 
    frame.
    
        As described in the Tier 2 proposal, manufacturers would meet the 
    Tier 2 NOX standard by certifying to one of seven emission 
    bins, and using averaging to meet the corporate average NOX 
    standard of 0.07 g/mi. The proposed Tier 2 exhaust emission standards 
    for all bins are shown in Table 7 and Table 8.
    
                 Table 7.--Tier 2 Light-Duty Full Useful Life (120,000 mile) Exhaust Emission Standards
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                 Bin No.                    NOX            NMOG             CO             HCHO             PM
    ----------------------------------------------------------------------------------------------------------------
    7...............................            0.20           0.125             4.2           0.018            0.02
    6...............................            0.15           0.090             4.2           0.018            0.02
    5...............................            0.07           0.090             4.2           0.018            0.01
    4...............................            0.07           0.055             2.1           0.011            0.01
    3...............................            0.04           0.070             2.1           0.011            0.01
    2...............................            0.02           0.010             2.1           0.004            0.01
    1...............................            0.00           0.000             0.0           0.000            0.00
    ----------------------------------------------------------------------------------------------------------------
    
    
              Table 8.--Tier 2 Light-Duty Intermediate Useful Life (50,000 mile) Exhaust Emission Standards
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                 Bin No.                    NOX            NMOG             CO             HCHO             PM
    ----------------------------------------------------------------------------------------------------------------
    7...............................            0.14           0.100             3.4           0.015  ..............
    6...............................            0.11           0.075             3.4           0.015  ..............
    5...............................            0.05           0.075             3.4           0.015  ..............
    4...............................            0.05           0.040             1.7           0.008  ..............
    ----------------------------------------------------------------------------------------------------------------
    
    
    [[Page 58506]]
    
    b. Interim Standards for New HLDTs
        Between 2004 and 2007, these new HLDT vehicles would have two 
    options; to participate in early banking for the Tier 2 program, or be 
    part of the Tier 2 HLDT Interim program along with LDT3 and LDT4 
    vehicles. The early banking option is described in detail for HLDT in 
    the Tier 2 proposal.
        The Interim program proposed in Tier 2 phases in between 2004 and 
    2007 (see Table 6). Our interim standards for HLDTs would begin in 
    2004. The Interim Program for HLDTs would set a corporate average 
    NOX standard of 0.20 g/mi that would be phased in between 
    2004 and 2007. The interim HLDT standards, like those for Tier 2 LDV/
    LLDTs would be built around a set of bins (see Tables 9 and 10). As 
    shown in Table 6, the phase-in would be 25 percent in the 2004 model 
    year, 50 percent in 2005, 75 percent in 2006, and 100 percent in 2007. 
    The program would remain in effect through 2008 to cover those HLDTs 
    not yet phased into the Tier 2 standards (a maximum of 50%). Vehicles 
    not subject to the interim corporate average NOX standard 
    during the 2004-2006 phase-in years would be subject to the least 
    stringent bin (Bin 5) so their NOX emissions would be 
    effectively capped at 0.60 lg/mi. These vehicles would be excluded from 
    the calculation to determine compliance with the interim 0.20 g/mi 
    average NOX standard.
    
                 Table 9.--Full Useful Life (120,000 mile) Interim Exhaust Emission Standards for HLDTs
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                 Bin No.                    NOX            NMOG             CO             HCHO             PM
    ----------------------------------------------------------------------------------------------------------------
    5...............................            0.60           0.230            4.2            0.018            0.06
    4...............................            0.30           0.180            4.2            0.018            0.06
    3...............................            0.20           0.156            4.2            0.018            0.02
    2...............................            0.07           0.090            4.2            0.018            0.01
    1...............................            0.0             0.00            0.0            0.000            0.0
    ----------------------------------------------------------------------------------------------------------------
    
    
             Table 10.--Intermediate Useful Life (50,000 mile) Interim Exhaust Emission Standards for HLDTs
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                        Bin No.                          NOX          NMOG          CO          HCHO          PM
    ----------------------------------------------------------------------------------------------------------------
    5..............................................         0.40        0.160          3.4        0.015  ...........
    4..............................................         0.20        0.140          3.4        0.015  ...........
    3..............................................         0.14        0.125          3.4        0.015  ...........
    2..............................................         0.05        0.075          3.4        0.015  ...........
    ----------------------------------------------------------------------------------------------------------------
    
        All other aspects of the Tier 2 proposal which covers HLDT vehicles 
    would apply to those 8,500-10,000 pound GVWR vehicles classified as 
    HLDTs according to the proposed definition described above. The reader 
    is encouraged to examine the Tier 2 proposal for a full description of 
    these provisions.
    c. Technological Feasibility of Tier 2 Standards for New HLDTs
        As discussed above, we believe this new definition of HLDTs between 
    8,500 and 10,000 pounds will capture vehicles designed for personal 
    transportation purposes, principally sport-utility vehicles and 
    passenger vans. Cargo vans and traditional pickups would not be 
    classified as HLDTs by this new definition. Table 11 represents our 
    estimates of the number of 8,500-10,000 pound GVWR vehicles which would 
    be covered by the proposed revision to the light-duty truck definition, 
    as well as sales estimates for the LDT3s and LDT4s which currently 
    comprise the HLDT category.
    
        Table 11.--EPA's Estimated 1998 Sales of LDT3, LDT4, and New HLDT
                  Vehicles Between 8,500 and 10,000 Pounds GVWR
    ------------------------------------------------------------------------
                                                                  New HLDTs
                                                                   between
                                             LDT3 and LDT4        8,500 and
                                                                    10,000
                                                                  pound GVWR
    ------------------------------------------------------------------------
    Gasoline Vehicle Sales...........  1.5 million.............      <70,000 diesel="" vehicle="" sales.............=""><1 percent="" of="" gasoline=""><5,000 ldt3="" and="" ldt4="" sales.="" ------------------------------------------------------------------------="" as="" can="" be="" seen="" in="" table="" 11,="" the="" revision="" of="" the="" ldt="" definition="" proposed="" today="" would="" increase="" the="" total="" number="" of="" hldt="" vehicles="" by="" less="" than="" 5="" percent.="" the="" proposed="" change="" in="" the="" definition="" of="" light-duty="" trucks="" would="" result="" in="" the="" diesel="" fraction="" being="" less="" than="" 0.5="" percent="" of="" all="" hldts.="" these="" new="" hldt="" vehicles="" are="" similar="" in="" engine="" design="" to="" existing="" ldt4="" vehicles,="" and="" we="" believe="" the="" technological="" feasibility="" arguments="" contained="" in="" the="" tier="" 2="" proposal="" apply="" to="" these="" vehicles="" as="" well.="" in="" addition="" to="" these="" arguments,="" tables="" 3-9="" in="" the="" draft="" ria="" for="" this="" proposal="" contains="" a="" list="" of="" 1998="" and="" 1999="" model="" year="" gasoline="" vehicles="" certified="" to="" the="" california="" medium="" duty="" vehicle="" program="" (using="" low="" sulfur="" california="" fuel).="" in="" the="" 8,500="" to="" 10,000="" pound="" gvwr="" range,="" a="" number="" of="" engine="" families="" have="" full="" useful="" life="" (120,000="" miles)="">X emissions in the 0.2 to 0.6 g/mile range, and a few 
    families are certified in the 0.1 to 0.3 g/mile NOX range. 
    These vehicles are all
    
    [[Page 58507]]
    
    tested at curb weight plus half-payload, while those captured by the 
    new definition would be tested at curb weight plus 300 pounds, a less 
    stringent test condition. Therefore, a large number of gasoline engine 
    families between 8,500 and 10,000 are already capable of meeting the 
    highest bin under the Tier 2 Interim program (0.6 g/mile), and a few 
    are approaching the Tier 2 NOX standard of 0.07 g/mile, and 
    are within the highest NOX bin under Tier 2 (0.2 g/mile 
    NOX). In addition, compared to the number of existing LDT3 
    and LDT4 vehicles, the number of vehicles captured by the new HLDT 
    definition are relatively small (< 5="" percent),="" and="" the="" averaging="" program="" proposed="" for="" tier="" 2="" will="" provide="" manufacturers="" with="" considerable="" lead="" time="" for="" applying="" control="" technology="" to="" these="" vehicles.="" as="" noted="" above,="" these="" new="" hldts="" are="" similar="" in="" their="" engine="" types="" and="" designs="" to="" existing="" ldt4="" vehicles,="" and="" because="" of="" this="" we="" expect="" that="" these="" new="" hldts="" will="" employ="" essentially="" the="" same="" types="" of="" technologies="" as="" existing="" ldt4="" vehicles="" to="" meet="" epa's="" proposed="" tier="" 2="" standards.="" similarly,="" the="" costs="" epa="" projected="" for="" bringing="" existing="" ldt4="" vehicles="" into="" compliance="" with="" the="" tier="" 2="" standards="" can="" also="" be="" carried="" over="" to="" these="" new="" hldts.="" these="" costs="" are="" discussed="" in="" detail="" in="" epa's="" proposal="" for="" tier="" 2="" standards,="" and="" the="" reader="" is="" urged="" to="" refer="" to="" that="" discussion="" for="" more="" information="" (see="" 64="" fr="" 26070,="" may="" 13,="" 1999).="" epa="" estimates="" that="" bringing="" these="" new="" hldts="" under="" the="" tier="" 2="" program="" would="" cost="" $270="" per="" vehicle,="" i.e.,="" the="" same="" as="" for="" other="" ldt4s.="" based="" on="" an="" estimate="" of="" approximately="" 75,000="" vehicles="" affected,="" annual="" costs="" would="" equal="" about="" $20="" million="" when="" the="" program="" is="" fully="" phased-in="" by="" 2009.="" per="" vehicle="">X emission reductions of 4.3 g/mi 
    would be expected from the current standards. This is a significantly 
    larger per vehicle reduction than expected for current LDT4s, so EPA 
    anticipates the near term cost effectiveness would be more cost 
    effective. We request comment on the application of these cost 
    estimates to the vehicles that would be covered by the proposed change 
    to the LDT definition. This issue will be analyzed more carefully as 
    part of the final rulemaking.
        As outlined above, Tier 2 standards are intended to be ``fuel 
    neutral.'' Under the principle of fuel neutrality, all cars and light 
    trucks, including those using diesel engines, would be required to meet 
    the proposed Tier 2 standards. EPA believes that the proposed program, 
    including the phase-in periods, would facilitate the advancement of 
    clean diesel engine technologies. EPA further believes that in the long 
    term the standards would be within reach for diesel-fueled vehicles in 
    combination with appropriate changes to diesel fuel to facilitate 
    aftertreatment technologies.
        As discussed in the Tier 2 proposal, the emission reduction 
    technology needed to meet these levels for a diesel HLDT would likely 
    require advanced diesel aftertreatment devices, such as NOX 
    absorbers and PM traps. These technologies have the potential to 
    provide emission reductions approaching 90 percent or greater. 
    Considering the long lead time available to manufacturers, we believe 
    these standards may be feasible for diesel HLDTs, including the 
    vehicles that would be captured by the proposed change to the 
    definition. In addition, the number of diesel powered vehicles between 
    8,500 and 10,000 pounds GVWR which would be classified as HLDTs by the 
    proposed new definition is very small, as shown in Table 11. The total 
    number of diesel HLDTs (including LDT3 and LDT4) would be less than 0.5 
    percent of all HLDTs. Averaging will likely provide the manufacturer 
    with additional flexibility to meet both the interim and final Tier 2 
    standards.78
    ---------------------------------------------------------------------------
    
        \78\ We generally expect that manufacturers would take advantage 
    of the flexibilities in the Tier 2 proposal to delay the need for 
    diesel vehicles to meet the final Tier 2 levels until late in the 
    phase-in period. Because diesel vehicles represent a very small 
    percentage of the LDT market, diesel LDTs would not fall under the 
    final Tier 2 standards until 2009, giving manufacturers a relatively 
    large amount of leadtime. As noted in the Tier 2 proposal, some new 
    diesel aftertreatment options may require lower sulfur diesel fuel 
    than is currently available. We have issued an Advance Notice of 
    Proposed Rulemaking intended to solicit comment on the need for 
    reduced sulfur in diesel fuel in order to meet these standards. We 
    also believe that the proposed interim standards would be feasible 
    for diesels by 2004, with or without the fuel change, given the 
    flexibilities associated with those standards.
    ---------------------------------------------------------------------------
    
        Considering all of these factors (long lead time, averaging 
    program, similarity to LDT3s and LDT4s, and existing certification 
    data) , we believe that these new HLDT vehicles will be able to meet 
    the Tier 2 interim standards and the Tier 2 final standards. As 
    discussed above, the number of these vehicles, compared to the existing 
    LDT3 and LDT4 fleet, is relatively small, and averaging will likely 
    provide the manufacturer with the needed flexibility to meet both the 
    interim and final Tier 2 standards. The conclusion of all of our 
    analyses is that the proposed Tier 2 standards for this new category of 
    HLDT vehicles would be feasible for gasoline-fueled vehicles operated 
    on low-sulfur gasoline. As gasoline-fueled vehicles represent the 
    overwhelming majority of the HLDT population (>99.5 percent), including 
    those covered by the proposed change in the HLDT definition, EPA 
    proposes to find that the proposed standards would be feasible overall 
    for HLDT vehicles.
        The Agency is considering adding a bin for HLDTs greater than 8,500 
    pounds GVWR for the 2004 thru 2008 model year time frame. This interim 
    bin would not be available in 2009 and beyond once the Tier 2 standards 
    are fully phased-in. This approach would create an appropriate 
    opportunity for flexibility during the phase-in years. We believe that 
    appropriate standards for an interim bin for HLDTs above 8,500 pounds 
    GVWR are the existing California Medium Duty Vehicle LEV-I standards 
    for this category of vehicles (0.9 and 0.12 g/mile for NOX 
    and PM, respectively). Under this proposal, these chassis-based 
    standards would already be in place for the heavy-duty vehicles between 
    8,500 and 10,000 pounds GVWR that would not be classified as HLDTs (see 
    section IV.E). In addition, manufacturers would already be meeting 
    these standards in California, and could carry over California vehicles 
    to the federal program. We request comment on whether such an approach 
    should be pursued in the final rule.
        We request comment on all aspects of this proposed change in the 
    definition of HLDTs, and the inclusion of these HLDTs in the Tier 2 
    program. We specifically seek comments on the appropriateness of the 
    10,000 pound GVWR limit as the upper cap for this program and on the 
    technological feasibility of the standards being proposed for these 
    passenger vehicles. After considering all comments received on this 
    proposed change in the definition of HLDTs, it is our intention to 
    finalize a change in the definition of LDTs in the Tier 2 final rule, 
    if timing permits. If this is deemed infeasible, we would likely 
    finalize this provision in the final rule for the heavy-duty 2004 
    standards. The Agency requests that any comments on this specific issue 
    be sent to the dockets for both this rulemaking and the Tier 2 
    rulemaking, A-97-10 (See Section XI for information on how to provide 
    written comments on this rule).
    
    G. On-Board Diagnostics
    
        Today's notice also contains proposed requirements for on-board 
    diagnostic systems on heavy-duty vehicles and engines up to 14,000 
    pounds GVWR, both Otto-cycle and diesel. The proposed OBD requirements 
    are essentially equivalent to those already in place for light-duty 
    vehicles and
    
    [[Page 58508]]
    
    trucks,79 including the optional provision that allows 
    demonstration of compliance with California OBDII requirements 
    80 as a means of satisfying today's federal OBD 
    requirements. The Agency is proposing to include OBD requirements in 
    today's notice because OBD systems help ensure continued compliance 
    with emission standards during in-use operation, and they help 
    mechanics to properly diagnose and repair malfunctioning vehicles while 
    minimizing the associated time and effort. The codification of OBD 
    system requirements would also allow for potential inclusion of heavy-
    duty vehicles and engines in inspection/maintenance programs via a 
    simple check of the OBD system.
    ---------------------------------------------------------------------------
    
        \79\ See 40 CFR 86.099-17; 40 CFR 86.1806-01.
        \80\ See, e.g., Title 13, California Code of Regulations (CCR) 
    Sec. 1968.1, as modified pursuant to California Mail Out #97-24 
    (December 9, 1997).
    ---------------------------------------------------------------------------
    
    1. Background on OBD
        Section 202(m) of the CAA, 42 U.S.C. 7521(m), directs EPA to 
    promulgate regulations requiring 1994 and later model year LDVs and 
    LDTs to contain an OBD system that monitors emission-related components 
    for malfunctions or deterioration ``which could cause or result in 
    failure of the vehicles to comply with emission standards established'' 
    for such vehicles. Section 202(m) also states that EPA may require such 
    OBD systems for heavy-duty vehicles and engines.
        On February 19, 1993, EPA published a final rule requiring 
    manufacturers of light-duty applications to install such OBD systems on 
    their vehicles beginning with the 1994 model year (see 58 FR 9468, 
    February 19, 1993). The OBD systems must monitor emission control 
    components for any malfunction or deterioration that could cause 
    exceedance of certain emission thresholds. The regulation also requires 
    that the driver be notified of any need for repair via a dashboard 
    light, or malfunction indicator light (MIL), when the diagnostic system 
    detects a problem. EPA also allows optional compliance with 
    California's second phase OBD requirements, referred to as OBDII (13 
    CCR 1968.1), for purposes of satisfying the EPA OBD requirements.
        Since publishing the 1993 OBD final rule, EPA has made several 
    revisions to the OBD requirements. On March 23, 1995, EPA published a 
    direct final rule that served largely to create more consistency 
    between the California OBDII requirements and the EPA OBD requirements 
    (see 60 FR 15242, March 23, 1995). The March 1995 rule also put into 
    place deficiency provisions for EPA OBD systems that allowed for 
    certification despite the presence of minor noncompliances that could 
    not be resolved within the time constraints of production schedules. On 
    August 30, 1996, EPA published another final rule to allow optional 
    compliance with California's newly revised OBDII requirements (61 FR 
    45898). On December 22, 1998, EPA published a final rulemaking that 
    achieved even further consistency with the California OBDII 
    requirements (see 63 FR 70681, December 22, 1998). This recent final 
    rulemaking results in essentially identical emission malfunction 
    thresholds and identical component monitoring requirements as required 
    by the California OBDII regulation.
        However, none of these federal rules extended OBD requirements to 
    heavy-duty vehicles and engines. Today's action proposes that the 
    existing light-duty OBD provisions be broadened to include both Otto-
    cycle and diesel heavy-duty vehicles and engines up to 14,000 pounds 
    GVWR. EPA is also proposing some revisions to existing light-duty OBD 
    requirements applicable to diesel vehicles and trucks. These light-duty 
    revisions are being proposed to maintain consistency across the 
    existing light-duty diesel OBD requirements and today's proposed heavy-
    duty diesel OBD requirements.
        The Agency believes it is appropriate to extend OBD requirements to 
    include heavy-duty vehicles and engines for many reasons. In the past, 
    heavy-duty diesel engines have relied primarily on in-cylinder 
    modifications to meet emission standards. For example, emission 
    standards have been met through changes in injection timing, piston 
    design, combustion chamber design, use of four valves per cylinder 
    rather than two valves, and piston ring pack design and location 
    improvements. In contrast, the 2004 standards represent a significant 
    technological challenge, and while manufacturers may make engine design 
    changes to comply with those standards, EPA expects the 2004 standards 
    will require EGR. Such ``add on'' devices can experience deterioration 
    and malfunction that, unlike the engine design elements listed earlier, 
    may go unnoticed by the driver. Because deterioration and malfunction 
    of these ``add-on'' devices can go unnoticed by the driver, and because 
    their sole purpose is emissions control, some form of detection is 
    crucial. The Agency believes that such detection can be effectively 
    achieved by employing a well designed OBD system.
        The same argument is true for Otto-cycle heavy-duty vehicles and 
    engines. While emission control is managed both with engine design 
    elements and ``add-on'' devices, the ``add-on'' devices, particularly 
    the catalytic converter, are the primary emission control features. The 
    Agency believes it is critical that the emission control system, 
    particularly the ``add-on'' type systems, be monitored for proper 
    operation to ensure that new vehicles and engines certified to the 
    standards proposed today continue to meet those standards throughout 
    their full useful life.
        Further, the industry trend is clearly toward increasing use of 
    computer and electronic controls for both engine and powertrain 
    management, and for emission control. In fact, the heavy-duty industry 
    has already gone a long way, absent any government regulation, to 
    standardize computer communication protocols.81 Computer and 
    electronic control systems, as opposed to mechanical systems, provide 
    improvements in many areas including, but not limited to, improved 
    precision and control, reduced weight, and lower cost. However, 
    electronic and computer controls also create increased difficulty in 
    diagnosing and repairing the malfunctions that inevitably occur in any 
    engine or powertrain system. Today's proposed OBD requirements would 
    build on the efforts already undertaken by the industry to ensure that 
    key emission related components will be monitored in future heavy-duty 
    vehicles and engines and that the diagnosis and repair of those 
    components will be as efficient and cost effective as possible.
    ---------------------------------------------------------------------------
    
        \81\ See ``On-Board Diagnostics, A Heavy Duty Perspective,'' SAE 
    951947, and, ``Recommended Practice for a Serial Control and 
    Communications Vehicle Network,'' SAE J1939.
    ---------------------------------------------------------------------------
    
        For these reasons, most manufacturers of vehicles, trucks, and 
    engines have incorporated OBD systems that are capable of identifying 
    when malfunctions occur, and in what systems. In the heavy-duty 
    industry, those OBD systems traditionally have been geared toward 
    detecting malfunctions causing driveability and/or fuel economy related 
    problems. Without specific requirements for manufacturers to include 
    OBD mechanisms to detect emission-related problems, those types of 
    malfunctions that could result in high emissions without a 
    corresponding adverse driveability or fuel economy impact could go 
    unnoticed by both the driver and the repair technician. The resulting 
    increase in emissions and detrimental impact on air quality could be 
    avoided by incorporating an OBD system capable of detecting emission 
    control system malfunctions.
    
    [[Page 58509]]
    
    2. CARB OBDII Requirements
        Current EPA OBD requirements apply only to light-duty vehicle and 
    light-duty truck categories (less than 8500 pounds GVWR). In contrast, 
    the CARB OBDII requirements include all light-duty categories and the 
    CARB medium-duty category (vehicles/engines up to 14,000 pounds GVWR). 
    As a result, while manufacturers of trucks and engines in the 8500 to 
    14,000 pound GVWR category have not certified federally to OBD 
    regulations, they have certified to the CARB OBDII requirements on all 
    their California applications beginning with the 1996 model 
    year.82
    ---------------------------------------------------------------------------
    
        \82\ This includes heavy-duty diesel and Otto-cycle applications 
    which fall into EPA's light heavy- duty category.
    ---------------------------------------------------------------------------
    
        Furthermore, while these manufacturer's federal certification 
    applications have not covered OBD requirements, the trucks and engines 
    nonetheless contain OBD systems with varying levels of sophistication. 
    This appears to be particularly true for diesel 
    applications.83 While the sophistication of some of the OBD 
    systems on existing federally certified heavy-duty vehicles and engines 
    may be less than that required by today's proposal, EPA believes that 
    the development work and lessons learned during implementation of CARB 
    OBDII systems in California can be readily transferred to federal 
    applications. With today's action, EPA proposes to implement OBD 
    requirements for heavy-duty vehicles nationwide so that the benefits of 
    OBD can be realized not only in California, but in the remaining 49 
    states as well.
    ---------------------------------------------------------------------------
    
        \83\ See ``On-Board Diagnostics, A Heavy Duty Perspective,'' SAE 
    951947; memo from T. Sherwood to Air Docket No. A-98-32, 
    ``Documentation of Sophisticated On-board Diagnostic (OBD) Systems 
    on Current Heavy-duty Diesel Engines, dated March 17, 1999; and 
    Internet websites for various heavy-duty diesel engine 
    manufacturers: www.cummins.com; www.detroitdiesel.com; 
    www.navistar.com.
    ---------------------------------------------------------------------------
    
    3. Proposed Federal OBD Requirements
        Today's proposed OBD requirements are discussed in detail below. 
    The requirements for heavy-duty Otto-cycle vehicles and engines are 
    identical to those already in place for light-duty Otto-cycle vehicles 
    and trucks. However, the proposed OBD requirements for heavy-duty 
    diesel vehicles and engines differ somewhat from the current light-duty 
    diesel requirements, specifically with regard to engine misfire and 
    aftertreatment monitoring requirements. As a result, and because the 
    Agency believes that the diesel provisions proposed today are more 
    appropriate for diesel applications, today's notice also proposes that 
    the light-duty diesel requirements be revised to be consistent with 
    today's proposed heavy-duty diesel requirements.
        In general, the OBD system must monitor emission-related powertrain 
    components for deterioration or malfunction causing emissions to exceed 
    1.5 times the applicable standards. Upon detecting a malfunction, a 
    dashboard MIL must be illuminated informing the driver of the need for 
    repair. To assist the repair technician in diagnosing and repairing the 
    malfunction, the OBD system must also incorporate standardization 
    features (e.g., the diagnostic data link connector; computer 
    communication protocols; etc.) the intent of which is to allow the 
    technician to diagnose and repair any OBD compliant truck or engine 
    through the use of a ``generic'' hand-held OBD scan tool.
    4. Federal OBD Malfunction Thresholds and Monitoring Requirements
        EPA proposes that, beginning in the 2004 model year, heavy-duty 
    vehicles and engines must be equipped with an OBD system capable of 
    detecting and alerting the driver of the following emission-related 
    malfunctions or deterioration as evaluated over the appropriate 
    certification test procedure: 84
    ---------------------------------------------------------------------------
    
        \84\ The FTP minus the Supplemental FTP for chassis certified 
    systems; the engine certification test procedure minus any 
    supplemental test procedures for engine certified systems. While 
    malfunction thresholds are based on certification test procedure 
    emissions, this does not mean that OBD monitors need operate only 
    during the test procedure. All OBD monitors that operate 
    continuously during the test procedure should operate in a similar 
    manner during non-test procedure conditions. The prohibition against 
    defeat devices in Sec. 86.004-16 applies to these OBD requirements.
    ---------------------------------------------------------------------------
    
        (a) Catalyst or particulate trap deterioration or malfunction:
        Otto-cycle--before it results in an increase in NMHC 85 
    emissions equal to or greater than 1.5 times the NMHC standard or FEL, 
    as compared to the NMHC emission level measured using a representative 
    4000 mile catalyst system; for engine certified systems, 
    NMHC+NOX would be used in place of NMHC.
    ---------------------------------------------------------------------------
    
        \85\ As a point of clarification, federal emissions standards 
    are expressed in terms of NMHC. Therefore, in order to remain 
    consistent, all references to HC will be referred to as NMHC.
    ---------------------------------------------------------------------------
    
        Diesel-cycle--before it results in exhaust emissions exceeding 1.5 
    times the applicable standard or FEL for NOX or PM. This 
    monitoring would not need to be done if the manufacturer can 
    demonstrate that deterioration or malfunction of the system will not 
    result in exceedance of the threshold; however, the presence of the 
    catalyst or particulate trap must still be verified. For engine 
    certified systems, NMHC+NOX would be used in place of 
    NOX.
        (b) Engine misfire:
        Otto-cycle--before it results in an exhaust emission exceedance of 
    1.5 times the applicable standard or FEL for NMHC, CO or 
    NOX; for engine certified systems, this would be 1.5 times 
    NMHC+NOX or CO.
        Diesel-cycle--when lack of combustion occurs.
        (c) If the vehicle or engine contains an oxygen sensor, then oxygen 
    sensor deterioration or malfunction before it results in an exhaust 
    emission exceedance of 1.5 times the applicable standard or FEL for 
    NMHC, CO or NOX; for engine certified systems, this would be 
    1.5 times NMHC+NOX or CO.
        (d) If the vehicle or engine contains an evaporative emission 
    control system, then any vapor leak in the evaporative and/or refueling 
    system (excluding the tubing and connections between the purge valve 
    and the intake manifold) greater than or equal in magnitude to a leak 
    caused by a 0.040 inch diameter orifice; an absence of evaporative 
    purge air flow from the complete evaporative emission control system. 
    On vehicles with fuel tank capacity greater than 25 gallons, the 
    Administrator would be required to revise the size of the orifice to 
    the feasibility limit, based on test data, if the most reliable 
    monitoring method available was unable to reliably detect a system leak 
    equal to a 0.040 inch diameter orifice.
        (e) Any deterioration or malfunction occurring in a powertrain 
    system or component directly intended to control emissions, including 
    but not necessarily limited to, the EGR system, if equipped, the 
    secondary air system, if equipped, and the fuel control system, 
    singularly resulting in exhaust emissions exceeding 1.5 times the 
    applicable emission standard or FEL for NMHC, CO, NOX, or 
    diesel PM. For vehicles equipped with a secondary air system, a 
    functional check, as described in paragraph (f) below, may satisfy the 
    proposed requirements of this paragraph provided the manufacturer can 
    demonstrate that deterioration of the flow distribution system is 
    unlikely. This demonstration would be subject to Administrator approval 
    and, if the demonstration and associated functional check are approved, 
    the diagnostic system would be required to indicate a malfunction when 
    some degree of secondary airflow is not detectable in the exhaust 
    system during the check.
        (f) Any other deterioration or malfunction occurring in an 
    electronic emission-related powertrain system or
    
    [[Page 58510]]
    
    component not otherwise described above that either provides input to 
    or receives commands from the on-board computer and has a measurable 
    impact on emissions; monitoring of components required by this 
    paragraph would be satisfied by employing electrical circuit continuity 
    checks and, wherever feasible, rationality checks for computer input 
    components (input values within manufacturer specified ranges based on 
    other available operating parameters), and functionality checks for 
    computer output components (proper functional response to computer 
    commands); malfunctions would be defined as a failure of the system or 
    component to meet the electrical circuit continuity checks or the 
    rationality or functionality checks.
        Upon detection of a malfunction, the MIL would be required to 
    illuminate and a fault code stored no later than the end of the next 
    driving cycle during which monitoring occurs provided the malfunction 
    is again detected. Alternatively, upon Administrator approval, a 
    manufacturer would be allowed to use a diagnostic strategy that employs 
    statistical algorithms for malfunction determination (e.g., 
    Exponentially Weighted Moving Averages (EWMA)). The Administrator 
    considers such strategies beneficial for some monitors because they 
    reduce the danger of illuminating the MIL falsely since more monitoring 
    events are used in making pass/fail decisions. However, the 
    Administrator would only approve such strategies provided the number of 
    trips required for a valid malfunction determination is not excessive 
    (e.g., six or seven monitoring events). Manufacturers would be required 
    to determine the appropriate operating conditions for diagnostic system 
    monitoring with the limitation that monitoring conditions are 
    encountered at least once during the applicable certification test 
    procedure or a similar test cycle as approved by the Administrator. 
    This is not meant to suggest that monitors be designed to operate only 
    under test procedure conditions, as such a design would not encompass 
    the complete operating range required for OBD malfunction detection.
        As an option to the above requirements, EPA proposes to allow 
    compliance demonstration according to the California OBDII 
    requirements. This option has been available to light-duty vehicles and 
    trucks since the implementation of the federal OBD program. This option 
    allows manufacturers to concentrate on one set of OBD requirements for 
    nationwide implementation (although federal OBD emission malfunction 
    thresholds and monitoring requirements are essentially equivalent to 
    those of the California OBDII regulation) and provides the highest 
    level of OBD system effectiveness toward meeting nationwide clean air 
    goals.
        However, there are differences between the California OBDII 
    requirements and today's proposed EPA OBD requirements. The California 
    OBDII regulation does not require catalyst or particulate trap 
    monitoring for diesel-cycle vehicles and engines. Today's notice 
    proposes such monitoring for EPA OBD systems. Therefore, if a 
    manufacturer chooses the California OBDII compliance option for a 
    diesel vehicle or engine, that manufacturer would still be required to 
    satisfy the catalyst or particulate trap OBD monitoring requirements of 
    today's proposal.
        The Agency requests comment on the above proposed OBD system 
    requirements, the emission threshold levels, and the California OBDII 
    compliance option. The Agency also wants to highlight and request 
    comment on a very minor change meant to clarify and define the meaning 
    behind rationality checks on applicable monitors. With this proposal, 
    reflected in paragraph (f) above, and sections 86.004-17(b)(6) and 
    86.1806-04(b)(6) of the proposed regulatory language, this definition 
    would be changed from ``rationality checks for computer input 
    components (input values within manufacturer specified ranges),'' to 
    read, ``rationality checks for computer input components (input values 
    within manufacturer specified ranges based on other available operating 
    parameters).'' This proposed change would apply to all OBD systems--
    light-duty, heavy-duty, chassis certified, engine certified, Otto-
    cycle, diesel--and only serves to clarify; it would not constitute a 
    new OBD requirement.
    5. Proposed Standardization Requirements
        The light-duty OBD regulations contain requirements for 
    standardization of certain critical aspects of the OBD system. These 
    critical aspects include the design of the data link connector, 
    protocols for on-board to off-board computer communication, formats for 
    diagnostic trouble codes, and types of test modes the on-board system 
    and the off-board scan tool must be capable of supporting. Today's 
    action proposes that these standards, tabulated below, also be required 
    for heavy-duty OBD systems. Today's action also proposes that, as an 
    alternative, manufacturers have the option of standardizing their 
    systems according to SAE J1939, ``Recommended Practice for a Serial 
    Controlled Communications Vehicle Network.'' This alternative standard, 
    SAE J1939, is a standard developed by the Society of Automotive 
    Engineers (SAE) specifically for heavy-duty applications.
    
                  Proposed Standards for Heavy-Duty OBD Systems
    ------------------------------------------------------------------------
              Proposed standards a            Alternative proposed standards
    ------------------------------------------------------------------------
    SAE J1850: communications protocol.....  SAE J1939: communications
                                              protocol; data link connector;
                                              test modes and downloading
                                              protocols; format for
                                              diagnostics trouble codes.
    ISO 9141-2: communications protocol....
    SAE J1962: data link connector.........
    SAE J1979: test modes and downloading
     protocols.
    SAE J2012: format for diagnostics
     trouble codes.
    ------------------------------------------------------------------------
    a SAE refers to the Society of Automotive Engineers; ISO refers to the
      International Organization of Standardization.
    
        The Agency requests comment on the appropriateness of the above 
    standards and the need to incorporate other standards not mentioned 
    above.
    6. Deficiency Provisions
        Today's action proposes to apply the same deficiency provisions to 
    heavy-duty OBD systems as currently apply to light-duty OBD systems. 
    This would allow the Administrator to accept an OBD system as compliant 
    even though specific requirements are not fully met. The deficiency 
    provisions were first introduced on March 23, 1995 (60 FR 15242), and 
    were recently revised on December 22, 1998 (63 FR 70681).
    
    [[Page 58511]]
    
        The Agency is proposing these deficiency provisions because, 
    despite the best efforts of manufacturers, many will likely need to 
    certify vehicles with some sort of deficiency when unanticipated 
    problems arise that can not be remedied in time to meet production 
    schedules. Given the considerable complexity of designing, producing, 
    and installing the components and systems that make up the OBD system, 
    manufacturers of light-duty vehicles and trucks have expressed and 
    demonstrated difficulty in complying with every aspect of the OBD 
    requirements. The same difficulty is expected for heavy-duty vehicles 
    and engines. While we believe that 100 percent compliance can be 
    achieved, we also believe that some sort of relief should be provided 
    to allow for certification of engines that, despite the best efforts of 
    the manufacturers, have deficient OBD systems.
        The EPA ``deficiency allowance'' should only be seen as an 
    allowance for minor deviations from the OBD requirements. In fact, EPA 
    expects to implement this deficiency allowance primarily for software 
    or calibration type problems, as opposed to cases where necessary 
    hardware is at fault or is not present. EPA expects that manufacturers 
    should have the necessary functioning OBD hardware in place, especially 
    given the lead time afforded to OBD in this proposal, the extensive 
    implementation of OBD that has already occurred on heavy-duty vehicles 
    and engines absent any federal regulation, and the experience gained by 
    those industry members affected by this proposal during several years 
    of light-duty and California medium-duty OBD implementation.
        Furthermore, EPA does not intend to certify vehicles with federal 
    OBD systems that have more than one OBD system deficiency, and EPA 
    would not allow carryover of any deficiency to the following model year 
    unless it can be demonstrated that correction of the deficiency 
    requires hardware modifications that absolutely cannot be accomplished 
    in the time available, as determined by the Administrator. These 
    limitations are intended to prevent a manufacturer from using the 
    deficiency allowance as a means to avoid compliance or delay 
    implementation of any OBD monitors or to compromise the overall 
    effectiveness of the OBD program. The Agency proposes that the 
    ``deficiency allowance'' be provided indefinitely, and requests comment 
    on this proposal.
    7. Applicability and Waivers
        Today's proposed federal OBD requirements would be implemented 
    beginning with the 2004 model year, as described below for all heavy-
    duty vehicles and engines for which emission standards are in place or 
    are subsequently developed and promulgated by EPA. EPA proposes that 
    there be a phase-in of the OBD requirements for heavy-duty vehicles up 
    to 14,000 pounds GVWR, and for heavy-duty engines up to 14,000 pounds 
    GVWR. The percentage phase-in schedule for such vehicles and engines 
    will be 40/60/80/100 for the 2004/05/06/07 model years, respectively, 
    based on projected sales. The phase-in percentages are determined 
    separately for vehicles and for engines, but are not dependent on fuel.
        Specific to Otto-cycle OBD, during model years 2004 through 2006, 
    EPA believes that any non-California Otto-cycle vehicles and engines 
    having essentially equivalent counterparts certified for sale in 
    California as compliant with the LEV emission standards and the CARB 
    OBDII requirements could be readily certified for sale in the remaining 
    49 states. That belief is based upon engineering judgement that such 
    vehicles and engines will have essentially equivalent emission 
    standards and OBD requirements. The sales mix of LEVs and ultra low 
    emission vehicles (ULEVs) in California is 40 percent and 60 percent, 
    respectively, with 100 percent of those in the less than 14,000 pound 
    GVWR category in compliance with California's OBDII requirements. EPA 
    considers the 40 percent LEV portion as easily certified for 49-state 
    sales. The phased implementation of OBD compliance during the 
    subsequent model years should provide sufficient lead time and 
    flexibility to manufacturers.
        In summary, the proposed applicability and phase-ins for heavy-duty 
    OBD compliance are as follows:
    
                                 Compliance Phase-In for Today's Proposed OBD Provisions
    ----------------------------------------------------------------------------------------------------------------
                  Model year                  Heavy-duty up to 14,000 pounds  GVWR           Diesel light duty
    ----------------------------------------------------------------------------------------------------------------
    2004 MY..............................  --40% compliance                            --100% compliance.
                                           --deficiencies available                    --deficiencies available.
                                           --alternative fuel waivers available        --alternative fuel waivers
                                                                                        available.
                                           --CARB OBDII option available*              --CARB OBDII option
                                                                                        available.*
    2005 MY..............................  --60% compliance                            --100% compliance.
                                           --deficiencies available                    --deficiencies available.
                                           --alternative fuel waivers available        --CARB OBDII option
                                                                                        available.*
                                           --CARB OBDII option available*
    2006 MY..............................  --80% compliance                            --same as 2005 MY.
                                           --deficiencies available
                                           --alternative fuel waivers available
                                           --CARB OBDII option available*
    2007+ MY.............................  --100% compliance                           --same as 2005 MY.
                                           --deficiencies available
                                           --CARB OBDII option available*              .............................
    ----------------------------------------------------------------------------------------------------------------
    *But diesels must meet EPA aftertreatment monitoring requirements.
    
        For heavy-duty vehicles and engines up to 14,000 pounds GVWR 
    operating on alternative fuel, EPA would grant OBD waivers during 
    alternative fuel operation through the 2006 model year to the extent 
    that manufacturers can justify the inability to fully comply with any 
    of today's proposed OBD requirements. 86 Such inability 
    would have to be based upon technological infeasibility, not resource 
    reasons. Further, any heavy-duty vehicles and
    
    [[Page 58512]]
    
    engines that are subsequently converted for operation on alternative 
    fuel would not be expected to comply with today's proposed OBD 
    requirements if the non-converted vehicle or engine does not comply. In 
    other words, if the vehicle or engine never completes any assembly 
    stage in OBD compliance, it need not comply with today's proposed OBD 
    requirements while operating on the alternative fuel. If the vehicle or 
    engine does complete any assembly stage with a compliant OBD system, it 
    would have to comply with today's OBD requirements while operating on 
    the fuel of original intent and, to the extent feasible, while 
    operating on the alternative fuel. For these latter situations, EPA 
    could grant waivers through the 2006 model year if the manufacturer can 
    show it is infeasible to meet the requirements. Beginning in the 2007 
    model year, all heavy-duty alternative fueled vehicles and engines up 
    to 14,000 pounds GVWR would have to be fully compliant during both 
    operation on the fuel of original intent and alternative fuel.
    ---------------------------------------------------------------------------
    
        \86\ Note that this provision currently exists for light-duty 
    vehicles and trucks operating on alternative fuel through the 2004 
    model year; that existing provision does not change with today's 
    proposal.
    ---------------------------------------------------------------------------
    
        EPA requests comments on all aspects of these OBD implementation 
    and phase-in provisions. In particular, EPA requests comments on the 
    phase-in percentages and their application to vehicles and engines 
    separately. The phase-in is proposed in this way because the regulatory 
    structure contains engine based OBD requirements in 40 CFR subpart A 
    and chassis based OBD requirements in 40 CFR subpart S. Therefore, the 
    phase-in percentages would have to be determined independently as they 
    apply to the OBD systems certified according to the provisions of the 
    specific subpart. If this creates unexpected burdens, or eliminates 
    intended flexibilities, comments should explain how and suggest 
    alternate phase-in language.
    8. Certification Provisions
        The OBD certification information requirements of today's proposal 
    are consistent with the Compliance Assurance Programs 2000 (CAP 2000) 
    rulemaking discussed above. The Part 1 Application must include, for 
    each OBD system: A description of the functional operating 
    characteristics of the diagnostic system; the method of detecting 
    malfunctions for each emission-related powertrain component; and a 
    description of any deficiencies including resolution plans and 
    schedules. Anything certified to the California OBDII regulations would 
    be required to comply with California ARB information requirements. EPA 
    may consider abbreviating the OBD information requirements through 
    rulemaking if it gains confidence that manufacturers are designing OBD 
    systems that are fully compliant with all applicable regulations.
        During EPA certification of vehicles optionally certified to the 
    California OBDII regulation, EPA may conduct audit and confirmatory 
    testing consistent with the provisions of the California OBDII 
    requirements. Therefore, while the Agency will consider California 
    certification in determining whether to grant a federal certificate, 
    EPA may also elect to conduct its own evaluation of that OBDII system. 
    While it is unlikely, EPA may make a compliance determination that is 
    not identical to that of the California Air Resources Board.
        Further, the Agency fully intends to allow a chassis certified and 
    chassis demonstrated OBD system to fulfill any demonstration 
    requirements of an engine certified OBD system (i.e., ``drop-in'' 
    demonstration). Likewise, we fully intend to allow an engine certified 
    and engine demonstrated OBD system to fulfill the demonstration 
    requirements of a chassis certified OBD system. However, any chassis 
    certified system would have to incorporate transmission diagnostics 
    even though the ``dropped-in'' engine system may not have been 
    certified with them.
        In other words, if a manufacturer demonstrates OBD compliance using 
    a chassis certified system, then wishes to employ engineering judgement 
    in demonstrating compliance of an engine certified OBD system, the 
    Agency would accept such a demonstration provided sound engineering 
    judgement is employed. The same would be true for an engine to chassis 
    situation (note the transmission diagnostic stipulation stated above). 
    This allowance is perhaps most applicable to Otto-cycle OBD systems, 
    but it would also apply for diesel systems. The Agency intends to make 
    this allowance because OBD systems tend to be essentially identical in 
    concept and approach across the product line of any given manufacturer, 
    even though specific calibrations may change from engine to engine or 
    model to model. The compliance allowance discussed here requires the 
    manufacturer to rigorously demonstrate its OBD concept and approach on 
    one engine or model, but allows the manufacturer to apply that 
    demonstration via engineering judgement to the different engine and 
    powertrain calibrations used across its fleet.
    
