97-23352. Direct Final Rule Amending the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and the Amending of Emission Standard Provisions for Gaseous Fueled Vehicles and Engines  

  • [Federal Register Volume 62, Number 172 (Friday, September 5, 1997)]
    [Rules and Regulations]
    [Pages 47114-47136]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 97-23352]
    
    
    
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    Part II
    
    
    
    
    
    Environmental Protection Agency
    
    
    
    
    
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    40 CFR Parts 9 and 86
    
    
    
    Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and 
    Trucks, and Emission Standard Provisions for Gaseous Fueled Vehicles, 
    and Engines, Amendments; Final Rule
    
    Federal Register / Vol. 62, No. 172 / Friday, September 5, 1997 / 
    Rules and Regulations
    
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    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Parts 9 and 86
    
    [FRL-5881-3]
    
    
    Direct Final Rule Amending the Test Procedures for Heavy-Duty 
    Engines, and Light-Duty Vehicles and Trucks and the Amending of 
    Emission Standard Provisions for Gaseous Fueled Vehicles and Engines
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Direct final rule.
    
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    SUMMARY: This action promulgates amendments to several sections of the 
    heavy-duty engine test procedure regulations in 40 CFR part 86. These 
    changes are needed in order to accommodate the use of new testing 
    equipment, to provide greater flexibility in the type of testing 
    equipment used and to ensure uniform calibration and use of the testing 
    equipment. The amendments will ensure the continued validity of testing 
    results and ensure that heavy-duty engines are being exercised 
    appropriately over the test procedures. This action also makes limited 
    changes to the light-duty vehicle and truck test procedure regulations 
    and the gaseous fuel emission standards in 40 CFR part 86. Because 
    changes are limited to technical issues, all of which have been 
    coordinated with industry, EPA expects no adverse comments.
    
    DATES: This rule will be effective January 5, 1998 unless notice is 
    received by October 6, 1997 that adverse or critical comments will be 
    submitted on a specific element of this rule. If such comments are 
    received, then EPA will publish a subsequent document in the Federal 
    Register withdrawing any regulation for which adverse or critical 
    comments were made.
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of January 5, 1998.
    
    ADDRESSES: Interested parties may submit written comments in response 
    to this notice (in duplicate, if possible) to Public Docket A-96-07 at 
    Air Docket Section, U.S. Environmental Protection Agency, First Floor, 
    Waterside Mall, Room M-1500, 401 M Street SW, Washington DC 20460. A 
    copy of the comments should also be sent to the contact person listed 
    below.
    
    FOR FURTHER INFORMATION CONTACT: Mr. Jaime Pagan, U.S. Environmental 
    Protection Agency, Engine Programs and Compliance Division, 2565 
    Plymouth Rd., Ann Arbor, MI 48105. Telephone: (313) 668-4574, fax: 
    (313) 741-7816.
    
    SUPPLEMENTARY INFORMATION:
    
    Table of Contents
    
    I. Introduction
    II. List of Changes to Test Procedures
    III. Environmental and Economic Impacts
    IV. Public Participation
    V. Statutory Authority
    VI. Administrative Designation and Regulatory Analysis
    VII. Compliance with Regulatory Flexibility Act
    VIII. Unfunded Mandates
    IX. Paperwork Reduction Act
    X. Submission to Congress and the General Accounting Office
    XI. Copies of Rulemaking Documents
    
    I. Introduction
    
        EPA's Smoke Exhaust and Gaseous and Particulate Exhaust Test 
    Procedures for certification and Selective Enforcement Audit (SEA) 
    provide a consistent method for testing and obtaining emissions data 
    from heavy-duty engines. This action promulgates amendments to the test 
    procedures in order to accommodate the use of new testing equipment and 
    clarify certain issues that have been identified since these procedures 
    were first published.
        Over the last few years, EPA and the Engine Manufacturers 
    Association (EMA) have worked together to identify the issues that 
    needed revision or clarification. During these interactions, 
    suggestions were made involving specific changes to the test 
    procedures. In general, the technical amendments included in this 
    action fall into two categories. First, many of the amendments are 
    simply clarifications that will help remove any potential ambiguities 
    or inconsistencies. Second, another group of amendments take into 
    account testing equipment and/or engine technology that was not as 
    widely used when the rule was first written.
        The changes to the Smoke Exhaust Test Procedure include 
    clarifications regarding the operation of the dynamometer, 
    accommodation of additional test equipment and more details on meter 
    light sources to be used. The test procedures for SEA contain a new 
    requirement that asks manufacturers to decide, before the initial cold 
    cycle, whether they will measure background particulate matter (PM) or 
    not. Promulgated amendments to the Gaseous and Particulate Test 
    Procedures cover the calibration requirements of gas analyzers, the use 
    of accessory loads, conditions for use of charge air cooling devices 
    and the permitted point deletions from regression analysis.
        Lastly, three minor changes to the Gaseous Fueled Vehicle Rule, 
    established in a September 21, 1994 notice (59 FR 48472), are made. The 
    regulatory text of that rule contained several minor errors and areas 
    where the applicability of various standards to gaseous-fueled vehicles 
    was not clear in the regulations, although all of the applicability 
    issues were discussed in the preamble. The following section presents a 
    more detailed overview of the specific amendments that EPA is 
    promulgating in this action.
    
    II. List of Changes to Test Procedures
    
        1. Changes and clarifications regarding dynamometer control 
    throughout the operation cycle for smoke emission tests (Sec. 86.884-
    7(a) and Sec. 86.884-13(b)(6)). These changes respond to the need to 
    better define the acceleration mode in the smoke test cycle. The 
    amendments to the regulatory language make the speed and acceleration 
    requirements more specific. In addition, it is clarified that during 
    the last 10 seconds of the lugging mode the average engine speed and 
    the average observed power shall be maintained within their specified 
    values. Furthermore, the regulations are revised to state that within 
    five seconds of the completion of the lugging mode, the dynamometer and 
    engine controls shall be returned to idle position. These 
    specifications are needed to ensure uniformity in how the procedures 
    are followed.
        2. Allow the use of newer in-line smokemeters and accommodate 
    multistack engines to the smoke exhaust test procedure (Sec. 86.884-
    8(c) and Sec. 86.884-14). In-line smokemeters, which were not available 
    when the original rule was written, are now taken into account in the 
    test procedure. The purpose of this addition is to provide engine 
    manufacturers the flexibility of using this type of equipment. The use 
    of in-line smokemeters is acceptable since it does not affect test 
    results. Also, specifications for the distance between the smokemeter 
    and the exhaust manifold, turbocharger outlet, aftertreatment device or 
    crossover junction (whichever is farthest downstream), are now included 
    in the regulations. Such distance specifications are needed to ensure a 
    uniform procedure and repeatable test results.
        3. Clarify the specifications for the type of light sources to be 
    used during smoke testing (Sec. 86.884-9 (b)(2) and (c)). These 
    clarifications specify the color temperature range and spectral peak 
    for
    
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    smokemeter light sources. It is also specified that light detectors 
    shall be a photocell or a photodiode. In addition, it is now specified 
    that the distance from the optical centerline of the smokemeter to the 
    exhaust pipe outlet is 10.25 inches. The new language adds 
    specificity by providing specific ranges for these parameters and adds 
    flexibility by allowing the use of more current smokemeter technology.
        4. Semantic clarification for the smoke test: Curb Idle rpm versus 
    Idle rpm (Sec. 86.884-7(a)(4) and Sec. 86.884-10(a)(8)). The word 
    ``Curb'' was eliminated from the term ``Curb Idle rpm'' in the smoke 
    test procedure. When running a smoke test on an engine with Curb Idle 
    Transmission Torque (CITT), it is very difficult to maintain the 
    desired idle speed without having to adjust the controls. The change in 
    the regulatory language simply allows to operate the engine at free 
    idle speed and does not affect test results.
        5. New calculations are provided to support the use of in-line 
    smokemeters (Sec. 86.884-14(a)). EPA provides an equation to determine 
    the standard half-second percent opacity, if the opacity is being 
    measured using a smokemeter with a different optical path length than 
    the one specified in Sec. 86.884-8. This calculation will help support 
    the use of current in-line smokemeters.
        6. Selective Enforcement Auditing Test Procedures: Require that 
    manufacturers decide, before the start of the cold cycle, whether they 
    will measure background particulate matter (PM). The test shall be 
    voided if the manufacturer fails to measure background PM after 
    initially saying it would (Sec. 86.1008-90(a), Sec. 86.1008-96(a), 
    Sec. 86.1008-2001(a) and Sec. 86.1111-87(a)). The CFR 
    (Sec. 86.1310(b)(1)(iv)(C)) states that the primary dilution air may be 
    sampled to determine background PM levels. Since this measurement is 
    not required, a valid test may be run without sampling for background 
    particulate. Background particulate can make a significant contribution 
    to the total particulate collected on the sample filter, especially at 
    emission levels of 0.10 g/bhp-hr and below. As a result, most 
    manufacturers choose to measure background particulate.
        During Selective Enforcement Audit (SEA) testing, manufacturers 
    will occasionally have problems measuring background particulate. 
    Improper handling of the background filters is the usual cause of these 
    problems. Manufacturers typically want to weigh the sample filters 
    before deciding whether or not to void the test. If the engine passes 
    based on the sample filter weights, the manufacturer will not void the 
    test since including background emissions will only lower an already 
    passing particulate value. However, if the engine fails based solely on 
    the sample filter weights, the manufacturer will want to void the test 
    since the engine may pass if background correction is included.
        Although it is certain that an engine that passes without 
    background correction will pass with background correction, it is 
    uncertain if an unmeasured background correction will lower the 
    particulate level of a failing engine enough to pass. An engine with 
    failing sample filter weights may pass when retested solely as the 
    result of test-to-test variability, lowering its emission level.
        Therefore EPA will now require that manufacturers decide, before 
    the start of the cold cycle, whether they will measure background PM. 
    The test shall be voided if the manufacturer fails to measure 
    background PM after initially saying it would.
        7. Clarify the procedure for sampling background particulate 
    (Sec. 86.1310-90(b)(1)(iv)(C)). The new language adds specificity to 
    the exhaust gas sampling method by stipulating that the primary 
    dilution air shall be sampled at the inlet to the primary dilution 
    tunnel, if unfiltered, or downstream of any primary dilution air 
    conditioning devices that are used.
        8. Clarify the hydrocarbon (HC) probe location and line temperature 
    requirements and introduce a new approach for demonstrating the 
    temperature profile of heated lines (Sec. 86.1310-90(b)(3)). This 
    clarification will provide more uniformity to the test procedures by 
    requiring specific probe locations and line temperature requirements. 
    The revisions to the regulations require that the temperature 
    requirements of the hydrocarbon (HC) sample line shall be met over its 
    entire length and not just at the measurement points. Since the gas 
    temperature can not instantly be brought up to the required 
    temperature, the length of the sample probe is defined as the length at 
    which the gas temperature must meet specifications.
        9. Require that all particulate matter (PM) filters (sample, 
    reference and background) are to be handled in pairs during all 
    weighing (Sec. 86.1310-90(b)(7), Sec. 86.1312-88(a) (3) & (4), and 
    Sec. 86.1337). This measure will help reduce error and ensure the 
    uniform use of all filter samples. More accurate measurements can be 
    obtained by weighing the filters in pairs.
        10. Recommend that PM filter loading be maximized consistent with 
    other temperature requirements and the requirement to avoid moisture 
    condensation (Sec. 86.1310-90(b)(7)(iv)). The new language will ensure 
    that PM measurements are accurate by having a filter loading that is 
    consistent with temperature and moisture requirements. Furthermore, EPA 
    recommends that the filter pair loading be proportional to the engine's 
    emission level. For example, a filter pair loading of 1 mg is typically 
    proportional to a 0.1 g/bhp-hr PM emission level. This change 
    eliminates the previous 5.3 milligram filter loading requirement which 
    is too difficult to achieve with today's low PM emitting engines.
        11. Apply the same proportional sampling requirement to the 
    Critical Flow Venturi (CFV-CVS) and the Positive Displacement Pump-
    Constant Volume Sampler (PDP-CVS) systems (Sec. 86.1310-90(b)(6), 
    Sec. 86.1337-90(a)(10), Sec. 86.1337-96(a)(10)). This new language 
    consolidates the requirement for demonstrating, during diesel 
    particulate testing, sample flow proportionality for both the single-
    dilution and double-dilution methods. Prior to the change, PDP-CVS 
    systems were only required to demonstrate that flow through the 
    particulate transfer tube was constant, plus or minus five percent. The 
    CFV-CVS was required to demonstrate that the ratio of main tunnel flow 
    to particulate sample flow did not change by more than plus or minus 
    five percent. The requirements for the two CVS systems are the same 
    assuming that flow through the PDP-CVS does not vary. Since this 
    assumption is not always true, the proportionality requirements for the 
    PDP-CVS and the CFV-CVS are not equivalent. To correct this, 
    laboratories with a PDP-CVS sampling system are required to meet the 
    same requirements as the CFV-CVS system, which is to demonstrate that 
    the ratio of main tunnel flow to particulate sample flow did not change 
    by more than plus or minus five percent.
        12. Clarify the ambient condition requirements for the filter 
    weighing room (Sec. 86.1312-88(a) (1) & (2)). This new language helps 
    resolve some inconsistencies between the light-and heavy-duty test 
    procedures. The new humidity requirement states that the room shall be 
    maintained at a dew point temperature of 282.5K 3K 
    (9.4 deg.C 3 deg.C) and a relative humidity of 45% 
    8%. The ambient temperature requirement in the room is 
    revised to 295K 3K (22 deg.C 3 deg.C) during 
    all filter conditioning and weighing.
        13. Allow a change in weight on the reference filters, between 
    weighings, by an absolute number rather than a percentage of the 
    nominal filter loading
    