    H. Durability Procedures
    
        Under the current certification regulations, manufacturers develop 
    deterioration factors based on testing of development engines and 
    emissions control systems. Because emissions control efficiency 
    generally decreases with the accumulation of service on the engine, the 
    regulations require that a DF be used in conjunction with engine test 
    results as the basis for determining compliance with the standards. The 
    regulations require that the manufacturer develop an appropriate DF, 
    which is then subject to review by EPA in the certification process. 
    These deterioration factors are applied to low mileage emissions levels 
    of certification engines in order to predict emissions at the end of 
    the engines' useful life. The emissions level after the deterioration 
    factor is applied is the engine certification level, which must be 
    below the standard for the engine to be certified. For engines equipped 
    with aftertreatment (e.g., catalysts), the DF must be 
    ``multiplicative'' (i.e., a factor that can be multiplied by the low 
    mileage emissions level of the certification engine to project 
    emissions at the end of the engine useful life). For engines lacking 
    aftertreatment (e.g., most current diesels), the DF must be 
    ``additive'' (i.e., a factor that can be added to the low mileage 
    emissions level of the certification engine to project emissions at the 
    end of the engine useful life).
        Manufacturers have argued that EPA should not propose a standard on 
    the basis of current low engine certification levels, even though these 
    levels are supposed to reflect anticipated emissions levels over the 
    life of the engine. Manufacturers also noted that the deterioration 
    factors capture deterioration for vehicles under typical use and not 
    severe use. Thus, the manufacturers stated that they account for severe 
    deterioration by targeting certification levels at half the standard. 
    EPA has given full consideration to each of these concerns in 
    developing the proposed standards.
        EPA believes that the manufacturer's durability process should 
    result in the same or greater level of deterioration than is observed 
    in-use for a significant majority of their vehicles, rather than simply 
    matching the average in-use deterioration. This is especially important 
    considering that incomplete vehicles and vehicles over 14,000 pounds 
    GVWR are more likely to be work vehicles and operated under more severe 
    conditions a greater percentage of their useful lives. In recent 
    certification applications (for the 1998 and 1999 model years, for 
    example), manufacturers have reported NOX DFs on the order 
    of 1.2 to 1.6 for heavy-duty Otto-cycle engines. Manufacturers have
    
    [[Page 58513]]
    
    indicated on several occasions that they certify at levels of half the 
    standard to address more severe in-use operation than is represented by 
    their deterioration factors. Based on manufacturer comments, if a 
    durability process is designed to represent the deterioration of a 
    significant majority of engines within an engine family, EPA would 
    expect manufacturers to calculate a multiplicative deterioration factor 
    which is higher than current DFs, on the order of 2.0 or more. 
    Manufacturers also presented EPA with an analysis of engine emissions 
    standards, which is discussed in detail in the Technological 
    Feasibility section below. The catalyst deterioration rates used in 
    that analysis indicate that the deterioration factor could be higher 
    than two in some cases.
        EPA believes that it is important for certification levels 
    (emissions tests adjusted by the DF) to represent anticipated in-use 
    emissions levels of a significant majority of in-use engines. This will 
    continue to be a key aspect of EPA's compliance programs. Deterioration 
    factors are also used during production line testing to verify the 
    emissions performance of production engines. Finally, the ABT program 
    relies on certification data as the basis for determining credits. 
    Although Otto-cycle engine manufacturers have not made wide use of the 
    ABT program to date, EPA expects more use of the program in future 
    years due to the new more stringent emissions standards and new ABT 
    flexibilities.
        EPA is proposing today that the compliance provisions for heavy-
    duty engines contained in 40 CFR part 86, subpart A would continue to 
    apply to HDVs subject to the engine-based standards, with modifications 
    designed to ensure that the durability demonstration procedures used by 
    manufacturers in the certification process, and deterioration factors 
    calculated by means of these procedures, predict the emission 
    deterioration of a significant majority of in-use engines to be covered 
    by the procedure.
        The deterioration factor determination procedures in the 
    regulations are proposed to be modified to specify that emission 
    control component aging procedures will predict the deterioration of 
    the significant majority of in-use engines over the breadth of their 
    product line which would ultimately be covered by this procedure 
    (manufacturers would be expected to show that their durability programs 
    cover on the order of ninety percent or higher of the distribution of 
    deterioration rates experienced by vehicles in actual use). In 
    addition, manufacturers would be required to calculate multiplicative 
    DFs by dividing high mileage exhaust emissions by the low milage 
    exhaust emissions (e.g., emissions at the useful life mileage by 
    exhaust emissions at 4,000 miles).87 This change only adds 
    specificity to the regulations so that DFs are calculated using a 
    consistent and credible methodology. These proposed modifications to 
    the engine-based HDV compliance procedures would be effective for any 
    engine family generating ABT credits prior to the 2004 model year. EPA 
    requests comment on the proposed modifications to the engine-based 
    compliance program durability procedures.
    ---------------------------------------------------------------------------
    
        \87\ Manufacturers are not required to accumulate actual mileage 
    on vehicles or engines in order to determine a deterioration rate. 
    In many cases, the accumulation of mileage (or ``service'') is 
    simulated by various ``bench aging'' techniques that allow the 
    process to consume less time and resources than accumulating actual 
    mileage.
    ---------------------------------------------------------------------------
    
    I. Non-Conformance Penalties
    
        Non-conformance penalties are monetary penalties that manufacturers 
    can pay instead of complying with an emission standard. (See CAA 
    section 206(g) and 40 CFR part 86, subpart L.) In the final rule for 
    the 2004 standards for diesel heavy-duty engines, we stated that 
    provisions related to NCPs would be addressed in the 1999 Review. (See 
    62 FR 54700; October 21, 1997.) In order to establish NCPs for a 
    specific standard, EPA must find that: (1) Substantial work will be 
    required to meet the standard for which the NCP is offered; and (2) 
    there is likely to be a ``technological laggard'' (i.e., a manufacturer 
    that cannot meet the standard because of technological (not economic) 
    difficulties and, without NCPs, might be forced from the marketplace). 
    We also must determine compliance costs so that appropriate penalties 
    can be established.
        For diesel heavy-duty engines, the most recent NCPs established 
    were for the 1994 particulate standard (0.10 g/bhp-hr) and the 1998 
    NOX standard (4.0 g/bhp-hr). NCPs have not been established 
    to date for Otto-cycle heavy-duty engines. NCPs were used extensively 
    by manufacturers of highway heavy-duty engines in the late 1980s, prior 
    to the implementation of our averaging, banking and trading program. 
    Since that time, however, their use has been rare. We believe 
    manufacturers have taken advantage of the averaging, banking and 
    trading program as a preferred alternative to incurring monetary 
    losses.
        At this time, EPA has insufficient information indicating that both 
    of the criteria described above are met for diesel or Otto-cycle heavy-
    duty engines. While we believe that substantial work will be required 
    to meet the 2004 standards, we have no information indicating that a 
    technological laggard is likely to exist. We also believe that the 
    existing NOX and particulate averaging, banking and trading 
    program already provides considerable flexibility to meet the emission 
    standards. Therefore, we are not proposing NCPs as part of today's 
    proposed program, but we request comment on whether NCPs are necessary 
    for the 2004 standards for diesel or Otto-cycle heavy-duty engines. 
    Particularly, commenters should address the two criteria described 
    above for establishing NCPs (``substantial work'' and ``technological 
    laggard''). We recognize that it may be premature for manufacturers to 
    comment on these criteria, since implementation of the 2004 standards 
    is still five years away. It may be more prudent to consider addressing 
    NCPs in a future action as we approach implementation of the 2004 
    standards.
    
    V. Additional Heavy-Duty Engine Provisions Under Consideration
    
        In addition to the provisions proposed in this notice, EPA is 
    currently reviewing several related regulatory issues concerning 
    control of emissions from heavy-duty vehicles and engines. As discussed 
    in section X below, EPA is reviewing the feasibility of more stringent 
    standards for heavy-duty vehicles and engines in the future, and the 
    impact of fuel quality on that question. In addition, EPA believes that 
    there are several provisions related to the need for an effective 
    emissions control program that will benefit from further evaluation and 
    development prior to proposal. EPA intends to explore these provisions 
    further in the coming months and publish a notice of proposed 
    rulemaking dealing with these issues in a separate regulatory process 
    within the next 12 months. We would expect to follow this with a final 
    rule in early 2001.
        In particular, there are four issues--a revised definition of rated 
    speed, OBD requirements for engines used in vehicles above 14,000 GVWR, 
    a manufacturer-based in-use test program, and application of the NTE 
    approach to heavy-duty Otto-cycle engines--that we intend to deal with 
    in the separate process. As explained below, EPA believes that there 
    are several open issues and/or informational gaps that need to be 
    reviewed regarding these issues prior to proposal of regulations.
    
    [[Page 58514]]
    
    As EPA wishes to complete the current rulemaking process as quickly as 
    possible, EPA believes that it is appropriate to proceed with the 
    current rulemaking without addressing these four issues at this time. 
    This will allow us to gather information and work with interested 
    parties in a separate process regarding these issues.
        In a letter to EPA dated July 1, 1999, the Engine Manufacturers 
    Association (EMA) committed to ``work diligently and cooperatively'' 
    with EPA and CARB to resolve the open questions in a timely 
    fashion.88 EMA's letter outlined a process that does not 
    preclude implementation of these programs in the 2004 model year, and 
    in fact, highlights model year 2004 implementation as a stated goal of 
    this cooperative effort. A cooperative approach to data-collecting, 
    analysis, and problem-solving can help in developing the proposals for 
    these issues. EPA will work with all parties involved, including states 
    and environmental organizations, to develop robust, creative, 
    environmentally protective and cost-effective proposals addressing 
    these issues.
    ---------------------------------------------------------------------------
    
        \88\ Letter from Mr. Jed R. Mandel, Neal Gerber & Eisenberg, to 
    Margo Oge, Office of Mobile Sources, July 1, 1999. Available in the 
    public docket for review.
    ---------------------------------------------------------------------------
    
    A. Revision to the Definition of Rated Speed
    
        The definition of rated speed, where speed is the angular velocity 
    of an engine's crankshaft (usually expressed in revolutions per minute, 
    or rpm) is an important aspect of the existing FTP for on-highway HD 
    diesel engines. The rated speed definition is important to the FTP 
    because it is used to define the range of engine speeds over which the 
    engine will be exercised during the test. The regulations require 
    engine manufacturers to declare rated speeds consistent with the 
    regulation for their engines for the purpose of testing on the FTP 
    cycle; however, past experience has raised our concern that selection 
    of rated speed for the purpose of FTP testing is not being performed 
    consistently across the entire HD industry. We are concerned that some 
    manufacturers have declared rated speeds which result in the FTP test 
    being run over a speed and torque range which are not representative of 
    the operating characteristics of a particular engine family, in order 
    to influence the parameters under which the engine family is certified. 
    Under the existing transient HD FTP, manufacturers could receive a 
    NOX emission benefit if they declared a rated speed that was 
    higher than that envisioned under the regulations.
        The on-highway HD diesel regulation defines rated speed as the 
    speed at which the manufacturer specifies the maximum rated horsepower 
    from the engine. The torque and rpm points used on the FTP are 
    determined in part from the measured rated rpm, which in turn is 
    determined using the rated speed or the calculated speed, whichever 
    yields the higher speed (see 40 CFR 1330-90(g)). The calculated rated 
    speed is determined by averaging the minimum and maximum speeds at 
    which 98 percent of maximum power is generated. This definition was 
    sufficient when it was developed in the late 1970's for engines with 
    mechanical fuel injection and mechanical speed governors. For these 
    engines, the slope of the power vs. speed lug curve remained monotonic 
    and positive as speed increased until the mechanical governor engaged. 
    At this point of governor control, the slope of the curve rapidly 
    became sharply negative as speed increased toward the maximum governed 
    speed. Therefore, maximum power occurred at nearly only one speed, and 
    this speed was clearly identifiable by the breakpoint in the lug curve 
    where the governor caused a rapid change in slope from positive to 
    sharply negative. Engine manufacturers typically reported this speed as 
    rated speed for sales and service literature as well as for FTP 
    testing. Furthermore, the calculated rated speed calculation returned 
    nearly the same speed, because of the nature of these lug curves with 
    respect to the calculation.
        With the advent of electronically fuel injected and governed 
    engines, manufacturers began to design engines with high torque rises 
    to meet customer demands. High torque rise engines often have lug 
    curves in which the maximum power-speed point occurs at a much lower 
    speed than mechanical engines. This power point is often at the 
    maximum, where to the left and right of the maxima, the slope is 
    slightly positive and negative, respectively. As speed increases beyond 
    this maximum, the power does not taper off sharply, as in the case of 
    mechanical engines. The electronic engines, on the other hand, have 
    gradually negative slopes, and sometimes they even have a slight 
    inflection to zero slope before the electronic speed governor engages. 
    These characteristics render the rated speed calculation less 
    meaningful because the two 98 percent speed points are often at very 
    different speeds along the gradual positive and negative slopes around 
    the actual maximum power-speed. Because of these characteristics of 
    electronic engines, EPA believes there now exists a need for an 
    objective and singular definition of rated speed for the purposes of 
    FTP testing.
        We believe a new definition of rated speed is warranted, and that a 
    new definition should be both objective and representative of in-use 
    operation. The rated speed definition should be objective and should 
    result in a single value for a given engine family. This would avoid 
    inequitable testing. The rated speed definition should also result in 
    an FTP test cycle which exercises the engine's emission control system 
    over a range of engine speeds and loads that are representative of in-
    use operation.
        The Agency is not proposing a new definition of HD rated speed in 
    today's action. While the Agency believes there are issues associated 
    with the current definition with rated speed, there are a number of 
    issues with developing a new definition which have not yet been 
    resolved. We intend to include a proposal for a new definition in a 
    forthcoming proposal, and we intend to work with the industry, the 
    California Air Resources Board, and other interested parties in the 
    upcoming months to develop such a proposal. The Agency recently 
    proposed a definition of rated speed for nonroad diesel marine engines 
    which may be an appropriate blueprint for the on-highway industry (see 
    63 FR 68528, October 21, 1998). The reader is encouraged to examine the 
    proposed nonroad diesel marine definition as one possible approach for 
    the on-highway HD diesel industry.
    
    B. A Manufacturer-Based In-Use Testing Program for Heavy-Duty Engines
    
        To help ensure that heavy-duty engines meet applicable emission 
    standards throughout their useful lives, the Agency must have 
    reasonable certainty that the emissions measured in the laboratory 
    during certification of prototype engines reflect those experienced 
    during real world operation of actual in-use engines. We believe that a 
    manufacturer-run in-use testing program is an important way to ensure 
    that the 2004 emission standards for heavy-duty engines are achieved in 
    actual use throughout their useful lives, as required by the Act. We 
    believe that manufacturers are best suited to run such an in-use 
    testing program for several reasons. First, we understand that 
    manufacturers commonly evaluate in-use engines on the road to support 
    their engine development process and troubleshoot customer concerns. 
    For manufacturers already conducting such in-use engine performance 
    testing, we see an in-use testing program as adding an emissions 
    measurement component.
    
    [[Page 58515]]
    
    Second, we also understand that, through these product development and 
    customer service/product warranty activities, manufacturers maintain a 
    close relationship with the purchasers of their engines. We believe 
    that this close customer relationship makes engine manufacturers best 
    suited to locate and obtain in-use vehicles for emissions testing. For 
    anyone other than the manufacturer, it would be difficult to locate in-
    use vehicles powered by a particular engine family, because heavy-duty 
    trucks travel throughout the country. Since these trucks often are 
    integral to business operations, owners may be unwilling to part with 
    them for testing by entities other than the manufacturer. However, we 
    expect that some owners, especially those of larger fleets, will view 
    participation of their vehicles in an in-use testing program as an 
    opportunity to establish an even stronger relationship with the 
    manufacturer. This arrangement with the manufacturer could lead to 
    other benefits to the owner, such as an opportunity to better 
    communicate product needs.
        Such a program would require manufacturers to measure emissions 
    from a sample of in-use vehicles. Several issues need to be reviewed 
    prior to proposal. These include the test procedures used for the in-
    use testing, the number of vehicles or engines that would be required 
    for testing, and whether such testing will be done on engines (or 
    vehicles) run in a laboratory or vehicles tested on the road. In the 
    past, the laboratory testing of HD engines has been difficult for a 
    number of reasons, with cost being one of the most significant 
    barriers. In recent years, important advancements have been made in a 
    number of emission measurement technologies as well as on-board engine 
    management technologies which could allow for the development of a new 
    and innovative in-use testing program for HD engines.
        Today's action does not contain a proposal for manufacturer in-use 
    testing of HD engines, with the exception of those HD Otto-cycle 
    chassis certified engines which would be covered by the CAP 2000 
    provisions of today's proposal (see section IV.E.5--Compliance 
    Assurance Program). The Agency does not believe that it currently has 
    enough information to determine the most appropriate parameters of a 
    manufacturer-run in-use testing program. However, the Agency intends to 
    work with the engine manufacturers, CARB, the emissions measurement 
    industry, and other interested parties over the next several months to 
    explore these issues in order to achieve the goal of a meaningful in-
    use testing program which would be run by the engine manufacturers.
    
    C. On-Board Diagnostics for Heavy-Duty Engines and Vehicles Above 
    14,000 Pounds GVWR
    
        Similar to the expected benefits of having OBD requirements on 
    light-duty vehicles and trucks, and heavy-duty vehicles and engines up 
    to 14,000 pounds GVWR, we believe that there are similar benefits to 
    having OBD requirements for applications over 14,000 pounds GVWR. 
    However, there are many potential issues associated with applying OBD 
    requirements to applications above 14,000 pounds GVWR that have not 
    been of similar concern regarding smaller vehicles. For example, trucks 
    this large tend to be equipped with power take-off units that are 
    operable a substantial portion of the time. Examples are refrigerator 
    trucks, garbage trucks, or cement mixers. Such vehicles often use 
    engine power to operate the refrigeration unit, the compactor, or the 
    cement mixer, in addition to powering the vehicle as it drives down the 
    road. Such devices, powered off the engine, are referred to as ``power 
    take-off units.'' Both CARB and EPA regulations currently allow 
    disablement of most OBD monitors during power take-off unit operation. 
    This has been of little concern for smaller vehicles, because of the 
    very small percentage of vehicles in the 14,000 lb. GVWR and under 
    weight range that use such units for a substantial portion of their 
    operation. However, this approach to OBD monitoring during power take-
    off unit operation is difficult for larger engines that use power take-
    off units during substantial portions of their operation. It makes 
    little sense to require a sophisticated OBD system on a vehicle if it's 
    allowed to remain disabled during essentially its entire operation due 
    to the power take-off unit.
        This represents just one issue which, while it can be dealt with 
    effectively, requires more time and cooperative efforts with industry 
    and others to develop a meaningful and effective set of OBD 
    regulations. Another such issue is the lack of vertical integration in 
    the heavy-duty industry, particularly in the classes above 14,000 
    pounds GVWR. This lack of vertical integration creates increased 
    difficulty associated with bringing together engine, transmission, 
    chassis, and safety related diagnostics because so many different 
    manufacturers are involved in creating the end product. For that 
    reason, we are not proposing OBD requirements for engines above 14,000 
    pounds GVWR at this time. We will gather further information and work 
    closely with interested parties during the coming months to develop 
    proposed OBD requirements for such engines.
    
    D. Applying the Not-To-Exceed Approach and Emission Limits to Heavy-
    Duty Otto-Cycle Engines
    
        Though today's action contains supplemental standards for HD diesel 
    engines (Not-to-Exceed test and associated standards, Supplemental 
    Steady State Test and associated standards, and the Load Response Test) 
    today's action does not include similar provisions for HD Otto-cycle 
    engines. As noted earlier, EPA's primary interest is developing an 
    effective means of controlling actual in-use emissions across a broad 
    range of in-use operation, a concern that extends to Otto-cycle engines 
    as much as it does diesel engines. We believe that the same concerns 
    which necessitate supplemental standards and test procedures for HD 
    diesel engines may also exist for HD Otto-cycle engines, and that 
    measures similar to those proposed for diesels to assure effective in-
    use control may also be warranted for Otto-cycle engines. We believe 
    that the NTE approach is a valuable concept for accomplishing this goal 
    for heavy-duty Otto-cycle engines, just as it is for diesels. However, 
    we have not had as much time to consider such an approach for Otto-
    cycle engines, and data collection enabling appropriate setting of an 
    NTE emission limit and definition of an Otto-cycle NTE zone is still 
    underway as of today's proposal. Like other issues described in this 
    section, we intend to work with the engine manufacturers, CARB, and 
    other interested parties over the next several months to develop an NTE 
    or similar approach to achieve the goal of assuring effective in-use 
    control of HD Otto-cycle engines over a broad range of in-use 
    operation.
    
    VI. Are the Proposed Requirements Technologically Feasible?
    
    A. 2004 Emission Standards for Heavy-Duty Diesel Engines
    
        Today's proposal contains a reaffirmation of the 2004 
    NMHC+NOX standards as well as several supplemental standards 
    and test cycles for 2004 model year HDDE;
    
    --2.4 g/bhp-hr NMHC + NOX or 2.5 g/bhp NMHC + NOX 
    with a limit of 0.5 g/bhp-hr on NMHC on the existing Federal Test 
    Procedure
    --Emission standards of 1.0 times the FTP standards on the new 
    Supplemental Steady-state Test Cycle
    
    [[Page 58516]]
    
    --Emission standards of 1.25 times the FTP standards under the new Not-
    to-Exceed test zone
    
        Based on the information currently available to EPA, we believe 
    manufacturers are making significant progress towards meeting the 2004 
    standards contained in today's proposal, and we believe the standards 
    are technologically feasible. Chapter 3 of the draft RIA for this 
    proposal contains a detailed description of the technologies we expect 
    engine manufacturers to utilize to meet the proposed 2004 standards. 
    The discussion here is a summary of the draft RIA discussion; the 
    reader should refer to the RIA for a more detailed discussion. We 
    request comment on this discussion and on our proposed feasibility 
    assessment.
        HD diesel engines being certified to the 1998 U.S. standards are 
    already utilizing several advanced technologies, including high-
    pressure fuel injection systems, redesigned combustion chambers, air-
    to-air aftercoolers, waste-gated turbochargers and electronic controls. 
    These technologies have allowed engine manufacturers to meet the 
    emission standards which went into effect in 1998, while continuing to 
    provide end users with improved fuel economy, improved durability, and 
    improved driveability. The Agency expects to see incremental 
    improvements in some of these strategies between now and 2004, but 
    these improvements alone will not lower NMHC+NOX emissions 
    to the levels needed to meet the 2004 standards, and also comply with 
    the current PM standard. To meet the 2004 standards, EPA expects that, 
    in addition to the aforementioned strategies, manufacturers will 
    utilize EGR, variable geometry turbo-chargers, fuel injection rate 
    shaping, and possibly exhaust aftertreatment.
    1. Probable Emission Control Strategies
        Exhaust Gas Recirculation. EGR is the recirculation of exhaust gas 
    from a point in an engine's exhaust system to a point in the intake 
    system. EGR is used to decrease nitric oxide (NO) emissions, the 
    primary species in diesel oxides of nitrogen. EGR dilutes intake air 
    with combustion products, namely carbon dioxide (CO2) and 
    water vapor. These diluents decrease the adiabatic stoichiometric flame 
    temperature for a given mass of fuel and oxygen burned.\89\ This 
    decrease in temperature exponentially decreases the oxidation rate of 
    dissociated nitrogen (N) to NO.\90\ EGR also decreases the mole 
    fraction of oxygen, which proportionally decreases the oxidation rate 
    of N to NO.\91\
    ---------------------------------------------------------------------------
    
        \89\ Heywood J.B.: Internal Combustion Engine Fundamentals, 
    McGraw-Hill, Inc, New York, p. 590, 1988.
        \90\ Dodge L.G., D.M. Leone, D.W. Naegeli, D.W. Dickey, K.R. 
    Swenson: ``A PC-Based Model for Predicting NOX Reductions 
    in Diesel Engines,'' SAE paper 962060, p.149, 1996.
        \91\ Ibid.
    ---------------------------------------------------------------------------
    
        EGR is very effective at decreasing NOX. Laboratory 
    studies have shown that EGR can reduce NOX emissions by up 
    to 90 percent at light load and up to 60 percent at full load near 
    rated speed.\92\ Additional studies have shown similar reductions at 
    other speeds and loads.\93\ However, because EGR decreases the overall 
    rate of combustion in the cylinder, EGR tends to increase PM emissions 
    and brake specific fuel consumption (BSFC). Furthermore, if EGR is not 
    cooled before it is introduced to the intake system, it will reduce the 
    density of the intake charge, and thus decrease the volumetric 
    efficiency of the engine, which will decrease maximum power and 
    increase BSFC. Hot EGR also offsets EGR's beneficial effect on 
    combustion temperature because hot EGR increases the initial 
    temperature of the air charge. Finally, EGR without additional boost 
    air can result in incomplete combustion and an increase in PM 
    emissions. Through proper EGR system design, however, researchers have 
    demonstrated that these undesirable effects of EGR can be minimized so 
    that the 2004 emission standards can be met, including fully offsetting 
    the potential increase in PM to enable engines to continue to comply 
    with the 0.1 g/bhp-hr standard.\94\ The draft RIA contains additional 
    discussion of how these issues are being addressed.
    ---------------------------------------------------------------------------
    
        \92\ Dickey D.W., T.W. Ryan III, A.C. Matheaus: ``NOX 
    Control in Heavy-Duty Engines--What is the Limit?'', SAE paper 
    980174, 1998. Dickey; and, Zelenka P., H. Aufinger, W. Reczek, W. 
    Cartellieri: ``Cooled EGR--A Key Technology for Future Efficient HD 
    Diesels,'' SAE paper 980190, 1998.
        \93\ Kohketsu S., K. Mori, K. Sakai, T. Hakozaki: ``EGR 
    Technologies for a Turbocharged and Intercooled Heavy-Duty Diesel 
    Engine,'' SAE paper 970340, 1997; Baert R., D.E. Beckman, A.W.M.J. 
    Veen: ``EGR Technology for Lowest Emissions,'' SAE paper 964112, 
    1996; and, Heavy-duty Engine Working Group, Mobile Source Technical 
    Advisory Subcommittee of the Clean Air Act Advisory Committee, 
    ``Phase 2 of the EPA HDEWG Program--Summary Document'', available in 
    EPA Air Docket A-98-32.
        \94\ Dickey D.W., T.W. Ryan III, A.C. Matheaus: ``NOX 
    Control in Heavy-Duty Engines-What is the Limit?'', SAE paper 
    980174, 1998.
    ---------------------------------------------------------------------------
    
        From a design perspective, EGR poses several challenges for it to 
    be technologically feasible. First, a sufficient positive pressure 
    difference must exist between the point in the exhaust system where the 
    exhaust gas is extracted and the point in the intake system where it is 
    introduced. Second, under most conditions, EGR should be cooled for 
    best performance. Third, the rate of EGR must be controlled accurately, 
    and the control system must respond quickly to changes in engine 
    operation.\95\ As discussed in more detail in the draft RIA, the Agency 
    believes engine and component manufacturers have either resolved these 
    design challenges, or have made significant progress towards a 
    resolution. EPA believes the remaining challenges can be resolved 
    considering the lead time remaining to engine manufacturers, and the 
    use of ABT to introduce the technology across the product line over a 
    period of time.
    ---------------------------------------------------------------------------
    
        \95\ Zelenka P., H. Aufinger, W. Reczek, W. Cartellieri: 
    ``Cooled EGR--A Key Technology for Future Efficient HD Diesels,'' 
    SAE paper 980190, 1998.
    ---------------------------------------------------------------------------
    
        Fuel Injection Rate-shaping. Another key emission control strategy 
    that EPA expects heavy-duty diesel engine manufacturers to use to meet 
    the 2004 emission standards is fuel injection rate shaping. Injection 
    rate shaping has been shown to simultaneously reduce NOX by 
    20 percent and PM by 50 percent under some conditions.96 It 
    has also been shown to reduce BSFC by up to 10 percent without 
    increasing NOX emissions.97 However, it can also 
    lead to increases in smoke emissions and may not be as effective on 
    low-NOX engines equipped with EGR. Fuel injection rate 
    shaping refers to precisely controlling the rate of fuel injected into 
    the cylinder on a crank-angle by crank-angle resolution. Specific rate-
    shaping methods include pilot injection where a pilot quantity of fuel, 
    typically less than two percent of the total fuel charge, is injected 
    at some crank angle before the main injection event.98 Split 
    fuel injection refers to splitting, more or less evenly, the main 
    injection into two or more separate injections (split injection is also 
    referred to as pilot injection). Other methods include ramping the main 
    injection event so that it resembles a triangular profile, rather than 
    a conventional, square-shaped profile. Effective injection rate-shaping 
    systems modulate the fuel injection timing, pressure, rate, and 
    duration independent of engine speed and load. This characteristic of 
    the fuel system
    
    [[Page 58517]]
    
    implies that it should be mechanically de-coupled from the engine. 
    Timing is then achieved, presumably, by electronic control.
    ---------------------------------------------------------------------------
    
        \96\ Dickey D.W., T.W. Ryan III, A.C. Matheaus: ``NOX 
    Control in Heavy-Duty Engines--What is the Limit?'', SAE paper 
    980174, 1998.
        \97\ Boehner W., K. Hummel: ``Common Rail Injection System for 
    Commercial Diesel Vehicles'', SAE paper 970345, 1997; and Uchida N, 
    K. Shimokawa, Y. Kudo, M. Shimoda: ``Combustion Optimization by 
    Means of Common Rail Injection System for Heavy-Duty Diesel 
    Engines'', SAE paper 982679, 1998.
        \98\ Boehner W., K. Hummel, ``Common Rail Injection System for 
    Commercial Diesel Vehicles'', SAE 970345, 1997.
    ---------------------------------------------------------------------------
    
        Rate shaping is used to control the rate of combustion within the 
    cylinder. By controlling combustion rate, the rate of pressure and 
    temperature rise is controlled. Therefore, rate shaping controls 
    NOX formation by one of the same mechanisms as EGR; it is 
    used to lower peak combustion temperatures. Rate shaping can affect the 
    time and temperature at which combustion ends, therefore it can also 
    lower PM emissions by enhancing the mechanisms of in-cylinder soot 
    oxidation.99
    ---------------------------------------------------------------------------
    
        \99\ Heywood, J.B., Internal Combustion Engine Fundamentals, 
    McGraw-Hill, Inc., New York, p. 643-644, 1988.
    ---------------------------------------------------------------------------
    
        Several manufacturers and fuel system suppliers have demonstrated 
    fuel injection systems that can achieve effective rate shaping. The 
    three most common systems are the common rail; the mechanically 
    actuated electronically controlled unit injector (MEUI); and the 
    hydraulically actuated, electronically controlled unit injector (HEUI). 
    These systems are described in more detail in the draft RIA (see 
    Chapter 3).
        Several studies have suggested rate-shaping methods to achieve 
    emissions benefits. Researchers have reported decreased NOX 
    and PM emissions at intermediate speeds and loads by optimizing 
    reduced-rate pilot injection with a high-pressure main injection, and 
    one report suggested a strategy at high loads.100 
    101 102 At intermediate loads, burnt pilot fuel 
    is used as a torch to decrease ignition delay of the main injection 
    event. This lowers peak flame temperatures and, thus, NOX 
    formation. At high loads the ignition delay is not as significant, but 
    a very early pilot event (>20 deg. before top-dead center) can be used 
    to distribute low-temperature burnt gas in the cylinder, similar to 
    EGR. This method can be optimized to decrease NOX, PM, and 
    BSFC simultaneously. Other reports have suggested ramped main injection 
    at high loads and high speeds to decrease NOX, square main 
    injection at peak torque to decrease PM, and split injection at idle to 
    decrease volatile PM (i.e. white smoke).
    ---------------------------------------------------------------------------
    
        \100\ Ikegami, M., K. Nakatani, S. Tanaka, K. Yamane: ``Fuel 
    Injection Rate Shaping and Its Effect on Exhaust Emissions in a 
    Direct-Injection Diesel Engine Using a Spool Acceleration Type 
    Injection System'', SAE paper 970347, 1997.
        \101\ Uchida N, K. Shimokawa, Y. Kudo, M. Shimoda: ``Combustion 
    Optimization by Means of Common Rail Injection System for Heavy-Duty 
    Diesel Engines'', SAE paper 982679, 1998.
        \102\ Dickey D.W., T.W. Ryan III, A.C. Matheaus: 
    ``NOX Control in Heavy-Duty Engines--What is the 
    Limit?'', SAE paper 980174, 1998.
    ---------------------------------------------------------------------------
    
        EPA expects manufacturers to utilize fuel injection rate shaping to 
    meet 2004 emission standards. EPA believes the strategy is 
    technologically feasible because fuel injection rate shaping is used to 
    a limited extent today to meet 1998 emissions standards, and several 
    manufacturers have announced the introduction in the next few years of 
    next-generation fuel injection systems with rate shaping ability. 
    Furthermore, EPA expects even greater emission control through rate 
    shaping as manufacturers continue to develop advanced fuel systems and 
    control algorithms. We request comment on the feasibility of rate 
    shaping and EGR in the 2004 time frame.
    2. Feasibility of 2004 HD Diesel Standards
        EPA expects manufacturers to utilize a combination of technologies 
    in order to meet the proposed 2004 standards, such as cooled EGR 
    systems with VNT and advanced fuel injection with rate shaping 
    capability. The draft RIA for this rule, as well as the final RIA for 
    the 1997 rule, contains a summary of the emission performance of a 
    number of technology combinations which have been published in the 
    referred literature in the past several years. These published results 
    are on a variety of laboratory test cycles, including the U.S. 
    transient heavy-duty FTP, the old European ECE-R49 13 mode steady-state 
    cycle, and the new European Euro III steady-state cycle (which the U.S. 
    EPA new supplemental steady-state cycle in this proposal is based on).
        The published results referenced in the draft RIA show a waste-
    gated turbocharged engine with a high-pressure loop EGR system and a 
    MEUI fuel system achieving NOX levels on the new Euro III 
    cycle at levels between 1.83 and 3.24 g/bhp-hr (the 1.83 level resulted 
    in a 2.4 percent increase in fuel consumption), with corresponding PM 
    levels between 0.15 and 0.06 g/bhp-hr. Results on a HD diesel engine 
    equipped with a VNT, high-pressure loop EGR system, and high pressure 
    fuel injection system achieved results on the older European ECE-R49 
    cycle for NOX between 1.80 and 2.24 g/bhp-hr (the 1.80 level 
    resulted in a 2.3 percent increase in fuel consumption). For both tests 
    a PM level of 0.08g/bhp-hr was reported. Results referenced in the 
    final RIA for the 1997 rule include a study which resulted in 
    HC+NOX levels of 2.54 g/bhp-hr on the U.S. HD transient FTP, 
    this engine was equipped with an EGR system, a rate-shaping fuel 
    injection system, and an oxidation catalyst and was run on a low sulfur 
    fuel.
        The Agency believes the technologies described above and in the 
    draft RIA will provide the emission reductions necessary to allow 
    engine manufacturers to meet the proposed 2004 standards. These control 
    technologies have been demonstrated to provide significant emission 
    reductions under both transient and steady-state test conditions. 
    Steady-state and transient operation are represented in this proposal 
    by the existing FTP, and the new NTE, LRT, and supplemental steady-
    state cycle.
        In order to meet the proposed NTE standards, manufacturers will 
    need to perform emission mapping of each engine family in order to 
    insure that over the NTE control zone, optimization of the emission 
    control system provides sufficient control of the emission map for each 
    pollutants which will maintain levels below the 1.25 times the FTP 
    standard over a 30 second interval. EPA believes the emission control 
    technologies discussed previously as well as in the RIA are capable of 
    providing this level of emission control. The emission control 
    capacities of these technologies are applicable to NTE and LRT test 
    conditions in the same manner as they apply to the transient and 
    steady-state test conditions. The less stringent levels for NTE should 
    also provide a level of assurance to manufacturers.
        As discussed, several publicly available studies have shown results 
    which approach or surpass the proposed standards, though several 
    indicate fuel economy penalties on the order of two percent. 
    Significant development and demonstration of cooled EGR, VNT, and fuel 
    injection systems has been performed in the past two years. Engine 
    manufacturers have four years of lead time available in which to 
    continue to fully develop and optimize these control technologies in 
    order to meet the proposed standards, as well as to minimize or 
    eliminate the fuel economy penalty associated with some technologies. 
    Finally, the 1997 rulemaking put in place ABT provisions for HD diesel 
    engines for the 2004 standards. These ABT provisions provide engine 
    manufacturers with considerable flexibility in determining how they 
    will meet the proposed standards on a corporate average, and thus 
    provides the manufacturers with some level of flexibility in 
    determining how to apply the range of technologies available across 
    their product line.
        Technology combinations of cooled EGR systems, VNTs, and advanced 
    fuel injection systems have been
    
    [[Page 58518]]
    
    demonstrated in the past several years which are capable of meeting the 
    proposed 2004 standards. Engine manufacturers have an additional four 
    years of lead time to develop and optimize these control systems. EPA 
    has considered the well known inverse relationship between 
    NOX and PM. As discussed previously, integrated emission 
    control technology packages (cooled EGR, VNT, and advanced fuel 
    injection system) have been demonstrated to significantly reduce 
    NOX with a minimal increase in PM. Considering the several 
    years of additional lead time available to manufacturers, achievement 
    of the 2004 standards is clearly feasible. In addition, as discussed in 
    the draft RIA, other control methods, such as aftertreatment, though 
    unnecessary to meet the 2004 standards, could be used to further reduce 
    emissions. The ABT provisions provide engine manufacturers some 
    flexibility in determining the appropriate mix of technologies across 
    their product line. For these reasons, EPA fully anticipates that 
    engine manufacturers will meet the 2004 standards contained in today's 
    proposal.
    
    B. 2004 Emission Standards for Heavy-Duty Otto-Cycle Vehicles and 
    Engines
    
        This section discusses the current technologies being used by 
    manufacturers and the key technology changes we believe would be 
    available to meet the proposed 2004 vehicle and engine standards. 
    Technological feasibility of the exhaust emissions standards is 
    presented first, followed by analyses for ORVR controls. Manufacturers 
    would ultimately decide what is best for their individual product 
    lines. Further information on the various available technologies and 
    EPA's technological feasibility assessment is contained in the 
    Technological Feasibility section of the Regulatory Impact Analysis. We 
    request comment on the following discussion and on our feasibility 
    assessment for heavy-duty Otto-cycle vehicles and engines.
    1. Current Technologies
        Gasoline engine manufacturers are already producing heavy-duty 
    engines that achieve a level of emission control better than the 
    control required by current standards. Table 12 provides a list of some 
    key technologies currently being used for HD engine emissions control. 
    Manufacturers have introduced improved systems as they have introduced 
    new or revised engine models. These systems can provide very good 
    emissions control and many engines are being certified to levels of 
    less than half the current standards. Many of the technologies have 
    been carried over from light-duty applications.
    Table 12.--Key Technologies for Current Heavy-Duty Otto-Cycle Engines
    Sequential Fuel Injection/electronic control
        3 way catalyst
        Pre and post catalyst heated oxygen sensors
    Electronic EGR
    Secondary air injection
    Improved electronic control modules
    
        Improving fuel injection has been proven to be an effective and 
    durable strategy for controlling emissions and reducing fuel 
    consumption from gasoline engines. Improved fuel injection will result 
    in better fuel atomization and a more homogeneous charge with less 
    cylinder-to-cylinder and cycle-to-cycle variation of the air-fuel 
    ratio. These engine performance benefits will increase as technology 
    advances allow fuel to be injected with better atomization. Increased 
    atomization of fuel promotes more rapid evaporation by increasing the 
    surface area to mass ratio of the injected fuel. This results in a more 
    homogeneous charge to the combustion chamber and more complete 
    combustion. Currently, sequential multi-port fuel injection (SFI) is 
    used in most, if not all, applications under the proposed standards 
    because of its proven effectiveness.
        One of the most effective means of reducing engine-out 
    NOX emissions is EGR. By recirculating spent exhaust gases 
    into the combustion chamber, the overall air-fuel mixture is diluted, 
    lowering peak combustion temperatures and reducing NOX. 
    Exhaust gas recirculation is currently used on heavy-duty Otto-cycle 
    engines as a NOX control strategy. Many manufacturers now 
    use electronic EGR in place of mechanical back-pressure designs. By 
    using electronic solenoids to open and close the EGR valve, the flow of 
    EGR can be more precisely controlled.
        EPA believes that the most promising overall emission control 
    strategy for heavy-duty Otto-cycle engines is the combination of a 
    three-way catalyst and closed loop electronic control of the air-fuel 
    ratio. Control of the air-fuel ratio is important because the three-way 
    catalyst is effective only if the air-fuel ratio is at a narrow band 
    near stoichiometry. For example, for an 80 percent conversion 
    efficiency of HC, CO, and NOX with a typical three-way 
    catalyst, the air-fuel ratio must be maintained within a fraction of 
    one percent of stoichiometry. During transient operation, this minimal 
    variation cannot be maintained with open-loop control. For closed-loop 
    control, the air-fuel ratio in the exhaust is measured by an oxygen 
    sensor and used in a feedback loop. The throttle position, fuel 
    injection, and spark timing can then be adjusted for given operating 
    conditions to result in the proper air-fuel ratio in the exhaust. Most 
    if not all engines have already been equipped with closed loop 
    controls. Some engines have been equipped with catalysts that achieve 
    efficiencies in excess of 90 percent. This is one key reason engine and 
    vehicle certification levels are very low. In addition, electronic 
    control can be used to adjust the air-fuel ratio and spark timing to 
    adapt to lower engine temperatures, therefore controlling HC emissions 
    during cold start operation.
        All HD Otto-cycle engines are already equipped with three-way 
    catalysts. Engines may be equipped with a variety of different catalyst 
    sizes and configurations. Manufacturers choose catalysts to fit their 
    needs for particular vehicles. Typically, catalyst systems are a single 
    converter or two converters in series or in parallel. A converter is 
    constructed of a substrate, washcoat, and catalytic material. The 
    substrate may be metallic or ceramic with a flow-through design similar 
    to a honeycomb. A high surface area coating, or washcoat, is used to 
    provide a suitable surface for the catalytic material. Under high 
    temperatures, the catalytic material will increase the rate of chemical 
    reaction of the exhaust gas constituents.
        Significant changes in catalyst formulation have been made in 
    recent years and additional advances in these areas are still possible. 
    Platinum, Palladium and Rhodium (Pt, Pd, and Rh) are the precious 
    metals typically used in catalysts. Historically, platinum has been 
    widely used. Today, palladium is being used much more widely due to its 
    ability to withstand very high exhaust temperatures. In fact, some HD 
    vehicles currently are equipped with palladium-only catalysts. Other 
    catalysts contain all three metals or contain both palladium and 
    rhodium. Some manufacturers have suggested that they will use Pd/Rh in 
    lieu of tri-metal or conventional Pt/Rh catalysts for underfloor 
    applications. Improvements in substrate and washcoat materials and 
    technology have also significantly improved catalyst performance.
    2. Chassis-Based Standards
        EPA is proposing to extend the California LEV-I MDV standards 
    nationwide. California began requiring some vehicles to meet LEV 
    standards in 1998 and the phase-in will be complete
    
    [[Page 58519]]
    
    in 2001. The technological feasibility assessment and technology 
    projections are based primarily on the mix of technologies being used 
    to achieve California LEV emissions levels.
        Of the anticipated changes, enhancements to the catalyst systems 
    are expected to be most critical. Catalyst configurations are likely to 
    continue to vary widely among the manufacturers because manufacturers 
    must design the catalyst configurations to fit the vehicles. One 
    potential change is that manufacturers may move the catalyst closer to 
    the engine (close-coupled) or may place a small catalyst close to the 
    engine followed by a larger underfloor catalyst. These designs provide 
    lower cold start emissions because the catalyst is closer to the engine 
    and warms up more quickly. Typically, the catalyst systems used in HD 
    applications have a large total volume but with lower precious metal 
    content per liter compared to light-duty catalyst systems. For 2004, 
    EPA projects an increase in overall precious metal loading of about 50 
    percent. EPA does not expect significant increases in total catalyst 
    volume.
        Calibration changes will also be important. The engine and catalyst 
    systems must be calibrated to optimize the performance of the systems 
    as a whole. Post catalyst oxygen sensors will allow further air fuel 
    control. Manufacturers are moving to more powerful computer systems and 
    EPA expects this trend to continue. Other technologies such as 
    insulated exhaust systems may also be used in some cases to reduce cold 
    start emissions.
        HD vehicles in California have typically been certified with full 
    life emissions levels in the 0.3-0.5 g/mile range for NOX 
    and the 0.1-0.3 g/mile range for NMOG. These levels are well within the 
    LEV standards and provide manufacturers with a compliance cushion. EPA 
    expects manufacturers to sell these vehicles or very similar vehicles 
    nationwide to meet the proposed EPA standards.
    3. Engine-Based Standards
        Currently, most engine families are certified with emissions levels 
    of less than half the standard. Only one engine family is certified 
    with NOX emissions levels within 10 percent of the current 
    4.0 g/bhp-hr NOX standards. Manufacturers have begun to 
    apply advanced system designs to their heavy-duty applications. 
    Recently introduced engine families have been certified with emissions 
    levels of 0.5 g/bhp-hr combined NMHC+NOX.103 
    These engines and systems feature precise air/fuel control and superior 
    catalyst designs comparable to the catalyst systems being used in the 
    California LEV program. Based on industry input, we believe that 
    manufacturers will continue the process of replacing their old engine 
    families with advanced engines over the next several years. As new and 
    more advanced engines are introduced, EPA anticipates that they will be 
    capable of achieving the proposed standards.
    ---------------------------------------------------------------------------
    
        \103\ EPA is not proposing to set the standard at this level 
    because EPA recognizes that a manufacturer needs to design their 
    technology to build in sufficient compliance margin, based on the 
    technology and standards at issue here.
    ---------------------------------------------------------------------------
    
        Manufacturers have stated on several occasions that they target 
    emissions certification levels of about half the standard, due to the 
    potential for in-use deterioration of catalysts and oxygen sensors. 
    Catalysts experience wide variations in exhaust temperature due to the 
    wide and varied usage of vehicles in the field. Some vehicles may 
    experience more severe in-use operation than is represented by the 
    durability testing currently conducted for engine certification. 
    Manufacturers have argued that EPA should not set new standards based 
    on certification data because certification levels do not account for 
    severe in-use deterioration. Based upon these comments EPA would expect 
    that manufacturers would certify engines at about 0.5 g/bhp-hr 
    NMHC+NOX in order to ensure compliance with the 1.0 
    g/bhp-hr standard.
        Catalyst systems with increased precious metal loading will be a 
    critical hardware change for meeting the proposed engine standards. 
    Optimizing and calibrating the catalyst and engine systems as a whole 
    will also be important in achieving the proposed standards. Increased 
    use of air injection to control cold start emissions may also be 
    needed, especially to reduce NMHC emissions during cold start 
    operation. Also, improved EGR systems and retarded spark timing may be 
    needed to reduce engine out NOX emissions levels.
        Catalyst system durability is a key issue in the feasibility of the 
    standards. Historically, catalysts have deteriorated when exposed to 
    very high temperatures and this has long been a concern for heavy-duty 
    work vehicles. Manufacturers have often taken steps to protect 
    catalysts by ensuring exhaust temperatures remain in an acceptable 
    range. Catalyst technologies in use currently are much improved over 
    the catalysts used only a few years ago. The improvements have come 
    with the use of palladium, which has superior thermal stability, and 
    through much improved washcoat technology. The catalysts have been 
    shown to withstand temperatures typically experienced in HD 
    applications. Manufacturers also continue to limit exhaust temperature 
    extremes not only to protect catalyst systems but also to protect the 
    engine.
        In addition to general comments noted above regarding the need for 
    compliance cushion, manufacturers presented EPA with an analysis of the 
    Otto-cycle engine emissions standards for 2004.104 The 
    analysis assumed:
    ---------------------------------------------------------------------------
    
        \104\ ``September 15, 1998 Meeting with Engine Manufacturers 
    Association (EMA)'', EPA Memorandum from John W. Mueller, Mechanical 
    Engineer, to docket A-95-27, November 4, 1998. Docket A-95-27, 
    Docket # IV-E-26.
        \105\ [Reserved]
    ---------------------------------------------------------------------------
    
         Worst-case NOX catalyst efficiency of 90.9 
    percent at the end of the engine's useful life
         Worst-case engine-out NOX level of 12 g/bhp-hr
         A cushion of .3 g/bhp-hr for engine variability and a 
    safety margin of 20 percent of the standard
         Tailpipe NMHC levels of 15 percent of the NOX 
    level (.26 g/bhp-hr)
        Based on these assumptions, manufacturers recommended a 2.0 g/bhp-
    hr  NMHC plus NOX standard, according to the following 
    methodology.
    
    Variability=0.3 g/bhp-hr  (eq. 1)
    Safety Margin=20% (NOX level)
        (eq. 2)
    NMHC Level=14.8 % (NOX Level)
        (eq. 3)
    Combined NMHC+NOX Standard=NOX Level+NMHC Level  
    (eq. 4)
    NOX Level=Post-catalyst NOX 
    rate+Variability+Safety Margin  (eq. 5)
    (Step 1) Post-catalyst NOX rate=(1-conversion 
    efficiency) x Engine-Out NOX level=(1-0.91) x 12 g/bhp-
    hr=1.09 g/bhp-hr  (eq. 6)
    (Step 2) Putting eq. (1), (2), and (6) into equation (5)--
    NOX Level=1.09 g/bhp-hr+0.3 g/bhp-hr+0.2 x NOX 
    Level  (eq. 5b)
    (Step 3) Solving Equation (5b) for NOX Level gives--
    NOX Level=(1.09 g/bhp-hr+0.3 g/bhp-hr)/(1-0.2)=1.74 g/bhp-hr
    (Step 4) Placing the results from (Step 3) into Equation 5 gives--NMHC 
    Level=14.8% NOX Level=0.148 x 1.74 g/bhp-hr=0.26 g/bhp-hr
    (Step 5) Placing the results from (Step 3) and (Step 4) into equation 
    (1) gives: Combined NMHC+NOX Standard=0.26 g/bhp-hr+1.74 g/
    bhp-hr=2 g/bhp-hr
    
    Manufacturers noted that a catalyst efficiency of about 97 percent 
    would be
    
    [[Page 58520]]
    
    needed to meet a 1.0 g/bhp-hr standard and that their assessments of 
    post-2000 catalysts indicate worst case performance well below this 
    level. The 2.0 g/bhp-hr standard recommended by manufacturers seems to 
    indicate that compliance cushions greater than half the standard are 
    needed.
        The deterioration factor for the engine and catalyst system in the 
    above analysis would be on the order of four or five.106 
    This is extremely high compared to the deterioration factors currently 
    used for certification which are typically between one and two. While 
    EPA understands that current deterioration factors may represent 
    typical deterioration and not severe deterioration, EPA believes that 
    deterioration factors of four or five are unreasonably high and 
    unlikely. EPA would expect a deterioration factor representing more 
    severe operation to be closer to two, which is consistent with 
    manufacturers' previous statements of certifying with certification 
    levels of half the standard to allow for needed compliance margin.
    ---------------------------------------------------------------------------
    
        \106\ During developmental testing the deterioration factor is 
    determined by dividing the full life emissions level for an engine 
    by the low mileage emissions level. The low mileage level of the 
    certification engine is then multiplied by the deterioration factor 
    to predict full life emissions.
    ---------------------------------------------------------------------------
    
        Manufacturers state that their catalyst assumptions represented 
    catalyst deterioration based on worst case vehicle operation (highly 
    loaded operation, high exhaust temperatures). Details of the catalyst 
    were not available except that manufacturers stated that the catalyst 
    represented post-2000 catalyst technology. Due to the lack of detail, 
    it is difficult to evaluate the assumption. However, EPA believes that 
    this assumption is somewhat conservative given the recent developments 
    in catalyst technology, the lead time available, and methods available 
    to protect catalysts under worst case vehicle operation.
        Engine-out NOX levels are also critical to the analysis. 
    In their analysis, manufacturers assumed engine-out NOX 
    levels of 12 g/bhp-hr, based on manufacturer development data for one 
    engine. EPA does not believe that the engine-out NOX level 
    of 12 g/bhp-hr is a reasonable or representative assumption. Other 
    available data indicates that several engines have engine-out 
    NOX emissions well below this level in the 6 to 10 g/bhp-hr 
    range. Also, a previous assessment of engine standards presented to EPA 
    by one manufacturer assumed much lower engine-out NOX 
    levels.107 EPA does not believe that the current standards 
    have encouraged manufacturers to place a high priority on engine-out 
    emissions levels. In fact, one manufacturer has removed EGR systems 
    from its engines. For recent engines, catalysts have provided the 
    majority of needed emissions control.
    ---------------------------------------------------------------------------
    
        \107\ The engine-out data and the details of this analysis are 
    considered Confidential Business Information.
        \108\ [Reserved]
    ---------------------------------------------------------------------------
    
        EPA also further considered the engine variability factor of 0.3 g/
    bhp-hr built into the manufacturers' analysis. The analysis as 
    presented assumes a 12 g/bhp-hr engine-out NOX level. 
    Manufacturer data for the developmental engine suggests that 12 g/bhp-
    hr is the worst case engine-out level anticipated (the actual highest 
    test point recorded was 12.65). It appears to EPA that manufacturers 
    double counted engine variability by using the worst case engine data 
    and an engine variability factor. Using engine-out NOX 
    levels of 12 g in the analysis but without the engine variability 
    factor yields a NOX + NMHC level of 1.6 g/bhp-hr. Without 
    including a safety margin, which may be appropriate considering the 
    analysis is already based on worst case engine and catalyst 
    assumptions, the level would be 1.3 g/bhp-hr. To reach the 1.0 g/bhp-hr 
    level with this engine and a 20 percent safety margin, a catalyst 
    efficiency of 94 percent would be needed, according to the following 
    assumptions and methodology.
    
    Combined NMHC + NOX Standard = 1.0 g/bhp-hr
    Engine-Out NOX level (worse-case) = 12 g/bhp-hr
    Safety Margin = 20 % (NOX level) (eq. 1)
    NMHC Level = 14.8 % (NOX Level) (eq. 2)
    Combined NMHC + NOX Standard = NOX Level + NMHC 
    Level (eq. 3)
    NOX Level = Post-catalyst NOX rate + Safety 
    Margin (eq. 4)
    Post-catalyst NOX rate = (1-Conversion Efficiency) x Engine-
    Out NOX level (eq. 5)
    (Step 1) Equation (3) can be solved for NOX Level--Combined 
    NMHC + NOX Standard = NOX Level + NMHC Level 1.0 
    g/bhp-hr = NOX Level + 0.148 NOX Level 
    NOX Level = 0.871 g/bhp-hr
    (Step 3) Placing the results from Step (1) and Equation (1) into 
    Equation (4), and solving for Post-catalyst NOx rate gives--
    NOX Level = Post-catalyst NOX rate + Safety 
    Margin 0.871 g/bhp-hr = Post-catalyst NOX rate + 0.2  x  
    0.871 g/bhp-hr Post-catalyst NOX rate = 0.697 g/bhp-hr
    (Step 4) Placing the results from Step (3) into Equation 5 and solving 
    for Conversion Efficiency gives:
        Post-catalyst NOX rate = (1-Conversion Efficiency)  x  
    Engine-Out NOX level
        0.697 g/bhp-hr = (1--Conversion Efficiency)  x  12 g/bhp-hr
        Conversion Efficiency = 0.94 = 94%
    
        EPA believes that the proposed standards would require 
    manufacturers to focus some effort on engine-out emissions control and 
    that engine-out NOX levels in the 6 to 8 g/bhp-hr range are 
    reasonably achievable. Some engines are already in this range. For 
    other engines, some recalibration of engine systems including the EGR 
    system and perhaps some modest hardware changes to those systems would 
    be necessary. EGR plays a key role in reducing engine-out 
    NOX, and system redesign may allow more effective use of 
    this technology.
        When coupled with a catalyst with worst case efficiencies in the 91 
    to 93 percent range, these engines could achieve the proposed 
    standards. Of course with higher catalyst efficiencies, manufacturers 
    would not have to achieve lower NOX engine-out levels. 
    Catalyst efficiencies of about 93 percent would allow manufacturers to 
    maintain compliance margins in the range of 25 and 45 percent of the 
    standard. EPA believes these margins are sufficient considering the 
    analysis is also based on worst case catalyst efficiencies.
        To help address phase in concerns that could arise for 
    manufacturers, EPA is proposing a modified ABT program for engines, as 
    described above. The ABT program can be an important tool for 
    manufacturers in implementing a new standard. The program allows 
    manufacturers to comply with the more stringent standards by 
    introducing emissions controls over a longer period of time, as opposed 
    to during a single model year. Manufacturers plan their product 
    introductions well in advance. With ABT, manufacturers can better 
    manage their product lines so that the new standards don't interrupt 
    their product introduction plans. Also, the program also allows 
    manufacturers to focus on higher sales volume vehicles first and use 
    credits for low sales volume vehicles. EPA believes manufacturers have 
    significant opportunity to earn credits in the pre-2004 time frame.
        Considering all of these factors, EPA believes that the 1.0 g/bhp-
    hr NMHC+NOX standard is an appropriate standard for HD Otto-
    cycle engines in the 2004 time frame; however, we are requesting 
    comment on a standard in
    
    [[Page 58521]]
    
    the range of 1.0 to 1.5 g/bhp-hr. Certification levels of 0.5 g/bhp-hr 
    NMHC+NOX have been achieved on recently introduced engines 
    of varied sizes. EPA believes that the proposed standard provides 
    sufficient opportunity for manufacturers to maintain a reasonable 
    compliance margin. As manufacturers continue with normal product plans 
    between now and 2004, improved engines will continue to replace older 
    models. The ABT program is available for manufacturers who have not 
    completely changed over to new engine models by 2004. ABT provides 
    manufacturers with the opportunity to earn credits prior to 2004 and 
    use the credits to continue to offer older engine models that have not 
    yet been redesigned or retired by 2004.
        EPA requests comments on the above analyses and directs the reader 
    to the Regulatory Impact Analysis for further detail on technological 
    feasibility. EPA continues to seek further information on emissions 
    control and engine system capability and durability. EPA requests 
    comment on the feasibility of the proposed standards and requests data 
    which would help the Agency further evaluate advanced system 
    durability.
    4. Onboard Refueling Vapor Recovery
        EPA believes that today's proposed ORVR requirements are 
    technologically feasible. In its previous ORVR rulemaking, EPA elected 
    to apply ORVR requirements only to LDVs and LDTs (see 59 FR 16262, 
    April 6, 1994). As previously discussed in the section on the proposed 
    ORVR standards, EPA chose at the time of the original rulemaking not to 
    apply ORVR to HDVs because of concerns over secondary manufacturers, 
    different fuel tank designs for larger HDVs than for LDVs and LDTs, and 
    the fact that HDVs are certified under an engine-based testing program. 
    These three issues are addressed in section IV.E.4.b) of this preamble. 
    In the original ORVR rule, however, EPA analyzed the potential 
    application of ORVR to all HDVs. In that analysis EPA concluded that 
    ORVR is technologically feasible for application to HDVs. EPA concluded 
    that the systems which would be required for the covered subset of HDVs 
    would be essentially the same as those for LDVs and LDTs. Such systems 
    have already been successfully implemented on a portion of the LDV 
    fleet. The Agency is aware of no information on fundamental changes to 
    HDV fuel system design which would cause it to believe that the 
    original analysis is no longer valid. EPA requests comment on this 
    view.
        ORVR systems must meet certain basic requirements in order to be 
    effective at controlling refueling emissions. In general, they must 
    provide for the routing of displaced vapors from the fuel tank to the 
    engine rather than allowing them to escape uncontrolled to the 
    atmosphere. This will likely be accomplished through the use of 1) a 
    fillneck seal which prevents the vapors from escaping out the fillneck, 
    2) a fuel tank vent mechanism, to allow for the controlled routing of 
    the vapors from the fuel tank, 3) vapor lines for transporting vapors, 
    4) a canister containing activated carbon to temporarily store the 
    vapors, and 5) a purge system to regenerate the canister and route the 
    vapors to the engine.
        The major components of an ORVR system are already in place on HDVs 
    in response to EPA's enhanced evaporative emission requirements (see 58 
    FR 16002, March 24, 1993). The primary differences between an enhanced 
    evaporative control system and an ORVR system lie in the need to 
    prevent vapors from escaping via the fillneck during a refueling event, 
    and the fact that the vapor flow rates out of the fuel tank are much 
    higher during refueling than during vehicle operation and diurnal 
    events that enhanced evaporative systems are designed to control. A 
    complete discussion of the major components of an ORVR system and how 
    they differ from those in a system designed to comply with the enhanced 
    evaporative requirements is contained in the Regulatory Impact 
    Analysis.
    
    C. On-Board Diagnostics
    
        For Otto-cycle vehicles and engines, the most difficult monitors to 
    implement are those for the catalyst system, the evaporative emission 
    control system, and engine misfire. While each of these monitors poses 
    technological challenges, none of them pose technological feasibility 
    concerns. Rather than concerns over technological feasibility, EPA 
    expects concerns, where today's proposal applies to Otto-cycle vehicles 
    and engines, over resource constraints for OBD calibration and 
    associated verification testing.
        EPA does not consider resource constraints a feasibility issue, nor 
    does EPA believe the manufacturers will be constrained by today's OBD 
    provisions. EPA believes this is true for both the Otto-cycle and the 
    diesel OBD requirements. Since the 1996 model year, manufacturers have 
    been equipping their vehicles and engines with OBD systems essentially 
    identical to those being proposed today. This is true federally for all 
    vehicles above 8500 pounds GVWR, and in California for all vehicles and 
    engines above 14,000 pounds GVWR. The Agency believes that the four 
    year lead time within today's proposal matched with the OBD phase-in of 
    40/60/80/100 percent provides adequate lead time to apply the real 
    world tested OBD system technology to their new sales fleet above 
    14,000 pounds GVWR without resource difficulties.
        The transmission represents an area of potential concern for engine 
    certified as opposed to chassis certified Otto-cycle and diesel 
    engines. Typically, the engine manufacturer certifies and sells its 
    engine, without an associated transmission, to a chassis manufacturer. 
    The chassis manufacturer then ``mates'' the engine to a transmission 
    purchased from a transmission manufacturer representing a third 
    industry party. The regulations proposed today require that chassis 
    certified systems employ transmission diagnostics, but would not 
    require that engine certified systems employ transmission diagnostics.
        EPA believes that it is reasonable to expect that electronically 
    controlled transmissions will be designed with some level of 
    diagnostics to ensure proper operation. In addition, the Agency expects 
    that those transmissions will utilize industry standard communication 
    protocols allowing the transmission and the engine control computers to 
    communicate, and allowing any transmission-related OBD codes to be 
    downloaded via the standard diagnostic data link connector without 
    engine manufacturer involvement. If either of these expectations is 
    inaccurate, EPA requests information concerning the likely operational 
    characteristics of electronic transmissions. If EPA's expectations are 
    accurate, we request comment on the appropriateness of the engine 
    certified OBD requirements, Otto-cycle and diesel, being limited to 
    engine diagnostics, and simply requiring that transmissions comply with 
    industry standard communication protocols.
        Specific to diesel vehicles and engines, the Agency believes there 
    are three areas of concern associated with technological feasibility: 
    EGR monitoring; misfire monitoring; and, aftertreatment monitoring. 
    With respect to EGR monitoring, the primary concern is expected to be 
    the cooling componentry of a cooled EGR system. Other aspects of the 
    EGR system, such as activation of the EGR valve, verification of proper 
    flow, etc., can be accomplished as is already being done on Otto-cycle 
    and diesel vehicles and
    
    [[Page 58522]]
    
    engines under 14,000 pounds GVWR.109 However, the cooling 
    system presents a new challenge. The Agency believes monitoring of the 
    cooling system is feasible by employing temperature sensors to ensure 
    proper EGR cooling (heat transfer) given existing engine conditions, 
    and coolant flow. If the cooling system becomes fouled, its ability to 
    transfer heat from the exhaust gases to the coolant will be diminished 
    and a resultant temperature inconsistency should be observed. Likewise, 
    if coolant ceases to flow through the cooling system, a resultant 
    temperature inconsistency should be observed. In fact, EPA believes 
    that manufacturers will monitor EGR cooling system performance absent a 
    requirement to do so. As discussed in Chapter 3 of the Draft Regulatory 
    Impact Analysis for today's proposal, manufacturers will be designing 
    their EGR systems to cool the EGR to specific design targets to 
    optimize engine performance and to minimize condensation of sulfuric 
    acid. The only way to ensure that engine performance is being optimized 
    is to monitor the performance of the EGR system and compare it to the 
    specific design targets.
    ---------------------------------------------------------------------------
    
        \109\ Current EGR monitoring systems may use the existing intake 
    air temperature sensor--opening the EGR valve should result in an 
    increased intake air temperature. Systems may also use an intake air 
    pressure sensor--opening the EGR valve will change the intake air 
    pressure.
    ---------------------------------------------------------------------------
    
        As for diesel misfire monitoring, the Agency believes that the 
    proposed requirement is technologically feasible. In fact, 
    manufacturers are certifying compliant diesel misfire monitors for sale 
    in California on vehicles and engines under 14,000 pounds GVWR. We 
    believe, like CARB, that diesel misfire is an air quality concern. 
    Also, we believe that most users of diesel vehicles and engines under 
    14,000 pounds GVWR, particularly vehicles and engines less than 10,000 
    pounds GVWR, will not notice or may ignore diesel misfires. In 
    contrast, we believe that most users of engines above 14,000 pounds 
    GVWR will notice and not ignore misfires. We believe this is true 
    because most of these engines are driven by professionals for whom 
    minimizing fuel consumption and maximizing engine performance is a 
    primary business concern. Conversely, most vehicles and engines under 
    14,000 pounds GVWR, particularly vehicles and engines under 10,000 
    pounds GVWR, are driven by individuals as personal transportation or 
    for small business use. Such drivers are probably less familiar with 
    the day-to-day operating characteristics of their engines and are 
    probably less concerned with fuel consumption and engine performance. 
    Nonetheless, we are interested in comments on the misfire monitoring 
    requirements of today's proposal. In addition, we request data, such as 
    warranty data, showing misfire rates and possible differences between 
    engines above and below 14,000 pounds GVWR.
        With respect to diesel catalyst monitoring, the Agency expects such 
    monitoring to be conducted using temperature sensing devices to detect 
    an exotherm within the aftertreatment device. The Agency requests 
    comment on this expectation and on the probable magnitude of the 
    exotherm. Comments should consider whether limiting the operating modes 
    during which the exotherm is measured (for example, during steady-state 
    operation at a specific engine load, etc.) might increase the accuracy 
    of the monitoring method. Comments should also consider whether, given 
    the provision for back pressure monitoring in lieu of performance 
    monitoring provided test data demonstrate that emissions will not 
    exceed today's proposed malfunction threshold, manufacturers will even 
    have to employ diesel catalyst emission performance monitors. The 
    Agency expects manufacturers to demonstrate that emissions will not 
    exceed the malfunction thresholds, even with the aftertreatment device 
    removed, and then employ the more basic back pressure sensor. This back 
    pressure sensor is intended to indicate the presence of the 
    aftertreatment device. While the back pressure sensor cannot directly 
    detect the performance characteristics of the aftertreatment device, it 
    nonetheless provides some level of assurance that emissions are being 
    controlled due to the presence of the device. The Agency requests 
    comment on the diesel aftertreatment monitoring requirements and data 
    on feasibility, and comment on the appropriateness of the diesel 
    aftertreatment presence detection requirement. The Agency also requests 
    comments and supporting data on the durability of diesel aftertreatment 
    devices.
        Note that, for diesel vehicles and engines, the Agency considers 
    the EGR system to be the primary emission control system that will be 
    used to meet the 2004 standards. This makes the EGR system somewhat 
    analogous to the catalyst in an Otto-cycle emission control system. 
    Because the Otto-cycle catalyst is responsible for roughly 90 percent 
    of emission control, the Agency considers it imperative that the 
    catalyst be monitored via OBD to ensure its continued performance. 
    Likewise, the diesel EGR system is expected to account for roughly 50 
    percent of the emission control, making it perhaps the single largest 
    contributor to emission control on a diesel engine. Therefore, the 
    Agency considers it imperative that the EGR system be monitored on a 
    diesel vehicle or engine. This is especially true given what the Agency 
    considers to be a rather low cost associated with today's proposed 
    requirement for monitoring this critical emission control 
    system.110 The Agency fully expects that manufacturers will 
    employ OBD techniques on their diesel EGR systems to ensure 
    satisfactory engine performance for their customers. Today's proposal 
    simply ensures that the monitoring will occur, and it ensures that the 
    monitoring will consider not only engine performance, but also emission 
    performance.
    ---------------------------------------------------------------------------
    
        \110\ The Agency estimates $3 to $7 per vehicle/engine for 
    today's proposed OBD requirements, primarily for development and 
    demonstration testing given that most of the diesel monitoring will 
    be done by the manufacturer absent any requirement to do so.
    ---------------------------------------------------------------------------
    
    VII. What Are the Environmental Benefits of This Proposal?
    
    A. 2004 Emission Standards for Heavy-Duty Diesel Engines
    
        In Chapter 6 of the draft Regulatory Impact Analysis, EPA provides 
    a detailed explanation of the methodology used to determine the 
    environmental benefits from heavy-duty diesel engines associated with 
    this proposal. EPA requests comment on all aspects of the emissions 
    inventory analysis. The following discussion gives a general overview 
    of the methodology and results.
        In the 1997 rulemaking, EPA's emission inventory modeling assumed 
    that all HDDE's which would certify to the future 2004 standards would 
    be meeting those standards in-use, under all operating conditions, 
    i.e., EPA was not aware of the high NOX emissions being 
    emitted by certain HDDE's under certain operating conditions. The 
    supplemental standards and testing provisions will help assure that 
    assumptions used for the 1997 rulemaking are realized. Therefore, the 
    emission inventory modeling discussed below and in the draft RIA for 
    today's rule uses the same methodology as the 1997 rule, including the 
    same emission factors. For this reason, the emission benefits are 
    similar in magnitude to the estimates from the 1997 rulemaking. In 
    addition, the emission estimates presented here do not include the 
    large, previously unknown, excess emissions from engines manufactured 
    from 1988 to 1998.
    
    [[Page 58523]]
    
        We did not include the excess emissions in the modeling for this 
    proposal. While the impact from these previously produced engines would 
    affect the total estimate of the emission impact from the in-use fleet 
    of HDDE in 2004 and beyond, it would not impact the predicted emission 
    benefit resulting from the lowering of the 1998 standard to the 2004 
    standards, because the predictions for both standards properly do not 
    include these excess emissions. It is this emission reduction which is 
    important for this rulemaking. In the future, the Agency will be making 
    the necessary changes to future versions of the official EPA mobile 
    source emission factor model (currently known as MOBILE 5) to reflect 
    the increased NOX emission factors from the engines affected 
    by the consent decrees.
        The inventory analysis performed for this proposal builds on the 
    inventory analysis associated with the 1997 FRM for heavy-duty diesel 
    engines. 111 However, EPA made some modifications to the 
    1997 inventory analysis due to recent studies that have been performed 
    with the intent of improving the understanding of the emissions impact 
    of mobile sources. These modifications included new estimates for 
    conversion factors (bhp-hr/mile), scrappage rates, and vehicle miles 
    traveled. The Draft RIA discusses the recent studies and their effects 
    on the calculated HDDE emissions inventories.
    ---------------------------------------------------------------------------
    
        \111\ ``Control of Emissions of Air Pollution from Highway 
    Heavy-Duty Engines; Final Rule,'' 62 FR 54694-54730, October 21, 
    1997.
    ---------------------------------------------------------------------------
    
        To determine total emissions by calendar year, EPA multiplied the 
    emission factor times the total vehicle miles traveled (VMT) in that 
    year. The emission factors were determined using EPA's emission factor 
    model (MOBILE5) for NMHC and NOX with adjustments for the 
    new scrappage rates, conversion factors, and VMT distribution. Although 
    NMHC and NOX are proposed to be combined as a single 
    standard, EPA believes that it is useful to model NMHC and 
    NOX separately. Given the technologies that are expected to 
    be used on heavy-duty diesel engines to comply with the proposed 
    standards, we believe it is reasonable to model the fleet-average 
    impact of the proposed standards as being equivalent to a 2.0 g/bhp-hr 
    NOX standard and a 0.4 g/bhp-hr NMHC standard.
        Table 13 shows the national projections of total NMHC and 
    NOX emissions and the estimated NOX benefits for 
    selected years. The emissions are projected to decline over the next 
    several years, due to implementation of stricter controls, but then 
    begin to increase due to growth in the number of vehicle miles 
    traveled, unless there are additional controls. By the year 2015, 
    without these additional controls, total national NOX 
    emissions are projected to exceed current levels. Figure 5 presents the 
    national projections of total NMHC plus NOX with and without 
    the proposed engine controls.
    
                           Table 13.--Estimated National NMHC and NOX Emissions and Proposed Benefits From Heavy-Duty Diesel Vehicles
     
                                                                 [Thousand short tons per year]
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   NMHC                                             NOx
                              Year                           -----------------------------------------------------------------------------------------------
                                                                 Baseline      With controls      Benefit        Baseline      With controls      Benefit
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    2005....................................................             198             196               3           2,136           1,933             203
    2010....................................................             184             174              10           2,191           1,504             686
    2015....................................................             197             182              15           2,479           1,433           1,046
    2020....................................................             225             205              20           2,900           1,535           1,365
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
    
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        Although this proposal does not require reductions in direct PM 
    emissions, the proposed standards are expected to reduce the 
    concentrations of secondary PM. Secondary PM is formed when 
    NOX reacts with ammonia in the atmosphere to yield ammonium 
    nitrate particulate. EPA estimates that the 1.4 million tons per year 
    total NOX reduction projected for HDDEs in 2020 would result 
    in about a 56,000 tons per year reduction in secondary PM. This 
    calculation is described in the Draft RIA, Chapter 6, Section V.B. It 
    should be noted that these estimates include a calculation involving 
    weighting of the southern California conversion rate by VMT, but the 
    Federal standards do not regulate new vehicles sold in California. 
    Therefore, these nationwide estimates are somewhat over estimated. We 
    intend to address this issue in the final rule.
        The term ``hydrocarbons'' includes many different molecules. 
    Speciation of the hydrocarbons would show that many of the molecules 
    are those which are considered to be air toxics including benzene, 
    formaldehyde, acetaldehyde, and 1,3-butadiene. Hydrocarbons from a HDDE 
    include approximately 1.1 percent benzene, 7.8 percent formaldehyde, 
    2.9 percent acetaldehyde, and 0.6 percent 1,3-butadiene. Therefore, the 
    20,000 tons per year reduction in NMHC projected for 2020 would result 
    in about a 2,400 tons per year reduction in air toxics. This is 
    discussed in more detail in the Draft RIA.
        EPA also believes the proposed regulations will tend to reduce 
    noise. One important source of noise in diesel combustion is the sound 
    associated with the combustion event itself. When a premixed charge of 
    air and fuel ignites, the very rapid combustion leads to a sharp 
    increase in pressure, which is easily heard and recognized as the 
    characteristic sound of a diesel engine. The conditions that lead to 
    high noise levels also cause high levels of NOX formation. 
    Fuel injection changes and other NOX control strategies 
    therefore typically reduce engine noise.
    
    B. 2004 Emission Standards for Heavy-Duty Otto-Cycle Vehicles and 
    Engines
    
        In evaluating the environmental impact of the proposed heavy-duty 
    gasoline engine and vehicle standards, EPA developed estimates of 
    exhaust NOX and NMHC inventories from HDGVs (excluding 
    California, Alaska, and Hawaii) both with and without the effect of the 
    proposed standards. Full details of the environmental impact analysis 
    can be found in Chapter 7 of the draft RIA for today's proposal. The 
    following paragraphs summarize the key results. The public is 
    encouraged to read the full analysis and to comment on all aspects of 
    the work.
        Figure 6 shows the projections of nationwide exhaust 
    NMHC+NOx emissions from HDGVs both with and without the 
    proposed controls. Table 14 contains the estimated NOx and 
    NMHC exhaust emission inventories and reductions due to the proposed 
    heavy-duty gasoline engine and vehicle standards. The NOx 
    inventory for HDGVs is projected to increase from current levels 
    without further controls. With implementation of the proposed 
    standards, the exhaust NOx emissions from HDGVs are expected 
    to decrease from the baseline by 38 percent by the year 2010 and 61 
    percent by the year 2020. Exhaust NMHC emissions are projected to 
    decline over the next several years, but then begin to increase 
    beginning around 2010. With implementation of the proposed standards, 
    the exhaust NMHC emissions from HDGVs are expected to decrease from the 
    baseline by 8 percent by the year 2010 and 13 percent by the year 2020.
    
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          Table 14.--Estimated NOX and NMHC Inventories and Reductions From the Proposed Exhaust Standards for Heavy-Duty Gasoline Engines and Vehicles
                                                                    [Thousand tons per year]
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   NMHC                                             NOX
                              Year                           -----------------------------------------------------------------------------------------------
                                                                 Baseline     With  controls     Reduction       Baseline     With  controls     Reduction
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    2005....................................................             236             232               4             329             290              38
    2010....................................................             225             208              17             365             223             142
    2015....................................................             236             209              27             394             183             212
    2020....................................................             255             221              34             432             168             264
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
        In a similar fashion to that noted for the heavy-duty diesel engine 
    standards, the NOX reductions from HDGVs are expected to 
    result in reduced secondary PM concentrations. EPA estimates that the 
    264,000 tons of NOX reduction in 2020 would result in 
    approximately a 10,000 tons per year reduction in secondary PM. This 
    calculation is described in the draft RIA, Chapter 6, Section V(B), and 
    Chapter 7, Section IV. As noted above, these estimates include a 
    calculation involving weighting of the southern California conversion 
    rate by VMT, but the Federal standards do not regulate new vehicles 
    sold in California. Therefore, these nationwide estimates are somewhat 
    over estimated. We intend to address this issue in the final rule.
    
    C. Benefits of the Supplemental Standards and In-Use Control Measures 
    of Today's Proposal
    
        The supplemental standards and in-use control measures of today's 
    proposal are expected to play an integral role in achieving the 
    emission reductions expected from the 2004 diesel and Otto-cycle 
    standards. These measures include the new supplemental standards and 
    test procedure requirements for diesel engines, the OBD requirements 
    for vehicles and engines below 14,000 lbs GVWR, and the in-use testing 
    requirements for Otto-cycle vehicles below 14,000 lbs GVWR.
        These measures are considered vital, as a whole, to assuring that 
    the full benefits of the 2004 standards are being achieved. The new 
    supplemental standards and test procedure requirements will ensure that 
    engines are designed to meet the appropriate standards under a broad 
    range of operating conditions. The in-use testing requirements will 
    ensure that engines meet the appropriate standards throughout their 
    useful lives. Finally, the OBD requirements will help ensure that 
    engines in-use continue to operate according to design intent and that 
    designs are durable and robust in the field. If vehicles and engines 
    malfunction or deteriorate in ways that are not noticed by the driver, 
    emissions may be far above the design intent of the engine or vehicle 
    for thousands, if not tens of thousands of miles. On-board diagnostic 
    systems are uniquely suited to identify such malfunctions. Such 
    identification serves to ensure that the engines and vehicles continue 
    to operate as designed, thereby ensuring they continue to provide the 
    air quality benefits expected by the new standards.
        For example, we expect widespread use of EGR to comply with the 
    2004 diesel standards. The emission reduction from the EGR system will 
    likely be as high as 50 percent, that is, the engine out emissions will 
    be cut in half as a result of the EGR system. Should the EGR system 
    malfunction, the emissions could essentially double, and the driver 
    would probably not be aware of the malfunction without an OBD 
    detection. The same could be true for Otto-cycle vehicles and engines, 
    in which case the primary emission control technology will be the 
    catalyst, which is responsible for as much as 90 percent of the 
    emission control. Should the catalyst deteriorate or fail, emissions 
    could increase from 150 percent to 900 percent. 112 Similar 
    statements can be made in regards to evaporative leak detection 
    monitors. We know that emissions from leaking evaporative systems can 
    be very large. In their most recent Staff Report on the OBDII program, 
    the California Air Resources Board states that data from current 
    evaporative system designs show that leaks approaching a 0.020 inch 
    hole begin to rapidly generate excess evaporative emissions (up to 15 
    times the standard, which equates to 30 grams per test). 113 
    The emissions from a heavy-duty Otto-cycle vehicle, having a fuel tank 
    well over 15 gallons, would likely be even higher. Without the OBD 
    system, those emissions would probably never be identified and the 
    malfunctions would probably never be repaired.
    ---------------------------------------------------------------------------
    
        \112\ Assuming a properly operating catalyst conversion 
    efficiency of 90 percent, and a deteriorated conversion efficiency 
    of anywhere from 75 percent down to 0 percent, which would lead to a 
    150 percent to 900 percent emission increase, respectively.
        \113\ Staff Report: Initial Statement of Reasons for 
    Rulemaking--Technical Status and Proposed Revisions to Malfunction 
    and Diagnostic System Requirements for 1994 and Subsequent Model-
    Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and 
    Engines (OBD II); October 25, 1996.
    ---------------------------------------------------------------------------
    
        Further, the primary goal of OBD is to provide the industry with an 
    additional incentive to improve emission control system durability. OBD 
    serves that goal by encouraging durable components and systems in order 
    to avoid the OBD detection and MIL illumination that will result upon 
    their malfunction. Indeed, the light-duty industry has expressed on 
    numerous occasions that their primary goal with respect to OBD is to 
    avoid MIL illumination because of the adverse way they expect their 
    customers to react. 114 Therefore, the presence of the OBD 
    system is expected not only to identify malfunctions and deterioration, 
    but also to minimize their occurrence.
    ---------------------------------------------------------------------------
    
        \114\ Stated more appropriately, their primary goal is to avoid 
    MIL illumination while still complying with the OBD requirements.
    ---------------------------------------------------------------------------
    
        Benefits such as those described above are not easily quantified, 
    but are critical to the success of our program as a whole. Without any 
    one of these compliance and in-use control measures, the benefits of 
    today's proposal could be diminished.
    
    VIII. What Are the Economic Impacts of the Proposal?
    
    A. 2004 Emission Standards for Heavy-Duty Diesel Engines
    
    1. Expected Technologies
        In assessing the economic impact of the 2004 emission standards 
    (including the standards finalized in 1997 and the standards proposed 
    today), EPA has used a current best judgement of the combination of 
    technologies that an engine manufacturer might use to meet the new 
    standards at an acceptable cost. Full details of EPA's cost analysis, 
    including information not presented here, can be found in the Draft
    
    [[Page 58527]]
    
    Regulatory Impact Analysis in the public docket. The costs presented 
    here were developed assuming that heavy-duty diesel engines would need 
    high-flow cooled EGR, combustion chamber optimization, improved 
    electronic fuel injection, and variable geometry turbochargers (except 
    for light heavy-duty engines). The costs also include testing costs 
    necessary to comply with the OBD and not-to-exceed requirements.
        The analysis also assumes that manufacturers would introduce the 
    improved electronic fuel injection systems and variable geometry 
    turbochargers for some engine models even without the more stringent 
    standard in 2004. Both of these technologies will provide significant 
    performance benefits both directly, and by allowing manufacturers to 
    reduce the use of injection timing retard to comply with the current 
    4.0 g/bhp-hr NOX standard. The Agency believes that 
    manufacturers may draw similar conclusions for using EGR on some of 
    these same engines, however, as a conservative assumption, EPA is 
    assuming that no EGR would be used to comply with the current 4.0 g/
    bhp-hr NOX standard. For this analysis EPA is also assuming 
    that only 50 percent of the costs for the improved electronic fuel 
    injection and the use of variable geometry turbochargers are 
    attributable to emission control. This is because EPA believes that 
    manufacturers would make these improvements for many of their engines, 
    even in the absence of these emission standards, to reduce fuel 
    consumption and improve engine performance, a similar approach was used 
    in the 1997 final rule. The docket for this rulemaking contains 
    additional information on this aspect of the Agency's cost analysis, 
    including a cost sensitivity analysis regarding the fifty percent 
    assumption.115 The Agency requests comment on this approach 
    which we intend to revisit in the final rule if appropriate. In 
    addition, Chapter 8, Section IV of the draft RIA for this proposal 
    contains an estimate of the impact this 50 percent assumption has on 
    the HD diesel cost-effectiveness. We recognize this 50 percent 
    assumption is not a precise approach to characterizing the costs which 
    could otherwise be attributed to our baseline assumptions. However, 
    developing a more precise estimate is problematic due to the complexity 
    of market demand as well as other uncertainties. Nevertheless, we 
    intend to consider developing a more precise estimate of the baseline 
    for the final rule analysis. In addition, it may be more appropriate to 
    consider performance benefits (improved fuel economy, drive-ability) 
    with the other secondary benefits rather than with costs, and we intend 
    to reconsider this issue for the final rule. EPA also requests comment 
    regarding how the early introduction of these technologies would affect 
    compliance costs. EPA also requests comment on whether variable 
    geometry turbochargers can serve the function of exhaust braking for 
    heavy heavy-duty engines, and what cost savings this would provide for 
    manufacturers.
    ---------------------------------------------------------------------------
    
        \115\ See EPA Air Docket A-98-32, ``Analysis of Costs and 
    Benefits of VGT and Improved Fuel Injection'', EPA Memorandum from 
    Charles Moulis.
    ---------------------------------------------------------------------------
    
    2. Per Engine Costs
        Estimated per engine cost increases are broken into purchase price 
    and total life-cycle operating costs. The incremental purchase price 
    for new engines is comprised of variable costs (for hardware and 
    assembly time) and fixed costs (for R&D, retooling, and certification). 
    Total operating costs include expected increases in maintenance. Cost 
    estimates based on these projected technology packages represent an 
    expected incremental cost of engines in the 2004 model year. Costs in 
    subsequent years would be reduced by several factors, as described 
    below. Separate projected costs were derived for engines used in three 
    service classes of heavy-duty diesel engines. All costs are presented 
    in 1995 dollars. Life-cycle costs have been discounted to the year of 
    sale.
        The costs of the technologies necessary for meeting the 2004 model 
    year standards are itemized in the Draft Regulatory Impact Analysis and 
    summarized in Table 8. These estimated costs are higher than those 
    estimated for the previous FRM because they include costs for variable 
    geometry turbochargers and full use of high-flow cooled EGR, as well as 
    small additional costs for the new OBD and compliance testing 
    requirements. For light heavy-duty vehicles, the cost of a new 2004 
    model year engine is estimated to increase by $428 (compared to the 
    previous estimate of $258). For medium heavy duty vehicles the purchase 
    price of a new engine is estimated to increase by $593 (compared to the 
    previous estimate of $397). Similarly, for heavy heavy-duty engines, 
    the initial purchase price is expected to increase by $707 (compared to 
    the previous estimate of $406).
        For the long term, EPA has identified various factors that would 
    cause cost impacts to decrease over time. First, the analysis 
    incorporates the expectation that manufacturers will apply ongoing 
    research to making emission controls more effective and less costly 
    over time. This expectation is similar to manufacturers' stated goal of 
    decreasing their reliance on catalysts to meet emission standards in 
    the future. Second, research in the costs of manufacturing has 
    consistently shown that as manufacturers gain experience in production, 
    they are able to apply innovations to simplify machining and assembly 
    operations, use lower cost materials, and reduce the number or 
    complexity of component parts. The analysis incorporates the effects of 
    this learning curve by projecting that the variable costs of producing 
    the low-emitting engines decreases by 20 percent starting with the 
    third year of production (2006 model year) and by reducing variable 
    costs again by 20 percent starting with the sixth year of production. 
    Chapter 4, Section III in the draft RIA for this proposal, as well as 
    Chapter V, Section IV of the final RIA for the 1997 final rulemaking 
    (see Docket A-95-27, Docket Item 35#V-B-01) contain additional 
    discussion of the application of this learning curve. The 2004 HD 
    diesel standards will require a fundamental change in technology for 
    the engine manufacturers. Considering this change, we believe the 
    learning curve concept is appropriate for this rulemaking. The Agency 
    requests comments and data regarding the application of this learning 
    curve approach to the heavy-duty diesel industry, including information 
    regarding any observed reduction in manufacturer costs for the past 
    application of similar technology changes for the heavy-duty on-highway 
    industry, or other technology changes to the diesel engine industry as 
    a whole. We also request comment on the learning curve theory. 
    Specifically, we request comment and supporting data regarding the 
    theory that manufacturing costs continues to decrease over time, 
    possibly ad infinitum, albeit at a slower rate as time progresses.
        Finally, since fixed costs (excluding in-use testing costs) are 
    assumed to be recovered over a five-year period, these costs are not 
    included in the analysis after the first five model years. Table 15 
    lists the projected schedule of costs for each category of vehicle over 
    time.
    
    [[Page 58528]]
    
    
    
                               Table 15.--Projected Diesel Engine Cost and Price Increases
                                        [1995 Dollars Discounted to Year of Sale]
    ----------------------------------------------------------------------------------------------------------------
                                                                                                        Life-cycle
                   Vehicle class                              Model year              Purchase price     operating
                                                                                          increase         cost
    ----------------------------------------------------------------------------------------------------------------
    Light heavy-duty...........................  2004...............................            $428              $7
                                                 2009 and later.....................             221               7
    Medium heavy-duty..........................  2004...............................             593              45
                                                 2009 and later.....................             252              45
    Heavy heavy-duty...........................  2004...............................             707              96
                                                 2009 and later.....................             324              96
    ----------------------------------------------------------------------------------------------------------------
    
    3. Aggregate Costs to Society
        The above analysis develops per-vehicle cost estimates for each 
    vehicle class. Using current data for the size and characteristics of 
    the heavy-duty vehicle fleet and making projections for the future, 
    these costs can be used to estimate the total cost to the nation for 
    the new emission standards in any year. The result of this analysis is 
    a projected total cost starting at $424 million (1995 dollars) in 2004. 
    Per-vehicle costs savings over time reduce projected costs to a minimum 
    value of $223 million in 2009, after which the growth in truck 
    population leads to an increase in costs to $285 million in 2020. Total 
    costs for these years are presented by vehicle class in Table 16. The 
    calculated total costs represent a combined estimate of fixed costs as 
    they are allocated over fleet sales, variable costs assessed at the 
    point of sale, and operating costs as they are incurred in each 
    calendar year. Future sales are projected for years beyond 1995, sales 
    are projected to increase each year by a constant value equal to 2 
    percent of the number of engines sold in 1995. EPA used a similar 2 
    percent growth estimate for the 1997 rulemaking for HD engines, we 
    request comment and supporting data which would refine this 
    estimate.116 EPA also requests comment and supporting data 
    on what impact, if any, costs associated with these new standards might 
    have on the sales rate of HD diesel engines in the future. In addition, 
    EPA requests comment on whether or not a 2 percent per year increase 
    specifically for the light-heavy heavy duty diesel market is an 
    appropriate estimate for future growth, considering the recent trend of 
    increasing sales of sport-utility vehicles weighing over 8,500 pounds.
    ---------------------------------------------------------------------------
    
        \116\ ``Draft Regulatory Impact Analysis: Control of Emissions 
    of Air Pollution from Highway Heavy-Duty Engines'', Chapter 7, 
    Section II, Available in EPA Air Docket A-95-27, Item # III-B-01
    
       Table 16.--Estimated Annual Costs for Improved Heavy-Duty Vehicles
                             [Millions of dollars])
    ------------------------------------------------------------------------
                 Category                  2004         2009         2020
    ------------------------------------------------------------------------
    Light heavy-duty.................          142           81           95
    Medium heavy-duty................          198           46           59
    Heavy heavy-duty.................          185           97          130
                                      --------------------------------------
        Total........................          424          159           97
    ------------------------------------------------------------------------
    
    B. 2004 Emission Standards for Heavy-Duty Otto-Cycle Vehicles and 
    Engines
    
        This section contains a summary of the Agency's comprehensive 
    analyses of the economic impacts of today's proposed regulations for 
    heavy-duty Otto-cycle vehicles and engines. The following separate 
    factors are analyzed: (1) The technologies expected to be used and 
    their projected rates of application; (2) the costs of these technology 
    packages incremental to today's vehicle designs (presented on a per-
    vehicle basis separately for chassis and engine certified 
    configurations) and; (3) the aggregate cost to society of the proposed 
    requirements. More information on these analyses can be found in the 
    Regulatory Impact Analysis contained in the docket for this rule.
    1. Expected Technologies
        The various technologies that could be used to comply with today's 
    proposed regulations were previously discussed in the section on 
    technological feasibility. In developing costs for the associated 
    technologies EPA looked at the current technology used on HDVs and 
    compared that to the technology expected to be used to meet the 
    proposed regulations. The incremental costs difference was then 
    calculated based on the differences between the current (i.e., 
    baseline) technology packages and those expected to be used in 2004. 
    Table 17 shows both the current baseline and expected technologies for 
    complete vehicles. Table 18 shows the current baseline and expected 
    technologies for the engine-based standards. These tables only show the 
    technologies which are expected to change in some way from their 
    current design or be applied to different percentages of the fleet than 
    they are currently. Technologies such as sequential multi-port fuel 
    injection and EGR, while important to meeting the proposed standards, 
    are not expected to be fundamentally changed in their design, or be 
    utilized in different percentages of the fleet than they currently are. 
    Thus, such technologies are not included in these tables. However, in 
    some cases the cost of optimizing such technologies is included in the 
    cost estimates.
    