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    (Sec. 86.1312-88(a)(4)). Sample and background filter pairs that are in 
    the process of stabilization shall be discarded if the average weight 
    of the reference filter pair changes by more than 40 micrograms. This 
    change simplifies the old requirement where a 5 percent 
    change from the nominal filter loading was allowed. EPA considers that 
    it is better practice to have a filter weight variation requirement 
    that does not vary with the nominal filter loading since a specific 
    loading is not required, but is only recommended.
        14. Change in the conditioning room timing requirement 
    (Sec. 86.1312-88(a)(5)). If any of the environmental conditions in the 
    conditioning room, as specified in the test procedures, are not met, 
    then it is required that the filters remain in the conditioning room 
    for at least one hour after correct conditions are met prior to 
    weighing. This amendment eliminates a previously unnecessary timing 
    requirement and adds a new option for manufacturers that gives them 
    greater flexibility in following the test procedures.
        15. Specify a new ASTM procedure for measuring aromatic composition 
    in diesel fuel (Sec. 86.1313-91, Sec. 86.1313-94, Sec. 86.1313-98). The 
    amendment allows, for heavy-duty diesel engines of model years 1987 
    thru 1997, the use of ASTM procedure D5186-91 for measuring aromatic 
    composition. For model years 1998 and later, ASTM D5186-91 will be the 
    required procedure for measuring aromatic composition.
        16. For diesel fuel testing only, change the requirement of 
    calibrating the CO analyzer to bi-monthly or immediately after 
    maintenance (Sec. 86.1316-90). This amendment loosens the monthly 
    calibration requirement due to the typically low levels of CO, relative 
    to the standard, produced by heavy-duty diesel engines.
        17. Change a requirement to generate new calibration curves each 
    month (Sec. 86.1316-90, Sec. 86.1316-94). This amendment adds 
    flexibility to the test procedure by allowing the manufacturer not to 
    generate a new calibration curve for an analyzer if they have 
    demonstrated that it has not significantly varied from its last 
    calibration. This change does not affect the accuracy of the analyzers, 
    but simplifies the calibration process.
        18. Clarify the method for issuing speed and torque command 
    setpoints throughout the test cycle (Sec. 86.1327-90(b), Sec. 86.1327-
    94(b), Sec. 86.1327-96(b)). The frequency for issuing the command 
    setpoints for engine torque and speed were not specified in the 
    original rule. It is now clarified that the torque and speed command 
    setpoints shall be issued at 5 Hz or greater.
        19. Clarify the exhaust system and insulation requirements for 
    diesel engines equipped with catalysts (Sec. 86.1327-90(f), 
    Sec. 86.1327-94(f), Sec. 86.1327-96(f)). These amendments respond to 
    the need to account for exhaust aftertreatment technology, which is 
    seeing a wider use in current heavy-duty engines. The language being 
    added to the regulations specifies that the exhaust pipe diameter shall 
    be the same as that found in-use. In addition, it is specified that for 
    gasoline and diesel engines, the catalyst container may be removed 
    during all test sequences prior to the practice cycle, and replaced 
    with an equivalent container having an inactive catalyst support. The 
    reason for allowing such option to manufacturers is that the catalyst 
    may be consumed by the high exhaust temperatures experienced during 
    testing. Finally, it is also specified that the distance from the 
    exhaust manifold flange or turbocharger outlet to any exhaust 
    aftertreatment device shall be the same as the vehicle configuration or 
    within the distance specifications that the engine manufacturers 
    provide for the installation of such devices.
        20. Clarify that loading from accessories is considered parasitic 
    in nature and that their work shall not be included in the emission 
    calculations (Sec. 86.1327-98, Sec. 86.1341-98(b)(3)).  The accessory 
    loading is considered parasitic because it is not providing any 
    ``useful work''. ``Useful work'' is the work that the application (that 
    uses the engine in question) does when commanded by an operator. The 
    amendment clarifies that accessories such as oil coolers, alternators, 
    air compressors, etc., if used, shall be applied to all engine testing 
    operations. Their work, however, shall not be included in the 
    integrated work used in emission calculations. This clarification adds 
    consistency between emission test results from different engines, which 
    do not necessarily operate with the same accessories.
        21. Require the following of SAE Recommended Practice J1937 for 
    simulating the use of a charge air cooling device while running the FTP 
    in a dynamometer test cell (Sec. 86.1330-84(b)(5), Sec. 86.1330-
    90(b)(5)). The following of this procedure will help ensure the uniform 
    use of such devices, which were not of common use when the original 
    rule was written.
        22. Define new intake and exhaust restriction setting requirements 
    for diesel fueled heavy-duty engines (Sec. 86.1330-84(f) and 
    Sec. 86.1330-90(f)). This new language replaces earlier language that 
    required the manufacturers to demonstrate some average restrictions 
    that their engines would typically experience in-use. The old 
    requirements were very difficult to meet. The new requirement for the 
    air inlet specifies a restriction setting which is midway between a 
    clean filter and the maximum restriction specified by the manufacturer. 
    In addition, the new requirement for exhaust restriction is 80 percent 
    of the manufacturer's recommended maximum specified exhaust 
    restriction. Furthermore, EPA still holds the manufacturer accountable 
    for the entire range of restrictions that the engine might experience 
    in-use.
        23. Correct the temperature requirement of the CVS dilution air 
    (Sec. 86.1330-84(b), Sec. 86.1330-90(b)). The language added makes the 
    dilution air temperature requirement consistent with Sec. 86.1310-90, 
    which is 68 deg.F (20 deg.C) for Otto cycle engines and between 
    68 deg.F and 86 deg.F (20 deg.C and 30 deg.C) for diesel cycle engines.
        24. Change the required torque command set-points in the FTP that 
    utilize the provisions related to Curb Idle Torque (CITT) 
    (Sec. 86.1333-90). The manufacturer is allowed to modify all torque 
    command set-points to CITT when the speed command set-point is equal to 
    or less than zero percent and the ``initial'' torque command set-point 
    is less than CITT. This language corrects a problem where, in certain 
    cases, a low torque command resulted in a real torque command less than 
    CITT, which is an operating condition that these engines do not 
    typically encounter in-use.
        25. Clarify the idle torque requirements for cycle validation 
    (Sec. 86.1333-90). The existing language for idle torque requirements 
    is clarified to make it more understandable.
        26. Apply a single set of requirements to both forced and natural 
    cool downs which precede the cold start exhaust emissions test 
    (Sec. 86.1334-84 and Sec. 86.1335-90).  This change defines a cold 
    engine as one with oil and water temperatures between 68 and 86 deg.F. 
    This is a change from the existing natural cool down requirements which 
    call for only oil temperature to be stabilized between 68 and 86 
    deg.F. The temperature requirements for forced cool down are now the 
    same as for natural cool down, thus providing one definition for a cold 
    engine regardless of the cool down procedure.
        27. Correct an oversight regarding the first FTP idle definition 
    (Sec. 86.1337-90 and Sec. 86.1337-96). This amendment adds language to 
    Sec. 86.1337-90 and Sec. 86.1337-96 that was inadvertently lost
    
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    from Sec. 86.1337-88. It also corrects a paragraph reference in the 
    same sections and eliminates specifications for particulate testing 
    without the use of flow compensation because these specifications are 
    no longer needed since the same particulate sampling requirements now 
    apply for systems with and without flow compensation.
        28. Clarify the procedure for calibrating gaseous emission 
    analyzers (Sec. 86.1321-90, Sec. 86.1321-94, Sec. 86.1322-84, 
    Sec. 86.1323-84, Sec. 86.1324-84 and Sec. 86.1325-94, Sec. 86.1338-84). 
    The data points requirements for calibrating analyzers below 15 percent 
    of full scale are specified in order to ensure an accurate curve. The 
    previous calibration procedure was defined by the type of gas divider 
    used for the calibration. Not all gas dividers were covered by the 
    previous procedure and no procedure was provided for a laboratory which 
    uses gas bottles. Changes to the procedure now allow the generation of 
    calibration data with six points that are approximately equally spaced. 
    Finally, analyzer response over 100% of full scale may be used if it 
    can be shown that readings in this range are accurate. These changes 
    give more flexibility without affecting the accuracy of the 
    calibrations.
        29. Require that particulate sample filters be placed in unsealed 
    petri dishes during conditioning after the emissions test 
    (Sec. 86.1339-90). This language will help ensure that particulate 
    filters will be handled consistently in all laboratories and makes it 
    consistent with the pre-conditioning requirements. The unsealed petri 
    dish requirement is needed in order to have a uniform method for 
    handling PM filters that also eliminates the possibility of filter 
    contamination.
        30. Eliminate the 80 hour maximum for pre-conditioning PM filters 
    (Sec. 86.1339-90). This change simplifies the filter pre-conditioning 
    procedure by eliminating the 80 hour maximum time requirement. It was 
    found that only the minimum 1 hour requirement was of meaningful value 
    for filter pre-conditioning.
        31. Clarify the permitted point deletions from regression analysis 
    for validation statistics (Sec. 86.1341-90, Sec. 86.1341-98 and 
    Appendix I, paragraph (f)(2)). A table that describes the permitted 
    point deletions from regression analysis is simplified by removing some 
    language and adding three sentences. The changes will make the table 
    easier to understand and do not affect test results.
        32. Correct an oversight regarding the calculation of cycle work 
    (Sec. 1341-90). This clarification adds language to Sec. 86.1341-90 
    that was inadvertently not included from Sec. 86.1341-84.
        33. Clarify that no useful work is generated from spurious non-
    zero/CITT torques that occur during idle (Sec. 86.1341-98(b) (3) & 
    (4)). For manual transmissions, all spurious non-zero torques at 
    reference idle portions of the cycle shall be set equal to zero and 
    included in the horsepower-hour calculation used for emission 
    determinations. For automatic transmissions, all spurious non-CITT 
    torques at reference idle portions of the cycle shall be included in 
    the horsepower-hour calculation used in the emission determination.
        34. Clarify the calculations for converting emission measurements 
    from as-measured dry concentrations to wet concentrations 
    (Sec. 86.1342-90, Sec. 86.1342-94). An equation used to convert as-
    measured dry concentrations to wet concentrations is amended in order 
    to correct an error in its derivation.
        35. Correct an error that occurred from Sec. 86.1342-84 to 
    Sec. 86.1342-90 when some guidelines for converting dry measurements to 
    wet concentrations became subordinate to a section describing the 
    calculation of brake-specific fuel consumption (Sec. 86.1342-90, 
    Sec. 86.1342-94).
        36. Clarify what calculations should be used for determining the 
    emission of particulate matter depending on what type of CVS sampling 
    system is used (Sec. 86.1343-88). The original language did not 
    distinguish between critical flow venturi (CFV) CVS and positive 
    displacement pump (PDP) CVS, which require different calculations for 
    determining the mass of particulate matter. The new language now 
    provides distinct calculations for both systems for emission 
    calculation purposes.
        37. Add provisions for testing heavy-duty engines and light-duty 
    vehicles that require the manufacturer to verify that the venturi is 
    achieving sonic flow when using a CFV-CVS sampling system (Sec. 86.119-
    90, Sec. 86.1319-84 and Sec. 86.1319-90). Having sonic flow during 
    emission tests, when using a CFV-CVS sampling system, is of critical 
    importance in order to achieve accurate and reliable emission results. 
    Manufacturers have two options for verifying sonic flow. The first 
    option involves calculating CFV pressure ratio, which must be less than 
    or equal to the calibration pressure ratio limit derived from the CFV 
    calibration data. Other sonic flow verification methods may be allowed 
    with prior approval from the Administrator.
        38. Revise Incorporation by Reference (Sec. 86.1). Section 86.1 
    contains a listing of all items in part 86 which are incorporated by 
    reference, along with the section numbers where they are incorporated. 
    The SAE Recommended Practice J1937 and the standard test method ASTM 
    5186-91 are added to such list. In addition, several minor corrections 
    to section 86.1 are made. In the Gaseous Fuels Rule the changes to 
    section 86.1 to incorporate the standards ASTM D2163-91 and ASTM D1945-
    91 were in some cases incorrect and did not properly list the part 86 
    sections in which these standards were incorporated.
        39. Correct Certification Specifications for Diesel Fuel for Light-
    Duty Vehicles and Trucks (Sec. 86.113-94). In the Gaseous Fuels Rule 
    (59 FR 48472) the section specifying certification fuel parameters for 
    light-duty vehicles and trucks (Sec. 86.113-94) was modified to include 
    natural gas and liquefied petroleum gas specifications. In addition to 
    new gaseous fuels specifications, this section was restructured to make 
    future additions of other fuels easier. Although these were the only 
    intended changes, some changes were inadvertently made to the 
    specifications for diesel fuel as well. Thus, in this notice such 
    section is being revised to correct for these inadvertent changes to 
    the diesel fuel specifications. Corrections involve the cetane number 
    and cetane index in paragraph (b)(2), and the cetane index, 90 percent 
    distillation point and gravity in paragraph (b)(3). These changes will 
    bring the diesel fuel certification specifications back to their 
    original state, prior to the publication of the Gaseous Fuels Rule.
        40. Clarify Gaseous Fuel Standards Applicability (Sec. 86.094-8, 
    Sec. 86.094-9, Sec. 86.094-11, Sec. 86.096-8 and Sec. 86.096-11). In 
    the Gaseous Fuels Rule there were several instances where the 
    regulatory text did not mirror the preamble discussion concerning the 
    applicability of various standards to gaseous-fueled vehicles, 
    especially as they relate to the options on the applicability of the 
    standards prior to the 1997 model year. EPA is revising the regulatory 
    text to clarify the provisions of the Gaseous Fuels Rule regulations. 
    The clarifications are summarized briefly in the following sentences. 
    In sections 86.094-8, 86.094-9, 86.096-8 and 86.096-11, the language 
    concerning the crankcase emissions prohibition is being clarified to 
    show that it is optional for the 1994 through 1996 model years and also 
    optional for 1997 model year turbocharged gaseous fueled heavy-duty 
    engines. In sections 86.094-9 and 86.096-11 the language concerning 
    exhaust emission standards is being
    