    [[Page 58529]]
    
    
    
                   Table 17.--Current and Expected Technology Packages for Complete Vehicle Standards
    ----------------------------------------------------------------------------------------------------------------
              Technology                     Baseline Federal                          Estimated 2004
    ----------------------------------------------------------------------------------------------------------------
    Catalysts.....................  60% single underfloor               13% single enhanced underfloor.
                                    40% dual underfloor                 50% dual enhanced underfloor.
                                                                        37% dual close-coupled and dual enhanced
                                                                         underfloor.
    Oxygen sensors................  70% dual heated                     13% dual heated.
                                    10% triple heated                   87% quadruple heated.
                                    20% quadruple heated
    ECM...........................  50% 32 bit computers                100% 32 bit computers.
                                    50% 16 bit computers
    Adaptive learning.............  0%                                  80%
    Individual cylinder A/F         0%                                  10%
     control.
    Leak free exhaust.............  90%                                 100%
    Insulated exhaust.............  0%                                  40%
    Secondary air injection.......  20%                                 30%
    ORVR..........................  0%                                  100% A
    ----------------------------------------------------------------------------------------------------------------
    A ORVR is only proposed to apply to complete vehicles 10,000 lbs GVWR and under, and is proposed to be phased in
      over three years, with 100% application to those vehicles in 2006.
    
    
                     Table 18.--Current and Expected Technology Packages for Engine-Based Standards
    ----------------------------------------------------------------------------------------------------------------
              Technology                     Baseline Federal                          Estimated 2004
    ----------------------------------------------------------------------------------------------------------------
    Catalysts.....................  60% single underfloor               13% single enhanced underfloor.
                                    40% dual underfloor                 87% dual enhanced underfloor.
    Oxygen sensors A..............  70% dual heated                     13% triple heated.
                                    10% triple heated                   87% quadruple heated.
                                    20% four heated
    ECM...........................  50% 32 bit computers                100% 32 bit computers.
                                    50% 16 bit computers
    Improved fuel control.........  50%                                 100%
    Secondary air injection.......  20%                                 50%
    ----------------------------------------------------------------------------------------------------------------
    A The estimated breakdown for 2004 reflects OBD requirements for all HDGEs. However, at this time OBD is only
      proposed to apply to HDGEs under 14,000 lbs GVWR (approximately 60 percent of HDGEs).
    
    2. Per Vehicle Costs
        The costs of the projected technologies presented in the previous 
    section are itemized and discussed in detail in the RIA. On a per-
    vehicle basis these costs are summarized in Table 14. They are 
    presented in two components: purchase price and operating cost. The 
    operating costs only apply to ORVR-equipped vehicles and include the 
    combined effects of a small fuel economy penalty due to the increased 
    weight of the ORVR hardware, and a larger fuel economy benefit 
    resulting from the vehicle being able to utilize fuel vapors that would 
    otherwise escape to the atmosphere in the absence of ORVR.
        EPA believes that the manufacturers will recover the fixed costs 
    associated with research and development, tooling and certification 
    over the first five years of production. Thus, these fixed costs are 
    not included in the analysis after the first five model years. We 
    request comment on whether a five-years amortization period is a 
    reasonable estimate. The fixed costs associated with the proposed in-
    use testing programs will continue indefinitely. The projected per 
    vehicle costs impacts are summarized in Table 19.
    
                               Table 19.--Projected HDV Price and Operating Cost Increases
    ----------------------------------------------------------------------------------------------------------------
                                                                                              Purchase     Lifetime
                         Class                                    Model year                   price      operating
                                                                                              increase       cost
    ----------------------------------------------------------------------------------------------------------------
    Complete Vehicles.............................  2004 a................................         $302          -$6
                                                    2009 and later........................          297           -6
    Engines.......................................  2004 b................................          287
                                                    2009 and later........................          248
                                                                                            ...........
    ----------------------------------------------------------------------------------------------------------------
    a This cost includes both ORVR and OBD, which are phased inbeginning with the 2004 model year, but which are not
      proposed to be required on all complete vehicles until the 2006 model year for ORVR and the 2007 model year
      for OBD.
    b This cost includes an OBD hardware cost. OBD requirements are phased in beginning with the 2004 model year,
      but are not proposed to be required on all engines under 14,000 lbs GVWR until the 2007 model year.
    
    3. Aggregate Cost to Society
        In addition to the per vehicle costs just described, EPA also 
    calculated the aggregate cost to society. This was done by combining 
    the per vehicle costs with assumed future sales of HDVs. The results of 
    this analysis are summarized in Table 20. The recovery of most fixed 
    costs results in slightly reduced costs beginning in 2009, after which 
    costs begin to rise in accordance with projected increased sales. The 
    aggregate
    
    [[Page 58530]]
    
    costs represent a combined estimate of the fixed costs for research and 
    development, tolling and certification as they are allocated over the 
    first five years of sales, variable costs assessed at the point of 
    sale, and operating costs (primarily in the form of fuel cost savings) 
    for ORVR-equipped vehicles (calculated to net present value and applied 
    at the point of sale). Future sales are projected for years beyond 
    1996, sales are projected to increase each year by a constant value 
    equal to 2 percent of the number of engines sold in 1996. EPA used a 
    similar 2 percent growth estimate for the 1997 rulemaking for HD 
    engines, we request comment and supporting data which would refine this 
    estimate. 117 EPA requests comment and supporting data on 
    what impact, if any, costs associated with these proposed standards 
    might have on the sales rate of HD Otto-cycle engines in the future. We 
    also request comment on whether or not a 2 percent per year increase 
    specifically for the light-heavy heavy duty Otto-cycle market is an 
    appropriate estimate for future growth, considering the recent trend of 
    increasing sales of sport-utility vehicles weighing over 8,500 pounds 
    GVWR.
    ---------------------------------------------------------------------------
    
        \117\ ``Draft Regulatory Impact Analysis: Control of Emissions 
    of Air Pollution from Highway Heavy-Duty Engines'', Chapter 7, 
    Section II, Available in EPA Air Docket A-95-27, Item # III-B-01.
    
      Table 20.--Aggregate Cost to Society of the Proposed Heavy-Duty Otto-
                               Cycle Requirements
    ------------------------------------------------------------------------
                                                                   Cost
                              Year                              ($million)
    ------------------------------------------------------------------------
    2004....................................................            $124
    2009....................................................             151
    2020....................................................             177
    ------------------------------------------------------------------------
    
    IX. What is the Cost-Effectiveness of the Proposal?
    
    A. 2004 Emission Standards for Heavy-Duty Diesel Engines
    
        EPA has estimated the per-vehicle cost-effectiveness (i.e., the 
    cost per ton of emission reduction) of the model year 2004 
    NMHC+NOX standards over the typical lifetime of heavy-duty 
    diesel vehicles covered by today's rule. The RIA contains a more 
    detailed discussion of the cost-effectiveness analyses. As described 
    above in the cost section, the cost of complying with the standards 
    will vary by model year. Therefore, the cost-effectiveness will also 
    vary from model year to model year. For comparison purposes, the 
    discounted costs, emission reductions and cost-effectiveness of the 
    standards are shown in Table 21 for the same model years discussed 
    above in the cost section. The cost-effectiveness results contained in 
    Table 21 present the range in cost-effectiveness resulting from the two 
    cost-effectiveness scenarios described above.
    
      Table 21.--Discounted Per-Vehicle Costs, Emission Reductions and Cost-Effectiveness of the NMHC+NOX Standard
    ----------------------------------------------------------------------------------------------------------------
                                                                      Discounted lifetime reductions    Discounted
                                                        Discounted                (tons)                   cost-
             Vehicle class             Model year        lifecycle   --------------------------------  effectiveness
                                                           costs            NOX            NMHC           ($/ton)
    ----------------------------------------------------------------------------------------------------------------
    Light Heavy-Duty Diesel         2004............            $435           0.310           0.004           $1380
     vehicles.                      2009 and later..             228                                             725
    Medium Heavy-Duty Diesel        2004............             638           0.872           0.012             720
     vehicles.                      2009 and later..             296                                             335
    Heavy-Duty Diesel Vehicles....  2004............             803           3.401           0.048             230
                                    2009 and later..             420                                             120
    Overall (For All Heavy-Duty...  2004............  ..............  ..............  ..............             400
                                    2009 and later                                                               200
    ----------------------------------------------------------------------------------------------------------------
    
        In addition to the benefits of reducing ozone within and 
    transported into urban ozone nonattainment areas, the NOX 
    reductions from the new engine standards are expected to have 
    beneficial impacts with respect to crop damage, secondary particulate, 
    acid deposition, eutrophication, visibility, and forest health. Due to 
    the difficulty in accurately quantifying the monetary value of these 
    societal benefits, the cost-effectiveness values presented do not 
    assign any numerical value to these additional benefits. EPA requests 
    comments on all aspects of the cost-effectiveness analysis for heavy-
    duty diesel engines.
    
    B. 2004 Emission Standards for Heavy-Duty Otto-Cycle Vehicles and 
    Engines
    
        EPA has estimated the per-vehicle cost-effectiveness (i.e., the 
    cost per ton of emission reduction) of the proposed NMHC plus 
    NOX emission standards over the lifetime of typical heavy-
    duty gasoline vehicles. The RIA contains a more detailed discussion of 
    the cost-effectiveness analysis. EPA requests comments on all aspects 
    of the cost-effectiveness analysis for heavy-duty gasoline engines and 
    vehicles. EPA plans to conduct cost-effectiveness analyses of 
    alternatives to the proposed Otto-cycle standards in the final rule 
    based on comments received as appropriate.
        As described above, the cost of complying with the proposed 
    standards will vary by vehicle category (i.e., a complete Class 2b 
    heavy-duty gasoline vehicle, a complete Class 3 heavy-duty gasoline 
    vehicle, or an incomplete heavy-duty gasoline vehicle) and model year. 
    Therefore, the lifetime cost-effectiveness of the proposed standards 
    will vary by model year. For comparison purposes, the discounted 
    lifetime costs, emission reductions (in short tons), and cost-
    effectiveness of the proposed standards are shown in Table 22 for the 
    same model years discussed in the Economic Impact section.
    
    [[Page 58531]]
    
    
    
                Table 22.--Cost-Effectiveness of the Proposed Standards for Heavy-Duty Gasoline Vehicles
    ----------------------------------------------------------------------------------------------------------------
                                                                                        Discounted
                                                                                         lifetime       Discounted
                 HDGV category                 Year of production       Discounted       NMHC+NOX     lifetime cost-
                                                                       lifetime cost     Reduction     effectiveness
                                                                                          (tons)          ($/ton)
    ----------------------------------------------------------------------------------------------------------------
    Class 2B Complete.....................  1.......................            $296       0.56 tons            $530
                                            6 and later.............             291                             520
    Class 3 Complete......................  1.......................             296            0.55             530
                                            6 and later.............             291                             520
    Incomplete HDGV.......................  1.......................             287            0.61             480
                                            6 and later.............             248                             410
    All HDGVs.............................  1.......................             294            0.57             520
                                            6 and later.............             281                             490
    ----------------------------------------------------------------------------------------------------------------
    
        EPA has also estimated the cost-effectiveness of the proposed ORVR 
    for Class 2B heavy-duty gasoline vehicles. Table 23 contains the 
    discounted lifetime cost-effectiveness of the proposed ORVR 
    requirements.
    
      Table 23.--Discounted, Lifetime Cost-Effectiveness of the Proposed ORVR Requirements for Class 2B Heavy-Duty
                                                    Gasoline Vehicles
    ----------------------------------------------------------------------------------------------------------------
                                                                                        Discounted
                                                                                      lifetime  NMHC    Discounted
                           Year of production                           Discounted     NOX  Emission  lifetime cost-
                                                                       lifetime cost    Reductions     effectiveness
                                                                                          (tons)          ($/ton)
    ----------------------------------------------------------------------------------------------------------------
    1...............................................................              $5           0.035            $130
    6...............................................................               2           0.035              50
    ----------------------------------------------------------------------------------------------------------------
    
        In addition to the benefits of reducing ozone within and 
    transported into urban ozone nonattainment areas, the NOX 
    emission reductions from the proposed heavy-duty gasoline vehicle and 
    engine standards are expected to have beneficial impacts with respect 
    to crop damage, secondary particulate, acid deposition, eutrophication, 
    visibility, and forest health. The cost-effectiveness values presented 
    above do not assign any numerical value to these additional benefits. 
    Based on existing studies that have estimated the value of such 
    benefits in the past, EPA believes that the actual monetary value of 
    the multiple environmental and public health benefits that would be 
    produced by the NOX reductions under this proposal will be 
    greater than the estimated compliance costs.
    
    X. Are Future Reductions in HD Emissions Possible?
    
    A. Potential Future Standards for Heavy-Duty Diesel Vehicles and 
    Engines
    
    1. Possible Future Reductions in Heavy-Duty Diesel NOX and 
    NMHC
        As discussed in section II (What is the Environmental Need for this 
    Proposal?), heavy-duty vehicles are a major source of national 
    NOX emissions and a source of NMHC emissions in the U.S., 
    both of which are precursors for tropospheric ozone. Despite the 
    important reductions in NOX and NMHC which will occur from 
    HD diesel 2004 standards, it is possible that additional reductions in 
    NOX and NMHC from heavy-duty diesels will be necessary in 
    the future in order for air quality goals to be achieved across the 
    country.
        The Agency received written comments from local and state air 
    quality agencies and from several environmental organizations in 
    response to the 2004 NMHC+NOX proposal in the June 27,1996 
    NPRM urging the Agency to finalize more stringent NOX 
    standards for the 2004 model year, or to consider standards resulting 
    in the largest NOX reduction possible from HD engines. These 
    organizations cited future air quality concerns which would require 
    additional NOX and NMHC reductions from HD engines and 
    vehicles in the future. 116 Though the Agency did not 
    finalize more stringent standards, the stakeholders' air quality 
    concerns remain.
    ---------------------------------------------------------------------------
    
        \116\ See EPA Air Docket A-95-27, Docket Item's IV-D-08, IV-D-
    15, and IV-D-16.
    ---------------------------------------------------------------------------
    
        The HD SOP signed in July, 1995 included a discussion of future 
    research goals for further reductions in NOX and PM from on-
    highway HD diesel engines. As described in the SOP, these research 
    goals suggested a target value of 1.0 g/bhp-hr NOX. In 
    addition, the Agency is aware that the European Union is currently 
    considering a range of HD engine NOX levels for potential 
    Euro IV emission limits in 2005. At present, the European Union is 
    considering Euro IV NOX limits ranging from 1.5 to 2.6 g/
    bhp-hr.
        The RIA for this proposal includes a discussion of several 
    promising emission control technologies which may offer the potential 
    for NOX reductions down to, or even beyond the research 
    goals identified in the SOP. These emission control technologies 
    include lean NOX adsorption catalysts and urea-based 
    selective catalytic reduction systems (SCR). Each of these technologies 
    have demonstrated significant NOX reduction capability (up 
    to 75 percent and some projections range up to 90 percent). However, 
    each technology is still under development, and each has its own set of 
    potential difficulties for wide-spread HD application in the U.S. For 
    example, current generation NOX adsorber catalysts have been 
    shown to be susceptible to fuel sulfur poisoning, and urea-based SCR 
    systems would likely require a national distribution system for urea. 
    In addition, costs, durability, tamper resistance, and in-use emission 
    performance associated with each technology have not been well defined. 
    For this reason, EPA does not believe more stringent standards based on 
    such
    
    [[Page 58532]]
    
    technology is achievable for the 2004 model year, taking into 
    consideration cost, energy, and safety factors. However, such more 
    stringent standards may be appropriate in later model years, once these 
    technologies are further developed. Furthermore improvement in diesel 
    fuel quality, particularly lower sulfur levels, would likely be needed 
    to enable these technologies. These issues were the subject of the 
    Advance Notice of Proposed Rulemaking on ``Control of Diesel Fuel 
    Quality'' that EPA published in May (64 FR 26142, May 13, 1999).
        The Agency requests comment on the need for future reductions in 
    NOX and NMHC emissions from HD diesel engines, the time 
    frame in which future standards should be considered, and what 
    standards should be considered. In addition, the Agency requests 
    comment and supporting data, including emission testing data, 
    durability data, cost data, and other relevant information, on what 
    technologies may be available for meeting more stringent HD diesel 
    NOX and/or NMHC levels. The Agency requests comment 
    specifically on the feasibility of these advanced aftertreatment 
    technologies to attain reductions cited above in the 2007 time frame. 
    Finally, the Agency requests comment on what role, if any, diesel fuel 
    quality plays in enabling additional reductions from HD diesel engines.
    2. Potential Future Reductions in Heavy-Duty Diesel Engine PM
        Section II of this preamble (``What is the Environmental Need for 
    this Proposal?''), includes: a discussion of the adverse health 
    consequences associated with particulate matter; a discussion of the 
    contribution of HD diesel engine PM to national emission inventories; a 
    discussion of several recent source apportionment studies for PM; and a 
    discussion of the negative health impacts associated specifically with 
    diesel exhaust PM, including the potential carcinogenicity of diesel 
    PM. The Agency requests comment on whether additional control of HD 
    diesel PM beyond the current 0.1g/bhp-hr level may be needed in the 
    future to protect the public's health.
        EPA received written comments from several state and local air 
    quality agencies as well as several environmental organizations 
    regarding the HDDE PM standard in response to the June 27, 1996 NPRM 
    for on-highway heavy-duty engines.119 In general, these 
    organizations felt that maintaining the current PM standard of 0.1 g/
    bhp-hr in model year 2004 was not adequate for protection of human 
    health. The commentors stressed the particularly harmful nature of 
    diesel PM, and they believed technology was available to justify a 
    lower PM standard in 2004.
    ---------------------------------------------------------------------------
    
        \119\ See EPA Air Docket A-95-27, Item's IV-D-03, IV-D-08, IV-D-
    15, IV-D-19
    ---------------------------------------------------------------------------
    
        The HD SOP signed in 1995 included a discussion of a HD diesel PM 
    research goal of 0.05 g/bhp-hr. The Agency is also aware that the 
    European Union is currently considering a range of PM levels for 
    potential Euro IV emission limits for HD diesel in 2005. At present, 
    the European Union is considering Euro IV PM limits ranging from 0.015 
    to 0.04 g/bhp-hr.
        The RIA for this proposal includes a discussion of the current 
    state of the art for HDDE control technologies for both NOX 
    and PM control, as well as the technologies the Agency expects 
    manufacturers to use to meet the 2004 NMHC+NOX standards. 
    The inverse relationship between in-cylinder 120 
    NOX and PM emissions is a well documented phenomenon; in-
    cylinder modifications which result in lower NOX tend to 
    result in an increase in PM. As discussed in the RIA, there are 
    technologies available to minimize this inverse relationship, but there 
    are limits to what can be done in-cylinder. Data available to date 
    indicate the 2004 NMHC+NOX standard and the 0.1g/hp-hr PM 
    standard is near the limit of what can be done utilizing only known in-
    cylinder technologies (including EGR as an in-cylinder control 
    technology). However, a number of promising aftertreatment technologies 
    may be available for wide spread HD application which could allow 
    manufacturers to meet a PM standard lower than 0.1g/bhp-hr while not 
    negatively impacting NOX emissions. As discussed in the RIA, 
    these technologies include diesel oxidation catalysts (DOCs) and 
    particulate traps. DOCs have the potential to offer modest levels of PM 
    control (approximately 10-30 percent), and the level of control is 
    dependent on the amount of volatile organic component present in the 
    engine's exhaust PM. Particulate traps have the potential to achieve 
    large reductions in exhaust PM, approaching 80-90 percent reduction. 
    However, dependable regeneration techniques, in-use durability and 
    reasonable cost are some of the important issues which still need to be 
    addressed. In addition, NOX control technologies such as 
    NOX adsorber catalysts and SCR systems could potentially 
    allow manufacturers to favor the in-cylinder trade-offs between 
    NOX and PM for stringent in-cylinder PM control, and rely on 
    aftertreatment to provide NOX control.
    ---------------------------------------------------------------------------
    
        \120\ In-cylinder-an engineering term which refers to engine 
    design changes which affect emissions in the combustion chamber, as 
    compared to aftertreatment device.
    ---------------------------------------------------------------------------
    
        As discussed in section IV.B (``Are Changes in Diesel Fuel Quality 
    Necessary to Meet the 2004 Standards?''), and in more detail in the RIA 
    for this proposal, diesel fuel quality, and in particular, diesel fuel 
    sulfur level, can play an important role in enabling certain PM and 
    NOX control technologies. Some DOCs and continuously 
    regenerable PM traps, as well as current generation lean NOX 
    adsorber catalysts can be poisoned by high sulfur levels. Some versions 
    of passively regenerated catalyzed traps and DOCs are not poisoned at 
    current fuel sulfur levels, but can produce large amounts of sulfate PM 
    at current sulfur levels, decreasing their effectiveness. Given this 
    information, EPA has not included more stringent PM standards for the 
    2004 model year or later in today's proposal. However, the Agency 
    requests comment and supporting data on the air quality need, technical 
    feasibility, and costs associated with implementing more stringent PM 
    standards as early as the 2004 model year. The Agency requests comment 
    specifically on the feasibility of the application of PM traps to 
    achieve up to 90 percent reductions from today's levels. In addition, 
    the Agency requests comment on the range of PM limits currently being 
    considered by the European Union, namely 0.015 to 0.04 g/hp-hr. 
    Finally, the Agency requests comment on what role, if any, diesel fuel 
    quality plays in meeting a more stringent PM standard.
    3. Potential Structure of Future Diesel Emission Standards
        EPA regulations for heavy-duty vehicles (i.e., vehicles with a GVWR 
    greater than 8500 pounds) have historically been ``fuel-neutral,'' 
    meaning that the same standard applied to both gasoline and diesel 
    vehicles. Today's proposal moves away from that historical approach 
    because we believe there is a case to be made that heavy-duty Otto-
    cycle engines may be capable of significantly lower emissions than 
    heavy-duty diesel engines given current technology and fuels. In 
    addition to proposing tighter standards for heavy-duty Otto-cycle 
    engines, however, we have also proposed to change the fundamental 
    structure of the compliance program by requiring complete heavy-duty 
    Otto-cycle vehicles up to 14,000 pounds GVWR to be certified to 
    chassis-based standards, rather than the engine-based standards used 
    historically for the entire heavy-duty category. We request comment on
    
    [[Page 58533]]
    
    these changes to the structure of the EPA emission control program for 
    heavy-duty vehicles and engines and on the desirability of fuel-neutral 
    standards.
        There are several structural options that we are likely to consider 
    when we propose future tighter standards for heavy-duty vehicles. 
    Having already taken the step of proposing to move complete heavy-duty 
    Otto-cycle vehicles up to 14,000 pounds GVWR into a chassis-based 
    program with chassis-based standards, we request comment on whether we 
    should consider requiring complete diesel vehicles in the same weight 
    range to meet chassis-based standards, and if so, what appropriate 
    standards might be. Alternatively, the standards could be structured 
    such that complete diesel vehicles up to 10,000 pounds GVWR might be 
    subject to chassis-based standards, while those between 10,000 and 
    14,000 pounds GVWR could be subject to engine-based standards, as they 
    are today. We request comment on limiting chassis-based standards to 
    diesel vehicles in this manner.
        In addition to the type of standards (vehicle- or engine-based) 
    that we might consider in the future for diesel vehicles up to 14,000 
    pounds GVWR, another key issue is the level of the standards relative 
    to those that apply to Otto-cycle vehicles. This issue is equally 
    applicable to heavy-duty vehicles above and below 14,000 pounds GVWR. 
    In addition to requesting comment on a chassis-based program for some 
    heavy-duty diesel vehicles, we request comment on applying equivalent 
    chassis-based standards to diesel and Otto-cycle vehicles, and on the 
    role that diesel fuel quality might play in meeting such standards. In 
    the context of possible future changes to diesel fuel quality, we 
    believe that it may indeed be appropriate and technically feasible to 
    require some heavy-duty diesel vehicles up to 14,000 pounds GVWR to be 
    subject to the same standards as their Otto-cycle counterparts. In 
    addition to the specific issues raised above, we request comment on 
    general issues of fuel neutrality and structure of emission standards 
    as they might apply to heavy-duty vehicles.
    
    B. Potential Future Standards for Heavy-Duty Otto-Cycle Vehicles
    
    1. Exhaust Emission Standards
        California has adopted a new generation of standards for light-duty 
    and medium-duty vehicles, referred to as the LEV-II standards. The new 
    California standards for vehicles above 8,500 pounds GVWR are shown in 
    Table 24. The light-duty standards are phased in beginning in 2004 
    according to an established phase-in schedule. For heavy-duty vehicles, 
    there is no set phase-in schedule. California requires that 100 percent 
    of HD vehicles comply with the standards shown in Table 24 beginning in 
    MY 2007. While the focus of today's notice is on 2004 standards, EPA is 
    exploring the appropriateness of adopting standards equivalent to those 
    in Table 24 in a future rulemaking. Doing so would allow federal and 
    California standards for heavy-duty Otto-cycle vehicles to continue to 
    be harmonized beyond the 2007 model year. Thus, today EPA requests 
    comment on the feasibility of, cost-effectiveness, and the need for 
    standards such as those shown in Table 24, and on the issues noted 
    above regarding the fuel-neutrality of future emission standards and 
    the possibility of applying equivalent standards to diesel and Otto-
    cycle vehicles. In addition, any future rulemaking action would likely 
    assess SFTP standards that would apply in conjunction with FTP 
    standards. EPA requests comment on the application of SFTP standards to 
    heavy-duty Otto-cycle vehicles under 14,000 pounds GVWR.
    
       Table 24.--California LEV II Full-Life Emission Standards for 2007 and Later Model Year Vehicles over 8,500
                                                       Pounds GVWR
                                                    [Grams per mile]
    ----------------------------------------------------------------------------------------------------------------
                                                                        Nonmethane       Oxides of        Carbon
                     Vehicle weight category (GVWR)                     organic gas      nitrogen        monoxide
    ----------------------------------------------------------------------------------------------------------------
    8,500--10,000 lbs...............................................           0.195             0.2             6.4
    10,001--14,000 lbs..............................................           0.23              0.4             7.3
    ----------------------------------------------------------------------------------------------------------------
    
    2. Evaporative standards
        EPA is not proposing any changes to the Otto-cycle evaporative 
    numerical emission standards in today's notice. However, the 1998 
    certification results show that, in general, heavy-duty Otto-cycle 
    vehicles are meeting the current evaporative standards with a 
    substantial safety margin. EPA is concerned that, in the absence of 
    more stringent evaporative standards, manufacturers will reduce the 
    safety margins they currently use in order to cut costs, resulting in 
    rising evaporative emissions. The 1999 certification results appear to 
    show this beginning to happen.
        The California Air Resources Board recently proposed and adopted 
    new evaporative emission standards applicable to all categories of Otto 
    cycle vehicles and engines in the context of the LEV II standards 
    discussed in the previous section. Those new evaporative standards call 
    for dramatic reductions in the levels of emissions for both the three 
    day diurnal plus hot soak and the supplemental two day diurnal plus hot 
    soak measurements. In response to CARB's recent LEV II proposal, the 
    vehicle manufacturers presented CARB with an alternate proposal for 
    revised evaporative emission standards.121 These proposed 
    levels, while not as stringent as the standards CARB proposed and 
    subsequently adopted, are significantly more stringent than the current 
    federal standards. However, most 1998 model year HDVs were certified at 
    levels below the manufacturers proposed standards, including 
    comfortable safety margins. The current federal standards, CARB's new 
    standards, and the manufacturers' proposed standards are all presented 
    in the Table 25.
    ---------------------------------------------------------------------------
    
        \121\ A copy of the handouts presented to CARB on October 8, 
    1998 are in the docket for this rule.
    
    [[Page 58534]]
    
    
    
            Table 25.--``Existing Federal and CARB, and Manufacturer-Proposed Evaporative Emission Standards
    ----------------------------------------------------------------------------------------------------------------
                                                           Three day diurnal plus hot     Two day diurnal plus hot
                                                                  soak (g/test)                 soak (g/test)
    ----------------------------------------------------------------------------------------------------------------
    8,500 lbs <>14,000 lbs:
        Current federal standards.......................                           3.0                           3.5
        New CARB standards .............................                           1.0                          1.25
        Manufacturer-proposed standards.................                           1.5                           1.7
    GVWR  14,000 lbs:                          ............................  ............................
    Current federal standards                                                      4.0                           4.5
    New CARB standards A                                                           1.0                          1.25
    Manufacturer-proposed standards A                                              1.5                         2.25
    ----------------------------------------------------------------------------------------------------------------
    A Note--These standards would be phased in as a % of sales at a rate of 25, 50, 75, and 100 percent beginning
      with the 2004 model year.
    
        EPA requests comment whether more stringent evaporative emission 
    standards for HDVs may be appropriate, especially considering the 
    current certification levels. The Agency also requests comment on our 
    belief that the manufacturer-proposed standards are feasible at little 
    or no cost. EPA also requests comment on the feasibility and cost of 
    other more stringent standards than those proposed by the 
    manufacturers, including the standards recently adopted by CARB.
    
    XI. What Are the Opportunities for Public Participation?
    
    A. Comments and the Public Docket
    
        EPA today opens a formal comment period for this NPRM and will 
    accept comments through 30 days after the date of the public hearing. 
    The Agency encourages all parties that have an interest in this 
    proposal to offer comment on various topics. Of particular interest to 
    the Agency are detailed comments in the following areas:
         The technical feasibility, cost-effectiveness, and 
    appropriateness under the Clean Air Act of the 2004 NMHC+NOX 
    emission standard for heavy-duty diesel engines.
         The feasibility of the 2004 NMHC+NOX standards 
    with current diesel fuel, and the specific issue of full useful life 
    durability and the impact of sulfuric acid formation on EGR systems.
         The technical feasibility, cost-effectiveness, and 
    appropriateness under the Clean Air Act of the proposed 1.0 g/bhp-hr 
    NMHC+NOX standard for heavy-duty Otto-cycle engines.
         The appropriateness and design of the proposed ABT program 
    for heavy-duty Otto-cycle engines.
         The technical feasibility, cost-effectiveness, and 
    appropriateness of the proposed supplemental tests and associated 
    emission limits for diesel-cycle heavy-duty engines.
         The technical feasibility, cost-effectiveness, and 
    appropriateness of the proposed chassis-based emission standards for 
    Otto-cycle heavy-duty vehicles under 14,000 pounds GVWR.
         The proposed ABT program for Otto-cycle heavy-duty 
    vehicles under 14,000 pounds GVWR.
         The technical feasibility, cost-effectiveness, and 
    appropriateness of the proposed ORVR requirements for complete Otto-
    cycle heavy-duty vehicles under 10,000 pounds GVWR.
         The technical feasibility, cost-effectiveness, and 
    appropriateness of the proposed OBD requirements for heavy-duty engines 
    and vehicles at or below 14,000 lbs GVWR.
         Fuel neutrality of emission standards for diesel and Otto-
    cycle heavy-duty vehicles and engines.
        Although the Agency specifically requests comments on the 
    identified topics, the Agency welcomes comments on any aspect of the 
    proposal. The most useful comments are those supported by appropriate 
    and detailed rationales, data, and analyses. The Agency also encourages 
    commenters that disagree with elements of the proposal to suggest and 
    analyze alternate approaches to meeting the air quality goals of this 
    proposal. All comments, with the exception of proprietary information, 
    should be directed to the EPA Air Docket Section, Docket No. A-98-32 
    before the date specified above. Information related to this rulemaking 
    is also found in dockets A-95-27 and A-97-10.
        Commenters who wish to submit proprietary information for 
    consideration should clearly separate such information from other 
    comments by (1) labeling proprietary information ``Confidential 
    Business Information'' and (2) sending proprietary information directly 
    to the contact person listed (see FOR FURTHER INFORMATION CONTACT) and 
    not to the public docket. This will help ensure that proprietary 
    information is not inadvertently placed in the docket. If a commenter 
    wants EPA to use a submission of confidential information as part of 
    the basis for the final rule, then a non-confidential version of the 
    document that summarizes the key data or information should be sent to 
    the docket. Any information or data that constitutes, in whole or in 
    part, a basis of EPA's regulatory actions will be made public.
        Information covered by a claim of confidentiality will be disclosed 
    by EPA only to the extent allowed and in accordance with the procedures 
    set forth in 40 CFR part 2. If no claim of confidentiality accompanies 
    the submission when it is received by EPA, it will be made available to 
    the public without further notice to the commenter.
    
    B. Public Hearing
    
        The Agency will hold a public hearing as noted in the DATES section 
    above. Any person desiring to present testimony at the public hearing 
    is asked to notify the contact person listed above at least one week 
    prior to the date of the hearing. This notification should include an 
    estimate of the time required for the presentation of the testimony and 
    any need for audio/visual equipment. EPA suggests that sufficient 
    copies of the statement or material to be presented be available to the 
    audience. In addition, it is helpful if the contact person receives a 
    copy of the testimony or material prior to the hearing.
        The hearing will be conducted informally, and technical rules of 
    evidence will not apply. A sign-up sheet will be available at the 
    hearing for scheduling the order of testimony. A written transcript of 
    the hearing will be prepared. The official record of the hearing will 
    be kept open for 30 days after the hearing to allow submittal of 
    supplementary information.
    
    XII. What Administrative Requirements Apply to This Proposal?
    
    A. Compliance With Executive Order 12866
    
        Under Executive Order 12866 (58 FR 51735), the Agency must 
    determine whether this regulatory action is ``significant'' and 
    therefore subject to review by the Office of Management and
    
    [[Page 58535]]
    
    Budget (OMB) and the requirements of the Executive Order. The Order 
    defines a ``significant regulatory action'' as one that is likely to 
    result in a rule that may:
        (1) Have an annual effect on the economy of $100 million or more or 
    adversely affect in a material way the economy, a sector of the 
    economy, productivity, competition, jobs, the environment, public 
    health or safety, or State, local, or tribal governments or 
    communities;
        (2) Create a serious inconsistency or otherwise interfere with an 
    action taken or planned by another agency;
        (3) Materially alter the budgetary impact of entitlements, grants, 
    user fees, or loan programs or the rights and obligations of recipients 
    thereof; or
        (4) raise novel legal or policy issues arising out of legal 
    mandates, the President's priorities, or the principles set forth in 
    the Executive Order.
        Pursuant to the terms of Executive Order 12866, EPA has determined 
    that this proposed rule is a ``significant regulatory action'' because 
    the proposed regulatory provisions, if implemented, would have an 
    annual effect on the economy in excess of $100 million. A Regulatory 
    Impact Analysis has been prepared and is available in the docket 
    associated with this rulemaking. This action was submitted to OMB for 
    review as required by Executive Order 12866. Any written comments from 
    OMB and any EPA response to OMB comments are in the public docket for 
    this rule.
    
    B. Impact on Small Entities
    
        The Regulatory Flexibility Act (5 U.S.C. 601) requires federal 
    agencies to consider potential impacts of federal regulations upon 
    small entities. If a preliminary analysis indicates that a regulation 
    would have a significant adverse economic impact on a substantial 
    number of small entities, then EPA must prepare a regulatory 
    flexibility analysis.
        The Agency has determined that this action would not have a 
    significant adverse impact on a substantial number of small entities, 
    and thus it is not necessary to prepare a regulatory flexibility 
    analysis in connection with this rule. Only two small entities are 
    known to be affected by this rule. The entities are small businesses 
    that certify alternative fuel engines or vehicles, either newly 
    manufactured or modified from previously certified gasoline versions. 
    EPA contacted these businesses and discussed the proposed rule with 
    them, identifying their concerns. The concerns they expressed prompted 
    revisions to the proposal, which are addressed elsewhere in the 
    preamble. Rule revisions proposed by EPA are intended to minimize 
    adverse impacts on the small entities affected by the proposed rule.
        Therefore, as required under section 605 of the Regulatory 
    Flexibility Act, 5 U.S.C. 601 et. seq., as amended, I hereby certify 
    that this regulation will not have a significant adverse impact on a 
    substantial number of small entities.
    
    C. Unfunded Mandates Reform Act
    
        Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
    Law 104-4, establishes requirements for Federal agencies to assess the 
    effects of their regulatory actions on State, local, and tribal 
    governments and the private sector. Under sections 202 and 205 of the 
    UMRA, EPA generally must prepare a written statement to accompany any 
    proposed and final rule that includes a federal mandate that may result 
    in expenditures by state, local, and tribal governments in the 
    aggregate, or by the private sector, of $100 million or more for any 
    one year. Before promulgating an EPA rule for which a written statement 
    is needed, section 205 of the UMRA generally requires EPA to identify 
    and consider a reasonable number of regulatory alternatives and adopt 
    the least costly, most cost effective, or least burdensome alternative 
    that achieves the objectives of the rule. The provisions of section 205 
    do not apply when they are inconsistent with applicable law. Moreover, 
    section 205 allows EPA to adopt an alternative other than the least 
    costly, most cost effective, or least burdensome alternative if the 
    Administrator publishes with the final rule an explanation of why that 
    alternative was not adopted. Before EPA establishes any regulatory 
    requirements that may significantly or uniquely affect small 
    governments, including tribal governments, it must have developed under 
    section 203 of the UMRA a small government agency plan. The plan must 
    provide for notifying potentially affected small governments, enabling 
    officials of affected small governments to have meaningful and timely 
    input in the development of EPA regulatory proposals with significant 
    federal intergovernmental mandates, and informing, educating, and 
    advising small governments on compliance with the regulatory 
    requirements.
        Today's proposal contains no Federal mandates (under the regulatory 
    provisions of Title II of the UMRA) for State, local, or tribal 
    governments. The rule imposes no enforceable duties on any of these 
    governmental entities. Nothing in the program would significantly or 
    uniquely affect small governments. EPA has determined that this rule 
    contains federal mandates that may result in expenditures of $100 
    million or more in any one year for the private sector.
        As explained in section III.B of this preamble (``1999 Review of 
    Heavy-duty Diesel Engine NMHC+NOX Standards''), the 2004 
    heavy-duty diesel standards reaffirmed in this rulemaking were 
    established in the Agency's 1997 final rulemaking for heavy-duty 
    diesels, and the 1997 rulemaking laid the ground work for this 
    proposal. Today's proposal for HD diesel engines is simply a review of 
    the appropriateness under the Clean Air Act of the standard finalized 
    in 1997, including the need for and technical and economic feasibility 
    of the standard based on information available in 1999. Therefore, 
    today's proposal does not contain any further analysis of other, 
    alternative standards for heavy-duty diesel engines. The reader is 
    directed to the rulemaking record for the 1997 rule, contained in EPA 
    Air Docket A-95-27, for information on alternatives the Agency 
    considered during that rulemaking.
        Today's proposal includes an analysis of an alternative standard 
    for HD Otto-cycle engines. Section VI.B of this preamble, and Chapter 
    3, Section III(H) of the draft RIA, contain a detailed description of 
    the alternative standard proposed by the engine manufacturers. Section 
    202(a)(3) of the Clean Air Act requires that EPA must set emission 
    standards for heavy-duty engines to reflect the greatest degree of 
    emission reduction achievable through the application of technology 
    which EPA determines will be available for the model year to which the 
    standards apply, giving appropriate consideration to cost, energy, and 
    safety factors associated with the application of such technology.
        As indicated above, EPA believes the standards proposed reflect the 
    greatest degree of emission reduction achievable by HD Otto-cycle 
    engines in the 2004 model year and have a reasonable cost-effectiveness 
    level. EPA is requesting comment on the proposed standard and 
    alternatives. Based on comments received and information available at 
    the time of the final rulemaking, EPA will make a final determination 
    under Sec. 202(a)(3) of the CAA. EPA will address the requirements of 
    UMRA Sec. 205 in connection with the final rule.
    
    D. Reporting and Recordkeeping Requirements
    
        The information collection requirements in this proposed rule have 
    been submitted for approval to the Office of Management and Budget 
    (OMB) under the Paperwork Reduction
    
    [[Page 58536]]
    
    Act, 44 U.S.C. 3501 et seq. An Information Collection Request (ICR) 
    document has been prepared by EPA (ICR No. 2060-0104) and a copy may be 
    obtained from Sandy Farmer by mail at OPPE Regulatory Information 
    Division; U.S. Environmental Protection Agency (2137); 401 M St., S.W.; 
    Washington, DC 20460, by email at farmer.sandy@epamail.epa.gov, or by 
    calling (202) 260-2740. A copy may also be downloaded off the internet 
    at
    http://www.epa.gov/icr. The following ICR document has been prepared by 
    EPA:
    
    ------------------------------------------------------------------------
                     EPA ICR #                              Title
    ------------------------------------------------------------------------
    0783.38...................................  Heavy Duty Engine Emission
                                                 Certification.
    ------------------------------------------------------------------------
    
        The Agency proposes to collect information related to certification 
    results. This information will be used to ensure compliance with and 
    enforce the provisions in this rule. Responses will be mandatory in 
    order to complete the certification process. Section 208(a) of the 
    Clean Air Act requires that manufacturers provide information the 
    Administrator may reasonably require to determine compliance with the 
    regulations; submission of the information is therefore mandatory. EPA 
    will consider confidential all information meeting the requirements of 
    Sec. 208(c) of the Clean Air Act.
        This collection of information affects an estimated 66 respondents 
    with a total of 459 responses per year and a total hour burden of 
    65,859 hours, for an estimated 143 hours per response, with estimated 
    total annualized costs of $1,599,684 per year. The hours and annual 
    cost of information collection activities by a given manufacturer 
    depends on manufacturer-specific variables, such as the number of 
    engine families, production changes, emissions defects, and so forth. 
    Burden means the total time, effort, or financial resources expended by 
    persons to generate, maintain, retain, or disclose or provide 
    information to or for a Federal agency. This includes the time needed 
    to review instructions; develop, acquire, install, and utilize 
    technology and systems for the purposes of collecting, validating, and 
    verifying information, processing and maintaining information, and 
    disclosing and providing information; adjust the existing ways to 
    comply with any previously applicable instructions and requirements; 
    train personnel to be able to respond to a collection of information; 
    search data sources; complete and review the collection of information; 
    and transmit or otherwise disclose the information.
        An Agency may not conduct or sponsor, and a person is not required 
    to respond to a collection of information unless it displays a 
    currently valid OMB control number. The OMB control numbers for EPA's 
    regulations are listed in 40 CFR Part 9 and 48 CFR Chapter 15.
        Comments are requested on the Agency's need for this information, 
    the accuracy of the provided burden estimates, and any suggested 
    methods for minimizing respondent burden, including through the use of 
    automated collection techniques. Send comments on the ICR to the 
    Director, OPPE Regulatory Information Division; U.S. Environmental 
    Protection Agency (2137); 401 M St., S.W.; Washington, DC 20460; and to 
    the Office of Information and Regulatory Affairs, Office of Management 
    and Budget, 725 17th St., N.W., Washington, DC 20503, marked 
    ``Attention: Desk Officer for EPA.'' Include the ICR number in any 
    correspondence. Since OMB is required to make a decision concerning the 
    ICR between 30 and 60 days after October 29, 1999, a comment to OMB is 
    best assured of having its full effect if OMB receives it by November 
    29, 1999. The final rule will respond to any OMB or public comments on 
    the information collection requirements contained in this proposal.
    
    E. Compliance With Executive Order 13045
    
        Executive Order 13045: ``Protection of Children from Environmental 
    Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
    to any rule that: (1) is determined to be ``economically significant'' 
    as defined under Executive Order 12866, and (2) concerns an 
    environmental health or safety risk that EPA has reason to believe may 
    have a disproportionate effect on children. If the regulatory action 
    meets both criteria, the Agency must evaluate the environmental health 
    or safety effects of the planned rule on children, and explain why the 
    planned regulation is preferable to other potentially effective and 
    reasonably feasible alternatives considered by the Agency.
        EPA interprets Executive Order 13045 as applying only to those 
    regulatory actions that are based on health or safety risks, such that 
    the analysis required under section 5-501 of the Order has the 
    potential to influence the regulation. Today's proposal falls into that 
    category only in part: risk considerations may be taken into account 
    only to the extent the Agency may consider the inherent toxicity of a 
    regulated pollutant, and any differential impacts such a pollutant may 
    have on children's health, in deciding how to take cost and other 
    relevant factors into consideration.
        This rulemaking will achieve important reductions of various 
    emissions from heavy-duty trucks, primarily emissions of 
    NOX. The rulemaking also addresses NMHC and PM. These 
    pollutants raise concerns about a disproportionately greater effect on 
    children's health, such as impacts from ozone, PM, and certain toxic 
    air pollutants. See section II of this proposal and the RIA for a 
    further discussion of these issues. The effects of ozone and PM on 
    children's health was addressed in detail in EPA's rulemaking to 
    establish these NAAQS, and EPA is not revisiting those issues here. EPA 
    also believes the emissions reductions from the proposed strategies 
    will reduce air toxics and the related impacts on children's health. 
    EPA will be addressing the issues raised by air toxics from motor 
    vehicles and their fuels in a separate rulemaking that EPA is 
    initiating in the near future under section 202(l)(2) of the Act. That 
    rulemaking will address the emissions of hazardous air pollutants from 
    motor vehicles and fuels, and the appropriate level of control of 
    hazardous air pollutants from these sources.
        In this proposal EPA has evaluated several regulatory strategies 
    for reductions in these emissions from heavy-duty engines. For the 
    reasons described in this preamble, EPA believes that the strategies 
    proposed are preferable under the Clean Air Act to other potentially 
    effective and reasonably feasible alternatives considered by the 
    Agency, for purposes of reducing emissions from these sources as a way 
    of helping areas achieve and maintain the NAAQS for ozone and PM. 
    Moreover, consistent with the Clean Air Act, the proposed levels of 
    control are designed to achieve the greatest degree of reduction of 
    emissions of these pollutants achievable through technology that will 
    be available, taking cost and other factors into consideration.
    
    F. Enhancing Intergovernmental Partnerships
    
        Under Executive Order 12875, EPA may not issue a regulation that is 
    not required by statute and that creates a mandate upon a State, local 
    or tribal government, unless the Federal government provides the funds 
    necessary to pay the direct compliance costs incurred by those 
    governments, or EPA consults with those governments. If EPA complies by 
    consulting, Executive Order 12875 requires EPA to provide to the Office 
    of Management and Budget a description of the extent of EPA's prior
    
    [[Page 58537]]
    
    consultation with representatives of affected State, local and tribal 
    governments, the nature of their concerns, copies of any written 
    communications from the governments, and a statement supporting the 
    need to issue the regulation. In addition, Executive Order 12875 
    requires EPA to develop an effective process permitting elected 
    officials and other representatives of State, local and tribal 
    governments ``to provide meaningful and timely input in the development 
    of regulatory proposals containing significant unfunded mandates.''
        Today's rule does not create a mandate on State, local or tribal 
    governments. The rule does not impose any enforceable duties on these 
    entities. The rule will be implemented at the Federal level and imposes 
    compliance obligations only on private industry. Accordingly, the 
    requirements of section 1(a) of Executive Order 12875 do not apply to 
    this rule.
    
    G. Consultation and Coordination With Indian Tribal Governments
    
        Under Executive Order 13084, EPA may not issue a regulation that is 
    not required by statute, that significantly or uniquely affects the 
    communities of Indian tribal governments, and that imposes substantial 
    direct compliance costs on those communities, unless the Federal 
    government provides the funds necessary to pay the direct compliance 
    costs incurred by the tribal governments, or EPA consults with those 
    governments. If EPA complies by consulting, Executive Order 13084 
    requires EPA to provide to the Office of Management and Budget, in a 
    separately identified section of the preamble to the rule, a 
    description of the extent of EPA's prior consultation with 
    representatives of affected tribal governments, a summary of the nature 
    of their concerns, and a statement supporting the need to issue the 
    regulation. In addition, Executive Order 13084 requires EPA to develop 
    an effective process permitting elected officials and other 
    representatives of Indian tribal governments ``to provide meaningful 
    and timely input in the development of regulatory policies on matters 
    that significantly or uniquely affect their communities.''
        Today's rule does not significantly or uniquely affect the 
    communities of Indian tribal governments. The rule will be implemented 
    at the Federal level and imposes compliance obligations only on private 
    industry. Accordingly, the requirements of section 3(b) of Executive 
    Order 13084 do not apply to this rule.
    
    H. National Technology Transfer and Advancement Act
    
        Section 12(d) of the National Technology Transfer and Advancement 
    Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C. 
    272 note) directs EPA to use voluntary consensus standards in its 
    regulatory activities unless doing so would be inconsistent with 
    applicable law or would be otherwise impractical. Voluntary consensus 
    standards are technical standards (e.g., materials specifications, test 
    methods, sampling procedures, and business practices) that are 
    developed or adopted by voluntary consensus standards bodies. NTTAA 
    directs EPA to provide Congress, through OMB, explanations when the 
    Agency decides not to use available and applicable voluntary consensus 
    standards. This rule involves technical standards. The Agency is 
    incorporating by reference applicable standards previously finalized by 
    the Society of Automotive Engineers and the International Standards 
    Organization. For a complete listing of the SAE and ISO standards 
    incorporated by reference in this final rule, please see Sec. 86.1, 
    ``Reference Materials'' in the regulatory language immediately 
    following this preamble.
    
    I. Compliance With Executive Order on Federalism
    
        On August 4, 1999, President Clinton issued a new executive order 
    on federalism, Executive Order 13132, which will go into effect on 
    November 2, 1999. In the interim, the current Executive Order 12612 on 
    federalism is still applicable. Under this order, this rule does not 
    have a substantial direct effect upon States, upon the relationship 
    between the national government and the States, or upon the 
    distribution of power and responsibilities among the various levels of 
    government. This rule directly regulates manufacturers of heavy duty 
    vehicles and engines, and does not impose any duties or obligations on, 
    or restrict the powers of, any state.
    
    XIII. What Is EPA's Statutory Authority for This Proposal?
    
        Section 202(a)(3) authorizes EPA to establish emission standards 
    for heavy duty vehicles and engines.122 These standards are 
    to reflect the greatest degree of emission reduction achievable through 
    the application of technology which EPA determines will be available 
    for the model year to which the standards apply. EPA is to give 
    appropriate consideration to cost, energy, and safety factors 
    associated with the application of such technology. Section 
    202(a)(3)(C) requires that promulgated standards apply for no less than 
    three years and go into effect no less than 4 years after promulgation. 
    Section 202(m) authorizes regulations requiring installation of on-
    board diagnostics systems for light-duty and heavy-duty vehicles and 
    engines. Pursuant to sections 202(a)(1) and 202(d), these emission 
    standards must be met throughout the entire useful life of the engine 
    or vehicle as determined by EPA's regulations. If the Administrator 
    determines that a substantial number of vehicles do not conform to 
    emission standards when in actual use throughout their useful lives, 
    section 207(c) of the Act requires EPA to make a determination of 
    nonconformity. Section 208 of the Act requires manufacturers to perform 
    tests (where not otherwise reasonably available), make reports and 
    provide information the Administrator may reasonably require to 
    determine whether the manufacturer is acting in compliance with the Act 
    and regulations thereunder. The remainder of section 202, as well as 
    sections 203, 206, 207, 208, and 301, provide additional authority for 
    promulgation of these regulations.
    ---------------------------------------------------------------------------
    
        \122\ U.S.C. 7521(a)(3).
    ---------------------------------------------------------------------------
    
    List of Subjects
    
    40 CFR Part 85
    
        Confidential business information, Imports, Incorporation by 
    reference, Labeling, Motor vehicle pollution, Reporting and 
    recordkeeping requirements, Research, Warranties.
    
    40 CFR Part 86
    
        Administrative practice and procedure, Confidential business 
    information, incorporation by reference, Labeling, Motor vehicle 
    pollution, Reporting and recordkeeping requirements.
    
        Dated: October 6, 1999.
    Carol M. Browner,
    Administrator.
    
        For the reasons set forth in the preamble, chapter I, title 40 of 
    the Code of Federal Regulations is proposed to be amended as follows:
    
    PART 85--CONTROL OF AIR POLLUTION FROM MOBILE SOURCES
    
        1. The authority citation for part 85 is revised to read as 
    follows:
    
        Authority: 42 U.S.C. 7521, 7522, 7524, 7525, 7541, 7542, 7543, 
    7547, and 7601(a).
    
    [[Page 58538]]
    
    Subpart F--[Amended]
    
        2. Section 85.501 is revised to read as follows:
    
    
    Sec. 85.501  General applicability.
    
        (a) Sections 85.502 through 85.505 are applicable to aftermarket 
    conversion systems for which an enforcement exemption is sought from 
    the tampering prohibitions contained in section 203 of the Act.
        (b) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of 40 CFR part 86, subpart S.
    
    Subpart P--[Amended]
    
        3. Section 85.1501 is amended by revising paragraph (c), to read as 
    follows:
    
    
    Sec. 85.1501  Applicability.
    
    * * * * *
        (c) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of 40 CFR part 86, subpart S.
    
    Subpart R--[Amended]
    
        4. Section 85.1701 is amended by revising paragraph (c), to read as 
    follows:
    
    
    Sec. 85.1701  General applicability.
    
    * * * * *
        (c) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of 40 CFR part 86, subpart S.
    
    PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES 
    AND ENGINES
    
        5. The authority citation for part 86 continues to read as follows:
    
        Authority: 42 U.S.C. 7401-7671q.
    
        6. Section 86.1 is amended by adding an entry to the table in 
    alphanumeric order in paragraphs (b)(2) and (b)(5), to read as follows:
    
    
    Sec. 86.1  Reference materials.
    
    * * * * *
        (b) * * *
        (2) * * *
    
    ------------------------------------------------------------------------
              Document No. and name              40 CFR part 86  reference
    ------------------------------------------------------------------------
     
    *                  *                  *                  *
                      *                  *                  *
    SAE J1939, Recommended Practice for a     86.004-17; 86.1806-04
     Serial Control and Communications
     Vehicle Network.
    ------------------------------------------------------------------------
    
    * * * * *
        (5) * * *
    
    ------------------------------------------------------------------------
              Document No. and name              40 CFR part 86  reference
    ------------------------------------------------------------------------
     
    *                  *                  *                  *
                      *                  *                  *
    ISO 14230-4 April 1996, Road Vehicles--   86.004-17; 86.1806-04
     Diagnostic systems--KWP 2000
     requirements for Emission-related
     systems.
    ------------------------------------------------------------------------
    
    Subpart A--[Amended]
    
        7. A new Sec. 86.000-15 is added to subpart A to read as follows:
    
    
    Sec. 86.000-15  NOX and particulate averaging, trading, and 
    banking for heavy-duty engines.
    
        Section 86.000-15 includes text that specifies requirements that 
    differ from Sec. 86.094-15 or Sec. 86.098-15. Where a paragraph in 
    Sec. 86.094-15 or Sec. 86.098-15 is identical and applicable to 
    Sec. 86.000-15, this may be indicated by specifying the corresponding 
    paragraph and the statement ``[Reserved]. For guidance see Sec. 86.094-
    15.'' or ``[Reserved]. For guidance see Sec. 86.098-15.''.
        (a) through (b) [Reserved] For guidance see Sec. 86.094-15.
        (c) [Reserved] For guidance see Sec. 86.098-15.
        (d) through (i) [Reserved] For guidance see Sec. 86.094-15.
        (j) Optional program for early banking for diesel engines. 
    Provisions set forth in Secs. 86.094-15 (a), (b), (d) through (i), and 
    86.098-15 (c) apply except as specifically stated otherwise in 
    Sec. 86.098-15 (j)(1) through (j)(3)(iii).
        (j)(1) through (j)(3)(iii) [Reserved] For guidance see Sec. 86.098-
    15.
        (k) Optional program for early banking for Otto-cycle engines. 
    Provisions set forth in Secs. 86.094-15(a), (b), (d) through (i), and 
    86.098-15(c) apply except as specifically stated otherwise in this 
    paragraph (k).
        (1) To be eligible for the optional program described in this 
    paragraph (k), the following must apply:
        (i) Credits are generated from Otto-cycle heavy-duty engines.
        (ii) During certification, the manufacturer shall declare its 
    intent to include specific engine families in the program described in 
    this paragraph. Separate declarations are required for each program and 
    no engine families may be included in both programs in the same model 
    year.
        (2) Credit generation and use. (i) Credits shall only be generated 
    by 2000 and later model year engine families.
        (ii) Credits may only be used for 2004 and later model year heavy-
    duty Otto-cycle engines. When used with 2004 and later model year 
    engines, NOx credits may be used to meet the NOx 
    plus NMHC standard, except as otherwise provided in Sec. 86.004-
    11(a)(1)(i)(D).
        (iii) If a manufacturer chooses to use credits generated under this 
    paragraph (k) prior to model year 2004, the averaging, trading, and 
    banking of such credits shall be governed by the program provided in 
    Secs. 86.094-15(a), (b), (d) through (i) and 86.098-15(c) and shall be 
    subject to all discounting, credit life limits and all other provisions 
    contained therein. In the case where the
    
    [[Page 58539]]
    
    manufacturer can demonstrate that the credits were discounted under the 
    program provided in this paragraph (k), that discount may be accounted 
    for in the calculation of credits described in Sec. 86.098-15(c).
        (3) Program flexibilities. (i) NOX credits that are 
    banked until model year 2004 under this paragraph (k) may be used in 
    2004 or any model year thereafter without being forfeited due to credit 
    age. The requirement in this paragraph (k)(3) applies instead of the 
    requirements in Sec. 86.094-15(f)(2)(i).
        (ii) There are no regional category restraints for averaging, 
    trading, and banking of credits generated under the program described 
    in this paragraph (k). This applies instead of the regional category 
    provisions described in the introductory text of Sec. 86.094-15 (d) and 
    (e).
        (iii) Credit discounting. (A) For NOX credits generated 
    under this paragraph (k) from engine families with NOX FELs 
    greater than 1.0 grams per brake horsepower-hour for oxides of 
    nitrogen, a Discount value of 0.9 shall be used instead of 0.8 in the 
    credit availability equation in Sec. 86.098-15(c)(1).
        (B) For NOX credits generated under this paragraph (k) 
    from engine families with NOX FELs less than or equal to 1.0 
    grams per brake horsepower-hour for oxides of nitrogen, a Discount 
    value of 1.0 shall be used in place of 0.8 in the credit availability 
    equation in Sec. 86.098-15 (c)(1).
        (iv) Credit calculation. For NOX credits generated under 
    this paragraph (k), a Std value of 2.0 grams per brake horsepower-hour 
    shall be used in place of the current and applicable NOX 
    standard in the credit availability equation in Sec. 86.098-15(c)(1).
        (l) Credit apportionment. At the manufacturer's option, credits 
    generated under the provisions described in this section may be sold to 
    or otherwise provided to another party for use in programs other than 
    the averaging, trading and banking program described in this section.
        (1) The manufacturer shall pre-identify two emission levels per 
    engine family for the purposes of credit apportionment. One emission 
    level shall be the FEL and the other shall be the level of the standard 
    that the engine family is required to certify to under Sec. 86.098-10 
    or Sec. 86.098-11, as applicable. For each engine family, the 
    manufacturer may report engine sales in two categories, ``ABT-only 
    credits'' and ``non-manufacturer-owned credits''.
        (i) For engine sales reported as ``ABT-only credits'', the credits 
    generated must be used solely in the ABT program described in this 
    section.
        (ii) The engine manufacturer may declare a portion of engine sales 
    ``non-manufacturer-owned credits'' and this portion of the credits 
    generated between the standard and the FEL, based on the calculation in 
    Sec. 86.098-15(c)(1), would belong to another party. For ABT, the 
    manufacturer may not generate any credits for the engine sales reported 
    as ``nonmanufacturer-owned credits''. Engines reported as ``non-
    manufacturer-owned credits'' shall comply with the FEL and the 
    requirements of the ABT program in all other respects.
        (2) Only manufacturer-owned credits reported as ``ABT-only 
    credits'' shall be used in the averaging, trading, and banking 
    provisions described in this section.
        (3) Credits shall not be double-counted. Credits used in the ABT 
    program may not be provided to an engine purchaser for use in another 
    program.
        (4) Manufacturers shall determine and state the number of engines 
    sold as ``ABT-only credits'' and ``non-manufacturer-owned credits'' in 
    the end-of-model year reports required under Sec. 86.098-23.
        8. Section 86.000-16 is amended by removing paragraphs (a) through 
    (d) introductory text, adding paragraphs (a), (b), (c), and (d) 
    introductory text, and revising paragraph (d)(1), to read as follows:
    
    
    Sec. 86.000-16  Prohibition of defeat devices.
    
    * * * * *
        (a) No new light-duty vehicle, light-duty truck, heavy-duty 
    vehicle, or heavy-duty engine shall be equipped with a defeat device.
        (b) The Administrator may test or require testing on any vehicle or 
    engine at a designated location, using driving cycles and conditions 
    which may reasonably be expected to be encountered in normal operation 
    and use, for the purpose of investigating a potential defeat device.
        (c) [Reserved]. For guidance see Sec. 86.094-16.
        (d) For vehicle and engine designs designated by the Administrator 
    to be investigated for possible defeat devices:
        (1) The manufacturer must show to the satisfaction of the 
    Administrator that the vehicle or engine design does not incorporate 
    strategies that unnecessarily reduce emission control effectiveness 
    exhibited during the Federal emissions test procedure when the vehicle 
    or engine is operated under conditions which may reasonably be expected 
    to be encountered in normal operation and use.
    * * * * *
        9. Section 86.001-1 is amended by revising paragraph (b) to read as 
    follows:
    
    
    Sec. 86.001-1  General applicability.
    
    * * * * *
        (b) Optional applicability. (1) A manufacturer may request to 
    certify any heavy-duty vehicle of 14,000 pounds Gross Vehicle Weight 
    Rating or less in accordance with the light-duty truck provisions 
    located in subpart S of this part through the 2003 model year. Heavy-
    duty engine or vehicle provisions of this subpart A do not apply to 
    such a vehicle.
        (2) Beginning with the 2001 model year, a manufacturer may certify 
    any Otto-cycle heavy-duty vehicle of 14,000 pounds Gross Vehicle Weight 
    Rating or less in accordance with the provisions for complete Otto-
    cycle heavy-duty vehicles located in subpart S of this part for 
    purposes of generating credits in the heavy-duty vehicle averaging, 
    banking, and trading program contained in Sec. 86.1817-04. Heavy-duty 
    engine or heavy-duty vehicle provisions of this subpart A do not apply 
    to such a vehicle.
    * * * * *
        10. A new Sec. 86.004-1 is added to subpart A to read as follows:
    
    
    Sec. 86.004-1  General applicability.
    
        Section 86.004-1 includes text that specifies requirements that 
    differ from Sec. 86.001-1. Where a paragraph in Sec. 86.001-1 is 
    identical and applicable to Sec. 86.004-1, this may be indicated by 
    specifying the corresponding paragraph and the statement ``[Reserved]. 
    For guidance see Sec. 86.001-1.''.
        (a) The provisions of this subpart generally apply to 2004 and 
    later model year new Otto-cycle heavy-duty engines used in incomplete 
    vehicles and vehicles above 14,000 pounds GVWR and new diesel-cycle 
    heavy-duty engines. In cases where a provision applies only to a 
    certain vehicle group based on its model year, vehicle class, motor 
    fuel, engine type, or other distinguishing characteristics, the limited 
    applicability is cited in the appropriate section or paragraph. The 
    provisions of this subpart continue to generally apply to 2000 and 
    earlier model year new Otto-cycle and diesel-cycle light-duty vehicles, 
    2000 and earlier model year new Otto-cycle and diesel-cycle light-duty 
    trucks, and 2003 and earlier model year new Otto-cycle complete heavy-
    duty vehicles at or below 14,000 pounds GVWR. Provisions generally 
    applicable to 2001 and later model year new Otto-cycle and diesel-cycle 
    light-duty vehicles, 2001 and later model year new Otto-cycle and 
    diesel-cycle light-duty trucks, and 2004 and
    
    [[Page 58540]]
    
    later model year Otto-cycle complete heavy-duty vehicles at or below 
    14,000 pounds GVWR are located in subpart S of this part.
        (b) Optional applicability. For 2004 and later model years, a 
    manufacturer may request to certify any incomplete heavy-duty vehicle 
    of 14,000 pounds Gross Vehicle Weight Rating or less in accordance with 
    the provisions for complete heavy-duty vehicles located in subpart S of 
    this part. Heavy-duty engine or heavy-duty vehicle provisions of this 
    subpart A do not apply to such a vehicle.
        (c) [Reserved]
        (d) [Reserved]
        (e) through (f) [Reserved]. For guidance see Sec. 86.001-1.
        11. Section 86.004-2 is amended by adding definitions in 
    alphabetical order for ``defeat device,'' ``heavy-duty vehicle,'' and 
    ``light-duty truck'' to read as follows:
    
    
    Sec. 86.004-2  Definitions.
    
    * * * * *
        Defeat device means an auxiliary emission control device (AECD) 
    that reduces the effectiveness of the emission control system under 
    conditions which may reasonably be expected to be encountered in normal 
    vehicle operation and use, unless:
        (1) Such conditions are substantially included in the applicable 
    Federal emission test procedure for heavy-duty vehicles and heavy-duty 
    engines described in subpart N of this part, excluding the test 
    procedure referred to as the ``Not-To-Exceed Test Procedure'' contained 
    in Sec. 86.1370, and excluding the Maximum Allowable Emission Limits 
    contained in Sec. 86.1370(f);
        (2) The need for the AECD is justified in terms of protecting the 
    vehicle against damage or accident; or
        (3) The AECD does not go beyond the requirements of engine 
    starting.
        Heavy-duty vehicle means any motor vehicle rated at more than 8,500 
    pounds GVWR or that has a vehicle curb weight of more than 6,000 pounds 
    or that has a basic vehicle frontal area in excess of 45 square feet, 
    excluding vehicles with a GVWR greater than 8,500 pounds and less than 
    or equal to 10,000 pounds that are defined as light-duty trucks.
        Light-duty truck means: (1) Any motor vehicle rated at 8,500 pounds 
    GVWR or less which has a curb weight of 6,000 pounds or less and which 
    has a basic vehicle frontal area of 45 square feet or less, which is:
        (i) Designed primarily for purposes of transportation of property 
    or is a derivation of such a vehicle; or
        (ii) Designed primarily for transportation of persons and has a 
    capacity of more than 12 persons; or
        (iii) Available with special features enabling off-street or off-
    highway operation and use; or
        (2) Any motor vehicle rated at greater than 8,500 pounds GVWR and 
    less than or equal to 10,000 pounds GVWR which is a complete vehicle 
    designed primarily for transportation of persons and has a capacity of 
    not more than 12 persons.
    * * * * *
        12. A new Sec. 86.004-10 is added to subpart A to read as follows:
    
    
    Sec. 86.004-10  Emission standards for 2004 and later model year Otto-
    cycle heavy-duty engines and vehicles.
    
        Section 86.004-10 includes text that specifies requirements that 
    differ from Sec. 86.099-10. Where a paragraph in Sec. 86.099-10 is 
    identical and applicable to Sec. 86.004-10, this may be indicated by 
    specifying the corresponding paragraph and the statement ``[Reserved]. 
    For guidance see Sec. 86.099-10.''.
        (a)(1) Exhaust emissions from new 2004 and later model year Otto-
    cycle HDEs shall not exceed:
        (i)(A) Oxides of Nitrogen plus Non-methane Hydrocarbons (NOX 
    + NMHC) for engines fueled with either gasoline, natural gas, or 
    liquefied petroleum gas. 1.0 grams per brake horsepower-hour (0.37 gram 
    per megajoule), as measured under transient operating conditions.
        (B) Oxides of Nitrogen plus Non-methane Hydrocarbon Equivalent 
    (NOX + NMHCE) for engines fueled with methanol. 1.0 grams 
    per brake horsepower-hour (0.37 gram per megajoule), as measured under 
    transient operating conditions.
        (C) A manufacturer may elect to include any or all of its Otto-
    cycle HDE families in any or all of the emissions ABT programs for 
    HDEs, within the restrictions described in Sec. 86.098-15. If the 
    manufacturer elects to include engine families in any of these 
    programs, the NOX plus NMHC (or NOX plus NMHCE 
    for methanol-fueled engines) FELs may not exceed 4.5 grams per brake 
    horsepower-hour (1.7 grams per megajoule). This ceiling value applies 
    whether credits for the family are derived from averaging, banking, or 
    trading programs.
        (ii)(A) Carbon monoxide for engines intended for use in all 
    vehicles, except as provided in paragraph (a)(1)(ii)(B) of this 
    section. 14.4 grams per brake horsepower-hour (5.36 grams per 
    megajoule), as measured under transient operating conditions.
        (B) Carbon monoxide for engines intended for use only in vehicles 
    with a Gross Vehicle Weight Rating of greater than 14,000 pounds. 37.1 
    grams per brake horsepower-hour (13.8 grams per megajoule), as measured 
    under transient operating conditions.
        (C) Idle carbon monoxide. For all Otto-cycle HDEs utilizing 
    aftertreatment technology: 0.50 percent of exhaust gas flow at curb 
    idle.
        (2) The standards set forth in paragraph (a)(1) of this section 
    refer to the exhaust emitted over the operating schedule set forth in 
    paragraph (f)(1) of appendix I to this part, and measured and 
    calculated in accordance with the procedures set forth in subpart N or 
    P of this part.
        (3)(i) A manufacturer may certify one or more Otto-cycle HDE 
    configurations intended for use in all vehicles to the emission 
    standard set forth in paragraphs (a)(1)(ii)(B) of this section: 
    Provided, that the total model year sales of such configuration(s), 
    segregated by fuel type, being certified to the emission standard in 
    paragraph (a)(1)(ii)(B) of this section represent no more than five 
    percent of total model year sales of each fuel type Otto-cycle HDE 
    intended for use in vehicles with a Gross Vehicle Weight Rating of up 
    to 14,000 pounds by the manufacturer.
        (ii) The configurations certified to the emission standards of 
    paragraphs (a)(1) (ii)(B) of this section under the provisions of 
    paragraph (a)(3)(i) of this section shall still be required to meet the 
    evaporative emission standards set forth in Sec. 86.099-10(b)(1)(i), 
    (b)(2)(i) and (b)(3)(i).
        (4) [Reserved]
        (b) [Reserved]. For guidance see Sec. 86.099-10.
        (c) No crankcase emissions shall be discharged into the ambient 
    atmosphere from any new 1998 or later model year Otto-cycle HDE.
        (d) Every manufacturer of new motor vehicle engines subject to the 
    standards prescribed in this section shall, prior to taking any of the 
    actions specified in section 203(a)(1) of the Act, test or cause to be 
    tested motor vehicle engines in accordance with applicable procedures 
    in subpart N or P of this part to ascertain that such test engines meet 
    the requirements of this section.
        13. Section 86.004-11 is amended by adding paragraphs (a)(3) and 
    (a)(4) and (b)(1)(iv), and by revising paragraph (b)(2), to read as 
    follows:
    
    
    Sec. 86.004-11  Emission standards for 2004 and later model year diesel 
    heavy-duty engines and vehicles.
    
        (a) * * *
        (3)(i) The weighted average exhaust emissions, as determined under 
    Sec. 86.1360-2004(e)(5) pertaining to the supplemental steady-state 
    test cycle, for each regulated pollutant shall not exceed 1.0 times the 
    applicable
    
    [[Page 58541]]
    
    emission standards or FELs specified in paragraph (a)(1) of this 
    section.
        (ii) Exhaust emissions shall not exceed the Maximum Allowable 
    Emission Limits (for the corresponding speed and load), as determined 
    under Sec. 86.1360-2004(f), when the engine is operated in the steady-
    state control area defined under Sec. 86.1360-2004(d).
        (4)(i) The weighted average emissions, as determined under 
    Sec. 86.1370 pertaining to the not-to-exceed test procedures, for each 
    regulated pollutant shall not exceed 1.25 times the applicable emission 
    standards or FELs specified in paragraph (a)(1) of this section, except 
    as noted in paragraph (a)(4)(ii) of this section.
         Exhaust emissions shall not exceed either the Maximum Allowable 
    Emission Limits (for the corresponding speed and load), as determined 
    under Sec. 86.1360(f) or the exhaust emissions specified in paragraph 
    (a)(4)(i) of this section, whichever is numerically lower, when the 
    engine is operated in the steady-state control area defined under 
    Sec. 86.1360(d).
        (b) * * *
        (1) * * *
        (iv) A filter smoke number of 1.0, or the following alternate 
    opacity limits:
        (A) A 30 second transient test average opacity limit of 4% for a 5 
    inch path; and
        (B) A 10 second steady state test average opacity limit of 4% for a 
    5 inch path.
        (2)(i) The standards set forth in paragraphs (b)(1)(i) through 
    (iii) of this section refer to exhaust smoke emissions generated under 
    the conditions set forth in subpart I of this part and measured and 
    calculated in accordance with those procedures.
        (ii) The standards set forth in paragraph (b)(1)(iv) of this 
    section refer to exhaust smoke emissions generated under the conditions 
    set forth in Sec. 86.1380 and calculated in accordance with the 
    procedures set forth in Sec. 86.1372.
    * * * * *
        14. Section 86.004-15 is amended by revising the section heading 
    and paragraphs (a)(1), (b) introductory text, (b)(1)(i), (b)(1)(ii), 
    (c)(1) introductory text, (c)(1)(iii), (d) introductory text, 
    (d)(1)(i), (d)(1)(ii), (f) heading, (f)(1)(i), (f)(2)(i), (f)(2)(ii), 
    (f)(3)(ii), (f)(3)(iii), (g)(1), (g)(2) introductory text, (g)(2)(i), 
    (g)(2)(ii), (g)(4), (j) introductory text, (j)(1) introductory text, 
    (k) heading and introductory text, removing paragraphs (a)(2)(iii) and 
    (d)(1)(iii), and adding paragraph (l), to read as follows:
    
    
    Sec. 86.004-15  NOX plus NMHC and particulate averaging, 
    trading, and banking for heavy-duty engines.
    
        (a)(1) Heavy-duty engines eligible for NOX plus NMHC and 
    particulate averaging, trading and banking programs are described in 
    the applicable emission sandards sections in this subpart. All heavy-
    duty engine families which include any engines labeled for use in 
    clean-fuel vehicles as specified in 40 CFR part 88 are not eligible for 
    these programs. Participation in these programs is voluntary.
    * * * * *
        (b) Participation in the NOX plus NMHC and/or 
    particulate averaging, trading, and banking programs shall be done as 
    follows:
        (1) * * *
        (i) Declare its intent to include specific engine families in the 
    averaging, trading and/or banking programs. Separate declarations are 
    required for each program and for each pollutant (i.e., NOX 
    plus NMHC, and particulate).
        (ii) Declare an FEL for each engine family participating in one or 
    more of these two programs.
        (A) The FEL must be to the same level of significant digits as the 
    emission standard (one-tenth of a gram per brake horsepower-hour for 
    NOX plus NMHC emissions and one-hundredth of a gram per 
    brake horsepower-hour for particulate emissions).
        (B) In no case may the FEL exceed the upper limit prescribed in the 
    section concerning the applicable heavy-duty engine NOX plus 
    NMHC and particulate emission standards.
    * * * * *
        (c)(1) For each participating engine family, NOX plus 
    NMHC, and particulate emission credits (positive or negative) are to be 
    calculated according to one of the following equations and rounded, in 
    accordance with ASTM E29-93a, to the nearest one-tenth of a Megagram 
    (Mg). Consistent units are to be used throughout the equation.
    * * * * *
        (iii) For purposes of the equation in paragraphs (c)(1)(i) and (ii) 
    of this section:
    
    Std = the current and applicable heavy-duty engine NOX 
    plus NMHC or particulate emission standard in grams per brake 
    horsepower hour or grams per Megajoule.
    FEL = the NOX plus NMHC, or particulate family emission 
    limit for the engine family in grams per brake horsepower hour or 
    grams per Megajoule.
    CF = a transient cycle conversion factor in BHP-hr/mi or MJ/mi, as 
    given in paragraph (c)(2) of this section.
    UL = the useful life described in Sec. 86.004-2, or alternative life 
    as described in Sec. 86.004-21(f), for the given engine family in 
    miles.
    Production = the number of engines produced for U.S. sales within 
    the given engine family during the model year. Quarterly production 
    projections are used for initial certification. Actual production is 
    used for end-of-year compliance determination.
    Discount = a one-time discount applied to all credits to be banked 
    or traded within the model year generated. Except as otherwise 
    allowed in paragraphs (k) and (l) of this section, the discount 
    applied here is 0.9. Banked credits traded in a subsequent model 
    year will not be subject to an additional discount. Banked credits 
    used in a subsequent model year's averaging program will not have 
    the discount restored.
    * * * * *
        (d) Averaging sets for NOX plus NMHC emission credits. 
    The averaging and trading of NOX plus NMHC emission credits 
    will only be allowed between heavy-duty engine families in the same 
    averaging set. The averaging sets for the averaging and trading of 
    NOX plus NMHC emission credits for heavy-duty engines are 
    defined as follows:
        (1) For NOX+NMHC credits from Otto-cycle heavy-duty 
    engines:
        (i) Otto-cycle heavy-duty engines constitute an averaging set. 
    Averaging and trading among all Otto-cycle heavy-duty engine families 
    is allowed. There are no subclass restrictions.
        (ii) Otto-cycle heavy-duty vehicles certified under the chassis-
    based provisions of Subpart S of this Part may not average or trade 
    with heavy-duty Otto-cycle engines.
    * * * * *
        (f) Banking of NOX plus NMHC, and particulate emission 
    credits. (1) * * * (i) NOX plus NMHC, and particulate 
    emission credits may be banked from engine families produced in any 
    model year.
    * * * * *
        (2) * * * (i) NOX plus NMHC and particulate credits 
    generated in 2004 and later model years do not expire.
        (ii) Manufacturers withdrawing banked NOX plus NMHC, 
    and/or particulate credits shall indicate so during certification and 
    in their credit reports, as described in Sec. 86.091-23.
        (3) * * *
        (ii) Banked credits may not be used for NOX plus NMHC or 
    particulate averaging and trading to offset emissions that exceed an 
    FEL. Banked credits may not be used to remedy an in-use nonconformity 
    determined by a Selective Enforcement Audit or by recall testing. 
    However, banked credits may be
    
    [[Page 58542]]
    
    used for subsequent production of the engine family if the manufacturer 
    elects to recertify to a higher FEL.
        (iii) Banked NOX credits from 2003 and earlier model 
    years may be used in place of NOX plus NMHC credits after 
    2003 provided that they are used in the correct averaging set and the 
    NOX credits have not expired.
        (g)(1) This paragraph (g) assumes NOX plus NMHC, and 
    particulate nonconformance penalties (NCPs) will be available for the 
    2004 and later model year HDEs.
        (2) Engine families using NOX plus NMHC and/or 
    particulate NCPs but not involved in averaging:
        (i) May not generate NOX plus NMHC or particulate 
    credits for banking and trading.
        (ii) May not use NOX plus NMHC or particulate credits 
    from banking and trading.
    * * * * *
        (4) If a manufacturer has any engine family in a given averaging 
    set which is using NOX plus NMHC and/or particulate NCPs, 
    none of that manufacturer's engine families in that averaging set may 
    generate credits for banking and trading.
    * * * * *
        (j) Credit apportionment. At the manufacturer's option, credits 
    generated under the provisions described in this section may be sold to 
    or otherwise provided to another party for use in programs other than 
    the averaging, trading and banking program described in this section.
        (1) The manufacturer shall pre-identify two emission levels per 
    engine family for the purposes of credit apportionment. One emission 
    level shall be the FEL and the other shall be the level of the standard 
    that the engine family is required to certify to under Sec. 86.004-10 
    or Sec. 86.004-11. For each engine family, the manufacturer may report 
    engine sales in two categories, ``ABT-only credits'' and 
    ``nonmanufacturer-owned credits'.
    * * * * *
        (k) Additional flexibility for diesel-cycle engines. If a diesel-
    cycle engine family meets the conditions of either paragraph (k)(1) or 
    (2) of this section, a Discount of 1.0 may be used in the trading and 
    banking calculation, for both NOX plus NMHC and for 
    particulate, described in paragraph (c)(1) of this section.
    * * * * *
        (l) Additional flexibility for Otto-cycle engines. If an Otto-cycle 
    engine family meets the conditions of paragraph (l)(1) or (2) of this 
    section, a discount of 1.0 may be used in the trading and banking 
    credits calculation for NOX plus NMHC described in paragraph 
    (c)(1) of this section.
        (1) The engine family has a FEL of 0.5 g/bhp-hr NOX plus 
    NMHC or lower;
        (2) All of the following conditions are met:
        (i) For model years 2004, 2005, and 2006 only;
        (ii) An engine family is certified using carry-over certification 
    data from a 2003 or earlier model year where the sum of the 
    NOX FEL plus the HC (or hydrocarbon equivalent where 
    applicable) certification level is below 1.0 g/bhp-hr.
        15. Section 86.004-16 is added to subpart A to read as follows:
    
    
    Sec. 86.004-16  Prohibition of defeat devices.
    
        (a) No new heavy-duty vehicle or heavy-duty engine shall be 
    equipped with a defeat device.
        (b) The Administrator may test or require testing on any vehicle or 
    engine at a designated location, using driving cycles and conditions 
    which may reasonably be expected to be encountered in normal operation 
    and use, for the purpose of investigating a potential defeat device.
        (c) [Reserved]
        (d) For vehicle and engine designs designated by the Administrator 
    to be investigated for possible defeat devices:
        (1) General. The manufacturer must show to the satisfaction of the 
    Administrator that the vehicle or engine design does not incorporate 
    strategies that unnecessarily reduce emission control effectiveness 
    exhibited during the Federal emissions test procedures, described in 
    subpart N of this part, excluding the test procedure referred to as the 
    ``Not-To-Exceed Test Procedure'' contained in Sec. 86.1370, and the 
    Maximum Allowable Emission Limits contained in Sec. 86.1360(f), when 
    the vehicle or engine is operated under conditions which may reasonably 
    be expected to be encountered in normal operation and use.
        (2) Information submissions required. The manufacturer will provide 
    an explanation containing detailed information (including information 
    which the Administrator may request to be submitted) regarding test 
    programs, engineering evaluations, design specifications, calibrations, 
    on-board computer algorithms, and design strategies incorporated for 
    operation both during and outside of the Federal emission test 
    procedure described in subpart N of this part, excluding the test 
    procedure referred to as the ``Not-To-Exceed Test Procedure'' contained 
    in Sec. 86.1370.
        16. Section 86.004-17 is added to subpart A, to read as follows:
    
    
    Sec. 86.004-17  On-board diagnostics.
    
        (a) General. All heavy-duty engines intended for use in a heavy-
    duty vehicle weighing 14,000 pounds GVWR or less must be equipped with 
    an on-board diagnostic (OBD) system capable of monitoring all emission-
    related engine systems or components during the applicable useful life. 
    Heavy-duty engines intended for use in a heavy-duty vehicle weighing 
    14,000 pounds GVWR or less must meet the OBD requirements of this 
    section according to the phase-in schedule in paragraph (k) of this 
    section. All monitored systems and components must be evaluated 
    periodically, but no less frequently than once per applicable 
    certification test cycle as defined in Appendix I, paragraph (f), of 
    this part, or similar trip as approved by the Administrator.
        (b) Malfunction descriptions. The OBD system must detect and 
    identify malfunctions in all monitored emission-related engine systems 
    or components according to the following malfunction definitions as 
    measured and calculated in accordance with test procedures set forth in 
    subpart N of this part (engine-based test procedures) excluding the 
    test procedure referred to as the ``Not-To-Exceed Test Procedure'' 
    contained in Sec. 86.1370, and excluding the test procedure referred to 
    as the ``Load Response Test'' contained in Sec. 86.1380.
        (1) Catalysts and particulate traps. (i) Otto-cycle. Catalyst 
    deterioration or malfunction before it results in an increase in NMHC 
    emissions 1.5 times the NMHC+NOX standard or FEL, as 
    compared to the NMHC+NOX emission level measured using a 
    representative 4000 mile catalyst system.
        (ii) Diesel. If equipped, catalyst or particulate trap 
    deterioration or malfunction before it results in exhaust emissions 
    exceeding 1.5 times the applicable standard or FEL for 
    NMHC+NOX or PM. This monitoring need not be done if the 
    manufacturer can demonstrate that deterioration or malfunction of the 
    system will not result in exceedance of the threshold; however, the 
    presence of the catalyst or particulate trap must still be monitored.
        (2) Engine Misfire. (i) Otto-cycle. Engine misfire resulting in 
    exhaust emissions exceeding 1.5 times the applicable standard or FEL 
    for NMHC+NOX or CO; and any misfire capable of damaging the 
    catalytic converter.
        (ii) Diesel. Lack of cylinder combustion must be detected.
    