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    clarified to show that those standards are optional for gaseous-fueled 
    vehicles through the 1996 model year. In section 86.094-9 the language 
    concerning idle carbon monoxide (CO) emission standards is being 
    clarified to show that those standards are applicable to gaseous-fueled 
    engines, but optional through the 1996 model year. Finally, the section 
    86.094-11 language concerning smoke standards is being clarified to 
    show that those standards are applicable to gaseous-fueled vehicles, 
    but optional through the 1996 model year.
        41. Clarify Exhaust Emission Calculations Sec. 86.144-94). In 
    section 86.144-94, the density of nonmethane hydrocarbons in natural 
    gas and liquefied petroleum gas is used for emission calculations. The 
    description of this term incorrectly specifies that it be defined 
    simply as the density of hydrocarbon components in the fuel. This 
    definition does not exclude methane, as it should. The definition is 
    being corrected here to refer to the density of only the nonmethane 
    components.
        42. Clarify Changes to the Flame Ionization Detector (FID) 
    optimization (Sec. 86.1321-90 and Sec. 86.1321-94). More language is 
    incorporated to resolve some previous inconsistencies with the 
    procedure. For instance, the FID response now can be optimized with 
    respect to fuel flow or to fuel pressure. Furthermore, it is also 
    clarified that the optimum fuel, air, and sample pressures or flow 
    rates shall be recorded after their determination.
    
    III. Environmental and Economic Impacts
    
        EPA believes that these technical amendments will not have any 
    significant economic or environmental impacts. The changes have the 
    objective to clarify inconsistencies that might have been present in 
    the original rule or to allow the use of new testing equipment that 
    gives more flexibility, but does not affect test results.
    
    IV. Public Participation
    
        EPA believes that the provisions of this action are 
    noncontroversial since all the changes to the test procedures have been 
    previously discussed and resolved with the Engine Manufacturers 
    Association (EMA) and its members. Nonetheless, if public comments are 
    to be submitted, the Agency requests that wherever applicable, full 
    supporting data and detailed analysis should be submitted to allow EPA 
    to make maximum use of the comments. Commentators should provide 
    specific suggestions for any changes to any aspect of the regulations 
    that they believe need to be modified or improved. If EPA receives 
    adverse or critical comments regarding any specific element of this 
    rule, EPA will withdraw those regulations for which adverse or critical 
    comments were received. All comments should be directed to EPA Air 
    Docket, Docket No. A-96-07. The official comment period will last for 
    30 days following publication of this notice.
        Commentators desiring to submit proprietary information for 
    consideration should clearly distinguish such information from other 
    comments to the greatest extent possible, and clearly label it 
    ``Confidential Business Information''. Submissions containing such 
    proprietary information should be sent directly to the contact person 
    listed above, and not to the public docket, to ensure that proprietary 
    information is not inadvertently placed in the docket.
        Information covered by such a claim of confidentiality will be 
    disclosed by EPA only to the extent allowed and by the procedures set 
    forth in 40 CFR part 2. If no claim of confidentiality accompanies the 
    submission when it is received by EPA, it may be made available to the 
    public without further notice to the commentator.
    
    V. Statutory Authority
    
        The statutory authority for this action is granted by Sections 202, 
    206, 207, 208 and 301(a) of the Clean Air Act.
    
    VI. Administrative Designation and Regulatory Analysis
    
        Under Executive Order 12866 (58 FR 51735 (October 4, 1993)), the 
    Agency must determine whether this regulatory action is ``significant 
    and therefore subject to Office of Management and Budget (OMB) review 
    and the requirements of the Executive Order. The Order defines 
    ``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 believes that 
    this action is not a ``significant'' regulatory action within the 
    meaning of the Executive Order.
    
    VII. Compliance With Regulatory Flexibility Act
    
        EPA has determined that it is not necessary to prepare a regulatory 
    flexibility analysis in connection with this final rule. In support of 
    its proposed rule entitled Control of Emissions of Air Pollution from 
    Highway Heavy-Duty Engines (61 FR 33421, June 27, 1996), EPA 
    characterized the heavy-duty engine manufacturing industry in Chapter 3 
    of its Regulatory Impact Analysis (RIA). Based on that 
    characterization, EPA has determined that these technical amendments 
    will not have a significant impact on a substantial number of small 
    entities.
    
    VIII. Unfunded Mandates
    
        Under section 202 of the Unfunded Mandates Reform Act of 1995 
    (``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
    must prepare a written statement to accompany any rule where the 
    estimated costs to State, local, or tribal governments, or to the 
    private sector will be $100 million or more in any one year. Under 
    section 205, EPA must select the most cost-effective and least 
    burdensome alternative that achieves the objective of the rule and that 
    is consistent with statutory requirements. Section 203 requires EPA to 
    establish a plan for informing and advising any small governments that 
    may be significantly and uniquely impacted by the rule. EPA estimates 
    that the costs to State, local, or tribal governments, or the private 
    sector, from this rule will be less than $100 million.
    
    IX. Paperwork Reduction Act
    
        The technical amendments promulgated by this action do not create 
    or change the information collection burden under the provisions of the 
    Paperwork Reduction Act, 44 U.S.C. 3501 et. seq. The Office of 
    Management and Budget (OMB) has previously approved the information 
    collection requirements already contained in all the Part 86 sections 
    amended by this action and has assigned OMB control numbers 2060-0104 
    and 2060-0064.
    
    X. Submission to Congress and the General Accounting Office
    
        Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business 
    Regulatory Enforcement Fairness Act of 1996, EPA
    
    [[Page 47119]]
    
    submitted a report containing this rule and other required information 
    to the U.S. Senate, the U.S. House of Representatives and the 
    Comptroller General of the General Accounting Office prior to 
    publication of this rule in today's Federal Register. This rule is not 
    a ``major rule'' as defined by 5 U.S.C. 804(2).
    
    XI. Copies of Rulemaking Documents
    
        The preamble and regulatory language are available in the public 
    docket as described under ADDRESSES above and is also available 
    electronically on the Technology Transfer Network (TTN), which is an 
    electronic bulletin board system (BBS) operated by EPA's Office of Air 
    Quality Planning and Standards and via the Internet. The service is 
    free of charge, except for the cost of the phone call.
    
    A. Technology Transfer Network (TTN)
    
        Users are able to access and download TTN files on their first call 
    using a personal computer and modem per the following information.
    
    TTN BBS: 919-541-5742 (1200-14400 bps, no parity, 8 data bits, 1 stop 
    bit)
    Voice Helpline: 919-541-5384
    Also accessible via Internet: TELNET ttnbbs.rtpnc.epa.gov
    Off-line: Mondays from 8:00 AM to 12:00 Noon ET
    
        A user who has not called TTN previously will first be required to 
    answer some basic informational questions for registration purposes. 
    After completing the registration process, proceed through the 
    following menu choices from the Top Menu to access information on this 
    rulemaking.
    
         GATEWAY TO TTN TECHNICAL AREAS (Bulletin Boards)
         OMS--Mobile Sources Information
         Rulemaking & Reporting
        <5> Heavy-duty/Diesel
        <1> File area #1 . . . Heavy-duty Truck and Bus Standards
    
        At this point, the system will list all available files in the 
    chosen category in reverse chronological order with brief descriptions. 
    To download a file, select a transfer protocol that is supported by the 
    terminal software on your own computer, then set your own software to 
    receive the file using that same protocol.
        If unfamiliar with handling compressed (i.e. ZIP'ed) files, go to 
    the TTN top menu, System Utilities (Command: 1) for information and the 
    necessary program to download in order to unZIP the files of interest 
    after downloading to your computer. After getting the files you want 
    onto your computer, you can quit the TTN BBS with the oodbye 
    command.
        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.
    
    B. Internet
    
        Rulemaking documents may be found on the Internet as follows:
    
    World Wide Web: http://www.epa.gov/omswww
    FTP: ftp://ftp.epa.gov Then CD to the /pub/gopher/OMS/ directory
    Gopher: gopher://gopher.epa.gov:70/11/Offices/Air/OMS
    
        Alternatively, go to the main EPA gopher, and follow the menus:
    
    gopher.epa.gov
        EPA Offices and Regions
        Office of Air and Radiation
        Office of Mobile Sources
    
    List of Subjects
    
    40 CFR Part 9
    
        Reporting and recordkeeping requirements.
    
    40 CFR Part 86
    
        Environmental protection, Administrative practice and procedures, 
    Air pollution control, Confidential business information, Gasoline, 
    Incorporation by reference, Labeling, Motor vehicles, Motor vehicle 
    pollution, Reporting and recordkeeping requirements.
    
        Dated: August 18, 1997.
    Carol M Browner,
    Administrator.
    
        For the reasons set forth in the preamble, parts 9 and 86 of title 
    40 of chapter I of the Code of Federal Regulations are amended as 
    follows:
    
    PART 9--[AMENDED]
    
        1. The authority citation for part 9 continues to read as follows:
    
        Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003, 
    2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33 
    U.S.C. 1251 et seq., 1311, 1313d, 1314, 1321, 1326, 1330, 1344, 1345 
    (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR 1971-1975 Comp. p. 
    973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-1, 300g-2, 
    300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3, 300j-4, 
    300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-9657, 
    11023, 11048.
    