    [[Page 58543]]
    
        (3) Oxygen sensors. If equipped, oxygen sensor deterioration or 
    malfunction resulting in exhaust emissions exceeding 1.5 times the 
    applicable standard or FEL for NMHC+NOX or CO.
        (4) Evaporative leaks. If equipped, any vapor leak in the 
    evaporative and/or refueling system (excluding the tubing and 
    connections between the purge valve and the intake manifold) greater 
    than or equal in magnitude to a leak caused by a 0.040 inch diameter 
    orifice; an absence of evaporative purge air flow from the complete 
    evaporative emission control system. Where fuel tank capacity is 
    greater than 25 gallons, the Administrator may, following a request 
    from the manufacturer, revise the size of the orifice to the smallest 
    orifice feasible, based on test data, if the most reliable monitoring 
    method available cannot reliably detect a system leak equal to a 0.040 
    inch diameter orifice.
        (5) Other emission control systems. Any deterioration or 
    malfunction occurring in an engine system or component directly 
    intended to control emissions, including but not necessarily limited 
    to, the exhaust gas recirculation (EGR) system, if equipped, the 
    secondary air system, if equipped, and the fuel control system, 
    singularly resulting in exhaust emissions exceeding 1.5 times the 
    applicable emission standard or FEL for NMHC+NOX, CO or 
    diesel PM. For engines equipped with a secondary air system, a 
    functional check, as described in paragraph (b)(6) of this section, may 
    satisfy the requirements of this paragraph (b)(5) provided the 
    manufacturer can demonstrate that deterioration of the flow 
    distribution system is unlikely. This demonstration is subject to 
    Administrator approval and, if the demonstration and associated 
    functional check are approved, the diagnostic system must indicate a 
    malfunction when some degree of secondary airflow is not detectable in 
    the exhaust system during the check. For engines equipped with positive 
    crankcase ventilation (PCV), monitoring of the PCV system is not 
    necessary provided the manufacturer can demonstrate to the 
    Administrator's satisfaction that the PCV system is unlikely to fail.
        (6) Other emission-related engine components. Any other 
    deterioration or malfunction occurring in an electronic emission-
    related engine system or component not otherwise described above that 
    either provides input to or receives commands from the on-board 
    computer and has a measurable impact on emissions; monitoring of 
    components required by this paragraph (b)(6) must be satisfied by 
    employing electrical circuit continuity checks and rationality checks 
    for computer input components (input values within manufacturer 
    specified ranges based on other available operating parameters), and 
    functionality checks for computer output components (proper functional 
    response to computer commands) except that the Administrator may waive 
    such a rationality or functionality check where the manufacturer has 
    demonstrated infeasibility. Malfunctions are defined as a failure of 
    the system or component to meet the electrical circuit continuity 
    checks or the rationality or functionality checks.
        (7) Performance of OBD functions. Oxygen sensor or any other 
    component deterioration or malfunction which renders that sensor or 
    component incapable of performing its function as part of the OBD 
    system must be detected and identified on vehicles so equipped.
        (c) Malfunction indicator light (MIL). The OBD system must 
    incorporate a malfunction indicator light (MIL) readily visible to the 
    vehicle operator. When illuminated, the MIL must display ``Check 
    Engine,'' ``Service Engine Soon,'' a universally recognizable engine 
    symbol, or a similar phrase or symbol approved by the Administrator. 
    More than one general purpose malfunction indicator light for emission-
    related problems should not be used; separate specific purpose warning 
    lights (e.g. brake system, fasten seat belt, oil pressure, etc.) are 
    permitted. The use of red for the OBD-related malfunction indicator 
    light is prohibited.
        (d) MIL illumination. The MIL must illuminate and remain 
    illuminated when any of the conditions specified in paragraph (b) of 
    this section are detected and verified, or whenever the engine control 
    enters a default or secondary mode of operation considered abnormal for 
    the given engine operating conditions. The MIL must blink once per 
    second under any period of operation during which engine misfire is 
    occurring and catalyst damage is imminent. If such misfire is detected 
    again during the following driving cycle (i.e., operation consisting 
    of, at a minimum, engine start-up and engine shut-off) or the next 
    driving cycle in which similar conditions are encountered, the MIL must 
    maintain a steady illumination when the misfire is not occurring and 
    then remain illuminated until the MIL extinguishing criteria of this 
    section are satisfied. The MIL must also illuminate when the vehicle's 
    ignition is in the ``key-on'' position before engine starting or 
    cranking and extinguish after engine starting if no malfunction has 
    previously been detected. If a fuel system or engine misfire 
    malfunction has previously been detected, the MIL may be extinguished 
    if the malfunction does not reoccur during three subsequent sequential 
    trips during which similar conditions are encountered and no new 
    malfunctions have been detected. Similar conditions are defined as 
    engine speed within 375 rpm, engine load within 20 percent, and engine 
    warm-up status equivalent to that under which the malfunction was first 
    detected. If any malfunction other than a fuel system or engine misfire 
    malfunction has been detected, the MIL may be extinguished if the 
    malfunction does not reoccur during three subsequent sequential trips 
    during which the monitoring system responsible for illuminating the MIL 
    functions without detecting the malfunction, and no new malfunctions 
    have been detected. Upon Administrator approval, statistical MIL 
    illumination protocols may be employed, provided they result in 
    comparable timeliness in detecting a malfunction and evaluating system 
    performance, i.e., three to six driving cycles would be considered 
    acceptable.
        (e) Storing of Computer Codes. The OBD system shall record and 
    store in computer memory diagnostic trouble codes and diagnostic 
    readiness codes indicating the status of the emission control system. 
    These codes shall be available through the standardized data link 
    connector per specifications as referenced in paragraph (h) of this 
    section.
        (1) A diagnostic trouble code must be stored for any detected and 
    verified malfunction causing MIL illumination. The stored diagnostic 
    trouble code must identify the malfunctioning system or component as 
    uniquely as possible. At the manufacturer's discretion, a diagnostic 
    trouble code may be stored for conditions not causing MIL illumination. 
    Regardless, a separate code should be stored indicating the expected 
    MIL illumination status (i.e., MIL commanded ``ON,'' MIL commanded 
    ``OFF'').
        (2) For a single misfiring cylinder, the diagnostic trouble code(s) 
    must uniquely identify the cylinder, unless the manufacturer submits 
    data and/or engineering evaluations which adequately demonstrate that 
    the misfiring cylinder cannot be reliably identified under certain 
    operating conditions. For diesel engines only, the specific cylinder 
    for which combustion cannot be detected need not be identified if new 
    hardware would be required to do so. The diagnostic trouble
    
    [[Page 58544]]
    
    code must identify multiple misfiring cylinder conditions; under 
    multiple misfire conditions, the misfiring cylinders need not be 
    uniquely identified if a distinct multiple misfire diagnostic trouble 
    code is stored.
        (3) The diagnostic system may erase a diagnostic trouble code if 
    the same code is not re-registered in at least 40 engine warm-up 
    cycles, and the malfunction indicator light is not illuminated for that 
    code.
        (4) Separate status codes, or readiness codes, must be stored in 
    computer memory to identify correctly functioning emission control 
    systems and those emission control systems which require further engine 
    operation to complete proper diagnostic evaluation. A readiness code 
    need not be stored for those monitors that can be considered 
    continuously operating monitors (e.g., misfire monitor, fuel system 
    monitor, etc.). Readiness codes should never be set to ``not ready'' 
    status upon key-on or key-off; intentional setting of readiness codes 
    to ``not ready'' status via service procedures must apply to all such 
    codes, rather than applying to individual codes. Subject to 
    Administrator approval, if monitoring is disabled for a multiple number 
    of driving cycles (i.e., more than one) due to the continued presence 
    of extreme operating conditions (e.g., ambient temperatures below 
    40 deg.F, or altitudes above 8000 feet), readiness for the subject 
    monitoring system may be set to ``ready'' status without monitoring 
    having been completed. Administrator approval shall be based on the 
    conditions for monitoring system disablement, and the number of driving 
    cycles specified without completion of monitoring before readiness is 
    indicated.
        (f) Available diagnostic data. (1) Upon determination of the first 
    malfunction of any component or system, ``freeze frame'' engine 
    conditions present at the time must be stored in computer memory. 
    Should a subsequent fuel system or misfire malfunction occur, any 
    previously stored freeze frame conditions must be replaced by the fuel 
    system or misfire conditions (whichever occurs first). Stored engine 
    conditions must include, but are not limited to: engine speed, open or 
    closed loop operation, fuel system commands, coolant temperature, 
    calculated load value, fuel pressure, vehicle speed, air flow rate, and 
    intake manifold pressure if the information needed to determine these 
    conditions is available to the computer. For freeze frame storage, the 
    manufacturer must include the most appropriate set of conditions to 
    facilitate effective repairs. If the diagnostic trouble code causing 
    the conditions to be stored is erased in accordance with paragraph (d) 
    of this section, the stored engine conditions may also be erased.
        (2) The following data in addition to the required freeze frame 
    information must be made available on demand through the serial port on 
    the standardized data link connector, if the information is available 
    to the on-board computer or can be determined using information 
    available to the on-board computer: Diagnostic trouble codes, engine 
    coolant temperature, fuel control system status (closed loop, open 
    loop, other), fuel trim, ignition timing advance, intake air 
    temperature, manifold air pressure, air flow rate, engine RPM, throttle 
    position sensor output value, secondary air status (upstream, 
    downstream, or atmosphere), calculated load value, vehicle speed, and 
    fuel pressure. The signals must be provided in standard units based on 
    SAE specifications incorporated by reference in paragraph (h) of this 
    section. Actual signals must be clearly identified separately from 
    default value or limp home signals.
        (3) For all OBD systems for which specific on-board evaluation 
    tests are conducted (catalyst, oxygen sensor, etc.), the results of the 
    most recent test performed by the vehicle, and the limits to which the 
    system is compared must be available through the standardized data link 
    connector per the appropriate standardized specifications as referenced 
    in paragraph (h) of this section.
        (4) Access to the data required to be made available under this 
    section shall be unrestricted and shall not require any access codes or 
    devices that are only available from the manufacturer.
        (g) Exceptions. The OBD system is not required to evaluate systems 
    or components during malfunction conditions if such evaluation would 
    result in a risk to safety or failure of systems or components. 
    Additionally, the OBD system is not required to evaluate systems or 
    components during operation of a power take-off unit such as a dump 
    bed, snow plow blade, or aerial bucket, etc.
        (h) Reference materials. The OBD system shall provide for 
    standardized access and conform with the following Society of 
    Automotive Engineers (SAE) standards and/or the following International 
    Standards Organization (ISO) standards. The following documents are 
    incorporated by reference (see Sec. 86.1):
        (1) SAE material. Copies of these materials may be obtained from 
    the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, 
    Warrendale, PA 15096-0001.
        (i) SAE J1850 ``Class B Data Communication Network Interface,'' 
    (July 1995) shall be used as the on-board to off-board communications 
    protocol. All emission related messages sent to the scan tool over a 
    J1850 data link shall use the Cyclic Redundancy Check and the three 
    byte header, and shall not use inter-byte separation or checksums.
        (ii) Basic diagnostic data (as specified in Secs. 86.094-17(e) and 
    (f)) shall be provided in the format and units in SAE J1979 E/E 
    Diagnostic Test Modes,''(July 1996).
        (iii) Diagnostic trouble codes shall be consistent with SAE J2012 
    ``Recommended Practices for Diagnostic Trouble Code Definitions,'' 
    (July 1996).
        (iv) The connection interface between the OBD system and test 
    equipment and diagnostic tools shall meet the functional requirements 
    of SAE J1962 ``Diagnostic Connector,'' (January 1995).
        (v) As an alternative to the above standards, heavy-duty engines 
    may conform to the specifications of SAE J1939 ``Recommended Practice 
    for a Serial Control and Communications Vehicle Network.''
        (2) ISO materials. Copies of these materials may be obtained from 
    the International Organization for Standardization, Case Postale 56, 
    CH-1211 Geneva 20, Switzerland.
        (i) ISO 9141-2 ``Road vehicles--Diagnostic systems--Part 2: CARB 
    requirements for interchange of digital information,'' (February 1994) 
    may be used as an alternative to SAE J1850 as the on-board to off-board 
    communications protocol.
        (ii) ISO 14230-4 ``Road vehicles--Diagnostic systems--KWP 2000 
    requirements for Emission-related systems'' may also be used as an 
    alternative to SAE J1850.
        (i) Deficiencies and Alternate Fueled Engines. Upon application by 
    the manufacturer, the Administrator may accept an OBD system as 
    compliant even though specific requirements are not fully met. Such 
    compliances without meeting specific requirements, or deficiencies, 
    will be granted only if compliance would be infeasible or unreasonable 
    considering such factors as, but not limited to: technical feasibility 
    of the given monitor and lead time and production cycles including 
    phase-in or phase-out of engines or vehicle designs and programmed 
    upgrades of computers. Unmet requirements should not be carried over 
    from the previous model year except where unreasonable hardware or 
    software modifications would be necessary to correct the deficiency, 
    and
    
    [[Page 58545]]
    
    the manufacturer has demonstrated an acceptable level of effort toward 
    compliance as determined by the Administrator. Furthermore, EPA will 
    not accept any deficiency requests that include the complete lack of a 
    major diagnostic monitor (``major'' diagnostic monitors being those for 
    exhaust aftertreatment devices, oxygen sensor, engine misfire, 
    evaporative leaks, and diesel EGR, if equipped), with the possible 
    exception of the special provisions for alternate fueled engines. For 
    alternate fueled heavy-duty engines (e.g. natural gas, liquefied 
    petroleum gas, methanol, ethanol), beginning with the model year for 
    which alternate fuel emission standards are applicable and extending 
    through the 2006 model year, manufacturers may request the 
    Administrator to waive specific monitoring requirements of this section 
    for which monitoring may not be reliable with respect to the use of the 
    alternate fuel. At a minimum, alternate fuel engines must be equipped 
    with an OBD system meeting OBD requirements to the extent feasible as 
    approved by the Administrator.
        (j) California OBDII Compliance Option. For heavy-duty engines at 
    or below 14,000 pounds GVWR, demonstration of compliance with 
    California OBD II requirements (Title 13 California Code Sec. 1968.1), 
    as modified pursuant to California Mail Out #97-24 (December 9, 1997), 
    shall satisfy the requirements of this section, except that the 
    exemption to the catalyst monitoring provisions of California Code Sec. 
    1968.1(b)(1.1.2) for diesel engines does not apply, and compliance with 
    California Code Secs. 1968.1(b)(4.2.2), pertaining to 0.02 inch 
    evaporative leak detection, and 1968.1(d), pertaining to tampering 
    protection, are not required to satisfy the requirements of this 
    section. Also, the deficiency fine provisions of California Code Secs. 
    1968.1(m)(6.1) and (6.2) do not apply.
        (k) Phase-in for Heavy-Duty Engines. Manufacturers of heavy-duty 
    engines must comply with the OBD requirements in this section according 
    to the following phase-in schedule, based on the percentage of 
    projected engine sales within each category:
    
                   OBD Compliance Phase-in Heavy-Duty Engines
    [Intended for use in a heavy-duty vehicle weighing 14,000 pounds GVWR or
                                      less]
    ------------------------------------------------------------------------
                                               Phase-in based on projected
                   Model year                             sales
    ------------------------------------------------------------------------
    2004 MY................................  --40% compliance.
                                             --alternative fuel waivers
                                              available.
    2005 MY................................  --60% compliance.
                                             --alternative fuel waivers
                                              available.
    2006 MY................................  --80% compliance.
                                             --alternative fuel waivers
                                              available.
    2007+ MY...............................  --100% compliance.
    ------------------------------------------------------------------------
    
        17. Section 86.004-21 is amended by adding paragraphs (m) through 
    (p), to read as follows:
    
    
    Sec. 86.004-21  Application for certification.
    
    * * * * *
        (m) For diesel heavy-duty engines, the manufacturer must provide 
    the following additional information pertaining to the supplemental 
    steady-state test conducted under Sec. 86.1360-2004:
        (1) Weighted average emissions data, calculated according to 
    Sec. 86.1360-2004(e)(5), for all pollutants for which an emission 
    standard is established in Sec. 86.004-11(a);
        (2) Brake specific gaseous emission data for each of the 13 test 
    points (identified under Sec. 86.1360-2004(b)(1)) and the 3 EPA-
    selected test points (identified under Sec. 86.1360-2004(b)(2));
        (3) Concentrations and mass flow rates of all regulated gaseous 
    emissions plus carbon dioxide;
        (4) Exhaust smoke opacity (``k'' value);
        (5) Values of all emission-related engine control variables at each 
    test point;
        (6) Weighted average particulate matter;
        (7) A statement that the test results correspond to the maximum 
    NOX producing condition for a 30 second or longer averaging 
    period reasonably expected to be encountered at each test point during 
    normal engine operation and use. This statement corresponds to the test 
    requirement under Sec. 86.1360-2004(e)(3). The manufacturer also must 
    provide a detailed description of all testing, engineering analyses, 
    and other information which provides the basis for this statement;
        (8) A statement that the engines will comply with the weighted 
    average emissions standard and Maximum Allowable Emission Limits 
    specified in Sec. 86.004-11(a)(3) during all normal engine operation 
    and use. The manufacturer also must provide a detailed description of 
    all testing, engineering analyses, and other information which provides 
    the basis for this statement.
        (n) The manufacturer must provide a statement in the application 
    for certification that the diesel heavy-duty engine for which 
    certification is being requested will comply with the applicable Not-
    To-Exceed Limits specified in Sec. 86.004-11(a)(4) when operated under 
    all conditions which may reasonably be expected to be encountered in 
    normal vehicle operation and use. The manufacturer also must provide a 
    detailed description of all testing, engineering analyses, and other 
    information which provides the basis for this statement.
        (o) The manufacturer must provide in each application for 
    certification of a heavy-duty diesel engine emission test results from 
    the Load Response Test conducted according to Sec. 86.1380, including 
    at a minimum test results conducted at each of the speeds identified in 
    Sec. 86.1380.
        (p) Upon request from EPA, a manufacturer must provide to EPA 
    hardware (including scan tools), passwords, and/or documentation 
    necessary for EPA to read and interpret (in engineering units if 
    applicable) any information broadcast by an engine's on-board computers 
    and electronic control modules which relates in anyway to emission 
    control devices and auxiliary emission control devices. Passwords 
    include any information necessary to enable generic scan tools or 
    personal computers access to proprietary emission related information 
    broadcast by an engine's on-board computer, if such passwords exist. 
    This requirement includes access by EPA to any proprietary code 
    information which may be broadcast by an engine's on-board computer and 
    electronic control modules. Information which is confidential business 
    information must be marked as such. Engineering units refers to the 
    ability to read and interpret information in commonly understood 
    engineering units, for example, engine speed in revolutions per minute 
    or per second, injection timing parameters such as start of injection 
    in degree's before top-dead center, fueling rates in cubic centimeters 
    per stroke, vehicle speed in milers per hour or per kilometer.
        18. Section 86.004-30 is amended by revising paragraph (f), to read 
    as follows:
    
    
    Sec. 86.004-30  Certification.
    
    * * * * *
    
    [[Page 58546]]
    
        (f) For engine families required to have an OBD system, 
    certification will not be granted if, for any test vehicle approved by 
    the Administrator in consultation with the manufacturer, the 
    malfunction indicator light does not illuminate under any of the 
    following circumstances, unless the manufacturer can demonstrate that 
    any identified OBD problems discovered during the Administrator's 
    evaluation will be corrected on production vehicles.
        (1)(i) Otto-cycle. A catalyst is replaced with a deteriorated or 
    defective catalyst, or an electronic simulation of such, resulting in 
    an increase of 1.5 times the NMHC+NOX standard or FEL above 
    the NMHC+NOX emission level measured using a representative 
    4000 mile catalyst system.
        (ii) Diesel. If monitored for emissions performance--a catalyst or 
    particulate trap is replaced with a deteriorated or defective catalyst 
    or trap, or an electronic simulation of such, resulting in exhaust 
    emissions exceeding 1.5 times the applicable standard or FEL for 
    NMHC+NOX or PM. If not monitored for emissions performance--
    removal of the catalyst or particulate trap is not detected and 
    identified.
        (2)(i) Otto-cycle. An engine misfire condition is induced resulting 
    in exhaust emissions exceeding 1.5 times the applicable standards or 
    FEL for NMHC+NOX or CO.
        (ii) Diesel. An engine misfire condition is induced and is not 
    detected.
        (3) If so equipped, any oxygen sensor is replaced with a 
    deteriorated or defective oxygen sensor, or an electronic simulation of 
    such, resulting in exhaust emissions exceeding 1.5 times the applicable 
    standard or FEL for NMHC+NOX or CO.
        (4) If so equipped, a vapor leak is introduced in the evaporative 
    and/or refueling system (excluding the tubing and connections between 
    the purge valve and the intake manifold) greater than or equal in 
    magnitude to a leak caused by a 0.040 inch diameter orifice, or the 
    evaporative purge air flow is blocked or otherwise eliminated from the 
    complete evaporative emission control system.
        (5) A malfunction condition is induced in any emission-related 
    engine system or component, including but not necessarily limited to, 
    the exhaust gas recirculation (EGR) system, if equipped, the secondary 
    air system, if equipped, and the fuel control system, singularly 
    resulting in exhaust emissions exceeding 1.5 times the applicable 
    emission standard or FEL for NMHC+NOX, CO or PM.
        (6) A malfunction condition is induced in an electronic emission-
    related engine system or component not otherwise described above that 
    either provides input to or receives commands from the on-board 
    computer resulting in a measurable impact on emissions.
        20. Subpart B is amended by revising the heading of the subpart, to 
    read as follows:
    
    Subpart B--Emission Regulations for 1977 and Later Model Year New 
    Light-Duty Vehicles and New Light-Duty Trucks and New Otto-Cycle 
    Complete Heavy-Duty Vehicles; Test Procedures
    
        21. Section 86.101 is amended by revising paragraphs (a) 
    introductory text and (d), and by adding paragraph (e) to read as 
    follows:
    
    
    Sec. 86.101  General applicability.
    
        (a) The provisions of this subpart are applicable to 1997 and later 
    model year new light-duty vehicles and light duty trucks, and 2004 and 
    later model year new Otto-cycle complete heavy-duty vehicles.
    * * * * *
        (d) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of Subpart S of this part.
        (e) References in this subpart to light-duty vehicles or light-duty 
    trucks shall be deemed to apply to light-duty vehicles, light-duty 
    trucks, or Otto-cycle complete heavy-duty vehicles as applicable for 
    manufacturers certifying new light-duty vehicles, light-duty trucks, 
    and Otto-cycle complete heavy-duty vehicles under the provisions of 
    Subpart S of this part.
        22. Section 86.129-94 is amended by revising paragraph (a) to read 
    as follows:
    
    
    Sec. 86.129-94  Road load power, test weight, inertia weight class 
    determination, and fuel temperature profile.
    
    * * * * *
        (a) Flywheels, electrical, or other means of simulating test weight 
    as shown in the following table shall be used. If the equivalent test 
    weight specified is not available on the dynamometer being used, the 
    next higher equivalent test weight (not to exceed 250 pounds) available 
    shall be used:
    
    ------------------------------------------------------------------------
                                                Equivalent
              Test weight basis 4,5             test weight   Inertia weight
                                                 (pounds)     class (pounds)
    ------------------------------------------------------------------------
             Road load power at 50 mi/hour--light-duty trucks 1,2,3
    ------------------------------------------------------------------------
    Up to 1062..............................           1,000           1,000
    1063 to 1187............................           1,125           1,000
    1188 to 1312............................           1,250           1,250
    1313 to 1437............................           1,375           1,250
    1438 to 1562............................           1,500           1,500
    1563 to 1687............................           1,625           1,500
    1688 to 1812............................           1,750           1,750
    1813 to 1937............................           1,875           1,750
    1938 to 2062............................           2,000           2,000
    2063 to 2187............................           2,125           2,000
    2188 to 2312............................           2,250           2,250
    2313 to 2437............................           2,375           2,250
    2438 to 2562............................           2,500           2,500
    2563 to 2687............................           2,625           2,500
    2688 to 2812............................           2,750           2,750
    2813 to 2937............................           2,875           2,750
    2938 to 3062............................           3,000           3,000
    3063 to 3187............................           3,125           3,000
    3188 to 3312............................           3,250           3,000
    3313 to 3437............................           3,375           3,500
    
    [[Page 58547]]
    
     
    3438 to 3562............................           3,500           3,500
    3563 to 3687............................           3,625           3,500
    3688 to 3812............................           3,750           3,500
    3813 to 3937............................           3,875           4,000
    3938 to 4125............................           4,000           4,000
    4126 to 4375............................           4,250           4,000
    4376 to 4625............................           4,500           4,500
    4626 to 4875............................           4,750           4,500
    4876 to 5125............................           5,000           5,000
    5126 to 5375............................           5,250           5,000
    5376 to 5750............................           5,500           5,500
    5751 to 6250............................           6,000           6,000
    6251 to 6750............................           6,500           6,500
    6751 to 7250............................           7,000           7,000
    7251 to 7750............................           7,500           7,500
    7751 to 8250............................           8,000           8,000
    8251 to 8750............................           8,500           8,500
    8751 to 9250............................           9,000           9,000
    9251 to 9750............................           9,500           9,500
    9751 to 10250...........................          10,000          10,000
    10251 to 10750..........................          10,500          10,500
    10751 to 11250..........................          11,000          11,000
    11251 to 11750..........................          11,500          11,500
    11751 to 12250..........................          12,000          12,000
    12251 to 12750..........................          12,500          12,500
    12751 to 13250..........................          13,000          13,000
    13251 to 13750..........................          13,500          13,500
    13751 to 14000..........................          14,000         14,000
    ------------------------------------------------------------------------
    \1\ For all light-duty trucks except vans, and for heavy-duty vehicles
      optionally certified as light-duty trucks, and for complete heavy-duty
      vehicles, the road load power (horsepower) at 50 mi/h shall be 0.58
      times B (defined in footnote 3 of this table) rounded to the nearest
      \1/2\ horsepower.
    \2\ For vans, the road load power at 50 mi/h (horsepower) shall be 0.50
      times B (defined in footnote 3 of this table) rounded to the nearest
      \1/2\ horsepower.
    \3\ B is the basic vehicle frontal area (square foot) plus the
      additional frontal area (square foot) of mirrors and optional
      equipment exceeding 0.1 ft2 which are anticipated to be sold on more
      than 33 percent of the car line. Frontal area measurements shall be
      computed to the nearest 10th of a square foot using a method approved
      in advance by the Administrator.
    \4\ For model year 1994 and later heavy light-duty trucks not subject to
      the Tier 0 standards of Sec.  86.094-9, test weight basis is as
      follows: for emissions tests, the basis shall be adjusted loaded
      vehicle weight, as defined in Sec.  86.094-2; and for fuel economy
      tests, the basis shall be loaded vehicle weight, as defined in Sec.
      86.082-2, or, at the manufacturer's option, adjusted loaded vehicle
      weight as defined in Sec.  86.094-2. For all other vehicles, test
      weight basis shall be loaded vehicle weight, as defined in Sec.
      86.082-2.
    \5\ Light-duty vehicles over 5,750 lb. loaded vehicle weight shall be
      tested at a 5,500 lb. equivalent test weight.
    
    * * * * *
    
    Subpart H--[Amended]
    
        23. Section 86.701-94 is revised to read as follows:
    
    
    Sec. 86.701-94  General applicability.
    
        (a) The provisions of this subpart apply to: 1994 and later model 
    year Otto-cycle and diesel light-duty vehicles; 1994 and later model 
    year Otto-cycle and diesel light-duty trucks; and 1994 and later model 
    year Otto-cycle and diesel heavy-duty engines; and 2004 and later model 
    year Otto-cycle complete heavy-duty vehicles. The provisions of subpart 
    B of this part apply to this subpart.
        (b) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of subpart S of this part.
    
    Subpart K--[Amended]
    
        24. Section 86.1001-84 is amended by revising paragraph (b), to 
    read as follows:
    
    
    Sec. 86.1001-84  Applicability.
    
    * * * * *
        (b) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of subpart S of this part.
    
    Subpart L--[Amended]
    
        25. Section 86.1101-87 is revised to read as follows:
    
    
    Sec. 86.1101-87  Applicability.
    
        (a) The provisions of this subpart are applicable for 1987 and 
    later model year gasoline-fueled and diesel heavy-duty engines and 
    heavy-duty vehicles. These vehicles include light-duty trucks rated in 
    excess of 6,000 pounds gross vehicle weight.
        (b) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty trucks 
    and Otto-cycle complete heavy-duty vehicles under the provisions of 
    subpart S of this part.
    
    Subpart N--[Amended]
    
        26. Section 86.1304-90 is revised to read as follows:
    
    
    Sec. 86.1304-90  Section numbering; construction.
    
        (a) Section numbering. The model year of initial applicability is 
    indicated by the section number. The two digits following the hyphen 
    designate the first model year for which a section is applicable. The 
    section continues to apply to subsequent model years unless a later 
    model year section is adopted.
    
        Example: Section 86.18xx-01 applies to the 2001 and subsequent 
    model years. If a
    
    [[Page 58548]]
    
    Sec. 86.18xx-03 is promulgated it would apply beginning with the 
    2003 model year; Sec. 86.18xx-01 would apply to model years 2001 
    through 2002.
    
        (b) A section reference without a model year suffix refers to the 
    section applicable for the appropriate model year.
        27. A new Sec. 86.1305-2004 is added to subpart N, to read as 
    follows:
    
    
    Sec. 86.1305-2004  Introduction; structure of subpart.
    
        (a) This subpart describes the equipment required and the 
    procedures to follow in order to perform exhaust emissions test on 
    Otto-cycle and diesel heavy duty engines. Subpart A of this part sets 
    forth the emission standards and general testing requirements to comply 
    with EPA certification procedures.
        (b) This subpart contains five key sets of requirements, as 
    follows: specifications and equipment needs (Secs. 86.1306 through 
    86.1314); calibration methods and frequencies (Secs. 86.1316 through 
    86.1326); test procedures (Secs. 86.1327 through 86.1341 and 
    Secs. 86.1360 through 86.1380); calculation formulas (Secs. 86.1342 and 
    86.1343); and data requirements (Sec. 86.1344).
        29. A new Sec. 86.1360-2004 is added to subpart N to read as 
    follows:
    
    
    Sec. 86.1360-2004  Supplemental steady-state test; test cycle and 
    procedures.
    
        (a) Applicability. This section applies to diesel heavy duty 
    engines.
        (b) Test cycle. (1) The following 13-mode cycle must be followed in 
    dynamometer operation on the test engine:
    
    ----------------------------------------------------------------------------------------------------------------
                                                                                 Percent     Weighting   Mode length
                      Mode No.                           Engine speed              load        factor      (minutes)
    ----------------------------------------------------------------------------------------------------------------
    1..........................................  Idle                          ...........         0.15            4
    2..........................................  A                                     100         0.08            2
    3..........................................  B                                      50         0.10            2
    4..........................................  B                                      75         0.10            2
    5..........................................  A                                      50         0.05            2
    6..........................................  A                                      75         0.05            2
    7..........................................  A                                      25         0.05            2
    8..........................................  B                                     100         0.09            2
    9..........................................  B                                      25         0.10            2
    10.........................................  C                                     100         0.08            2
    11.........................................  C                                      25         0.05            2
    12.........................................  C                                      75         0.05            2
    13.........................................  C                                      50         0.05            2
    ----------------------------------------------------------------------------------------------------------------
    
        (2) In addition to the 13 test points identified in paragraph 
    (b)(1) of this section, EPA may select, and require the manufacturer to 
    conduct the test using, up to 3 additional test points within the 
    control area (as defined in paragraph (d) of this section). EPA will 
    notify the manufacturer of these supplemental test points in writing in 
    a timely manner before the test.
        (c) Determining Engine Speeds. (1) The engine speeds A, B and C, 
    referenced in the table in paragraph (b)(1) of this section, and speeds 
    D and E, referenced in Sec. 86.1380, must be determined as follows:
    
    Speed A = nlo + 25% (nhi-nlo)
    Speed B = nlo+ 50% (nhi-nlo)
    Speed C = nlo + 75% (nhi-nlo)
    Speed D = nlo + 100% (nhi-nlo)
    Speed E = nlo + 15% (nhi-nlo)
    
    Where:
    
    nhi = High speed as determined by calculating 70% of the 
    maximum power. The highest engine speed where this power value occurs 
    on the power curve is defined as nhi.
    nlo = Low speed as determined by calculating 50% of the 
    maximum power. The lowest engine speed where this power value occurs on 
    the power curve is defined as nlo.
    Maximum power = the maximum observed power calculated from the torque/
    speed ratios determined according to the engine mapping procedures 
    defined in Sec. 86.1332. Power = (speed  x  torque)/5252, where speed 
    is in revolutions per minute and torque is in foot-pounds.
    
        (2) If the measured engine speeds A, B, and C are within 3 % of the 
    engine speeds as declared by the manufacturer, the declared engine 
    speeds shall be used for the emissions test. If the tolerance is 
    exceeded for any of the engine speeds, the measured engine speeds shall 
    be used for the emissions test.
        (d) Determining the control area. The control area is the area 
    between the engine speeds A and C, as defined in paragraph (c) of this 
    section, and between 25 to 100 percent load.
        (e) Test requirements. (1) Engine warm-up. Prior to beginning the 
    test sequence, the engine must be warmed-up according to the procedures 
    in Sec. 86.1332-90(d)(3).
        (2) Test sequence. The test must be performed in the order of the 
    mode numbers in paragraph (b)(1) of this section. The EPA-selected test 
    points identified under paragraph (b)(2) of this section must be 
    performed immediately upon completion of mode 13. The engine must be 
    operated for the prescribed time in each mode, completing engine speed 
    and load changes in the first 20 seconds of each mode. The specified 
    speed must be held to within 50 rpm and the specified 
    torque must be held to within 2 percent of the maximum 
    torque at the test speed.
        (3) The test must be conducted with all emission-related engine 
    control variables in the highest brake-specific NOX 
    emissions state which could be encountered for a 30 second or longer 
    averaging period at the given test point.
        (4) Exhaust emissions measurements and calculations. (i) 
    Manufacturers must follow the exhaust emissions sample analysis 
    procedures under Sec. 86.1340, and the calculation formulas and 
    procedures under Sec. 86.1342, for the 13-mode cycle and the 3 EPA-
    selected test points.
        (ii) Prior to starting the measurements for the EPA-selected test 
    points, the engine must be conditioned at mode 13 for a period of three 
    minutes.
        (5) Calculating the weighted average emissions. For each regulated 
    gaseous pollutant, the weighted average emissions must be calculated as 
    follows:
    [GRAPHIC] [TIFF OMITTED] TP29OC99.005
    
    Where:
    
    AWA = Weighted average emissions for each regulated gaseous 
    pollutant, in grams per brake horse-power hour.
    AWM = Weighted mass emissions level, in grams per brake 
    horse-power hour, as defined in Sec. 86.1342.
    
    [[Page 58549]]
    
    WF = Weighting factor corresponding to each mode of the 
    steady-state test cycle, as defined in paragraph (b)(1) of this 
    section.
    i = The modes of the steady-state test cycle, as defined in paragraph 
    (b)(1) of this section.
    n = 13, corresponding to the 13 modes of the steady-state test cycle, 
    as defined in paragraph (b)(1) of this section.
    
        (f) Maximum Allowable Emission Limits. (1) For gaseous emissions, 
    the 12 non-idle test point results and the four-point linear 
    interpolation procedure specified in paragraph (g) of this section for 
    intermediate conditions, shall define Maximum Allowable Emission Limits 
    for purposes of Sec. 86.004-11(a)(3). The control area extends from the 
    25% to the 75% engine speeds, at engine loads of 25% to 100%, as 
    defined in paragraph (d) of this section. Figure 1 of this paragraph 
    (f)(1) depicts a sample Maximum Allowable Emission Limit curve, for 
    illustration purposes only, as follows:
    
    BILLING CODE 6560-50-P
    [GRAPHIC] [TIFF OMITTED] TP29OC99.006
    
    
    BILLING CODE 6560-50-C
        (2) If the weighted average emissions, calculated according to 
    paragraph (e)(5) of this section, for any gaseous pollutant is lower 
    than required by Sec. 86.004-11(a)(3), each of the 13 test values for 
    that pollutant shall first be multiplied by the ratio of the applicable 
    emission standard (under Sec. 86.004-11(a)(3)) to the weighted average 
    emissions value, and then by 1.05 for interpolation allowance, before 
    determining the Maximum Allowable Emission Limits under paragraph 
    (f)(1) of this section.
        (3) If the Maximum Allowable Emission Limit for any point, as 
    calculated under paragraphs (f)(1) and (2) of this section, is greater 
    than the applicable Not-to-Exceed limit (if within the Not-to-Exceed 
    control area defined in Sec. 86.1370-2004(b)), then the Maximum 
    Allowable Emission Limit for that point shall be defined as the 
    applicable Not-to-Exceed limit.
        (g) Calculating intermediate test points. (1) For the three test 
    points selected by EPA under paragraph (b)(2) of this section, the 
    emissions must be measured and calculated according to Sec. 86.1342 and 
    also determined by interpolation from the modes of the test cycle 
    closest to the respective test point according to paragraph (g)(2) of 
    this section. The measured values then must be compared to the 
    interpolated values according to paragraph (g)(3) of this section.
        (2) Interpolating emission values from the test cycle. The gaseous 
    emissions for each regulated pollutant for each of the control points 
    (Z) must be interpolated from the four closest modes of the test cycle 
    that envelop the selected control point Z as shown in Figure 2 of this 
    paragraph (g)(2).
        (i) For these modes (R, S, T, U), the following definitions apply:
    
    Speed (R) = Speed(T) = nRT
    Speed (S) = Speed(U) = nSU
    Per cent load (R) = Per cent load (S)
    Per cent load (T) = Per cent load (U)
    
        (ii) The gaseous emissions of the selected control point (Z) must 
    be calculated as follows:
    
    EZ = ERS + (ETU-ERS) * 
    (MZ-MRS)/(MTU-MRS)
    ETU = ET + 
    (EU-ET)*(nZ-nRT)/
    (nSU-nRT)
    ERS = ER + 
    (ES-ER)*(nZ-nRT)/
    (nSU-nRT)
    MTU = 
    MT+(MU-MT)*(nZ-nRT
    )/(nSU-nRT)
    (E) MRS = 
    MR+(MS-MR)*(nZ-nRT
    )/(nSU-nRT)
    
    Where:
    
    ER, ES, ET, EU = for each 
    regulated pollutant, specific gaseous emissions of the enveloping modes
    
    [[Page 58550]]
    
    calculated in accordance with Sec. 86.1342.
    MR, MS, MT, MU = engine 
    torque of the enveloping modes.
    
        (iii) Figure 2 follows:
    
    BILLING CODE 6560-50-P
    [GRAPHIC] [TIFF OMITTED] TP29OC99.007
    
    
    BILLING CODE 6560-50-C
        (3) Comparing calculated and interpolated emission values. The 
    measured specific gaseous emissions of the control point Z 
    (XZ) must be compared to the interpolated value 
    (EZ) as follows:
    
    Xdiff = 100*(XZ-EZ)/EZ
    
        30. A new Sec. 86.1361-2004 is added to subpart N, to read as 
    follows:
    
    
    Sec. 86.1361-2004  Maximum allowable emission limits; compliance in 
    actual operation.
    
        (a) Applicability. This section applies to diesel heavy-duty 
    engines.
        (b) General. Compliance with the Maximum Allowable Emission Limits 
    under Sec. 86.004-11(a)(3)(ii) may be determined under any conditions 
    that may reasonably be expected to be encountered in normal vehicle 
    operation and use. The engine may be tested in a vehicle in actual use 
    or on a dynamometer, under steady state or transient conditions, and 
    under varying ambient conditions. To determine compliance, test results 
    within the control area, defined in Sec. 86.1360-2004(d), shall be 
    compared to the Maximum Allowable Emission Limits, as determined in 
    Sec. 86.1360-2004(f), for the same engine speed and load. The engine, 
    when operated within the control area, must comply with the Maximum 
    Allowable Emission Limits.
        (c) Test conditions. Where the test conditions identified in 
    paragraph (b) of this section require departure from specific 
    provisions of this subpart (e.g., sampling time), testing shall be 
    conducted using good engineering practices. The manufacturer shall 
    submit a detailed description of any departures from the specific 
    testing provisions of this subpart and the justification for modifying 
    the test procedures, along with any test results submitted to EPA.
        (1) If EPA requires engine dynamometer testing by the manufacturer 
    outside of FTP conditions, such testing may be done at the 
    manufacturer's facility on existing equipment, and must be carried out 
    only within the limits of operation of the manufacturer's available 
    test equipment with regard to ambient temperature, humidity and 
    altitude. EPA may conduct its own testing at any ambient temperature, 
    humidity or altitude.
        (2) When tested under transient conditions, emission values to be 
    compared to the Maximum Allowable Emission Limits shall represent an 
    average of at least 30 seconds.
        (3) NOX emissions shall be corrected for humidity to a 
    standard level of 75 grains of water per pound of dry air. Outside the 
    temperature range of 68-86 degrees F, NOX and PM emissions 
    shall be corrected to 68 degrees F if below 68 degrees F, or to 86 
    degrees F if above 86 degrees F. Where a manufacturer test requires 
    such correction factors, the manufacturer must use good engineering 
    judgement and generally accepted engineering practice to determine the 
    appropriate correction factors, subject to EPA review.
        31. A new Sec. 86.1370-2004 is added to subpart N, to read as 
    follows:
    
    
    Sec. 86.1370-2004  Not-To-Exceed test procedures.
    
        (a) General. The purpose of this test procedure is to measure in-
    use emissions of heavy-duty diesel engines while operating within a 
    broad range of speed and load points (the Not-To-Exceed Control Area) 
    and under conditions which can reasonably be expected to be encountered 
    in normal vehicle operation and use. Emission results from this test 
    procedure are to be compared to the Not-To-Exceed Limits specified in 
    Sec. 86.004-11 (a)(4).
        (b) Not-To-Exceed Control Area for diesel heavy-duty engines. The 
    Not-To-Exceed Control Area for diesel heavy-
    
    [[Page 58551]]
    
    duty engines consists of the following engine speed and load points:
        (1) All operating speeds greater than the speed calculated using 
    the following formula, where nhi and nlo are 
    determined according to the provisions in Sec. 86.1360(c):
    
    nlo+0.15nhi(nhi-nlo)
    
        (2) All engine load points greater than or equal to 30% or more of 
    the maximum torque value produced by the engine.
        (3) Notwithstanding the provisions of paragraphs (b)(1) and (b)(2) 
    of this section, all operating speed and load points with brake 
    specific fuel consumption (BSFC) values within 5% of the minimum BSFC 
    value of the engine. The manufacturer may petition the Administrator at 
    certification to exclude such points if the manufacturer can 
    demonstrate that the engine is not expected to operate at such points 
    in normal vehicle operation and use. Engines equipped with drivelines 
    with multi-speed manual transmissions or automatic transmissions with a 
    finite number of gears are not subject the requirements of this 
    paragraph (b)(3).
        (4) Notwithstanding the provisions of paragraphs (b)(1) through 
    (b)(3) of this section, speed and load points below 30% of the maximum 
    power value produced by the engine shall be excluded from the Not-To-
    Exceed Control Area for all emissions.
        (5) For particulate matter only, speed and load points determined 
    by one of the following methods, whichever is applicable, shall be 
    excluded from the Not-To-Exceed Control Area. B and C engine speeds 
    shall be determined according to the provisions of Sec. 86.1350 (c):
        (i) If the C speed is below 2400 rpm, the speed and load points to 
    the right of or below the line formed by connecting the following two 
    points:
        (A) 30% of maximum torque or 30% of maximum power, whichever is 
    greater, at the B speed;
        (B) 70% of maximum power at 100% speed (nhi);
        (ii) If the C speed is above 2400 rpm, the speed and load points to 
    the right of the line formed by connecting the two points in paragraphs 
    (b)(5)(ii)(A) and (B) of this section and below the line formed by 
    connecting the two points in paragraphs (b)(5)(ii)(B) and (C) of this 
    section:
        (A) 30% of maximum torque or 30% of maximum power, whichever is 
    greater, at the B speed;
        (B) 50% of maximum power at 2400 rpm;
        (C) 70% of maximum power at 100% speed (nhi).
        (c) [Reserved]
        (d) Not-To-Exceed Control Area Limits. (1) When operated within the 
    Not-To-Exceed Control Area defined in paragraph (b) of this section, 
    diesel engine emissions shall not exceed the applicable Not-To-Exceed 
    Limits specified in Sec. 86.004-11 (a)(4) when averaged over any period 
    of time greater than or equal to 30 seconds.
        (2) [Reserved]
        (e) Ambient Corrections. The measured data shall be corrected based 
    on the ambient conditions under which it was taken. The temperature and 
    humidity correction factors will be based on good engineering practice.
        (1) NOX emissions shall be corrected for humidity to a 
    standard humidity level of 50 grains (7.14 g/kg) if the humidity of the 
    intake air was below 50 grains, or to 75 grains (10.71 g/kg) if above 
    75 grains.
        (2) NOX and PM emissions shall be corrected for 
    temperature to a temperature of 55 degrees F (12.8 degrees C) for 
    intake air temperatures below 55 degrees F or to 95 degrees F (35.0 
    degrees C) if the intake air is above 95 degrees F.
        (3) No temperature or humidity correction factors shall be used 
    within the ranges of 50-75 grains or 55-95 degrees F.
        33. A new Sec. 86.1372-2004 is added to subpart N, to read as 
    follows:
    
    
    Sec. 86.1372-2004  Measuring smoke emissions.
    
        This section contains the measurement techniques to be used for 
    determining compliance with the filter smoke limit or opacity limits in 
    Sec. 86.004-11(b)(1)(iv).
        (a) For steady-state or transient smoke testing using full-flow 
    opacimeters, equipment meeting the requirements of subpart I of this 
    part or ISO/DIS-11614 ``Reciprocating internal combustion compression-
    ignition engines--Apparatus for measurement of the opacity and for 
    determination of the light absorption coefficient of exhaust gas' is 
    required. This document is incorporated by reference (see Sec. 86.1).
        (1) All full-flow opacimeter measurements shall be reported as the 
    equivalent percent opacity for a five inch effective optical path 
    length using the Beer-Lambert relationship.
        (2) Zero and full-scale (100 percent opacity) span shall be 
    adjusted prior to testing.
        (3) Post test zero and full scale span checks shall be performed. 
    For valid tests, zero and span drift between the pre-test and post-test 
    checks shall be less than two percent of full-scale.
        (4) Opacimeter calibration and linearity checks shall be performed 
    using manufacturer's recommendations or good engineering practice.
        (b) For steady-state testing using a filter-type smokemeter, 
    equipment meeting the requirements of ISO/FDIS-10054 ``Internal 
    combustion compression-ignition engines--Measurement apparatus for 
    smoke from engines operating under steady-state conditions--Filter-type 
    smokemeter'' is recommended.
        (1) All filter-type smokemeter results shall be reported as a 
    filter smoke number (FSN) that is similar to the Bosch smoke number 
    (BSN) scale.
        (2) Filter-type smokemeters shall be calibrated every 90 days using 
    manufacturer's recommended practices or good engineering practice.
        (c) For steady-state testing using a partial-flow opacimeter, 
    equipment meeting the requirements of ISO-8178-3 and ISO/DIS-11614 is 
    recommended.
        (1) All partial-flow opacimeter measurements shall be reported as 
    the equivalent percent opacity for a five inch effective optical path 
    length using the Beer-Lambert relationship.
        (2) Zero and full scale (100 percent opacity) span shall be 
    adjusted prior to testing.
        (3) Post-test zero and full scale span checks shall be performed. 
    For valid tests, zero and span drift between the pre-test and post-test 
    checks shall be less than two percent of full scale.
        (4) Opacimeter calibration and linearity checks shall be performed 
    using manufacturer's recommendations or good engineering practice.
        (d) Replicate smoke tests may be run to improve confidence in a 
    single test or stabilization. If replicate tests are run, three 
    additional valid tests shall be run, and the final reported test 
    results must be the average of all the valid tests.
        (e) A minimum of thirty seconds sampling time shall be used for 
    average transient smoke measurements.
        34. A new Sec. 86.1380-2004 is added to subpart N, to read as 
    follows:
    
    
    Sec. 86.1380-2004  Load response test.
    
        (a) General. The purpose of this test procedure is to measure the 
    gaseous and particulate emissions from an engine as it is suddenly 
    loaded, with its fueling lever, at a given engine operating speed. This 
    procedure shall be conducted on a dynamometer.
        (b) Test sequence. (1) At each of the following speeds, the engine 
    fuel control shall be moved suddenly to the full fuel position and held 
    at that point for a minimum of two seconds, while the specified speed 
    is maintained constant:
        (i) The lowest speed in the Not-To-Exceed Control area determined 
    according to the provisions of Sec. 86.1370;
    
    [[Page 58552]]
    
        (ii) Speed A as determined in Sec. 86.1360(c);
        (iii) Speed B as determined in Sec. 86.1360(c);
        (iv) Speed C as determined in Sec. 86.1360(c);
        (v) Speed D as determined in Sec. 86.1360(c);
        (vi) Speed E as determined in Sec. 86.1360(c).
        (2) This test sequence may be repeated if it is necessary to obtain 
    sufficient sample amount for analysis.
        (3) The exhaust emissions sample shall be analyzed according to the 
    procedures under Sec. 86.1340, and the exhaust emission shall be 
    calculated according to the procedures under Sec. 86.1342.
    
    Subpart P--[Amended]
    
        35. Section 86.1501-94 is revised to read as follows:
    
    
    Sec. 86.1501-94  Scope; applicability.
    
        (a) This subpart contains gaseous emission idle test procedures for 
    light-duty trucks and heavy-duty engines for which idle CO standards 
    apply. It applies to 1994 and later model years. The idle test 
    procedures are optionally applicable to 1994 through 1996 model year 
    natural gas-fueled and liquified petroleum gas-fueled light-duty trucks 
    and heavy-duty engines.
        (b) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty trucks 
    and Otto-cycle complete heavy-duty vehicles under the provisions of 
    Subpart S of this part.
    
    Subpart Q--[Amended]
    
        36. Section 86.1601 is amended by revising paragraph (d), to read 
    as follows:
    
    
    Sec. 86.1601  General applicability.
    
    * * * * *
        (d) References in this subpart to engine families and emission 
    control systems shall be deemed to apply to durability groups and test 
    groups as applicable for manufacturers certifying new light-duty 
    vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 
    vehicles under the provisions of Subpart S of this part.
        37. Subpart S is amended by revising the subpart heading to read as 
    follows:
    
    Subpart S--General Compliance Provisions for Control of Air 
    Pollution From New and In-Use Light-Duty Vehicles, Light-Duty 
    Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles
    
        38. Section 86.1801-01 is amended by revising paragraphs (a), (b), 
    (c), and the last sentence of paragraph (d), to read as follows:
    
    
    Sec. 86.1801-01  Applicability.
    
        (a) Applicability. The provisions of this subpart apply to 2001 and 
    later model year new Otto-cycle and diesel-cycle light-duty vehicles, 
    2001 and later model year new Otto-cycle and diesel-cycle light-duty 
    trucks, and 2004 and later model year Otto-cycle complete heavy-duty 
    vehicles. These provisions also apply to 2001 model year and later new 
    incomplete light-duty trucks below 8,500 Gross Vehicle Weight Rating, 
    and to 2000 and later model year Otto-cycle complete heavy-duty 
    vehicles participating in the early banking provisions of the 
    averaging, trading, and banking program under the provisions of 
    Sec. 86.1817-04(n). In cases where a provision applies only to a 
    certain vehicle group based on its model year, vehicle class, motor 
    fuel, engine type, or other distinguishing characteristics, the limited 
    applicability is cited in the appropriate section of this subpart.
        (b) Aftermarket conversions. The provisions of this subpart apply 
    to aftermarket conversions of all model year Otto-cycle and diesel-
    cycle light-duty vehicles, light-duty trucks, and complete Otto-cycle 
    heavy-duty vehicles as defined in 40 CFR 85.502.
        (c) Optional applicability. (1) A manufacturer may request to 
    certify any Otto-cycle heavy-duty vehicle of 14,000 pounds Gross 
    Vehicle Weight Rating or less in accordance with the light-duty truck 
    provisions through the 2003 model year. Heavy-duty engine or heavy-duty 
    vehicle provisions of subpart A of this part do not apply to such a 
    vehicle.
        (2) Beginning with the 2001 model year, a manufacturer may request 
    to certify any incomplete Otto-cycle heavy-duty vehicle of 14,000 
    pounds Gross Vehicle Weight Rating or less in accordance with the 
    provisions for complete heavy-duty vehicles. Heavy-duty engine or 
    heavy-duty vehicle provisions of subpart A of this part do not apply to 
    such a vehicle.
        (3) A manufacturer may optionally use the provisions of this 
    subpart in lieu of the provisions of subpart A beginning with the 2000 
    model year for light-duty vehicles and light-duty trucks. Manufacturers 
    choosing this option must comply with all provisions of this subpart. 
    Manufacturers may elect this provision for either all or a portion of 
    their product line.
        (4) Upon preapproval by the Administrator, a manufacturer may 
    optionally certify an aftermarket conversion of a complete heavy-duty 
    vehicle greater than 10,000 pounds Gross Vehicle Weight Rating and of 
    14,000 pounds Gross Vehicle Weight Rating or less under the heavy-duty 
    engine or heavy-duty vehicle provisions of subpart A of this part. Such 
    preapproval will be granted only upon demonstration that chassis-based 
    certification would be infeasible or unreasonable for the manufacturer 
    to perform.
        (5) A manufacturer may optionally certify an aftermarket conversion 
    of a complete heavy-duty vehicle greater than 10,000 pounds Gross 
    Vehicle Weight Rating and of 14,000 pounds Gross Vehicle Weight Rating 
    or less under the heavy-duty engine or heavy-duty vehicle provisions of 
    subpart A of this part without advance approval from the Administrator 
    if the vehicle was originally certified to the heavy-duty engine or 
    heavy-duty vehicle provisions of subpart A of this part.
        (d) * * * The small volume manufacturer's light-duty vehicle, 
    light-duty truck and complete heavy-duty vehicle certification 
    procedures are described in Sec. 86.1838-01.
    * * * * *
        39. Section 86.1803-01 is amended by revising the definitions for 
    ``Car line,'' ``Curb idle,'' ``Durability useful life,'' and ``Van,'' 
    and by adding new definitions in alphabetical order, to read as 
    follows:
    
    
    Sec. 86.1803-01  Definitions.
    
    * * * * *
        Averaging for chassis-bases heavy-duty vehicles means the exchange 
    of NOX emission credits among test groups within a given 
    manufacturer's product line.
        Averaging set means a subcategory of complete heavy-duty vehicles 
    within which test groups can average and trade emission credits with 
    one another.
    * * * * *
        Banking means the retention of NOX emission credits for 
    complete heavy-duty vehicles by the manufacturer generating the 
    emission credits, for use in future model year certification programs 
    as permitted by regulation.
    * * * * *
        Car line means a name denoting a group of vehicles within a make or 
    car division which has a degree of commonality in construction (e.g., 
    body,
    
    [[Page 58553]]
    
    chassis). Car line does not consider any level of decor or opulence and 
    is not generally distinguished by characteristics as roofline, number 
    of doors, seats, or windows except for station wagons or light-duty 
    trucks. Station wagons, light-duty trucks, and complete heavy-duty 
    vehicles are considered to be different car lines than passenger cars.
    * * * * *
        Complete heavy-duty vehicle means any Otto-cycle heavy-duty vehicle 
    of 14,000 pounds Gross Vehicle Weight Rating or less that is not an 
    incomplete heavy-duty vehicle.
    * * * * *
        Curb-idle means, for manual transmission code motor vehicles, the 
    engine speed with the transmission in neutral or with the clutch 
    disengaged and with the air conditioning system, if present, turned 
    off. For automatic transmission code motor vehicles, curb-idle means 
    the engine speed with the automatic transmission in the park position 
    (or neutral position if there is no park position), and with the air 
    conditioning system, if present, turned off.
    * * * * *
        Durability useful life means the highest useful life mileage out of 
    the set of all useful life mileages that apply to a given vehicle. The 
    durability useful life determines the duration of service accumulation 
    on a durability data vehicle. The determination of durability useful 
    life shall reflect any light-duty truck or complete heavy-duty vehicle 
    alternative useful life periods approved by the Administrator under 
    Sec. 86.1805-01(c). The determination of durability useful life shall 
    exclude any standard and related useful life mileage for which the 
    manufacturer has obtained a waiver of emission data submission 
    requirements under Sec. 86.1829-01.
    * * * * *
        Emission credits mean the amount of emission reductions or 
    exceedances, by a complete heavy-duty vehicle test group, below or 
    above the emission standard, respectively. Emission credits below the 
    standard are considered as ``positive credits,'' while emission credits 
    above the standard are considered as ``negative credits.'' In addition, 
    ``projected credits'' refer to emission credits based on the projected 
    U.S. production volume of the test group. ``Reserved credits'' are 
    emission credits generated within a model year waiting to be reported 
    to EPA at the end of the model year. ``Actual credits'' refer to 
    emission credits based on actual U.S. production volumes as contained 
    in the end-of-year reports submitted to EPA. Some or all of these 
    credits may be revoked if EPA review of the end of year reports or any 
    subsequent audit actions uncover problems or errors.
    * * * * *
        Family emission limit (FEL) means an emission level declared by the 
    manufacturer which serves in lieu of an emission standard for 
    certification purposes in the averaging, trading and banking program. 
    FELs must be expressed to the same number of decimal places as the 
    applicable emission standard.
    * * * * *
        Incomplete heavy-duty vehicle means any heavy-duty vehicle which 
    does not have the primary load carrying device or container attached.
    * * * * *
        Non-methane organic gas means the sum of oxegenated and non-
    oxygenated hydrocarbons contained in a gas sample.
    * * * * *
        Trading means the exchange of complete heavy-duty vehicle 
    NOX emission credits between manufacturers.
    * * * * *
        Van means a light-duty truck or complete heavy-duty vehicle having 
    an integral enclosure, fully enclosing the driver compartment and load 
    carrying device, and having no body sections protruding more than 30 
    inches ahead of the leading edge of the windshield.
    * * * * *
        40. A new section 86.1803-04 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1803-04  Definitions.
    
        The definitions of Sec. 86.1803-01 continue to apply to this 
    subpart. The definitions listed in this section apply to this subpart 
    beginning with the 2004 model year.
        Heavy-duty vehicle means any motor vehicle rated at more than 8,500 
    pounds GVWR or that has a vehicle curb weight of more than 6,000 pounds 
    or that has a basic vehicle frontal area in excess of 45 square feet, 
    excluding vehicles with a GVWR greater than 8,500 pounds and less than 
    or equal to 10,000 pounds that are defined as light-duty trucks.
        Light-duty truck means:
        (1) Any motor vehicle rated at 8,500 pounds GVWR or less which has 
    a curb weight of 6,000 pounds or less and which has a basic vehicle 
    frontal area of 45 square feet or less, which is:
        (i) Designed primarily for purposes of transportation of property 
    or is a derivation of such a vehicle; or
        (ii) Designed primarily for transportation of persons and has a 
    capacity of more than 12 persons; or
        (iii) Available with special features enabling off-street or off-
    highway operation and use; or
        (2) Any motor vehicle rated at greater than 8,500 pounds GVWR and 
    less than or equal to 10,000 pounds GVWR which is a complete vehicle 
    designed primarily for transportation of persons and has a capacity of 
    not more than 12 persons.
        41. Section 86.1804-01 is amended by adding ``FEL,'' ``NMOG,'' and 
    ``HDV'' as new abbreviations in alphabetical order, to read as follows:
    
    
    Sec. 86.1804-01  Acronyms and abbreviations.
    
    * * * * *
    FEL--Family Emission Limit
    * * * * *
    HDV--Heavy-duty vehicle
    * * * * *
    NMOG--Non-Methane Organic Gas
    * * * * *
        42. Section 86.1805-01 is amended by revising paragraph (a) and the 
    first and last sentences of paragraph (c), and adding paragraph (b)(3), 
    to read as follows:
    
    
    Sec. 86.1805-01  Useful life.
    
        (a) For light-duty vehicles and light-duty trucks, intermediate 
    useful life is a period of use of 5 years or 50,000 miles, which ever 
    occurs first.
        (b) * * *
        (3) For complete heavy-duty vehicles, the full useful life is a 
    period of use of 11 years or 120,000 miles, which ever occurs first.
        (c) Manufacturers may petition the Administrator to provide 
    alternative useful life periods for light-duty trucks or complete 
    heavy-duty vehicles when they believe that the useful life periods are 
    significantly unrepresentative for one or more test groups (either too 
    long or too short). * * * For light-duty trucks, alternative useful 
    life periods will be granted only for THC, THCE, and idle CO 
    requirements.
        43. A new Sec. 86.1806-04 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1806-04  On-board diagnostics.
    
        (a) General. All light-duty vehicles, light-duty trucks, and heavy-
    duty vehicles intended for use in a heavy-duty vehicle weighing 14,000 
    pounds GVWR or less must be equipped with an on-board diagnostic (OBD) 
    system capable of monitoring all emission-related powertrain systems or 
    components during the applicable useful life. Heavy-duty vehicles 
    intended for use in a heavy-duty vehicle weighing 14,000 pounds GVWR or 
    less must meet the OBD requirements of this section according to the 
    phase-in schedule in paragraph (l) of this section. All monitored 
    systems and components
    
    [[Page 58554]]
    
    must be evaluated periodically, but no less frequently than once per 
    applicable certification test cycle as defined in paragraphs (a) and 
    (d) of Appendix I of this part.
        (b) Malfunction descriptions. The OBD system must detect and 
    identify malfunctions in all monitored emission-related powertrain 
    systems or components according to the following malfunction 
    definitions as measured and calculated in accordance with test 
    procedures set forth in subpart B of this part (chassis-based test 
    procedures), excluding those test procedures defined as 
    ``Supplemental'' test procedures in Sec. 86.004-2 and codified in 
    Secs. 86.158, 86.159, and 86.160.
        (1) Catalysts and particulate traps. (i) Otto-cycle. Catalyst 
    deterioration or malfunction before it results in an increase in NMHC 
    emissions 1.5 times the NMHC standard or FEL, as compared to the NMHC 
    emission level measured using a representative 4000 mile catalyst 
    system.
        (ii) Diesel. If equipped, catalyst or particulate trap 
    deterioration or malfunction before it results in exhaust emissions 
    exceeding 1.5 times the applicable standard or FEL for NOX 
    or PM. This monitoring need not be done if the manufacturer can 
    demonstrate that deterioration or malfunction of the system will not 
    result in exceedance of the threshold; however, the presence of the 
    catalyst or particulate trap must still be monitored.
        (2) Engine misfire. (i) Otto-cycle. Engine misfire resulting in 
    exhaust emissions exceeding 1.5 times the applicable standard or FEL 
    for NMHC, CO or NOX; and any misfire capable of damaging the 
    catalytic converter.
        (ii) Diesel. Lack of cylinder combustion must be detected.
        (3) Oxygen sensors. If equipped, oxygen sensor deterioration or 
    malfunction resulting in exhaust emissions exceeding 1.5 times the 
    applicable standard or FEL for NMHC, CO or NOX.
        (4) Evaporative leaks. If equipped, any vapor leak in the 
    evaporative and/or refueling system (excluding the tubing and 
    connections between the purge valve and the intake manifold) greater 
    than or equal in magnitude to a leak caused by a 0.040 inch diameter 
    orifice; an absence of evaporative purge air flow from the complete 
    evaporative emission control system. On vehicles with fuel tank 
    capacity greater than 25 gallons, the Administrator may, following a 
    request from the manufacturer, revise the size of the orifice to the 
    smallest orifice feasible, based on test data, if the most reliable 
    monitoring method available cannot reliably detect a system leak equal 
    to a 0.040 inch diameter orifice.
        (5) Other emission control systems. Any deterioration or 
    malfunction occurring in a powertrain system or component directly 
    intended to control emissions, including but not necessarily limited 
    to, the exhaust gas recirculation (EGR) system, if equipped, the 
    secondary air system, if equipped, and the fuel control system, 
    singularly resulting in exhaust emissions exceeding 1.5 times the 
    applicable emission standard or FEL for NMHC, CO, NOX, or 
    diesel PM. For vehicles equipped with a secondary air system, a 
    functional check, as described in paragraph (b)(6) of this section, may 
    satisfy the requirements of this paragraph provided the manufacturer 
    can demonstrate that deterioration of the flow distribution system is 
    unlikely. This demonstration is subject to Administrator approval and, 
    if the demonstration and associated functional check are approved, the 
    diagnostic system must indicate a malfunction when some degree of 
    secondary airflow is not detectable in the exhaust system during the 
    check. For vehicles equipped with positive crankcase ventilation (PCV), 
    monitoring of the PCV system is not necessary provided the manufacturer 
    can demonstrate to the Administrator's satisfaction that the PCV system 
    is unlikely to fail.
        (6) Other emission-related powertrain components. Any other 
    deterioration or malfunction occurring in an electronic emission-
    related powertrain system or component not otherwise described above 
    that either provides input to or receives commands from the on-board 
    computer and has a measurable impact on emissions; monitoring of 
    components required by this paragraph must be satisfied by employing 
    electrical circuit continuity checks and rationality checks for 
    computer input components (input values within manufacturer specified 
    ranges based on other available operating parameters), and 
    functionality checks for computer output components (proper functional 
    response to computer commands) except that the Administrator may waive 
    such a rationality or functionality check where the manufacturer has 
    demonstrated infeasibility. Malfunctions are defined as a failure of 
    the system or component to meet the electrical circuit continuity 
    checks or the rationality or functionality checks.
        (7) Performance of OBD functions. Oxygen sensor or any other 
    component deterioration or malfunction which renders that sensor or 
    component incapable of performing its function as part of the OBD 
    system must be detected and identified on vehicles so equipped.
        (c) Malfunction indicator light (MIL). The OBD system must 
    incorporate a malfunction indicator light (MIL) readily visible to the 
    vehicle operator. When illuminated, the MIL must display ``Check 
    Engine,'' ``Service Engine Soon,'' a universally recognizable engine 
    symbol, or a similar phrase or symbol approved by the Administrator. A 
    vehicle should not be equipped with more than one general purpose 
    malfunction indicator light for emission-related problems; separate 
    specific purpose warning lights (e.g. brake system, fasten seat belt, 
    oil pressure, etc.) are permitted. The use of red for the OBD-related 
    malfunction indicator light is prohibited.
        (d) MIL illumination. The MIL must illuminate and remain 
    illuminated when any of the conditions specified in paragraph (b) of 
    this section are detected and verified, or whenever the engine control 
    enters a default or secondary mode of operation considered abnormal for 
    the given engine operating conditions. The MIL must blink once per 
    second under any period of operation during which engine misfire is 
    occurring and catalyst damage is imminent. If such misfire is detected 
    again during the following driving cycle (i.e., operation consisting 
    of, at a minimum, engine start-up and engine shut-off) or the next 
    driving cycle in which similar conditions are encountered, the MIL must 
    maintain a steady illumination when the misfire is not occurring and 
    then remain illuminated until the MIL extinguishing criteria of this 
    section are satisfied. The MIL must also illuminate when the vehicle's 
    ignition is in the ``key-on'' position before engine starting or 
    cranking and extinguish after engine starting if no malfunction has 
    previously been detected. If a fuel system or engine misfire 
    malfunction has previously been detected, the MIL may be extinguished 
    if the malfunction does not reoccur during three subsequent sequential 
    trips during which similar conditions are encountered and no new 
    malfunctions have been detected. Similar conditions are defined as 
    engine speed within 375 rpm, engine load within 20 percent, and engine 
    warm-up status equivalent to that under which the malfunction was first 
    detected. If any malfunction other than a fuel system or engine misfire 
    malfunction has been detected, the MIL may be extinguished if the 
    malfunction does not reoccur during three subsequent sequential trips 
    during which the monitoring system responsible for illuminating the MIL
    
    [[Page 58555]]
    
    functions without detecting the malfunction, and no new malfunctions 
    have been detected. Upon Administrator approval, statistical MIL 
    illumination protocols may be employed, provided they result in 
    comparable timeliness in detecting a malfunction and evaluating system 
    performance, i.e., three to six driving cycles would be considered 
    acceptable.
        (e) Storing of computer codes. The OBD system shall record and 
    store in computer memory diagnostic trouble codes and diagnostic 
    readiness codes indicating the status of the emission control system. 
    These codes shall be available through the standardized data link 
    connector per specifications as referenced in paragraph (h) of this 
    section.
        (1) A diagnostic trouble code must be stored for any detected and 
    verified malfunction causing MIL illumination. The stored diagnostic 
    trouble code must identify the malfunctioning system or component as 
    uniquely as possible. At the manufacturer's discretion, a diagnostic 
    trouble code may be stored for conditions not causing MIL illumination. 
    Regardless, a separate code should be stored indicating the expected 
    MIL illumination status (i.e., MIL commanded ``ON,'' MIL commanded 
    ``OFF'').
        (2) For a single misfiring cylinder, the diagnostic trouble code(s) 
    must uniquely identify the cylinder, unless the manufacturer submits 
    data and/or engineering evaluations which adequately demonstrate that 
    the misfiring cylinder cannot be reliably identified under certain 
    operating conditions. For diesel vehicles only, the specific cylinder 
    for which combustion cannot be detected need not be identified if new 
    hardware would be required to do so. The diagnostic trouble code must 
    identify multiple misfiring cylinder conditions; under multiple misfire 
    conditions, the misfiring cylinders need not be uniquely identified if 
    a distinct multiple misfire diagnostic trouble code is stored.
        (3) The diagnostic system may erase a diagnostic trouble code if 
    the same code is not re-registered in at least 40 engine warm-up 
    cycles, and the malfunction indicator light is not illuminated for that 
    code.
        (4) Separate status codes, or readiness codes, must be stored in 
    computer memory to identify correctly functioning emission control 
    systems and those emission control systems which require further 
    vehicle operation to complete proper diagnostic evaluation. A readiness 
    code need not be stored for those monitors that can be considered 
    continuously operating monitors (e.g., misfire monitor, fuel system 
    monitor, etc.). Readiness codes should never be set to ``not ready'' 
    status upon key-on or key-off; intentional setting of readiness codes 
    to ``not ready'' status via service procedures must apply to all such 
    codes, rather than applying to individual codes. Subject to 
    Administrator approval, if monitoring is disabled for a multiple number 
    of driving cycles (i.e., more than one) due to the continued presence 
    of extreme operating conditions (e.g., ambient temperatures below 
    40 deg.F, or altitudes above 8000 feet), readiness for the subject 
    monitoring system may be set to ``ready'' status without monitoring 
    having been completed. Administrator approval shall be based on the 
    conditions for monitoring system disablement, and the number of driving 
    cycles specified without completion of monitoring before readiness is 
    indicated.
        (f) Available diagnostic data. (1) Upon determination of the first 
    malfunction of any component or system, ``freeze frame'' engine 
    conditions present at the time must be stored in computer memory. 
    Should a subsequent fuel system or misfire malfunction occur, any 
    previously stored freeze frame conditions must be replaced by the fuel 
    system or misfire conditions (whichever occurs first). Stored engine 
    conditions must include, but are not limited to: engine speed, open or 
    closed loop operation, fuel system commands, coolant temperature, 
    calculated load value, fuel pressure, vehicle speed, air flow rate, and 
    intake manifold pressure if the information needed to determine these 
    conditions is available to the computer. For freeze frame storage, the 
    manufacturer must include the most appropriate set of conditions to 
    facilitate effective repairs. If the diagnostic trouble code causing 
    the conditions to be stored is erased in accordance with paragraph (d) 
    of this section, the stored engine conditions may also be erased.
        (2) The following data in addition to the required freeze frame 
    information must be made available on demand through the serial port on 
    the standardized data link connector, if the information is available 
    to the on-board computer or can be determined using information 
    available to the on-board computer: Diagnostic trouble codes, engine 
    coolant temperature, fuel control system status (closed loop, open 
    loop, other), fuel trim, ignition timing advance, intake air 
    temperature, manifold air pressure, air flow rate, engine RPM, throttle 
    position sensor output value, secondary air status (upstream, 
    downstream, or atmosphere), calculated load value, vehicle speed, and 
    fuel pressure. The signals must be provided in standard units based on 
    SAE specifications incorporated by reference in paragraph (h) of this 
    section. Actual signals must be clearly identified separately from 
    default value or limp home signals.
        (3) For all OBD systems for which specific on-board evaluation 
    tests are conducted (catalyst, oxygen sensor, etc.), the results of the 
    most recent test performed by the vehicle, and the limits to which the 
    system is compared must be available through the standardized data link 
    connector per the appropriate standardized specifications as referenced 
    in paragraph (h) of this section.
        (4) Access to the data required to be made available under this 
    section shall be unrestricted and shall not require any access codes or 
    devices that are only available from the manufacturer.
        (g) Exceptions. The OBD system is not required to evaluate systems 
    or components during malfunction conditions if such evaluation would 
    result in a risk to safety or failure of systems or components. 
    Additionally, the OBD system is not required to evaluate systems or 
    components during operation of a power take-off unit such as a dump 
    bed, snow plow blade, or aerial bucket, etc.
        (h) Reference materials. The OBD system shall provide for 
    standardized access and conform with the following Society of 
    Automotive Engineers (SAE) standards and/or the following International 
    Standards Organization (ISO) standards. The following documents are 
    incorporated by reference (see Sec. 86.1):
        (1) SAE material. Copies of these materials may be obtained from 
    the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, 
    Warrendale, PA 15096-0001.
        (i) SAE J1850 ``Class B Data Communication Network Interface,'' 
    (July 1995) shall be used as the on-board to off-board communications 
    protocol. All emission related messages sent to the scan tool over a 
    J1850 data link shall use the Cyclic Redundancy Check and the three 
    byte header, and shall not use inter-byte separation or checksums.
        (ii) Basic diagnostic data (as specified in Secs. 86.094-17(e) and 
    (f)) shall be provided in the format and units in SAE J1979 E/E 
    Diagnostic Test Modes,''(July 1996).
        (iii) Diagnostic trouble codes shall be consistent with SAE J2012 
    ``Recommended Practices for Diagnostic Trouble Code Definitions,'' 
    (July 1996).
        (iv) The connection interface between the OBD system and test 
    equipment and
    
    [[Page 58556]]
    
    diagnostic tools shall meet the functional requirements of SAE J1962 
    ``Diagnostic Connector,'' (January 1995).
        (v) As an alternative to the above standards, heavy-duty vehicles 
    may conform to the specifications of SAE J1939 ``Recommended Practice 
    for a Serial Control and Communications Vehicle Network.''
        (2) ISO materials. Copies of these materials may be obtained from 
    the International Organization for Standardization, Case Postale 56, 
    CH-1211 Geneva 20, Switzerland.
        (i) ISO 9141-2 ``Road vehicles--Diagnostic systems--Part 2: CARB 
    requirements for interchange of digital information,'' (February 1994) 
    may be used as an alternative to SAE J1850 as the on-board to off-board 
    communications protocol.
        (ii) ISO 14230-4 ``Road vehicles--Diagnostic systems--KWP 2000 
    requirements for Emission-related systems'' may also be used as an 
    alternative to SAE J1850.
        (i) Deficiencies and alternate fueled vehicles. Upon application by 
    the manufacturer, the Administrator may accept an OBD system as 
    compliant even though specific requirements are not fully met. Such 
    compliances without meeting specific requirements, or deficiencies, 
    will be granted only if compliance would be infeasible or unreasonable 
    considering such factors as, but not limited to: technical feasibility 
    of the given monitor and lead time and production cycles including 
    phase-in or phase-out of engines or vehicle designs and programmed 
    upgrades of computers. Unmet requirements should not be carried over 
    from the previous model year except where unreasonable hardware or 
    software modifications would be necessary to correct the deficiency, 
    and the manufacturer has demonstrated an acceptable level of effort 
    toward compliance as determined by the Administrator. Furthermore, EPA 
    will not accept any deficiency requests that include the complete lack 
    of a major diagnostic monitor (``major'' diagnostic monitors being 
    those for exhaust aftertreatment devices, oxygen sensor, engine 
    misfire, evaporative leaks, and diesel EGR, if equipped), with the 
    possible exception of the special provisions for alternate fueled 
    vehicles. For alternate fueled vehicles (e.g. natural gas, liquefied 
    petroleum gas, methanol, ethanol), beginning with the model year for 
    which alternate fuel emission standards are applicable and extending 
    through the 2004 model year, manufacturers may request the 
    Administrator to waive specific monitoring requirements of this section 
    for which monitoring may not be reliable with respect to the use of the 
    alternate fuel; manufacturers may request this alternate fuel waiver 
    for heavy-duty vehicles through the 2006 model year. At a minimum, 
    alternate fuel vehicles must be equipped with an OBD system meeting OBD 
    requirements to the extent feasible as approved by the Administrator.
        (j) California OBDII Compliance Option. For light-duty vehicles, 
    light-duty trucks, and heavy-duty vehicles at or below 14,000 pounds 
    GVWR, demonstration of compliance with California OBD II requirements 
    (Title 13 California Code Sec. 1968.1), as modified pursuant to 
    California Mail Out #97-24 (December 9, 1997), shall satisfy the 
    requirements of this section, except that the exemption to the catalyst 
    monitoring provisions of California Code Sec. 1968.1(b)(1.1.2) for 
    diesel vehicles does not apply, and compliance with California Code 
    Secs. 1968.1(b)(4.2.2), pertaining to 0.02 inch evaporative leak 
    detection, and 1968.1(d), pertaining to tampering protection, are not 
    required to satisfy the requirements of this section. Also, the 
    deficiency fine provisions of California Code Sec. 1968.1(m)(6.1) and 
    (6.2) do not apply.
        (k) Certification. For test groups required to have an OBD system, 
    certification will not be granted if, for any test vehicle approved by 
    the Administrator in consultation with the manufacturer, the 
    malfunction indicator light does not illuminate under any of the 
    following circumstances, unless the manufacturer can demonstrate that 
    any identified OBD problems discovered during the Administrator's 
    evaluation will be corrected on production vehicles.
        (1)(i) Otto-cycle. A catalyst is replaced with a deteriorated or 
    defective catalyst, or an electronic simulation of such, resulting in 
    an increase of 1.5 times the NMHC standard or FEL above the NMHC 
    emission level measured using a representative 4000 mile catalyst 
    system.
        (ii) Diesel. If monitored for emissions performance--a catalyst or 
    particulate trap is replaced with a deteriorated or defective catalyst 
    or trap, or an electronic simulation of such, resulting in exhaust 
    emissions exceeding 1.5 times the applicable standard or FEL for 
    NOX or PM. If not monitored for emissions performance--
    removal of the catalyst or particulate trap is not detected and 
    identified.
        (2)(i) Otto-cycle. An engine misfire condition is induced resulting 
    in exhaust emissions exceeding 1.5 times the applicable standards or 
    FEL for NMHC, CO or NOX.
        (ii) Diesel. An engine misfire condition is induced and is not 
    detected.
        (3) If so equipped, any oxygen sensor is replaced with a 
    deteriorated or defective oxygen sensor, or an electronic simulation of 
    such, resulting in exhaust emissions exceeding 1.5 times the applicable 
    standard or FEL for NMHC, CO or NOX.
        (4) If so equipped, a vapor leak is introduced in the evaporative 
    and/or refueling system (excluding the tubing and connections between 
    the purge valve and the intake manifold) greater than or equal in 
    magnitude to a leak caused by a 0.040 inch diameter orifice, or the 
    evaporative purge air flow is blocked or otherwise eliminated from the 
    complete evaporative emission control system.
        (5) A malfunction condition is induced in any emission-related 
    powertrain system or component, including but not necessarily limited 
    to, the exhaust gas recirculation (EGR) system, if equipped, the 
    secondary air system, if equipped, and the fuel control system, 
    singularly resulting in exhaust emissions exceeding 1.5 times the 
    applicable emission standard or FEL for NMHC, CO, NOX or PM.
        (6) A malfunction condition is induced in an electronic emission-
    related powertrain system or component not otherwise described in this 
    paragraph (k) that either provides input to or receives commands from 
    the on-board computer resulting in a measurable impact on emissions.
        (l) Phase-in for Heavy-Duty Vehicles. Manufacturers of heavy-duty 
    vehicles intended for use in a heavy-duty vehicle weighing 14,000 
    pounds GVWR or less must comply with the OBD requirements in this 
    section according to the following phase-in schedule, based on the 
    percentage of projected vehicle sales within each category:
    
    [[Page 58557]]
    
    
    
                   OBD Compliance Phase-in Heavy-Duty Vehicles
    [intended for use in a heavy-duty vehicle weighing 14,000 pounds GVWR or
                                      less]
    ------------------------------------------------------------------------
                                               Phase-in based on projected
                   Model year                             sales
    ------------------------------------------------------------------------
    2004 MY................................  --40% compliance
    2005 MY................................  --60% compliance--alternative
                                              fuel waivers available
    2006 MY................................  --80% compliance--alternative
                                              fuel waivers available
    2007+ MY...............................  --100% compliance--alternative
                                              fuel waivers available
    ------------------------------------------------------------------------
    
        44. Section 86.1807-01 is amended by adding paragraph (c)(3), and 
    revising paragraphs (a)(3)(v), (d), (e), and (f), to read as follows:
    
    
    Sec. 86.1807-01  Vehicle labeling.
    
        (a) * * *
        (3) * * *
        (v) An unconditional statement of compliance with the appropriate 
    model year U.S. EPA regulations which apply to light-duty vehicles, 
    light-duty trucks, or complete heavy-duty vehicles;
    * * * * *
        (c) * * *
        (3) The manufacturer of any complete heavy-duty vehicle subject to 
    the emission standards of this subpart shall add the information 
    required by paragraph (c)(1)(iii) of this section to the label required 
    by paragraph (a) of this section. The required information will be set 
    forth in the manner prescribed by paragraph (c)(1)(iii) of this 
    section.
        (d)(1) Incomplete light-duty trucks shall have the following 
    prominent statement printed on the label required by paragraph 
    (a)(3)(v) of this section: ``This vehicle conforms to U.S. EPA 
    regulations applicable to 20xx Model year Light-Duty Trucks under the 
    special provisions of Sec. 86.1801-01(c)(1) when it does not exceed XXX 
    pounds in curb weight, XXX pounds in gross vehicle weight rating, and 
    XXX square feet in frontal area.''
        (2) Incomplete heavy-duty vehicles optionally certified in 
    accordance with the provisions for complete heavy-duty vehicles under 
    the special provisions of Sec. 86.1801-01(c)(2) shall have the 
    following prominent statement printed on the label required by 
    paragraph (a)(3)(v) of this section: ``This vehicle conforms to U.S. 
    EPA regulations applicable to 20xx Model year Complete Heavy-Duty 
    Vehicles under the special provisions of Sec. 86.1801-01(c)(2) when it 
    does not exceed XXX pounds in curb weight, XXX pounds in gross vehicle 
    weight rating, and XXX square feet in frontal area.''
        (e) The manufacturer of any incomplete light-duty vehicle, light-
    duty truck, or heavy-duty vehicle shall notify the purchaser of such 
    vehicle of any curb weight, frontal area, or gross vehicle weight 
    rating limitations affecting the emission certificate applicable to 
    that vehicle. This notification shall be transmitted in a manner 
    consistent with National Highway Safety Administration safety 
    notification requirements published in 49 CFR part 568.
        (f) All light-duty vehicles, light-duty trucks, and complete heavy-
    duty vehicles shall comply with SAE Recommended Practices J1877 
    ``Recommended Practice for Bar-Coded Vehicle Identification Number 
    Label,'' (July 1994), and J1892 ``Recommended Practice for Bar-Coded 
    Vehicle Emission Configuration Label (May 1988). SAE J1877 and J1892 
    are incorporated by reference (see Sec. 86.1).
    * * * * *
        45. Section 86.1809-01 is amended by revising paragraph (a), to 
    read as follows:
    
    
    Sec. 86.1809-01  Prohibition of defeat devices.
    
        (a) No new light-duty vehicle, light-duty truck, or complete heavy-
    duty vehicle shall be equipped with a defeat device.
    * * * * *
        46. A new Sec. 86.1810-04 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1810-04  General standards; increase in emissions; unsafe 
    conditions; waivers.
    
        This section applies to model year 2004 and later light-duty 
    vehicles, light-duty trucks, and complete heavy-duty vehicles fueled by 
    gasoline, diesel, methanol, natural gas and liquefied petroleum gas 
    fuels. Multi-fueled vehicles (including dual-fueled and flexible-fueled 
    vehicles) shall comply with all requirements established for each 
    consumed fuel (or blend of fuels in the case of flexible fueled 
    vehicles). The standards of this subpart apply to both certification 
    and in-use vehicles unless otherwise indicated. Section 86.1810-04 
    includes text that specifies requirements that differ from 
    Sec. 86.1810-01. Where a paragraph in Sec. 86.1810-04 is identical and 
    applicable to Sec. 86.1810-01, this may be indicated by specifying the 
    corresponding paragraph and the statement ``[Reserved]. For guidance 
    see Sec. 86.1810-01.''.
        (a) through (c) [Reserved] For guidance see Sec. 86.1810-01.
        (d) Crankcase emissions prohibited. No crankcase emissions shall be 
    discharged into the ambient atmosphere from any 2004 and later model 
    year light-duty vehicle, light-duty truck, or complete heavy-duty 
    vehicle.
        (e) On-board diagnostics. All light-duty vehicles, light-duty 
    trucks and complete heavy-duty vehicles must have an on-board 
    diagnostic system as described in Sec. 86.1806-04.
        (f) through (i) [Reserved] For guidance see Sec. 86.1810-01.
        (j) Evaporative emissions general provisions. (1) The evaporative 
    standards in Secs. 86.1811-01(d), 86.1812-01(d), 86.1813-01(d), 
    86.1814-04(d), 86.1815-04(d) and 86.1816-04(d) apply equally to 
    certification and in-use vehicles and trucks. The spitback standard 
    also applies to newly assembled vehicles.
        (2) For certification testing only, manufacturers may conduct 
    testing to quantify a level of nonfuel background emissions for an 
    individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from evaporative emission test results from certification 
    vehicles if approved in advance by the Administrator.
        (3) All fuel vapor generated in a gasoline-or methanol-fueled 
    light-duty vehicle, light-duty truck, or complete heavy-duty vehicle 
    during in-use operation shall be routed exclusively to the evaporative 
    control system (e.g., either canister or engine purge.) The only 
    exception to this requirement shall be for emergencies.
        (k) Refueling emissions general provisions. (1) Implementation 
    schedules. Table S04-5 of this section gives the minimum percentage of 
    a manufacturer's sales of the applicable model year's gasoline- and 
    methanol-fueled Otto-cycle and petroleum-fueled and methanol-fueled 
    diesel-cycle heavy light-duty trucks and complete heavy-duty vehicles 
    which shall be tested under the applicable procedures in subpart B of 
    this part, and shall not exceed the standards described in 
    Secs. 86.1813-04(e), 86.1814-04(e), and
    
    [[Page 58558]]
    
    86.1816-04(e). Vehicles waived from the emission standards under the 
    provisions of paragraphs (m) and (n) of this section shall not be 
    counted in the calculation of the percentage of compliance. Either 
    manufacturer sales or actual production intended for sale in the United 
    States may be used to determine combined volume, at the manufacturers 
    option. Table S04-5 follows:
    
      Table S04-5--Heavy Light-Duty Trucks and Complete Heavy-Duty Vehicles
    ------------------------------------------------------------------------
                             Model year                           Percentage
    ------------------------------------------------------------------------
    2004.......................................................           40
    2005.......................................................           80
    2006.......................................................          100
    ------------------------------------------------------------------------
    
        (2) Determining sales percentages. Sales percentages for the 
    purposes of determining compliance with the applicable refueling 
    emission standards for heavy light-duty trucks and complete heavy-duty 
    vehicles shall be based on total actual U.S. sales of heavy light-duty 
    trucks and complete heavy-duty vehicles of the applicable model year by 
    a manufacturer to a dealer, distributor, fleet operator, broker, or any 
    other entity which comprises the point of first sale.
        (3) Refueling receptacle requirements. Refueling receptacles on 
    natural gas-fueled light-duty vehicles, light-duty trucks, and complete 
    heavy-duty vehicles shall comply with the receptacle provisions of the 
    ANSI/AGA NGV1-1994 standard (as incorporated by reference in 
    Sec. 86.1(b)(3)). This requirement is subject to the phase-in schedules 
    in Tables S01-3 and S01-4 in Sec. 86.1810-01 (k)(1), and Table S04-5 in 
    paragraph (k)(1) of this section.
        (l) Fuel dispensing spitback testing waiver. (1) Vehicles certified 
    to the refueling emission standards set forth in Secs. 86.1811-01(e), 
    86.1812-01(e), 86.1813-01(e), 86.1814-04(e), 86.1815-04(e), and 
    86.1816-04(e) are not required to demonstrate compliance with the fuel 
    dispensing spitback standard contained in that section provided that:
        (i) The manufacturer certifies that the vehicle inherently meets 
    the fuel dispensing spitback standard as part of compliance with the 
    refueling emission standard; and
        (ii) This certification is provided in writing and applies to the 
    full useful life of the vehicle.
        (2) EPA retains the authority to require testing to enforce 
    compliance and to prevent noncompliance with the fuel dispensing 
    spitback standard.
        (m) Inherently low refueling emission testing waiver. 
        (1) Vehicles using fuels/fuel systems inherently low in refueling 
    emissions are not required to conduct testing to demonstrate compliance 
    with the refueling emission standards set forth in Secs. 86.1811-01(e), 
    86.1812-01(e), 86.1813-01(e), 86.1814-04(e), and 86.1815-04(e), 
    provided that:
        (i) This provision is only available for petroleum diesel fuel. It 
    is only available if the Reid Vapor Pressure of in-use diesel fuel is 
    equal to or less than 1 psi (7 kPa) and for diesel vehicles whose fuel 
    tank temperatures do not exceed 130 deg.F (54 deg. C); and
        (ii) To certify using this provision the manufacturer must attest 
    to the following evaluation: ``Due to the low vapor pressure of diesel 
    fuel and the vehicle tank temperatures, hydrocarbon vapor 
    concentrations are low and the vehicle meets the 0.20 grams/gallon 
    refueling emission standard without a control system.''
        (2) The certification required in paragraph (m)(1)(ii) of this 
    section must be provided in writing and must apply for the full useful 
    life of the vehicle.
        (3) EPA reserves the authority to require testing to enforce 
    compliance and to prevent noncompliance with the refueling emission 
    standard.
        (n) Fixed liquid level gauge waiver. Liquefied petroleum gas-fueled 
    vehicles which contain fixed liquid level gauges or other gauges or 
    valves which can be opened to release fuel or fuel vapor during 
    refueling, and which are being tested for refueling emissions, are not 
    required to be tested with such gauges or valves open, as outlined in 
    Sec. 86.157-98(d)(2), provided the manufacturer can demonstrate, to the 
    satisfaction of the Administrator, that such gauges or valves would not 
    be opened during refueling in-use due to inaccessibility or other 
    design features that would prevent or make it very unlikely that such 
    gauges or valves could be opened.
        47. Section 86.1811-01 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1811-01  Emission standards for light-duty vehicles.
    
    * * * * *
        (g) Manufacturers may request to group light-duty vehicles into the 
    same test group as vehicles subject to more stringent standards, so 
    long as those light-duty vehicles meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        48. Section 86.1812-01 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1812-01  Emission standards for light-duty trucks 1.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 1's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 1's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and(d)(4).
        49. Section 86.1813-01 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1813-01  Emission standards for light-duty trucks 2.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 2's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 2's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        50. Section 86.1814-01 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1814-01  Emission standards for light-duty trucks 3.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 3's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 3's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        51. Section 86.1814-02 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1814-02  Emission standards for light-duty trucks 3.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 3's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 3's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        52. Section 86.1815-01 is amended by adding paragraph (h), to read 
    as follows:
    
    
    Sec. 86.1815-01  Emission standards for light-duty trucks 4.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 4's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 4's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        53. Section 86.1815-02 is amended by adding paragraph (h), to read 
    as follows:
    
    [[Page 58559]]
    
    Sec. 86.1815-02  Emission standards for light-duty trucks 4.
    
    * * * * *
        (h) Manufacturers may request to group light-duty truck 4's into 
    the same test group as vehicles subject to more stringent standards, so 
    long as those light-duty truck 4's meet the most stringent standards 
    applicable to any vehicle within that test group, as provided at 
    Sec. 86.1827(a)(5) and (d)(4).
        54. A new section 86.1816-04 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1816-04  Emission standards for complete heavy-duty vehicles
    
        This section applies to 2004 and later model year complete heavy-
    duty vehicles fueled by gasoline, methanol, natural gas and liquefied 
    petroleum gas fuels except as noted. This section also applies to 2000 
    and later model year complete heavy duty vehicles participating in the 
    early banking provisions of the averaging, trading and banking program 
    as specified in Sec. 86.1817-04(n). Multi-fueled vehicles shall comply 
    with all requirements established for each consumed fuel. For methanol 
    fueled vehicles, references in this section to hydrocarbons or total 
    hydrocarbons shall mean total hydrocarbon equivalents and references to 
    non-methane hydrocarbons shall mean non-methane hydrocarbon 
    equivalents.
        (a) Exhaust emission standards. (1) Exhaust emissions from 2004 and 
    later model year complete heavy-duty vehicles at and above 8,500 pounds 
    Gross Vehicle Weight Rating but equal to or less than 10,000 Gross 
    Vehicle Weight Rating pounds shall not exceed the following standards 
    at full useful life:
        (i) [Reserved]
        (ii) Non-methane organic gas. 0.280 grams per mile; this 
    requirement may be satisfied by measurement of non-methane hydrocarbons 
    or total hydrocarbons, at the manufacturer's option.
        (iii) Carbon monoxide. 7.3 grams per mile.
        (iv) Oxides of nitrogen. 0.9 grams per mile.
        (v) [Reserved]
        (2) Exhaust emissions from 2004 and later model year complete 
    heavy-duty vehicles above 10,000 pounds Gross Vehicle Weight Rating but 
    less than 14,000 pounds Gross Vehicle Weight Rating shall not exceed 
    the following standards at full useful life:
        (i) [Reserved]
        (ii) Non-methane organic gas. 0.330 grams per mile; this 
    requirement may be satisfied by measurement of non-methane hydrocarbons 
    or total hydrocarbons, at the manufacturer's option.
        (iii) Carbon monoxide. 8.1 grams per mile.
        (iv) Oxides of nitrogen. 1.0 grams per mile.
        (v) [Reserved]
        (b) [Reserved]
        (c) [Reserved]
        (d) Evaporative emissions. Evaporative hydrocarbon emissions from 
    gasoline-fueled, natural gas-fueled, liquefied petroleum gas-fueled, 
    and methanol-fueled complete heavy-duty vehicles shall not exceed the 
    following standards. The standards apply equally to certification and 
    in-use vehicles. The spitback standard also applies to newly assembled 
    vehicles.
        (1) For the full three-diurnal test sequence, diurnal plus hot soak 
    measurements: 3.0 grams per test.
        (2) Gasoline and methanol fuel only. For the supplemental two-
    diurnal test sequence, diurnal plus hot soak measurements: 3.5 grams 
    per test.
        (3) Gasoline and methanol fuel only. Running loss test: 0.05 grams 
    per mile.
        (4) Gasoline and methanol fuel only. Fuel dispensing spitback test: 
    1.0 grams per test.
        (e) Refueling emissions. (1) Refueling emissions from complete 
    heavy-duty vehicles equal to or less than 10,000 pounds Gross Vehicle 
    Weight Rating shall be phased in, in accordance with the schedule in 
    Table S04-5 in Sec. 1810-04 not to exceed the following emission 
    standards:
        (i) For gasoline-fueled and methanol-fueled vehicles: 0.20 grams 
    hydrocarbon per gallon (0.053 gram per liter) of fuel dispensed.
        (ii) For liquefied petroleum gas-fueled vehicles: 0.15 grams 
    hydrocarbon per gallon (0.04 gram per liter) of fuel dispensed.
        (2) The provisions of Sec. 86.1816-04(e) do not apply to incomplete 
    heavy-duty vehicles optionally certified to complete heavy duty vehicle 
    standards under the provisions of Sec. 86.1801-01(c)(2).
        (f) [Reserved]
        (g) Idle exhaust emission standards, complete heavy-duty vehicles. 
    Exhaust emissions of carbon monoxide from 2004 and later model year 
    gasoline, methanol, natural gas- and liquefied petroleum gas-fueled 
    complete heavy-duty vehicles shall not exceed 0.50 percent of exhaust 
    gas flow at curb idle for a useful life of 11 years or 120,000 miles, 
    whichever occurs first.
        (h) Manufacturers may request to group complete heavy-duty vehicles 
    into the same test group as vehicles subject to more stringent 
    standards, so long as those complete heavy-duty vehicles meet the most 
    stringent standards applicable to any vehicle within that test group, 
    as provided at Sec. 86.1827(a)(5) and (d)(4).
        55. A new section 86.1817-04 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1817-04  Complete heavy-duty vehicle averaging, trading, and 
    banking program.
    