        1a. Section 9.1 is amended in the table by adding in numerical 
    order new entries under the center heading ``Control of Air Pollution 
    from New and In-Use Motor Vehicles and New and In-Use Motor Vehicle 
    Engines: Certification and Test Procedures,'' to read as follows:
    
    
    Sec. 9.1  OMB approvals under the Paperwork Reduction Act.
    
    * * * * *
    
                                                                            
                  40 CFR citation                      OMB control no.      
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
    
    * * * * *
    
    Control of Air Pollution From New and In-Use Motor Vehicles and New and 
    In-Use Motor Vehicle Engines: Certification and Test Procedures
    
    * * * * *
    
    86.1313-98.................................................    2060-0104
                                                                            
                      *        *        *        *        *                 
    86.1327-98.................................................    2060-0104
                                                                            
                      *        *        *        *        *                 
    86.1341-98.................................................    2060-0104
                                                                            
                      *        *        *        *        *                 
                                                                            
    
    PART 86--CONTROL OF AIR POLLUTION FROM NEW AND IN-USE MOTOR 
    VEHICLES AND NEW AND IN-USE MOTOR VEHICLE ENGINES: CERTIFICATION 
    AND TEST PROCEDURES
    
        1b. The authority citation for part 86 is revised to read as 
    follows:
    
        Authority: 42 U.S.C. 7401-7671q.
    
        2. In Sec. 86.1 the tables in paragraphs (b)(1) and (b)(2) are 
    amended by adding an entry for ASTM D5186-91 after ASTM E29-90, and by 
    revising the entries for ASTM D2163-91 and ASTM D1945-91 to read as 
    follows:
    
    
    Sec. 86.1  Reference materials.
    
    * * * * *
        (b) * * *
        (1) * * *
    
    ------------------------------------------------------------------------
             Document number and name             40 CFR part 86 reference  
    ------------------------------------------------------------------------
                                                                            
                  *        *        *        *        *                     
    ASTM D5186-91, Standard Test Method for     86.1313-91, 86.1313-94,     
     Determination of Aromatic Content of        86.1313-98.                
     Diesel Fuels by Supercritical Fluid                                    
     Chromatography.                                                        
    ASTM D2163-91, Standard Test Method for     86.113-94; 86.1213-94;      
     Analysis of Liquefied Petroleum (LP)        86.1313-94.                
     Gases and Propane Concentrates by Gas                                  
     Chromatography.                                                        
    
    [[Page 47120]]
    
                                                                            
    ASTM D1945-91, Standard Test Method for     86.113-94; 86.513-94;       
     Analysis of Natural Gas By Gas              86.1213-94; 86.1313-94.    
     Chromatography.                                                        
    ------------------------------------------------------------------------
    
        (2) * * *
    
    ------------------------------------------------------------------------
               Document No. and name              40 CFR part 86 reference  
    ------------------------------------------------------------------------
                                                                            
                  *        *        *        *        *                     
    SAE Recommended Practice J1937, November    86.1330-84; 86.1330-90.     
     1989, Engine Testing with Low Temperature                              
     Charge Air Cooler Systems in a                                         
     Dynamometer Test Cell.                                                 
    ------------------------------------------------------------------------
    
    * * * * *
        3. Section 86.094-8 of subpart A is amended by revising paragraph 
    (c) to read as follows:
    
    
    Sec. 86.094-8  Emission standards for 1994 and later model year light-
    duty vehicles.
    
    * * * * *
        (c) No crankcase emissions shall be discharged into the ambient 
    atmosphere from any 1994 and later model year Otto-cycle, or methanol-
    or gaseous-fueled diesel light-duty vehicle. This requirement is 
    optional for 1994 through 1996 model year gaseous-fueled light-duty 
    vehicles.
    * * * * *
        4. Section 86.094-9 of subpart A is amended by revising paragraphs 
    (a)(1)(i) introductory text, (a)(1)(ii) introductory text, (a)(1)(iii) 
    and (c), to read as follows:
    
    
    Sec. 86.094-9  Emission standards for 1994 and later model year light-
    duty trucks.
    
        (a) * * *
        (1) * * *
        (i) Light light-duty trucks. Exhaust emission from 1994 and later 
    model year light light-duty trucks shall meet all standards in Tables 
    A94-8, A94-9, A94-11 and A94-12 in the rows designated with the 
    applicable fuel type and loaded vehicle weight, according to the 
    implementation schedule in Tables A94-7 and A94-10 as follows (optional 
    for 1994 through 1996 model year gaseous-fueled light light-duty 
    trucks):
    * * * * *
        (ii) Heavy light-duty trucks. Exhaust emissions from 1994 and later 
    model year heavy light-duty trucks shall meet all standards in Tables 
    A94-14 and A94-15 in the rows designated with the applicable fuel type 
    and loaded vehicle weight or adjusted loaded vehicle weight, as 
    applicable, according to the implementation schedule in Table A94-13, 
    as follows (optional for 1994 through 1996 model year gaseous-fueled 
    heavy light-duty trucks):
    * * * * *
        (iii) Exhaust emissions of carbon monoxide from 1994 and later 
    model year light-duty trucks shall not exceed 0.50 percent of exhaust 
    gas flow at curb idle at a useful life of 11 years or 120,000 miles, 
    whichever first occurs (for Otto-cycle, and methanol-and gaseous-fueled 
    diesel light-duty trucks only--optional for 1994 through 1996 model 
    year gaseous-fueled light-duty trucks).
    * * * * *
        (c) No crankcase emissions shall be discharged into the ambient 
    atmosphere from any 1994 and later model year light-duty truck. This 
    requirement is optional for 1994 through 1996 model year gaseous-fueled 
    light-duty trucks.
    * * * * *
        5. Section 86.094-11 of subpart A is amended by revising paragraph 
    (b)(1) introductory text to read as follows:
    
    
    Sec. 86.094-11  Emission standards for 1994 and later model year diesel 
    heavy-duty engines and vehicles.
    
    * * * * *
        (b)(1) The opacity of smoke from new 1994 and later model year 
    diesel heavy-duty engines shall not exceed (optional for 1994 through 
    1996 model year gaseous-fueled diesel heavy-duty engines):
    * * * * *
        6. Section 86.096-8 of subpart A is amended by revising paragraph 
    (c) to read as follows:
    
    
    Sec. 86.096-8  Emission standards for 1996 and later model year light-
    duty vehicles.
    
    * * * * *
        (c) No crankcase emissions shall be discharged into the ambient 
    atmosphere from any 1996 and later model year Otto-cycle, or methanol-
    or gaseous-fueled diesel light-duty vehicle. This requirement is 
    optional for 1996 model year gaseous-fueled light-duty vehicles.
    * * * * *
        7. Section 86.096-11 of subpart A is amended by revising paragraphs 
    (a) introductory text and (c) to read as follows:
    
    
    Sec. 86.096-11  Emission standards for 1996 and later model year diesel 
    heavy-duty engines and vehicles.
    
        (a) Exhaust emissions from new 1996 and later model year diesel 
    heavy-duty engines shall not exceed the following (optional for 1996 
    model year gaseous-fueled diesel heavy-duty engines):
    * * * * *
        (c) No crankcase emissions shall be discharged into the ambient 
    atmosphere from any new 1996 or later model year methanol-or gaseous-
    fueled diesel, or any naturally aspirated diesel heavy-duty engine. For 
    petroleum-fueled engines only, this provision does not apply to engines 
    using turbochargers, pumps, blowers, or superchargers for air 
    induction. This provision is optional for all 1996 model year gaseous-
    fueled diesel heavy-duty engines, and for 1997 model year gaseous-
    fueled diesel heavy-duty engines using turbochargers, pumps, blowers or 
    superchargers for air induction.
    * * * * *
        8. Section 86.113-94 of subpart B is amended by revising the tables 
    after paragraphs (b)(2) and (b)(3) to read as follows:
    
    
    Sec. 86.113-94  Fuel specifications.
    
    * * * * *
        (b) * * *
        (2) * * *
    
    ----------------------------------------------------------------------------------------------------------------
                      Item                                                    ASTM test method No.       Type 2-D   
    ----------------------------------------------------------------------------------------------------------------
    Cetane Number...........................  ............................  D613                               40-48
    Cetane Index............................  ............................  D976                               40-48
    Distillation range:                                                                                             
      IBP...................................   deg.F                        D86                              340-400
                                              ( deg.C)                      .......................    (171.1-204.4)
      10 pct. point.........................   deg.F                        D86                              400-460
                                              ( deg.C)                      .......................    (204.4-237.8)
      50 pct. point.........................   deg.F                        D86                              470-540
                                              ( deg.C)                      .......................    (243.3-282.2)
    
    [[Page 47121]]
    
                                                                                                                    
      90 pct. point.........................   deg.F                        D86                              560-630
                                              ( deg.C)                      .......................    (293.3-332.2)
      EP....................................   deg.F                        D86                              610-690
                                              ( deg.C)                      .......................    (321.1-365.6)
    Gravity.................................   deg.API                      D287                               32-37
    Total sulfur............................  pct.                          D2622                          0.03-0.05
    Hydrocarbon composition:                                                                                        
      Aromatics, min........................  pct.                          D1319                                 27
      Paraffins, Naphthenes, Olefins........  ............................  D1319                                (1)
    Flashpoint, min.........................   deg.F                        D93                                  130
                                              ( deg.C)                      .......................           (54.4)
    Viscosity, centistokes..................  ............................  D445                            2.0-3.2 
    ----------------------------------------------------------------------------------------------------------------
    \1\ Remainder.                                                                                                  
    
        (3) * * *
    
    ----------------------------------------------------------------------------------------------------------------
                      Item                                                    ASTM test method No.       Type 2-D   
    ----------------------------------------------------------------------------------------------------------------
    Cetane Number...........................  ............................  D613                               38-58
    Cetane Index............................  ............................  D976                             min. 40
    Distillation range:                                                                                             
      90 pct. point.........................   deg.F                        D86                              540-630
                                              ( deg.C)                      .......................    (282.2-343.3)
    Gravity.................................   deg.API                      D287                               30-39
    Total sulfur............................  pct.                          D2622                          0.03-0.05
    Flashpoint, min.........................   deg.F                        D93                                  130
                                              ( deg.C)                      .......................           (54.4)
    Viscosity...............................  centistokes                   D445                             1.5-4.5
    ----------------------------------------------------------------------------------------------------------------
    
    * * * * *
        9. Section 86.119-90 of subpart B is amended by revising paragraph 
    (b)(3) and adding paragraph (b)(8) to read as follows:
    
    
    Sec. 86.119-90  CVS calibration.
    
    * * * * *
        (b) * * *
        (3) Measurements necessary for flow calibration are as follows:
    
                                                                  Calibration Data Measurements                                                             
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                   Parameter                         Symbol                          Units                                     Tolerances                   
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    Barometric pressure (corrected).......  Pb                       Inches Hg (kPa)                       .01 in Hg (.034 kPa).    
    Air temperature, flowmeter............  ETI                       deg.F ( deg.C)                       .25 deg.F (.14 deg.C).   
    Pressure depression upstream of LFE...  EPI                      Inches H2O (kPa)                      .05 in H2O (.012 kPa).   
    Pressure drop across LFE matrix.......  EDP                      Inches H2O (kPa)                      .005 in H2O (.001 kPa).  
    Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5 pct.                              
    CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa). 
    CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       0.05 in. Hg (0.17 kPa)   
    Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       0.5 deg.F (0.28 deg.C).  
    Specific gravity of manometer fluid     Sp. Gr                   ....................................  .................................................
     (1.75 oil).                                                                                                                                            
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
    * * * * *
        (8) Calculation of a parameter for monitoring sonic flow in the CFV 
    during exhaust emissions tests:
        (i) Option 1. (A) CFV pressure ratio. Based upon the calibration 
    data selected to meet the criteria for paragraphs (d)(7)(iv) and (v), 
    in which Kv is constant, select the data values associated 
    with the calibration point with the lowest absolute venturi inlet 
    pressure. With this set of calibration data, calculated the following 
    CFV pressure ratio limit, Prratio-lim:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.000
    
    Where:
    
    Pin-cal=Venturi inlet pressure (PPI in absolute pressure 
    units), and
    Pout-cal=Venturi outlet pressure (PPO in absolute pressure 
    units), measured at the exit of the venturi diffuser outlet.
    
        (B) The venturi pressure ratio (Prratio-i) during all 
    emissions tests must be less than, or equal to, the calibration 
    pressure ratio limit (Prratio-lim) derived from the CFV 
    calibration data, such that:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.001
    
    Where:
    
    Pin-i and Pout-i are the venturi inlet and outlet 
    pressures, in absolute
    
    [[Page 47122]]
    
    pressure units, at each i-th interval during the emissions test.
    