        (a)(1) Complete heavy-duty vehicles eligible for the NOX 
    averaging, trading and banking program are described in the applicable 
    emission standards section of this subpart. All heavy-duty vehicles 
    which include an engine labeled for use in clean-fuel vehicles as 
    specified in 40 CFR part 88 are not eligible for this program. 
    Participation in this averaging, trading, and banking program is 
    voluntary.
        (2)(i) Test groups with a family emission limit (FEL) as defined in 
    Sec. 86.1803-01 exceeding the applicable standard shall obtain emission 
    credits as defined in Sec. 86.1803-01 in a mass amount sufficient to 
    address the shortfall. Credits may be obtained from averaging, trading, 
    or banking, as defined in Sec. 86.1803-01 within the averaging set 
    restrictions described in paragraph (d) of this section.
        (ii) Test groups with an FEL below the applicable standard will 
    have emission credits available to average, trade, bank or a 
    combination thereof. Credits may not be used for averaging or trading 
    to offset emissions that exceed an FEL. Credits may not be used to 
    remedy an in-use nonconformity determined by a Selective Enforcement 
    Audit or by recall testing. However, credits may be used to allow 
    subsequent production of vehicles for the test group in question if the 
    manufacturer elects to recertify to a higher FEL.
        (b) Participation in the NOX averaging, trading, and 
    banking program shall be done as follows:
        (1) During certification, the manufacturer shall:
        (i) Declare its intent to include specific test groups in the 
    averaging, trading and banking program.
        (ii) Declare an FEL for each test group participating in the 
    program.
        (A) The FEL must be to the same level of significant digits as the 
    emission standard (one-hundredth of a gram per mile for NOX 
    emissions).
        (B) In no case may the FEL exceed the upper limit prescribed in the 
    section concerning the applicable complete heavy-duty vehicle chassis-
    based NOX emission standard.
        (iii) Calculate the projected NOX emission credits 
    (positive or negative) as defined in Sec. 86.1803-01 based on quarterly 
    production projections for each participating test group, using the 
    applicable equation in paragraph (c) of
    
    [[Page 58560]]
    
    this section and the applicable factors for the specific test group.
        (iv)(A) Determine and state the source of the needed credits 
    according to quarterly projected production for test groups requiring 
    credits for certification.
        (B) State where the quarterly projected credits will be applied for 
    test groups generating credits.
        (C) Emission credits as defined in Sec. 86.1803-01 may be obtained 
    from or applied to only test groups within the same averaging set as 
    defined in Sec. 86.1803-01. Emission credits available for averaging, 
    trading, or banking, may be applied exclusively to a given test group, 
    or designated as reserved credits as defined in Sec. 86.1803-01.
        (2) Based on this information, each manufacturer's certification 
    application must demonstrate:
        (i) That at the end of model year production, each test group has a 
    net emissions credit balance of zero or more using the methodology in 
    paragraph (c) of this section with any credits obtained from averaging, 
    trading or banking.
        (ii) The source of the credits to be used to comply with the 
    emission standard if the FEL exceeds the standard, or where credits 
    will be applied if the FEL is less than the emission standard. In cases 
    where credits are being obtained, each test group involved must state 
    specifically the source (manufacturer/test group) of the credits being 
    used. In cases where credits are being generated/supplied, each test 
    group involved must state specifically the designated use 
    (manufacturer/test group or reserved) of the credits involved. All such 
    reports shall include all credits involved in averaging, trading or 
    banking.
        (3) During the model year, manufacturers must:
        (i) Monitor projected versus actual production to be certain that 
    compliance with the emission standards is achieved at the end of the 
    model year.
        (ii) Provide the end-of-year reports required under paragraph (i) 
    of this section.
        (iii) For manufacturers participating in emission credit trading, 
    maintain the quarterly records required under paragraph (l) of this 
    section.
        (4) Projected credits based on information supplied in the 
    certification application may be used to obtain a certificate of 
    conformity. However, any such credits may be revoked based on review of 
    end-of-model year reports, follow-up audits, and any other compliance 
    measures deemed appropriate by the Administrator.
        (5) Compliance under averaging, banking, and trading will be 
    determined at the end of the model year. Test groups without an 
    adequate amount of NOX emission credits will violate the 
    conditions of the certificate of conformity. The certificates of 
    conformity may be voided ab initio for test groups exceeding the 
    emission standard.
        (6) If EPA or the manufacturer determines that a reporting error 
    occurred on an end-of-year report previously submitted to EPA under 
    this section, the manufacturer's credits and credit calculations will 
    be recalculated. Erroneous positive credits will be void. Erroneous 
    negative balances may be adjusted by EPA for retroactive use.
        (i) If EPA review of a manufacturer's end-of-year report indicates 
    a credit shortfall, the manufacturer will be permitted to purchase the 
    necessary credits to bring the credit balance for that test group to 
    zero, at the ratio of 1.2 credits purchased for every credit needed to 
    bring the balance to zero. If sufficient credits are not available to 
    bring the credit balance for the test group in question to zero, EPA 
    may void the certificate for that test group ab initio.
        (ii) If within 180 days of receipt of the manufacturer's end-of-
    year report, EPA review determines a reporting error in the 
    manufacturer's favor (i.e. resulting in a positive credit balance) or 
    if the manufacturer discovers such an error within 180 days of EPA 
    receipt of the end-of-year report, the credits will be restored for use 
    by the manufacturer.
        (c) For each participating test group, NOX emission 
    credits (positive or negative) are to be calculated according to one of 
    the following equations and rounded, in accordance with ASTM E29-93a, 
    to the nearest one-tenth of a Megagram (MG). Consistent units are to be 
    used throughout the equation.
        (1) For determining credit need for all test groups and credit 
    availability for test groups generating credits for averaging only:
    
    Emission credits=(Std-FEL)  x (UL) x (Production) x (10-6)
    
        (2) For determining credit availability for test groups generating 
    credits for trading or banking:
    
    Emission credits=(Std-FEL)  x (UL) x (Production) x (10-6) 
    (Discount)
    
        (3) For purposes of the equations in paragraphs (c)(1) and (c)(2) 
    of this section:
    
    Std=the current and applicable complete heavy-duty vehicle 
    NOX emission standard in grams per mile or grams per 
    kilometer for model year 2004 and later vehicles.
    Std=0.9 grams per mile for model year 2001 through 2003 heavy-duty 
    vehicles at and above 8,500 pounds Gross Vehicle Weight Rating but 
    equal to or less than 10,000 Gross Vehicle Weight Rating pounds and 1.0 
    grams per mile for heavy-duty vehicles above 10,000 pounds Gross 
    Vehicle Weight Rating but less than 14,000 pounds Gross Vehicle Weight 
    Rating.
    FEL=the NOX family emission limit for the test group in 
    grams per mile or grams per kilometer.
    UL=the useful life, or alternative life as described in paragraph (c) 
    of Sec. 86.1805-01, for the given test group in miles or kilometers.
    Production=the number of vehicles produced for U.S. sales within the 
    given test group during the model year. Quarterly production 
    projections are used for initial certification. Actual production is 
    used for end-of-year compliance determination.
    Discount=a one-time discount applied to all credits to be banked or 
    traded within the model year generated. Except as otherwise allowed in 
    paragraph (m) of this section, the discount applied here is 0.9. Banked 
    credits traded in a subsequent model year will not be subject to an 
    additional discount. Banked credits used in a subsequent model year's 
    averaging program will not have the discount restored.
    
        (d) Averaging sets. The averaging and trading of NOX 
    emission credits will be allowed between all test groups of complete 
    heavy-duty vehicle excluding those vehicles produced for sale in 
    California. Averaging, banking, and trading are not applicable to 
    vehicles sold in California.
        (e) Banking of NOX emission credits. (1) Credit 
    deposits. (i) NOX emission credits may be banked from test 
    groups produced in any model year.
        (ii) Manufacturers may bank credits only after the end of the model 
    year and after actual credits have been reported to EPA in the end-of-
    year report. During the model year and before submittal of the end-of-
    year report, credits originally designated in the certification process 
    for banking will be considered reserved and may be redesignated for 
    trading or averaging.
        (2) Credit withdrawals. (i) NOX credits generated in 
    2004 and later model years do not expire.
        (ii) Manufacturers withdrawing banked emission credits shall 
    indicate so during certification and in their credit reports, as 
    described in paragraph (i) of this section.
        (3) Use of banked emission credits. The use of banked credits shall 
    be
    
    [[Page 58561]]
    
    within the averaging set and geographic restrictions described in 
    paragraph (d) of this section, and only for the following purposes:
        (i) Banked credits may be used in averaging, or in trading, or in 
    any combination thereof, during the certification period. Credits 
    declared for banking from the previous model year but not reported to 
    EPA may also be used. However, if EPA finds that the reported credits 
    can not be proven, they will be revoked and unavailable for use.
        (ii) Banked credits may not be used for averaging and trading to 
    offset emissions that exceed an FEL. Banked credits may not be used to 
    remedy an in-use nonconformity determined by a Selective Enforcement 
    Audit or by recall testing. However, banked credits may be used for 
    subsequent production of the test group if the manufacturer elects to 
    recertify to a higher FEL.
        (f) In the event of a negative credit balance in a trading 
    situation, both the buyer and the seller would be liable.
        (g) Certification fuel used for credit generation must be of a type 
    that is both available in use and expected to be used by the vehicle 
    purchaser. Therefore, upon request by the Administrator, the vehicle 
    manufacturer must provide information acceptable to the Administrator 
    that the designated fuel is readily available commercially and would be 
    used in customer service.
        (h) Credit apportionment. At the manufacturers option, credits 
    generated from complete heavy-duty vehicles under the provisions 
    described in this section may be sold to or otherwise provided to the 
    another party for use in programs other than the averaging, trading and 
    banking program described in this section.
        (1) The manufacturer shall pre-identify two emission levels per 
    test group for the purposes of credit apportionment. One emission level 
    shall be the FEL and the other shall be the level of the standard that 
    the test group is required to certify to under Sec. 86.1816-04. For 
    each test group, the manufacturer may report vehicle sales in two 
    categories, ``ABT-only credits'' and ``nonmanufacturer-owned credits''.
        (i) For vehicle sales reported as ``ABT-only credits'', the credits 
    generated must be used solely in the averaging, trading and banking 
    program described in this section.
        (ii) The vehicle manufacturer may declare a portion of vehicle 
    sales ``nonmanufacturer-owned credits'' and this portion of the credits 
    generated between the standard and the FEL, based on the calculation in 
    paragraph (c)(1) of this section, would belong to the vehicle 
    purchaser. The manufacturer may not generate any credits for the 
    vehicle sales reported as ``nonmanufacturer-owned credits'' for this 
    averaging, trading and banking program. Vehicles reported as 
    ``nonmanufacturer-owned credits'' shall comply with the FEL and the 
    requirements of this averaging, trading and banking program in all 
    other respects.
        (2) Only manufacturer-owned credits reported as ``ABT-only 
    credits'' shall be used in the averaging, trading, and banking 
    provisions described in this section.
        (3) Credits shall not be double-counted. Credits used in this 
    averaging, trading and banking program may not be provided to a vehicle 
    purchaser for use in another program.
        (4) Manufacturers shall determine and state the number of vehicles 
    sold as ``ABT-only credits'' and ``nonmanufacturer-owned credits'' in 
    the end-of-model year reports required under paragraph (i) of this 
    section.
        (i) Manufacturers participating in the emissions averaging, trading 
    and banking program, shall submit for each participating test group the 
    items listed in paragraphs (i)(1) through (3) of this section.
        (1) Application for certification. (i) The application for 
    certification will include a statement that the vehicles for which 
    certification is requested will not, to the best of the manufacturer's 
    belief, when included in the averaging, trading and banking program, 
    cause the applicable NOX emissions standard to be exceeded.
        (ii) The application for certification will also include 
    identification of the section of this subpart under which the test 
    group is participating in the averaging, trading and banking program 
    (e.g., Sec. 86.1817-04), the type (NOX), and the projected 
    number of credits generated/needed for this test group, the applicable 
    averaging set, the projected U.S. production volumes (excluding 
    vehicles produced for sale in California), by quarter, and the values 
    required to calculate credits as given in the applicable averaging, 
    trading and banking section. Manufacturers shall also submit how and 
    where credit surpluses are to be dispersed and how and through what 
    means credit deficits are to be met, as explained in the applicable 
    averaging, trading and banking section. The application must project 
    that each test group will be in compliance with the applicable emission 
    standards based on the vehicle mass emissions and credits from 
    averaging, trading and banking.
        (2) [Reserved].
        (3) End-of-year report. The manufacturer shall submit end-of-year 
    reports for each test group participating in the averaging, trading and 
    banking program, as described in paragraphs (i)(3)(i) through (iv) of 
    this section.
        (i) These reports shall be submitted within 90 days of the end of 
    the model year to: Director, Engine Programs and Compliance Division 
    (6405J), U.S. Environmental Protection Agency, 401 M Street, SW, 
    Washington, DC 20460.
        (ii) These reports shall indicate the test group, the averaging 
    set, the actual U.S. production volume (excluding vehicles produced for 
    sale in California), the values required to calculate credits as given 
    in the applicable averaging, trading and banking section, and the 
    resulting type and number of credits generated/required. Manufacturers 
    shall also submit how and where credit surpluses were dispersed (or are 
    to be banked) and how and through what means credit deficits were met. 
    Copies of contracts related to credit trading must also be included or 
    supplied by the broker if applicable. The report shall also include a 
    calculation of credit balances to show that net mass emissions balances 
    are within those allowed by the emission standards (equal to or greater 
    than a zero credit balance). Any credit discount factor described in 
    the applicable averaging, trading and banking section must be included 
    as required.
        (iii) The production counts for end-of-year reports shall be based 
    on the location of the first point of retail sale (e.g., customer, 
    dealer, secondary manufacturer) by the manufacturer.
        (iv) Errors discovered by EPA or the manufacturer in the end-of-
    year report, including changes in the production counts, may be 
    corrected up to 180 days subsequent to submission of the end-of-year 
    report. Errors discovered by EPA after 180 days shall be corrected if 
    credits are reduced. Errors in the manufacturer's favor will not be 
    corrected if discovered after the 180 day correction period allowed.
        (j) Failure by a manufacturer participating in the averaging, 
    trading and banking program to submit any quarterly or end-of-year 
    report (as applicable) in the specified time for all vehicles that are 
    part of an averaging set is a violation of section 203(a)(1) of the 
    Clean Air Act (42 U.S.C. 7522(a)(1)) for such vehicles.
        (k) Failure by a manufacturer generating credits for deposit only 
    in the complete heavy-duty vehicle banking program to submit their end-
    of-year reports in the applicable specified time period (i.e., 90 days 
    after the end of the model year) shall result in the credits
    
    [[Page 58562]]
    
    not being available for use until such reports are received and 
    reviewed by EPA. Use of projected credits pending EPA review will not 
    be permitted in these circumstances.
        (l) Any manufacturer producing a test group participating in 
    trading using reserved credits, shall maintain the following records on 
    a quarterly basis for each test group in the trading subclass:
    
    (1) The test group;
    (2) The averaging set;
    (3) The actual quarterly and cumulative U.S. production volumes 
    excluding vehicles produced for sale in California;
    (4) The values required to calculate credits as given in paragraph (c) 
    of this section;
    (5) The resulting type and number of credits generated/required;
    (6) How and where credit surpluses are dispersed; and
    (7) How and through what means credit deficits are met.
    
        (m) Additional flexibility for complete heavy-duty vehicles. If a 
    complete heavy-duty vehicle has a NOX FEL of 0.6 grams per 
    mile or lower, a discount of 1.0 may be used in the trading and banking 
    credits calculation for NOX described in paragraph (c)(2) of 
    this section.
        (n) Early banking for complete heavy-duty vehicles. Provisions set 
    forth in paragraphs (a) through (m) of this section apply except as 
    specifically stated otherwise in paragraph (n) of this section.
        (1) To be eligible for the early banking program described in this 
    paragraph, the following must apply:
        (i) Credits are generated from complete heavy-duty vehicles.
        (ii) During certification, the manufacturer shall declare its 
    intent to include specific test groups in the early banking program 
    described in this paragraph.
        (2) Credit generation and use. (i) Credits shall only be generated 
    by model year 2000 through 2003 test groups.
        (ii) Credits may only be used for 2004 and later model year 
    complete heavy-duty vehicles and shall be subject to all discounting, 
    credit life, and all other provisions contained in paragraphs (a) 
    through (m) of this section.
        56. Section 86.1821-01 is amended by revising the first sentence of 
    paragraph (a), and the introductory text of paragraph (b), to read as 
    follows:
    
    
    Sec. 86.1821-01  Evaporative/refueling family determination.
    
        (a) The gasoline-, methanol-, liquefied petroleum gas-, and natural 
    gas-fueled light-duty vehicles, light-duty trucks, and complete heavy-
    duty vehicles described in a certification application will be divided 
    into groupings which are expected to have similar evaporative and/or 
    refueling emission characteristics (as applicable) throughout their 
    useful life. * * *
        (b) For gasoline-fueled or methanol-fueled light-duty vehicles, 
    light-duty trucks, and complete heavy-duty vehicles to be classed in 
    the same evaporative/refueling family, vehicles must be similar with 
    respect to the items listed in paragraphs (b)(1) through (9) of this 
    section.
    * * * * *
        57. Section 86.1823-01 is amended by revising the introductory 
    text, paragraph (c)(2) introductory text, and the first sentence of 
    paragraph (h), to read as follows:
    
    
    Sec. 86.1823-01  Durability demonstration procedures for exhaust 
    emissions.
    
        This section applies to light-duty vehicles, light-duty trucks, 
    complete heavy-duty vehicles, and heavy-duty vehicles certified under 
    the provisions of Sec. 86.1801-01(c). Eligible small volume 
    manufacturers or small volume test groups may optionally meet the 
    requirements of Secs. 86.1838-01 and 86.1826-01 in lieu of the 
    requirements of this section. For model years 2001, 2002, and 2003 all 
    manufacturers may elect to meet the provisions of paragraph (c)(2) of 
    this section in lieu of these requirements for light-duty vehicles or 
    light-duty trucks.
    * * * * *
        (c) * * *
        (2) For the 2001, 2002, and 2003 model years, for light-duty 
    vehicles and light-duty trucks the manufacturer may carry over exhaust 
    emission DF's previously generated under the Standard AMA Durability 
    Program described in Sec. 86.094-13(c), the Alternate Service 
    Accumulation Durability Program described in Sec. 86.094-13(e) or the 
    Standard Self-Approval Durability Program for light-duty trucks 
    described in Sec. 86.094-13(f) in lieu of complying with the durability 
    provisions of paragraph (a)(1) of this section.
    * * * * *
        (h) The Administrator may withdraw approval to use a durability 
    process or require modifications to a durability process based on the 
    data collected under Secs. 86.1845-01, 86.1846-01, and 86.1847-01 or 
    other information if the Administrator determines that the durability 
    processes have not been shown to accurately predict emission levels or 
    compliance with the standards (or FEL, as applicable) in use on 
    candidate vehicles (provided the inaccuracy could result in a lack of 
    compliance with the standards for a test group covered by this 
    durability process). * * *
    * * * * *
        58. Section 86.1824-01 is amended by revising the first sentence of 
    the introductory text, redesignating paragraphs (d) through (f) as 
    paragraphs (e) through (g), and by adding new paragraph (d), to read as 
    follows:
    
    
    Sec. 86.1824-01  Durability demonstration procedures for evaporative 
    emissions.
    
        This section applies to gasoline-, methanol-, liquefied petroleum 
    gas-, and natural gas-fueled light-duty vehicles, light-duty trucks, 
    complete heavy-duty vehicles, and heavy-duty vehicles certified under 
    the provisions of Sec. 86.1801-01(c). * * *
    * * * * *
        (d) The durability process described in paragraph (a) of this 
    section must be described in the application for certification under 
    the provisions of Sec. 86.1844-01.
    * * * * *
        59. Section 86.1825-01 is amended by revising the first two 
    sentences of introductory text to read as follows:
    
    
    Sec. 86.1825-01  Durability demonstration procedures for refueling 
    emissions.
    
        This section applies to light-duty vehicles, light-duty trucks, and 
    complete heavy-duty vehicles, and heavy-duty vehicles which are 
    certified under light-duty rules as allowed under the provisions of 
    Sec. 86.1801-01(c) which are subject to refueling loss emission 
    compliance. Refer to the provisions of Secs. 86.1811-01, 86.1812-01, 
    86.1813-01, 86.1814-04, 86.1815-04, and 86.1816-04 to determine 
    applicability of the refueling standards to different classes of 
    vehicles for various model years. * * *
    * * * * *
        60. Section 86.1826-01 is amended by revising paragraphs (b)(2) 
    introductory text and (b)(3) introductory text, to read as follows:
    
    
    Sec. 86.1826-01  Assigned deterioration factors for small volume 
    manufacturers and small volume test groups.
    
    * * * * *
        (b) * *  *
        (2) Manufacturers with aggregated sales from and including 301 
    through 14,999 motor vehicles and motor vehicle engines per year 
    (determined under the provisions of Sec. 86.1838-01(b)) certifying 
    vehicles equipped with
    
    [[Page 58563]]
    
    proven emission control systems shall conform to the following 
    provisions:
    * * * * *
        (3) Manufacturers with aggregated sales from 301 through 14,999 
    motor vehicles and motor vehicle engines per year (determined under the 
    provisions of Sec. 86.1838-01(b)) certifying vehicles equipped with 
    unproven emission control systems shall conform to the following 
    provisions:
    * * * * *
        61. Section 86.1827-01 is amended by revising paragraph (a)(5), 
    removing ``and'' at the end of paragraph (d)(2), removing the period at 
    the end of paragraph (d)(3) and adding ``; and'' in its place, and 
    adding paragraph (d)(4), to read as follows:
    
    
    Sec. 86.1827-01  Test group determination.
    
    * * * * *
        (a) * * *
        (5) Subject to the same emission standards, except that a 
    manufacturer may request to group vehicles into the same test group as 
    vehicles subject to more stringent standards, so long as those all the 
    vehicles within the test group are certified to the most stringent 
    standards applicable to any vehicle within that test group. Light-duty 
    trucks which are subject to the same emission standards as light-duty 
    vehicles with the exception of the light-duty truck idle CO standard 
    and/or total HC standard may be included in the same test group.
    * * * * *
        (d) * * *
        (4) A statement that all vehicles within a test group are certified 
    to the most stringent standards applicable to any vehicle within that 
    test group.
        62. Section 86.1829-01 is amended by revising paragraphs 
    (b)(1)(ii)(B), (b)(2)(ii)(B), and (b)(5), to read as follows:
    
    
    Sec. 86.1829-01  Durability and emission testing requirements; waivers.
    
    * * * * *
        (b) * * *
        (1) * * *
        (ii) * * *
        (B) In lieu of testing vehicles according to the provisions of 
    paragraph (b)(1)(ii)(A) of this section, a manufacturer may provide a 
    statement in its application for certification that, based on the 
    manufacturer's engineering evaluation of appropriate high-altitude 
    emission testing, all light-duty vehicles, light-duty trucks, and 
    complete heavy-duty vehicles comply with the emission standards at high 
    altitude.
    * * * * *
        (2) * * *
        (ii) * * *
        (B) In lieu of testing vehicles according to the provisions of 
    paragraph (b)(2)(ii)(A) of this section, a manufacturer may provide a 
    statement in its application for certification that, based on the 
    manufacturer's engineering evaluation of such high-altitude emission 
    testing as the manufacturer deems appropriate, all light-duty vehicles, 
    light-duty trucks, and complete heavy-duty vehicles comply with the 
    emission standards at high altitude.
    * * * * *
        (5) Idle CO Testing. To determine idle CO emission compliance for 
    light-duty trucks and complete heavy-duty vehicles, the manufacturer 
    shall follow one of the following two procedures:
        (i) For test groups containing light-duty trucks and complete 
    heavy-duty vehicles, each EDV shall be tested in accordance with the 
    idle CO testing procedures of subpart B of this Part; or
        (ii) In lieu of testing light trucks and complete heavy-duty 
    vehicles for idle CO emissions, a manufacturer may provide a statement 
    in its application for certification that, based on the manufacturer's 
    engineering evaluation of such idle CO testing as the manufacturer 
    deems appropriate, all light-duty trucks and complete heavy-duty 
    vehicles comply with the idle CO emission standards.
    * * * * *
        63. Section 86.1834-01 is amended by redesignating paragraphs 
    (b)(3)(i), (b)(5) and (b)(6) as paragraphs (b)(3)(i)(A), (b)(6) and 
    (b)(7), respectively, revising paragraphs (b)(3) introductory text, 
    (b)(3)(ii) introductory text, (b)(3)(iii), (b)(3)(iv), the first 
    sentence of newly redesignated paragraph (b)(6)(iii), the seventh 
    sentence of newly redesignated paragraph (b)(7)(ii), the first sentence 
    of newly redesignated paragraph (b)(7)(iii), and the heading of 
    paragraph (d), adding paragraphs (b)(3)(i)(B), (b)(3)(v), (b)(3)(vi), 
    and (b)(6)(i)(H), and adding and reserving paragraph (b)(5), to read as 
    follows:
    
    
    Sec. 86.1834-01  Allowable maintenance.
    
    * * * * *
        (b) * * *
        (3) Emission-related maintenance in addition to, or at shorter 
    intervals than, that listed in paragraphs (b)(3)(i) through (vi) of 
    this section will not be accepted as technologically necessary, except 
    as provided in paragraph (b)(7) of this section.
        (i) * * *
        (B) The cleaning or replacement of complete heavy-duty vehicle 
    spark plugs shall occur at 25,000 miles (or 750 hours) of use and at 
    30,000-mile (or 750 hour) intervals thereafter, for vehicles certified 
    for use with unleaded fuel only.
        (ii) For light-duty vehicles and light-duty trucks, the adjustment, 
    cleaning, repair, or replacement of the following items shall occur at 
    50,000 miles of use and at 50,000-mile intervals thereafter:
    * * * * *
        (iii) For complete heavy-duty vehicles, the adjustment, cleaning, 
    repair, or replacement of the following items shall occur at 50,000 
    miles (or 1,500 hours) of use and at 50,000-mile (1,500 hour) intervals 
    thereafter:
    
        (A) Positive crankcase ventilation valve.
        (B) Emission-related hoses and tubes.
        (C) Ignition wires.
        (D) Idle mixture.
        (E) Exhaust gas recirculation system related filters and coolers.
    
        (iv) For light-duty trucks, light-duty vehicles, and complete 
    heavy-duty vehicles, the adjustment, cleaning, repair, or replacement 
    of the oxygen sensor shall occur at 80,000 miles (or 2,400 hours) of 
    use and at 80,000-mile (or 2,400-hour) intervals thereafter.
        (v) For light-duty trucks and light-duty vehicles, the adjustment, 
    cleaning, repair, or replacement of the following items shall occur at 
    100,000 miles of use and at 100,000-mile intervals thereafter:
    
        (A) Catalytic converter.
        (B) Air injection system components.
        (C) Fuel injectors.
        (D) Electronic engine control unit and its associated sensors 
    (except oxygen sensor) and actuators.
        (E) Evaporative and/or refueling emission canister(s).
        (F) Turbochargers.
        (G) Carburetors.
        (H) Superchargers.
        (I) Exhaust gas recirculation system including all related filters 
    and control valves.
    
        (vi) For complete heavy-duty vehicles, the adjustment, cleaning, 
    repair, or replacement of the following items shall occur at 100,000 
    miles (or 3,000 hours) of use and at 100,000-mile (or 3,000 hour) 
    intervals thereafter:
    
        (A) Catalytic converter.
        (B) Air injection system components.
        (C) Fuel injectors.
        (D) Electronic engine control unit and its associated sensors 
    (except oxygen sensor) and actuators.
        (E) Evaporative and/or refueling emission canister(s).
        (F) Turbochargers.
        (G) Carburetors.
        (H) Exhaust gas recirculation system (including all related control 
    valves and tubing) except as otherwise provided in paragraph 
    (b)(3)(iii)(E) of this section.
    * * * * *
    
    [[Page 58564]]
    
        (5) [Reserved]
        (6) * * *
        (i) * * *
        (H) Any other add-on emissions-related component (i.e., a component 
    whose sole or primary purpose is to reduce emissions or whose failure 
    will significantly degrade emissions control and whose function is not 
    integral to the design and performance of the engine.)
        (iii) Visible signal systems used under paragraph (b)(6)(ii)(C) of 
    this section are considered an element of design of the emission 
    control system. * * *
        (7) * * *
        (ii) * * * For maintenance items established as emission-related, 
    the Administrator will further designate the maintenance as critical if 
    the component which receives the maintenance is a critical component 
    under paragraph (b)(6) of this section. * * *
        (iii) Any manufacturer may request a hearing on the Administrator's 
    determinations in this paragraph (b)(7). * * *
        (d) Unscheduled maintenance on durability data vehicles. * * *
    * * * * *
        64. Section 86.1835-01 is amended by revising the third sentence of 
    paragraph (a)(1)(i), paragraph (b)(1) introductory text, and paragraph 
    (b)(3) introductory text, to read as follows:
    
    
    Sec. 86.1835-01  Confirmatory certification testing.
    
        (a) * * *
        (1) * * *
        (i) * * * The Administrator, in making or specifying such 
    adjustments, will consider the effect of the deviation from the 
    manufacturer's recommended setting on emissions performance 
    characteristics as well as the likelihood that similar settings will 
    occur on in-use light-duty vehicles, light-duty trucks, or complete 
    heavy-duty vehicles. * * *
    * * * * *
        (b) * * * (1) If the Administrator determines not to conduct a 
    confirmatory test under the provisions of paragraph (a) of this 
    section, light-duty vehicle and light-duty truck manufacturers will 
    conduct a confirmatory test at their facility after submitting the 
    original test data to the Administrator whenever any of the conditions 
    listed in paragraph (b)(1)(i) through (v) of this section exist, and 
    complete heavy-duty vehicles manufacturers will conduct a confirmatory 
    test at their facility after submitting the original test data to the 
    Administrator whenever the conditions listed in paragraph (b)(1)(i) or 
    (b)(1)(ii) of this section exist.
    * * * * *
        (3) For light-duty vehicles, and light-duty trucks, the 
    manufacturer shall conduct a retest of the FTP or highway test if the 
    difference between the fuel economy of the confirmatory test and the 
    original manufacturer's test equals or exceeds three percent (or such 
    lower percentage to be applied consistently to all manufacturer 
    conducted confirmatory testing as requested by the manufacturer and 
    approved by the Administrator).
    * * * * *
        65. Section 86.1840-01 is revised to read as follows:
    
    
    Sec. 86.1840-01  Special test procedures.
    
        (a) The Administrator may, on the basis of written application by a 
    manufacturer, prescribe test procedures, other than those set forth in 
    this part, for any light-duty vehicle, light-duty truck, or complete 
    heavy-duty vehicle which the Administrator determines is not 
    susceptible to satisfactory testing by the procedures set forth in this 
    part.
        (b) If the manufacturer does not submit a written application for 
    use of special test procedures but the Administrator determines that a 
    light-duty vehicle, light-duty truck, or complete heavy-duty vehicle is 
    not susceptible to satisfactory testing by the procedures set forth in 
    this part, the Administrator shall notify the manufacturer in writing 
    and set forth the reasons for such rejection in accordance with the 
    provisions of Sec. 86.1848(a)(2).
        66. Section 86.1844-01 is amended by revising the fourth sentence 
    of paragraph (d)(12), the fourth sentence of paragraph (e)(3), and 
    paragraph (g)(5), and adding paragraph (g)(14) to read as follows:
    
    
    Sec. 86.1844-01  Information requirements: Application for 
    certification and submittal of information upon request.
    
    * * * * *
        (d) * * *
        (12) * * * The description shall include, but is not limited to, 
    information such as model name, vehicle classification (light-duty 
    vehicle, light-duty truck, or complete heavy-duty vehicle), sales area, 
    engine displacement, engine code, transmission type, tire size and 
    parameters necessary to conduct exhaust emission tests such as 
    equivalent test weight, curb and gross vehicle weight, test horsepower 
    (with and without air conditioning adjustment), coast down time, shift 
    schedules, cooling fan configuration, etc. and evaporative tests such 
    as canister working capacity, canister bed volume and fuel temperature 
    profile. * * *
    * * * * *
        (e) * * *
        (3) * * * The description shall include, but is not limited to, 
    information such as model name, vehicle classification (light-duty 
    vehicle, light-duty truck, or complete heavy-duty vehicle), sales area, 
    engine displacement, engine code, transmission type, tire size and 
    parameters necessary to conduct exhaust emission tests such as 
    equivalent test weight, curb and gross vehicle weight, test horsepower 
    (with and without air conditioning adjustment), coast down time, shift 
    schedules, cooling fan configuration, etc and evaporative tests such as 
    canister working capacity, canister bed volume and fuel temperature 
    profile. * * *
    * * * * *
        (g) * * *
        (5) Any information necessary to demonstrate that no defeat devices 
    are present on any vehicles covered by a certificate including, but not 
    limited to, a description of the technology employed to control CO 
    emissions at intermediate temperatures, as applicable.
    * * * * *
        (14) For complete heavy-duty vehicles only, all hardware (including 
    scan tools) and documentation necessary for EPA to read and interpret 
    (in engineering units if applicable) any information broadcast by an 
    engine's on-board computers and electronic control modules which 
    relates in anyway to emission control devices and auxiliary emission 
    control devices. This requirement includes access by EPA to any 
    proprietary code information which may be broadcast by an engine's on-
    board computer and electronic control modules. Information which is 
    confidential business information must be marked as such. Engineering 
    units refers to the ability to read and interpret information in 
    commonly understood engineering units, for example, engine speed in 
    revolutions per minute or per second, injection timing parameters such 
    as start of injection in degree's before top-dead center, fueling rates 
    in cubic centimeters per stroke, vehicle speed in milers per hour or 
    per kilometer.
    * * * * *
        67. Section 86.1845-01 is amended by revising paragraph (a), to 
    read as follows:
    
    
    Sec. 86.1845-01  Manufacturer in-use verification testing requirements.
    
        (a) General requirements. A manufacturer light-duty vehicles, 
    light-duty trucks, and complete heavy-duty
    
    [[Page 58565]]
    
    vehicles shall test, or cause to have tested a specified number of 
    light-duty vehicles, light-duty trucks, and complete heavy-duty 
    vehicles. Such testing shall be conducted in accordance with the 
    provisions of this section. For purposes of this section, the term 
    vehicle shall include light-duty vehicles, light-duty trucks, and 
    complete heavy-duty vehicles.
    * * * * *
        68. Section 86.1845-04 is amended by revising paragraph (a), to 
    read as follows:
    
    
    Sec. 86.1845-04  Manufacturer in-use verification testing requirements.
    
        (a) General requirements. A manufacturer light-duty vehicles, 
    light-duty trucks, and complete heavy-duty vehicles shall test, or 
    cause to have tested a specified number of light-duty vehicles, light-
    duty trucks, and complete heavy-duty vehicles. Such testing shall be 
    conducted in accordance with the provisions of this section. For 
    purposes of this section, the term vehicle shall include light-duty 
    vehicles, light-duty trucks, and complete heavy-duty vehicles.
    * * * * *
        69. A new section 86.1846-07 is added to subpart S, to read as 
    follows:
    
    
    Sec. 86.1846-07  Manufacturer in-use confirmatory testing.
    
        (a) General requirements. A manufacturer of light-duty vehicles, 
    light-duty trucks, and/or complete heavy-duty vehicles shall test, or 
    cause testing to be conducted, under this section when the emission 
    levels shown by a test group sample from testing under Sec. 86.1845-04 
    exceeds the criteria specified in paragraph (b) of this section. The 
    testing required under this section applies separately to each test 
    group and at each test point (low and high mileage) that meets the 
    specified criteria. The testing requirements apply separately for each 
    model year, starting with model year 2006.
        (b) Criteria for additional testing. A manufacturer shall test a 
    test group or a subset of a test group as described in paragraph (j) of 
    this section when the results from testing conducted under 
    Sec. 86.1845-04 show mean emissions for that test group of any 
    pollutant(s) to be equal to or greater than 1.30 times the applicable 
    in-use standard and a failure rate, among the test group vehicles, for 
    the corresponding pollutant(s) of fifty percent or greater.
        (1) This requirement does not apply to Supplemental FTP testing 
    conducted under Sec. 86.1845-04(b)(5)(i) or evaporative/refueling 
    testing conducted under Sec. 86.1845-04. Testing conducted at high 
    altitude under the requirements of Sec. 86.1845-04 will be included in 
    determining if a test group meets the criteria triggering testing 
    required under this section.
        (2) The vehicle tested under the requirements of Sec. 86.1845-
    04(c)(2)(i) with a minimum odometer miles of 75% of useful life will 
    not be included in determining if a test group meets the triggering 
    criteria.
        (3) The SFTP composite emission levels shall include the IUVP FTP 
    emissions, the IUVP US06 emissions, and the values from the SC03 Air 
    Conditioning EDV certification test (without DFs applied). The 
    calculations shall be made using the equations prescribed in 
    Sec. 86.164-01. If more than one set of certification SC03 data exists 
    (due to running change testing or other reasons), the manufacturer 
    shall choose the SC03 result to use in the calculation from among those 
    data sets using good engineering judgment.
        (c) Useful life. Vehicles tested under the provisions of this 
    section must be within the useful life specified for the emission 
    standards which were exceeded in the testing under Sec. 86.1845-04. 
    Testing should be within the useful life specified, subject to sections 
    207(c)(5) and (c)(6) of the Clean Air Act where applicable.
        (d) Number of test vehicles. A manufacturer must test a minimum of 
    ten vehicles of the test group or Agency-designated subset. A 
    manufacturer may, at the manufacturer's discretion, test more than ten 
    vehicles under this paragraph for a specific test group or Agency-
    designated subset. If a manufacturer chooses to test more than the 
    required ten vehicles, all testing must be completed within the time 
    designated in the testing completion requirements of paragraph (g) of 
    this section. Any vehicles which are eliminated from the sample either 
    prior to or subsequent to testing, or any vehicles for which test 
    results are determined to be void, must be replaced in order that the 
    final sample of vehicles for which test results acceptable to the 
    Agency are available equals a minimum of ten vehicles. A manufacturer 
    may cease testing with a sample of five vehicles if the results of the 
    first five vehicles tested show mean emissions for each pollutant to be 
    less than 75.0 percent of the applicable standard, with no vehicles 
    exceeding the applicable standard for any pollutant.
        (e) Emission Testing. Each test vehicle of a test group or Agency-
    designated subset shall be tested in accordance with the Federal Test 
    Procedure and/or the Supplemental Federal Test Procedure (whichever of 
    these tests performed under Sec. 86.1845-04 produces emission levels 
    requiring testing under this section) as described in subpart B of this 
    part, when such test vehicle is tested for compliance with applicable 
    exhaust emission standards under this subpart.
        (f) Geographical limitations. (1) Test groups or Agency-designated 
    subsets certified to 50-state standards: For low altitude testing no 
    more than 50 percent of the test vehicles may be procured from 
    California. The test vehicles procured from the 49 state area must be 
    procured from a location with a heating degree day 30 year annual 
    average equal to or greater than 4000.
        (2) Test groups or Agency-designated subsets certified to 49 state 
    standards: For low-altitude testing all vehicles shall be procured from 
    a location with a heating degree day 30 year annual average equal to or 
    greater than 4000.
        (3) Vehicles procured for high altitude testing may be procured 
    from any area provided that the vehicle's primary area of operation was 
    above 4000 feet.
        (g) Testing. Testing required under this section must commence 
    within three months of completion of the testing under Sec. 86.1845-04 
    which triggered the confirmatory testing and must be completed within 
    seven months of the completion of the testing which triggered the 
    confirmatory testing. Any industry review of the results obtained under 
    Sec. 86.1845-04 and any additional vehicle procurement and/or testing 
    which takes place under the provisions of Sec. 86.1845-04 which the 
    industry believes may affect the triggering of required confirmatory 
    testing must take place within the three month period. The data and the 
    manufacturers reasoning for reconsideration of the data must be 
    provided to the Agency within the three month period.
        (h) Limit on manufacturer conducted testing. For each manufacturer, 
    the maximum number of test group(s)(or Agency-designated subset(s))of 
    each model year for which testing under this section shall be required 
    is limited to 50 percent of the total number of test groups of each 
    model year required to be tested by each manufacturer as prescribed in 
    Sec. 86.1845-04 rounded to the next highest whole number where 
    appropriate. For each manufacturer with only one test group under 
    Sec. 86.1845-04, such manufacturer shall have a maximum potential 
    testing requirement under this section of one test group (or Agency-
    designated subset) per model year.
        (i) Prior to beginning in-use confirmatory testing the manufacturer 
    must, after consultation with the Agency, submit a written plan
    
    [[Page 58566]]
    
    describing the details of the vehicle procurement, maintenance, and 
    testing procedures (not otherwise specified by regulation) it intends 
    to use.
        (j) Testing a subset. EPA may designate a subset of the test group 
    based on transmission type for testing under this section in lieu of 
    testing the entire test group when the results for the entire test 
    group from testing conducted under Sec. 86.1845-04 show mean emissions 
    and a failure rate which meet these criteria for additional testing.
        70. Section 86.1848-01 is amended by revising paragraphs (c)(4) and 
    the first sentence of paragraph (e) introductory text to read as 
    follows:
    
    
    Sec. 86.1848-01  Certification.
    
    * * * * *
        (c) * * *
        (4) For incomplete light-duty trucks and incomplete heavy-duty 
    vehicles, a certificate covers only those new motor vehicles which, 
    when completed by having the primary load-carrying device or container 
    attached, conform to the maximum curb weight and frontal area 
    limitations described in the application for certification as required 
    in Sec. 86.1844-01.
    * * * * *
        (e) A manufacturer of new light-duty vehicles, light-duty trucks, 
    and complete heavy-duty vehicles must obtain a certificate of 
    conformity covering such vehicles from the Administrator prior to 
    selling, offering for sale, introducing into commerce, delivering for 
    introduction into commerce, or importing into the United States the new 
    vehicle. * * *
    * * * * *
    [FR Doc. 99-26795 Filed 10-28-99; 8:45 am]
    BILLING CODE 6560-50-P
    
    
    

Document Information

Published:
10/29/1999
Department:
Environmental Protection Agency
Entry Type:
Proposed Rule
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
99-26795
Dates:
We must receive your comments on this NPRM by December 2, 1999. A public hearing will be held on November 2, 1999 (EPA has published notice of this hearing on October 22, 1999 (64 FR 56985).). EPA requests that parties who want to testify notify the contact person
Pages:
58472-58566 (95 pages)
Docket Numbers:
AMS-FRL-6456-3
RINs:
2060-AI12: Control of Emissions of Air Pollution From 2004 and Later Model Year Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty Truck Definition, 2060-AI23: Tier II Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline Sulfur Standards
RIN Links:
https://www.federalregister.gov/regulations/2060-AI12/control-of-emissions-of-air-pollution-from-2004-and-later-model-year-heavy-duty-highway-engines-and-, https://www.federalregister.gov/regulations/2060-AI23/tier-ii-light-duty-vehicle-and-light-duty-truck-emission-standards-and-gasoline-sulfur-standards
PDF File:
99-26795.pdf
CFR: (83)
40 CFR 86.1827(a)(5)
40 CFR 86.1(b)(3))
40 CFR 86.004-11(b)(1)(iv)
40 CFR 86.1805-01(c)
40 CFR 86.1801-01(c)
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