        (ii) Option 2. Other methods: With prior Administrator approval, 
    any other method may be used that assure that the venturi operates at 
    sonic conditions during emissions tests, provided the method is based 
    upon sound engineering principles.
    * * * * *
        10. Section 86.144-94 of subpart B is amended by revising paragraph 
    (c)(8)(ii)(B) to read as follows:
    
    
    Sec. 86.144-94  Calculations; exhaust emissions.
    
    * * * * *
        (c) * * *
        (8) * * *
        (ii) * * *
        (B) For natural gas and liquefied petroleum gas fuel; 
    DensityNMHC=1.1771(12.011+H/C(1.008))g/ft3-carbon 
    atom (0.04157(12.011+H/C(1.008))kg/m3-carbon atom), where H/
    C is the hydrogen to carbon ratio of the non-methane hydrocarbon 
    components of the test fuel, at 68 deg.F (20 deg.C) and 760 mm Hg 
    (101.3 kPa) pressure.
    * * * * *
        11. Section 86.884-7 of subpart I is amended by revising paragraphs 
    (a)(2)(i), (a)(3) and (a)(4) to read as follows:
    
    
    Sec. 86.884-7  Dynamometer operation cycle for smoke emission tests.
    
        (a) * * *
        (1) * * *
        (2) Acceleration mode. (i) The engine speed shall be increased to 
    200 50 rpm above the measured free idle speed measured at 
    the point where the throttle begins to move from part-throttle to the 
    full throttle position. The speed anywhere during this mode should not 
    exceed this checkpoint speed by more than 50 rpm. The duration of this 
    first acceleration shall be three seconds or less measured from the 
    point where the speed first begins to increase above idle to the point 
    where the throttle reaches full open position.
    * * * * *
        (3) Lugging mode. (i) Immediately upon the completion of the 
    preceding acceleration mode, the dynamometer controls shall be adjusted 
    to permit the engine to develop maximum horsepower at rated speed. This 
    transition period shall be 50 to 60 seconds in duration. During the 
    last 10 seconds of this period, the average engine speed shall be 
    maintained within 50 rpm of the rated speed, and the average observed 
    power (corrected, if necessary, to rating conditions) shall be no less 
    than 95 percent of the maximum horsepower developed during the 
    preconditioning prior to the smoke cycle.
        (ii) With the throttle remaining in the fully open position, the 
    dynamometer controls shall be adjusted gradually so that the engine 
    speed is reduced to the intermediate speed. This lugging operation 
    shall be performed smoothly over a period of 355 seconds. 
    The rate of slowing of the engine shall be linear, within 100 rpm, as 
    specified in Sec. 86.884-13(c).
        (4) Engine unloading. Within five seconds of completing the 
    preceding lugging mode, the dynamometer and engine controls shall be 
    returned to the idle position described in paragraph (a)(1) of this 
    section. The engine must be at free idle condition within one minute 
    after completion of the lugging mode.
    * * * * *
        12. Section 86.884-8 of subpart I is amended by revising paragraph 
    (c) to read as follows:
    
    
    Sec. 86.884-8  Dynamometer and engine equipment.
    
    * * * * *
        (c) An exhaust system with an appropriate type of smokemeter placed 
    10 to 32 feet from the exhaust manifold(s), turbocharger outlet(s), 
    exhaust aftertreatment device(s), or crossover junction (on Vee 
    engines), whichever is farthest downstream. The smoke exhaust system 
    can share the same hardware required in part 86, subpart N, 
    Sec. 86.1327-84(f)(2), insofar as that hardware also meets the 
    following smoke test requirements. The smoke exhaust system shall 
    present an exhaust backpressure within +0.2 inch Hg of the upper limit 
    at maximum rated horsepower, as established by the engine manufacturer 
    in his sales and service literature for vehicle application. The 
    following options may also be used:
        (1) For engines with multiple exhaust outlets, join the exhaust 
    outlets together into a single exhaust system and install the 
    smokemeter 10 to 32 feet downstream from the junction of the individual 
    exhaust outlets, or exhaust aftertreatment device(s), whichever is 
    farthest downstream.
        (2) For engines with multiple exhaust outlets, install a smokemeter 
    in each of the exhaust pipes 10 to 32 feet downstream from each exhaust 
    manifold, turbocharger outlet, or exhaust aftertreatment device, 
    whichever is farthest downstream.
        (3) For engines with multiple exhaust outlets, install a smokemeter 
    on the exhaust pipe which produces the highest smoke levels 10 to 32 
    feet downstream from the exhaust manifold, turbocharger outlet, or 
    exhaust aftertreatment device, whichever is farthest downstream. It may 
    be required to make smoke measurements from other exhaust outlets if 
    deemed appropriate by the Administrator.
        (4) When utilizing an end-of-line smokemeter, the terminal two feet 
    of the exhaust pipe used for smoke measurement shall be of a circular 
    cross section and be free of elbows and bends. The end of the pipe 
    shall be cut off squarely. The terminal two feet of the exhaust pipe 
    shall have a nominal inside diameter in accordance with the engine 
    being tested, as specified below:
    
    ------------------------------------------------------------------------
                                          Standard Exhaust Pipe Diameter,   
         Maximum Rated Horsepower                 inches (meters)           
    ------------------------------------------------------------------------
    Less than 101....................  2 (0.051)                            
    101 to 200.......................   3 (0.076)                           
    201 to 300.......................   4 (0.102)                           
    301 to 500.......................   5 (0.127)                           
    501 or more......................  5 (0.127)\1\ or 6 (0.152)\2\         
    ------------------------------------------------------------------------
    \1\ Applicable for on-highway engines.                                  
    \2\ Applicable for nonroad engines.                                     
    
        (5) When utilizing an in-line smokemeter, there shall be no change 
    in the exhaust pipe diameter within 3 exhaust pipe diameters before or 
    after the centerline of the smokemeter optics. Within 6 exhaust pipe 
    diameters upstream of the centerline of the smokemeter optics, no 
    change in exhaust pipe diameter may exceed a 12 degree half-angle.
    * * * * *
        13. Section 86.884-9 of subpart I is amended by revising paragraphs 
    (b)(2)(i), (b)(2)(ii), (b)(2)(iii), (b)(2)(iv), and (c)(1) to read as 
    follows:
    
    
    Sec. 86.884-9  Smoke measurement system.
    
    * * * * *
        (b) * * *
        (2) * * *
        (i) It is positioned so that a built-in light beam traverses the 
    exhaust smoke plume at right angles to the axis of the exhaust stream.
        (ii) The smokemeter light source shall be an incandescent lamp with 
    a color temperature range of 2800K to 3250K, or a light source with a 
    spectral peak between 550 to 570 nanometers.
        (iii) The light output is collimated to a beam with a maximum 
    diameter of 1.125 inches and an included angle of divergence within a 
    6 deg. included angle.
        (iv) The light detector shall be a photocell or photodiode. If the 
    light source is an incandescent lamp, the detector shall have a 
    spectral response similar to the photopic curve of the human eye (a 
    maximum response in the range of 550 to 570 nanometers, to less than 4 
    percent of that maximum
    
    [[Page 47123]]
    
    response below 430 nanometers and above 680 nanometers).
    * * * * *
        (c) Assembling equipment. (1) The optical unit of the smokemeter 
    shall be mounted radially to the exhaust pipe so that the measurement 
    will be made at right angles to the axis of the exhaust plume. For an 
    end-of-line smokemeter the distance from the optical centerline to the 
    exhaust pipe outlet shall be 1 0.25 inch. The full flow of 
    the exhaust stream shall be centered between the source and the 
    detector apertures (or windows and lenses) and on the axis of the light 
    beam.
    * * * * *
        14. Section 86.884-10 of subpart I is amended by revising paragraph 
    (a)(8) to read as follows:
    
    
    Sec. 86.884-10  Information.
    
    * * * * *
        (a) * * *
        (8) Idle rpm.
    * * * * *
        15. Section 86.884-13 of subpart I is amended by revising 
    paragraphs (b)(6)(ii) and (b)(6)(iii) to read as follows:
    
    
    Sec. 86.884-13  Data analysis.
    
    * * * * *
        (b) * * *
        (6) * * *
        (ii) Average speed during the last 10 seconds shall be within 
    50 rpm of rated speed.
        (iii) Average observed power during the last 10 seconds shall be at 
    least 95 percent of the horsepower developed during the preconditioning 
    mode.
    * * * * *
        16. Section 86.884-14 of subpart I is revised to read as follows:
    
    
    Sec. 86.884-14  Calculations.
    
        (a) If the measured half-second opacity values were obtained with a 
    smokemeter with an optical path length different than shown in the 
    table in Sec. 86.884-8(c), then convert the measured half-second values 
    or the original instantaneous values to the appropriate equivalent 
    optical path length values specified in the table. Convert the opacity 
    values according to the following equations:
    
    Ns=100 x (1-(1-Nm/
    100)Ls/Lm)
    
    Lm and Ls must use consistent units in the above 
    equation
    
    Where:
    
    Nm=Measured half-second value for conversion, percent 
    opacity
    Lm=Measuring smokemeter optical path length, meters
    Ls=Standard optical path length corresponding with engine 
    power, n
    Ns=Standard half-second value, percent opacity
    
        (b) Average the 45 readings in Sec. 86.884-13(d)(3) or the 
    equivalent converted values from paragraph (a) of this section if 
    appropriate, and designate the value as ``A''. This is the value for 
    the engine acceleration mode.
        (c) Average the 15 readings in Sec. 86.884-13(d)(4) or the 
    equivalent converted values from paragraph (a) of this section if 
    appropriate, and designate the value as ``B''. This is the value for 
    the engine lugging mode.
        (d) Average the 9 readings in Sec. 86.884-13(d)(5) or the 
    equivalent converted values from paragraph (a) of this section if 
    appropriate, and designate the value as ``C''. This is the value for 
    the peaks in either mode.
        (e)(1) If multiple smokemeters were used, the half-second values 
    for each mode from each smokemeter shall be combined and the calculated 
    average based upon the total number of combined values.
        (2) For example, if two smokemeters were used for acceleration mode 
    data, 45 half-second values in each data set from both smokemeters 
    would be combined to form a data set of 90 values, which would then be 
    averaged.
        17. Section 86.1008-90 of subpart K is amended by adding paragraph 
    (a)(1)(iii) to read as follows:
    
    
    Sec. 86.1008-90  Test procedures.
    
        (a)(1)(i) * * *
        (iii) During the testing of heavy-duty diesel engines, the 
    manufacturer shall decide for each engine, prior to the start of the 
    initial cold cycle, whether the measurement of background particulate 
    is required for the cold and hot cycles to be valid. The manufacturer 
    may choose to have different requirements for the cold and hot cycles. 
    If a manufacturer chooses to require the measurement of background 
    particulate, failure to measure background particulate shall void the 
    test cycle regardless of the test results. If a test cycle is void, the 
    manufacturer shall retest using the same validity requirements of the 
    initial test.
    * * * * *
        18. Section 86.1008-96 of subpart K is amended by revising 
    paragraph (a)(1) to read as follows:
    
    
    Sec. 86.1008-96  Test procedures
    
    * * * * *
        (a)(1)(i) For heavy-duty engines, the prescribed test procedure is 
    the Federal Test Procedure, as described in subparts N, I, and P of 
    this part.
        (ii) During the testing of heavy-duty diesel engines, the 
    manufacturer shall decide for each engine, prior to the start of the 
    initial cold cycle, whether the measurement of background particulate 
    is required for the cold and hot cycles to be valid. The manufacturer 
    may choose to have different requirements for the cold and hot cycles. 
    If a manufacturer chooses to require the measurement of background 
    particulate, failure to measure background particulate shall void the 
    test cycle regardless of the test results. If a test cycle is void, the 
    manufacturer shall retest using the same validity requirements of the 
    initial test.
    * * * * *
        19. Section 86.1008-2001 of subpart K is amended by adding 
    paragraph (a)(1)(iii) to read as follows:
    
    
    Sec. 86.1008-2001  Test procedures.
    
        (a)(1)(i) * * *
        (iii) During the testing of heavy-duty diesel engines, the 
    manufacturer shall decide for each engine, prior to the start of the 
    initial cold cycle, whether the measurement of background particulate 
    is required for the cold and hot cycles to be valid. The manufacturer 
    may choose to have different requirements for the cold and hot cycles. 
    If a manufacturer chooses to require the measurement of background 
    particulate, failure to measure background particulate shall void the 
    test cycle regardless of the test results. If a test cycle is void, the 
    manufacturer shall retest using the same validity requirements of the 
    initial test.
    * * * * *
        20. Section 86.1111-87 is amended by redesignating paragraph (a)(4) 
    as paragraph (a)(5) and adding a new paragraph (a)(4) to read as 
    follows:
    
    
    Sec. 86.1111-87  Test procedures for PCA testing.
    
    * * * * *
        (a) * * *
        (4) During the testing of heavy-duty diesel engines, the 
    manufacturer shall decide for each engine, prior to the start of the 
    initial cold cycle, whether the measurement of background particulate 
    is required for the cold and hot cycles to be valid. The manufacturer 
    may choose to have different requirements for the cold and hot cycles. 
    If a manufacturer chooses to require the measurement of background 
    particulate, failure to measure background particulate shall void the 
    test cycle regardless of the test results. If a test cycle is void, the 
    manufacturer shall retest using the same validity requirements of the 
    initial test.
    * * * * *
        21. Section 86.1310-90 of subpart N is amended by revising 
    paragraphs (b)(1)(iv)(C), (b)(3)(v), (b)(3)(vi), (b)(6)
    
    [[Page 47124]]
    
    introductory text, and (b)(7)(iv) to read as follows:
    
    
    Sec. 86.1310-90  Exhaust gas sampling and analytical system; diesel 
    engines.
    
    * * * * *
        (b) * * *
        (1) * * *
        (iv) * * *
        (C) Primary dilution air may be sampled to determine background 
    particulate levels, which can then be subtracted from the values 
    measured in the diluted exhaust stream. The primary dilution air shall 
    be sampled at the inlet to the primary dilution tunnel, if unfiltered, 
    or downstream of any primary dilution air conditioning devices, if 
    used.
    * * * * *
        (3) * * *
        (v) The continuous HC sampling system shall consist of a probe 
    (which must raise the sample to the specified temperature) and, where 
    used, a sample transfer system (which must maintain the specified 
    temperature). The continuous hydrocarbon sampling system (exclusive of 
    the probe) shall:
        (A) Maintain a wall temperature of 464K  11K (191 deg.C 
     11 deg.C) as measured at every separately controlled 
    heated component (i.e., filters, heated line sections), using permanent 
    thermocouples located at each of the separate components.
        (B) Have a wall temperature of 464K  11K (191 deg.C 
     11 deg.C) over its entire length. The temperature of the 
    system shall be demonstrated by profiling the thermal characteristics 
    of the system at initial installation and after any major maintenance 
    performed on the system. The temperature profile of the HC sampling 
    system shall be demonstrated by inserting thermocouple wires (typically 
    Teflon coated for ease of insertion) into the sampling 
    system assembled in-situ where possible, using good engineering 
    judgement. The wire should be inserted up to the HFID inlet. Stabilize 
    the sampling system heaters at normal operating temperatures. Withdraw 
    the wires in increments of 5 cm to 10 cm (2 inches to 4 inches) 
    including all fittings. Record the stabilized temperature at each 
    position. The system temperature will be monitored during testing at 
    the locations and temperature described in Sec. 86.1310-90(b)(v)(A). 
    Comment: It is understood that profiling of the sample line can be done 
    under flowing conditions also as required with the probe.
        (C) Maintain a gas temperature of 464K 11K (191 deg.C 
    11 deg.C) immediately before the heated filter and HFID. 
    These gas temperatures will be determined by a temperature sensor 
    located immediately upstream of each component.
        (vi) The continuous hydrocarbon sampling probe shall:
        (A) Be defined as the first 25.4 cm (10 in) to 76.2 cm (30 in) of 
    the continuous hydrocarbon sampling system.
        (B) Have a 0.483 cm (0.19 in) minimum inside diameter.
        (C) Be installed in the primary dilution tunnel at a point where 
    the dilution air and exhaust are well mixed (i.e., approximately 10 
    tunnel diameters downstream of the point where the exhaust enters the 
    dilution tunnel).
        (D) Be sufficiently distant (radially) from other probes and the 
    tunnel wall so as to be free from the influence of any wakes or eddies.
        (E) Increase the gas stream temperature to 464K 11K 
    (191 deg.C 11 deg.C) by the exit of the probe. The ability 
    of the probe to accomplish this shall be demonstrated at typical sample 
    flow rates using the insertion thermocouple technique at initial 
    installation and after any major maintenance. Compliance with the 
    temperature specification shall be demonstrated by monitoring during 
    each test the temperature of either the gas stream or the wall of the 
    sample probe at its terminus.
    * * * * *
        (6) Particulate sampling system. The particulate collection system 
    must be configured in either of two ways. The single-dilution method 
    collects a proportional sample from the primary tunnel, and then passes 
    this sample through the collection filter. The double-dilution method 
    collects a proportional sample from the primary tunnel, and then 
    transfers this sample to a secondary dilution tunnel where the sample 
    is further diluted; the double-diluted sample is then passed through 
    the collection filter. Proportionality (i.e., mass flow ratio) between 
    the primary tunnel flow rate and the sample flow rate must be 
    maintained within 5 percent. The requirements for these two 
    systems are:
    * * * * *
        (7) * * *
        (iv) It is recommended that the filter loading should be maximized 
    consistent with other temperature requirements and the requirement to 
    avoid moisture condensation. A filter pair loading of 1 mg is typically 
    proportional to a 0.1 g/bhp-hr emission level. All particulate filters, 
    reference filters, and background filters shall be handled in pairs 
    during all weighing operations for emissions testing.
    * * * * *
        22. Section 86.1312-88 of subpart N is amended by revising 
    paragraph (a) to read as follows:
    
    
    Sec. 86.1312-88  Weighing chamber and microgram balance specifications.
    
        (a) Ambient conditions. (1) Temperature. The ambient temperature of 
    the chamber (or room) in which the particulate filters are conditioned 
    and weighed shall be maintained at 295 K  3 K (22  deg.C 
     3  deg.C) during all filter conditioning and weighing.
        (2) Humidity. The humidity of the chamber (or room) in which the 
    particulate filters are conditioned and weighed shall be maintained at 
    a dew point temperature of 282.5 K  3 K (9.4  deg.C 
     3  deg.C) and a relative humidity of 45% 8%. 
    Either the dew point temperature or the relative humidity or both may 
    be averaged over the preceding 10 minute period on a moving average 
    basis.
        (3) The chamber (or room) environment shall be free of any ambient 
    contaminates (such as dust) that would settle on the particulate 
    filters during their stabilization. It is required that at least two 
    unused reference filter pairs remain in the weighing room at all times 
    in covered (to reduce dust contamination) but unsealed (to permit 
    humidity exchange) petri dishes. These reference filter pairs shall be 
    placed in the same general area as the sample filters. These reference 
    filter pairs shall be weighed within 4 hours of, but preferably at the 
    same time as, the sample filter pair weighings.
        (4) If the average weight of the reference filter pairs changes 
    between sample filter weighings by more than 40 micrograms, then all 
    sample filters and background filters in the process of stabilization 
    shall be discarded and the emissions tests repeated.
        (5) If the room (or chamber) environmental conditions are not met, 
    then the filters shall remain in the conditioning room for at least one 
    hour after correct conditions are met prior to weighing.
        (6) The reference filter pairs shall be changed at least once a 
    month, but never between clean and used weighings of a given sample 
    filter pairs. More than one set of reference filter pair may be used. 
    The reference filters shall be the same size and material as the sample 
    filters.
    * * * * *
        23. Section 86.1313-91 of subpart N is amended by revising 
    paragraph (b)(2) including Table N91-2 to read as follows:
    
    
    Sec. 86.1313-91  Fuel specifications.
    
    * * * * *
    
    [[Page 47125]]
    
        (b) * * *
        (2) Petroleum fuel for diesel engines meeting the specifications in 
    Table N91-2, or substantially equivalent specifications approved by the 
    Administrator, shall be used in exhaust emissions testing. The grade of 
    petroleum fuel used shall be commercially designated as ``Type 2-D'' 
    grade diesel fuel except that fuel commercially designated as ``Type 1-
    D'' grade diesel fuel may be substituted provided that the manufacturer 
    has submitted evidence to the Administrator demonstrating to the 
    Administrator's satisfaction that this fuel will be the predominant in-
    use fuel. Such evidence could include such things as copies of signed 
    contracts from customers indicating the intent to purchase and use 
    ``Type 1-D'' grade diesel fuel as the primary fuel for use in the 
    engines or other evidence acceptable to the Administrator.
    
                                                       Table N91-2                                                  
    ----------------------------------------------------------------------------------------------------------------
                       Item                                   ASTM                    Type 1-D          Type 2-D    
    ----------------------------------------------------------------------------------------------------------------
    Cetane Number............................  D613                                          48-54             42-50
    Cetane Index.............................  D86                                           40-54             40-48
    Distillation range:                                                                                             
        IBP  deg.F...........................  D86                                         330-390           340-400
        ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
        10 percent point,  deg.F.............  D86                                         370-430           400-460
        ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
        50 percent point,  deg.F.............  D86                                         410-480           470-540
        ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
        90 percent point,  deg.F.............  D86                                         460-520           560-630
        ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
        EP,  deg.F...........................  D86                                         500-560           610-690
        ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
    Gravity,  deg.API........................  D287                                          40-44             32-37
    Total Sulfur, percent....................  D2622                                     0.08-0.12         0.08-0.12
    Hydrocarbon composition:                                                                                        
        Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
        Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )
    Flashpoint,  deg.F.......................  D93                                             120               130
        ( deg.C).............................  .................................            (48.9)            (54.4)
        (minimum)............................  .................................  ................  ................
    Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
    ----------------------------------------------------------------------------------------------------------------
    \1\ Minimum.                                                                                                    
    \2\ Remainder.                                                                                                  
    
    * * * * *
        24. Section 86.1313-94 of subpart N is amended by revising 
    paragraph (b)(2) including Table N94-2 to read as follows:
    
    
    Sec. 86.1313-94  Fuel specifications.
    
    * * * * *
        (b) * * *
        (2) Petroleum fuel for diesel engines meeting the specifications in 
    Table N94-2, or substantially equivalent specifications approved by the 
    Administrator, shall be used in exhaust emissions testing. The grade of 
    petroleum fuel used shall be commercially designated as ``Type 2-D'' 
    grade diesel fuel except that fuel commercially designated at ``Type 1-
    D'' grade diesel fuel may be substituted provided that the manufacturer 
    has submitted evidence to the Administrator demonstrating to the 
    Administrator's satisfaction that this fuel will be the predominant in-
    use fuel. Such evidence could include such things as copies of signed 
    contracts from customers indicating the intent to purchase and use 
    ``Type 1-D'' grade diesel fuel as the primary fuel for use in the 
    engines or other evidence acceptable to the Administrator.
    
                                                       Table N94-2                                                  
    ----------------------------------------------------------------------------------------------------------------
                       Item                                   ASTM                    Type 1-D          Type 2-D    
    ----------------------------------------------------------------------------------------------------------------
    Cetane Number............................  D613                                          40-54             40-48
    Cetane Index.............................  D976                                          40-54             40-48
    Distillation range:                                                                                             
        IBP  deg.F...........................  D86                                         330-390           340-400
        ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
        10 percent point,  deg.F.............  D86                                         370-430           400-460
        ( deg.C).............................  (187.8-221.1)                         (204.4-237.8)                  
        50 percent point,  deg.F.............  D86                                         410-480           470-540
        ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
        90 percent point,  deg.F.............  D86                                         460-520           560-630
        ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
        EP,  deg.F...........................  D86                                         500-560           610-690
        ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
    Gravity,  deg.API........................  D287                                          40-44             32-37
    Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
    Hydrocarbon composition:                                                                                        
        Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
        Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )
    
    [[Page 47126]]
    
                                                                                                                    
    Flashpoint,  deg.F.......................  D93                                             120               130
        ( deg.C).............................  .................................            (48.9)            (54.4)
        (minimum)............................  .................................  ................  ................
    Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
    ----------------------------------------------------------------------------------------------------------------
    \1\ Minimum.                                                                                                    
    \2\ Remainder.                                                                                                  
    
    * * * * *
        25. Section 86.1313-98 is added to subpart N to read as follows:
    
    
    Sec. 86.1313-98  Fuel specifications.
    
        Section 86.1313-98 includes text that specifies requirements that 
    differ from Sec. 86.1313-94. Where a paragraph in Sec. 86.1313-94 is 
    identical and applicable to Sec. 86.1313-98, this may be indicated by 
    specifying the corresponding paragraph and the statement ``[Reserved]. 
    For guidance see Sec. 86.1313-94''.
        (a) through (b)(1) [Reserved]. For guidance see Sec. 86.1313-94.
        (b)(2) Petroleum fuel for diesel engines meeting the specifications 
    in Table N98-2, or substantially equivalent specifications approved by 
    the Administrator, shall be used in exhaust emissions testing. The 
    grade of petroleum fuel used shall be commercially designated as ``Type 
    2-D'' grade diesel fuel except that fuel commercially designated at 
    ``Type 1-D'' grade diesel fuel may be substituted provided that the 
    manufacturer has submitted evidence to the Administrator demonstrating 
    to the Administrator's satisfaction that this fuel will be the 
    predominant in-use fuel. Such evidence could include such things as 
    copies of signed contracts from customers indicating the intent to 
    purchase and use ``Type 1-D'' grade diesel fuel as the primary fuel for 
    use in the engines or other evidence acceptable to the Administrator.
    
                                                       Table N98-2                                                  
    ----------------------------------------------------------------------------------------------------------------
                       Item                                   ASTM                    Type 1-D          Type 2-D    
    ----------------------------------------------------------------------------------------------------------------
    Cetane Number............................  D613                                          40-54             40-48
    Cetane Index.............................  D976                                          40-54             40-48
    Distillation range:                                                                                             
        IBP  deg.F...........................  D86                                         330-390           340-400
        ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
        10 percent point,  deg.F.............  D86                                         370-430           400-460
        ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
        50 percent point,  deg.F.............  D86                                         410-480           470-540
        ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
        90 percent point,  deg.F.............  D86                                         460-520           560-630
        ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
        EP,  deg.F...........................  D86                                         500-560           610-690
        ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
    Gravity,  deg.API........................  D287                                          40-44             32-37
    Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
    Hydrocarbon composition:                                                                                        
        Aromatics, pct.......................  D5186                                         \1\ 8            \1\ 27
        Paraffins, Naphthenes, Olefins.......  D1319                                         (\2\)             (\2\)
    Flashpoint,  deg.F.......................  D93                                             120               130
        ( deg.C).............................  .................................            (48.9)            (54.4)
        (minimum)............................  .................................  ................  ................
    Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
    ----------------------------------------------------------------------------------------------------------------
    \1\ Minimum.                                                                                                    
    \2\ Remainder.                                                                                                  
    
        (b)(3) through (e) [Reserved]. For guidance see Sec. 86.1313-94.
        26. Section 86.1316-90 of subpart N is amended by revising 
    paragraph (b)(1) and adding paragraph (f) to read as follows:
    
    
    Sec. 86.1316-90  Calibrations; frequency and overview.
    
    * * * * *
        (b) * * *
        (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer, 
    carbon monoxide analyzer, oxides of nitrogen analyzer, methanol 
    analyzer and formaldehyde analyzer (certain analyzers may require more 
    frequent calibration depending on the equipment and use). New 
    calibration curves need not be generated each month if the existing 
    curve meets the requirements of Secs. 86.1321 through 86.1324.
    * * * * *
        (f) For diesel fuel testing only. The carbon monoxide analyzer 
    shall be calibrated at least every two months or after any maintenance 
    which could alter calibration.
        27. Section 86.1316-94 of subpart N is amended by revising 
    paragraph (b)(1) and adding paragraph (f) to read as follows:
    
    
    Sec. 86.1316-94  Calibrations; frequency and overview.
    
    * * * * *
        (b) * * *
        (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer, 
    carbon monoxide analyzer, and oxides of nitrogen analyzer (certain 
    analyzers may require more frequent calibration depending on the 
    equipment and use).
    
    [[Page 47127]]
    
    New calibration curves need not be generated each month if the existing 
    curve meets the requirements of Secs. 86.1321 through 86.1324.
    * * * * *
        (f) For diesel fuel testing only. The carbon monoxide analyzer 
    shall be calibrated at least every two months or after any maintenance 
    which could alter calibration.
        28. Section 86.1319-84 of subpart N is amended by revising 
    paragraph (d)(3) and adding paragraph (d)(8) to read as follows:
    
    
    Sec. 86.1319-84  CVS calibration.
    
    * * * * *
        (d) * * *
        (3) Measurements necessary for flow calibration are as follows:
    
                                                                  Calibration Data Measurements                                                             
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                   Parameter                         Symbol                          Units                                     Tolerances                   
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    Barometric pressure (corrected).......  Pb                       Inches Hg (kPa)                       .01 in Hg (.034 kPa).    
    Air temperature, flowmeter............  ETI                       deg.F ( deg.C)                       .25  deg.F (.14  deg.C). 
    Pressure depression upstream of LFE...  EPI                      Inches H2O (kPa)                      .05 in H2O (.012 kPa).   
    Pressure drop across LFE matrix.......  EDP                      Inches H2O (kPa)                      .005 in H2O (.001 kPa).  
    Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5 pct.                              
    CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa). 
    CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       .05 in Hg (0.17 kPa).    
    Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       0.5  deg.F (0.28  deg.C).
    Specific gravity of manometer fluid     Sp. Gr                                                                                                          
     (1.75 oil).                                                                                                                                            
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
    * * * * *
        (8) Calculation of a parameter for monitoring sonic flow in the CFV 
    during exhaust emissions tests:
        (i) Option 1. (A) CFV pressure ratio. Based upon the calibration 
    data selected to meet the criteria for paragraphs (d)(7)(iv) and (v) of 
    this section, in which Kv is constant, select the data 
    values associated with the calibration point with the lowest absolute 
    venturi inlet pressure. With this set of calibration data, calculated 
    the following CFV pressure ratio limit, Prratio-lim:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.002
    
    where:
    
    Pin-cal=Venturi inlet pressure (PPI in absolute pressure 
    units), and
    Pout-cal=Venturi outlet pressure (PPO in absolute pressure 
    units), measured at the exit of the venturi diffuser outlet.
    
        (B) The venturi pressure ratio (Prratio-i) during all 
    emissions tests must be less than, or equal to, the calibration 
    pressure ratio limit (Prratio-lim) derived from the CFV 
    calibration data, such that:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.003
    
    Where:
    
    Pin-i and Pout-i are the venturi inlet and outlet 
    pressures, in absolute pressure units, at each i-th interval during the 
    emissions test.
    
        (ii) Option 2. Other methods: With prior Administrator approval, 
    any other method may be used that assure that the venturi operates at 
    sonic conditions during emissions tests, provided the method is based 
    upon sound engineering principles.
    * * * * *
        29. Section 86.1319-90 of subpart N is amended by revising 
    paragraph (d)(3) and adding paragraph (d)(8) to read as follows:
    
    
    Sec. 86.1319-90  CVS calibration.
    
    * * * * *
        (d) * * *
        (3) Measurements necessary for flow calibration are as follows:
    
                                                                  Calibration Data Measurements                                                             
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                   Parameter                         Symbol                          Units                             Sensor-readout tolerances            
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    Barometric pressure (corrected).......  Pb                       in Hg (kPa)                           .01 in Hg (.034 kPa).    
    Air temperature, into flowmeter.......  ETI                       deg.F( deg.C)                        0.5  deg.F (0.28  deg.C).
    Pressure drop between the inlet and     EDP                      Inches H2O (kPa)                      0.05 in H2O (0.012 kPa). 
     throat of metering venturi.                                                                                                                            
    Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5% of NBS ``true'' value            
    CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa). 
    CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       .05 in Hg (.17 kPa).     
    Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       4.0  deg.F (2.22  deg.C).
    Specific gravity of manometer fluid     Sp. Gr                                                                                                          
     (1.75 oil).                                                                                                                                            
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
    * * * * *
        (8) Calculation of a parameter for monitoring sonic flow in the CFV 
    during exhaust emissions tests:
        (i) Option 1. (A) CFV pressure ratio. Based upon the calibration 
    data selected to meet the criteria for paragraphs (d)(7) (iv) and (v) 
    of this section, in which Kv is constant, select the data 
    values associated with the calibration point with the lowest absolute 
    venturi inlet pressure. With this set of calibration data, calculated 
    the following CFV pressure ratio limit, Prratio-lim:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.004
    
    Where:
    
    Pin-cal=Venturi inlet pressure (PPI in absolute pressure 
    units), and
    Pout-cal=Venturi outlet pressure (PPO in absolute pressure 
    units), measured at the exit of the venturi diffuser outlet.
    
        (B) The venturi pressure ratio (Prratio-i) during all 
    emissions tests must be less than, or equal to, the calibration 
    pressure ratio limit (Prratio-lim) derived from the CFV 
    calibration data, such that:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.005
    
    Where:
    
    
    [[Page 47128]]
    
    
    Pin-i and Pout-i are the venturi inlet and outlet 
    pressures, in absolute pressure units, at each i-th interval during the 
    emissions test.
    
        (ii) Option 2. Other methods: With prior Administrator approval, 
    any other method may be used that assure that the venturi operates at 
    sonic conditions during emissions tests, provided the method is based 
    upon sound engineering principles.
    * * * * *
        30. Section 86.1321-90 of subpart N is amended by revising 
    paragraphs (a) and (b)(3) to read as follows:
    
    
    Sec. 86.1321-90  Hydrocarbon analyzer calibration.
    
    * * * * *
        (a) Initial and periodic optimization of detector response. Prior 
    to introduction into service and at least annually thereafter, the FID 
    hydrocarbon analyzer shall be adjusted for optimum hydrocarbon 
    response.
        (1) Follow good engineering practices for initial instrument start-
    up and basic operating adjustment using the appropriate fuel (see 
    Sec. 86.1314) and zero-grade air.
        (2) Optimize the FID's response on the most common operating range. 
    The response is to be optimized with respect to fuel pressure or flow 
    while meeting the analyzer response time given in 
    Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall 
    be made to minimize response variations to different hydrocarbon 
    species that are expected to be in the exhaust. Good engineering 
    judgement is to be used to trade off optimal FID response to propane-
    in-air against reductions in relative responses to other hydrocarbons. 
    A good example of trading off response on propane for relative 
    responses to other hydrocarbon species is given in Society of 
    Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame 
    Ionization Detector for Determination of Hydrocarbon in Diluted 
    Automotive Exhausts''; author Glenn D. Reschke. It is also required 
    that the response be set to optimum condition with respect to air flow 
    and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at 
    their specified operating temperature.
        (3) One of the following procedures is to be used for FID or HFID 
    optimization:
        (i) Use the procedures outlined in Society of Automotive Engineers 
    (SAE) paper No. 770141, ``Optimization of Flame Ionization Detector for 
    Determination of Hydrocarbons in Diluted Automobile Exhaust''; author, 
    Glenn D. Reschke, as an example.
        (ii) The HFID optimization procedures outlined in 40 CFR part 86, 
    subpart D, Sec. 86.331-79(c).
        (iii) Alternative procedures may be used if approved in advance by 
    the Administrator.
        (iv) The procedures specified by the manufacturer of the FID or 
    HFID.
        (4) After the optimum fuel, air, and sample pressures or flow rates 
    have been determined, they shall be recorded for future reference.
        (b) * * *
        (3) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, propane-in-air calibration gases (e.g., 
    15, 30, 45, 60, 75, and 90 percent of that range). For each range 
    calibrated, if the deviation from a least-squares best-fit straight 
    line is within 2 percent of the value at each non-zero data 
    point and within 0.3 percent of full scale on the zero data 
    point, then concentration values may be calculated by using the linear 
    calibration equation for that range. If the deviation exceeds these 
    limits, then the best-fit non-linear equation which represents the data 
    within these limits shall be used to determine concentration values.
    * * * * *
        31. Section 86.1321-94 of subpart N is amended by revising 
    paragraphs (a) and (b)(3) to read as follows:
    
    
    Sec. 86.1321-94  Hydrocarbon analyzer calibration.
    
    * * * * *
        (a) Initial and periodic optimization of detector response. Prior 
    to introduction into service and at least annually thereafter, the FID 
    hydrocarbon analyzer shall be adjusted for optimum hydrocarbon 
    response.
        (1) Follow good engineering practices for initial instrument start-
    up and basic operating adjustment using the appropriate fuel (see 
    Sec. 86.1314) and zero-grade air.
        (2) Optimize the FID's response on the most common operating range. 
    The response is to be optimized with respect to fuel pressure or flow 
    while meeting the analyzer response time given in 
    Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall 
    be made to minimize response variations to different hydrocarbon 
    species that are expected to be in the exhaust. Good engineering 
    judgement is to be used to trade off optimal FID response to propane-
    in-air against reductions in relative responses to other hydrocarbons. 
    A good example of trading off response on propane for relative 
    responses to other hydrocarbon species is given in Society of 
    Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame 
    Ionization Detector for Determination of Hydrocarbon in Diluted 
    Automotive Exhausts''; author Glenn D. Reschke. It is also required 
    that the response be set to optimum condition with respect to air flow 
    and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at 
    their specified operating temperature.
        (3) One of the following procedures is to be used for FID or HFID 
    optimization:
        (i) Use the procedures outlined in Society of Automotive Engineers 
    (SAE) paper number 770141, ``Optimization of Flame Ionization Detector 
    for Determination of Hydrocarbons in Diluted Automobile Exhaust''; 
    author, Glenn D. Reschke, as an example. Available from Society of 
    Automotive Engineers International, 400 Commonwealth Dr., Warrendale, 
    PA 15096-0001.
        (ii) The procedure listed in subpart D, Sec. 86.331-79(c) of this 
    part.
        (iii) The procedures specified by the manufacturer of the FID or 
    HFID.
        (iv) Alternative procedures may be used if approved in advance by 
    the Administrator.
        (4) After the optimum fuel, air and sample pressures or flow rates 
    have been determined, they shall be recorded for future reference.
        (b) * * *
        (3) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, propane-in-air calibration gases (e.g., 
    15, 30, 45, 60, 75, and 90 percent of that range). For each range 
    calibrated, if the deviation from a least-squares best-fit straight 
    line is within 2 percent of the value at each non-zero data 
    point and within 0.3 percent of full scale on the zero data 
    point, then concentration values may be calculated by using the linear 
    calibration equation for that range. If the deviation exceeds these 
    limits, then the best-fit non-linear equation which represents the data 
    within these limits shall be used to determine concentration values.
    * * * * *
        32. Section 86.1322-84 of subpart N is amended by revising 
    paragraph (b)(3) to read as follows:
    
    
    Sec. 86.1322-84  Carbon monoxide analyzer calibration.
    
    * * * * *
        (b) * * *
        (3) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, carbon monoxide-in-N2 
    calibration gases (e.g., 15, 30, 45, 60, 75, and 90 percent of that 
    range). For each range calibrated, if the deviation from a least-
    squares best-fit straight line is within 2 percent of the
    
    [[Page 47129]]
    
    value at each non-zero data point and within 0.3 percent of 
    full scale on the zero data point, then concentration values may be 
    calculated by using the linear calibration equation for that range. If 
    the deviation exceeds these limits, then the best-fit not-linear 
    equation which represents the data within these limits shall be used to 
    determine concentration values.
    * * * * *
        33. Section 86.1323-84 of subpart N is amended by revising 
    paragraph (b)(3) to read as follows:
    
    
    Sec. 86.1323-84  Oxides of nitrogen analyzer calibration.
    
    * * * * *
        (b) * * *
        (3) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, NO-in-N2 calibration gases 
    (e.g., 15, 30, 45, 60, 75, and 90 percent of that range). For each 
    range calibrated, if the deviation from a least-squares best-fit 
    straight line is within 2 percent of the value at each non-
    zero data point and within 0.3 percent of full scale on the 
    zero data point, then concentration values may be calculated using the 
    linear calibration equation for that range. If the deviation exceeds 
    these limits, then the best-fit non-linear equation which represents 
    the data within these limits shall be used to determine concentration 
    values.
    * * * * *
        34. Section 86.1324-84 of subpart N is amended by revising 
    paragraph (c) to read as follows:
    
    
    Sec. 86.1324-84  Carbon dioxide analyzer calibration.
    
    * * * * *
        (c) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, carbon dioxide-in-N2 
    calibration or span gases (e.g., 15, 30, 45, 60, 75, and 90 percent of 
    that range). For each range calibrated, if the deviation from a least-
    squares best-fit straight line is within 2 percent or less 
    of the value at each non-zero data point and within 0.3 
    percent of full scale on the zero data point, then concentration values 
    may be calculated by using the linear calibration equation for that 
    range. If the deviation exceeds these limits, then the best-fit non-
    linear equation which represents the data within these limits shall be 
    used to determine concentration values.
    * * * * *
        35. Section 86.1325-94 of subpart N is amended by revising 
    paragraph (c) to read as follows:
    
    
    Sec. 86.1325-94  Methane analyzer calibration.
    
    * * * * *
        (c) Calibrate on each used operating range with a minimum of 6, 
    approximately equally spaced, CH4 in air calibration gases (e.g., 15, 
    40, 45, 60, 75, and 90 percent of that range). For each range 
    calibrated, if the deviation from a least-squares best-fit straight 
    line is within 2 percent of the value at each non-zero data 
    point and within 0.3 percent of full scale on the zero data 
    point, then concentration values may be calculated by using the linear 
    calibration equation for that range. If the deviation exceeds these 
    limits, then the best-fit non-linear equation which represents the data 
    within these limits shall be used to determine concentration values.
        36. Section 86.1327-90 of subpart N is amended by revising 
    paragraphs (b), (f)(1), (f)(2) introductory text and (f)(2)(i) to read 
    as follows:
    
    
    Sec. 86.1327-90  Engine dynamometer test procedures; overview.
    
    * * * * *
        (b) Engine torque and rpm command set points shall be issued at 5 
    (10 Hz recommended) Hz or greater during both the cold and hot start 
    tests. Feedback engine torque and rpm shall be recorded at least once 
    every second during the test.
    * * * * *
        (f) * * *
        (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A 
    chassis-type exhaust system shall be used. For all catalyst systems, 
    the distance from the exhaust manifold flange(s) to the catalyst shall 
    be the same as in the vehicle configuration unless the manufacturer 
    provides data showing equivalent performance at another location. The 
    catalyst container may be removed during all test sequences prior to 
    the practice cycle, and replaced with an equivalent container having an 
    inactive catalyst support.
        (2) Petroleum-fueled and methanol-fueled diesel engines. Either a 
    chassis-type or a facility-type exhaust system or both systems 
    simultaneously may be used. If the engine is equipped with an exhaust 
    aftertreatment device, the exhaust pipe must be the same diameter as 
    found in-use for at least 4 pipe diameters upstream to the inlet of the 
    beginning of the expansion section containing the aftertreatment 
    device. The exhaust backpressure or restriction shall follow the same 
    criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler 
    omitted). The catalyst container may be removed during all test 
    sequences prior to the practice cycle, and replaced with an equivalent 
    container having an inactive catalyst support.
        (i) The engine exhaust system shall meet the following 
    requirements:
        (A) The total length of the tubing from the exit of the engine 
    exhaust manifold, turbocharger outlet or aftertreatment device to the 
    primary dilution tunnel shall not exceed 32 feet (9.8 m).
        (B) The initial portion of the exhaust system may consist of a 
    typical in-use (i.e., length, diameter, material, etc.) chassis-type 
    exhaust system.
        (C) The distance from the exhaust manifold flange(s) or 
    turbocharger outlet to any exhaust aftertreatment device shall be the 
    same as in the vehicle configuration or within the distance 
    specifications provided by the manufacturer.
        (D) For engines which are not equipped with exhaust aftertreatment 
    devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
    turbocharger or exhaust manifold shall be insulated. For engines 
    equipped with exhaust aftertreatment devices, all tubing after the 
    aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
    insulated.
        (E) If the tubing is required to be insulated, the radial thickness 
    of the insulation must be at least 1.0 inch (25 mm). The thermal 
    conductivity of the insulating material must have a value no greater 
    than 0.75 BTU-in/hr/ft\2\/ deg.F (0.065 W/m-K) measured at 700  deg.F 
    (371  deg.C).
        (F) A smoke meter or other instrumentation may be inserted into the 
    exhaust system tubing. If this option is exercised in the insulated 
    portion of the tubing, then a minimal amount of tubing not to exceed 18 
    inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
    of tubing can be left uninsulated in total, including the length at the 
    smoke meter.
    * * * * *
        37. Section 86.1327-94 of subpart N is amended by revising 
    paragraphs (b), (f)(1), (f)(2) introductory text and (f)(2)(i) to read 
    as follows:
    
    
    Sec. 86.1327-94  Engine dynamometer test procedures; overview.
    
    * * * * *
        (b) Engine torque and rpm command set points shall be issued at 5 
    (10 Hz recommended) Hz or greater during both the cold and hot start 
    tests. Feedback engine torque and rpm shall be recorded at least once 
    every second during the test.
    * * * * *
        (f) * * *
        (1) Otto-cycle engines. A chassis-type exhaust system shall be 
    used. For all catalyst systems, the distance from the exhaust manifold 
    flange(s) to the catalyst shall be the same as in the
    
    [[Page 47130]]
    
    vehicle configuration unless the manufacturer provides data showing 
    equivalent performance at another location. The catalyst container may 
    be removed during all test sequences prior to the practice cycle, and 
    replaced with an equivalent container having an inactive catalyst 
    support.
        (2) Diesel engines. Either a chassis-type or a facility-type 
    exhaust system or both systems simultaneously may be used. If the 
    engine is equipped with an exhaust aftertreatment device, the exhaust 
    pipe must be the same diameter as found in-use for at least 4 pipe 
    diameters upstream to the inlet of the beginning of the expansion 
    section containing the aftertreatment device. The exhaust backpressure 
    or restriction shall follow the same criteria as in Sec. 86.1330-90 (f) 
    and may be set with a valve (muffler omitted). The catalyst container 
    may be removed during all test sequences prior to the practice cycle, 
    and replaced with an equivalent container having an inactive catalyst 
    support.
        (i) The engine exhaust system shall meet the following 
    requirements:
        (A) The total length of the tubing from the exit of the engine 
    exhaust manifold, turbocharger outlet or aftertreatment device to the 
    primary dilution tunnel shall not exceed 32 feet (9.8 m).
        (B) The initial portion of the exhaust system may consist of a 
    typical in-use (i.e., length, diameter, material, etc.) chassis-type 
    exhaust system.
        (C) The distance from the exhaust manifold flange(s) or 
    turbocharger outlet to any exhaust aftertreatment device shall be the 
    same as in the vehicle configuration or within the distance 
    specifications provided by the manufacturer.
        (D) For engines which are not equipped with exhaust aftertreatment 
    devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
    turbocharger or exhaust manifold shall be insulated. For engines 
    equipped with exhaust aftertreatment devices, all tubing after the 
    aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
    insulated.
        (E) If the tubing is required to be insulated, the radial thickness 
    of the insulation must be at least 1.0 inch (25 mm). The thermal 
    conductivity of the insulating material must have a value no greater 
    than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700 
     deg.F (371  deg.C).
        (F) A smoke meter or other instrumentation may be inserted into the 
    exhaust system tubing. If this option is exercised in the insulated 
    portion of the tubing, then a minimal amount of tubing not to exceed 18 
    inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
    of tubing can be left uninsulated in total, including the length at the 
    smoke meter.
    * * * * *
        38. Section 86.1327-96 of Subpart N is amended by revising 
    paragraphs (b), (f)(1), (f)(2) introductory text, and (f)(2)(i) to read 
    as follows:
    
    
    Sec. 86.1327-96   Engine dynamometer test procedures; overview.
    
    * * * * *
        (b) Engine torque and rpm command set points shall be issued at 5 
    (10 Hz recommended) Hz or greater during both the cold and hot start 
    tests. Feedback engine torque and rpm shall be recorded at least once 
    every second during the test.
    * * * * *
        (f) * * *
        (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A 
    chassis-type exhaust system shall be used. For all catalyst systems, 
    the distance from the exhaust manifold flange(s) to the catalyst shall 
    be the same as in the vehicle configuration unless the manufacturer 
    provides data showing equivalent performance at another location. The 
    catalyst container may be removed during all test sequences prior to 
    the practice cycle, and replaced with an equivalent container having an 
    inactive catalyst support.
        (2) Petroleum-fueled and methanol-fueled diesel engines. Either a 
    chassis-type or a facility-type exhaust system or both systems 
    simultaneously may be used. If the engine is equipped with an exhaust 
    aftertreatment device, the exhaust pipe must be the same diameter as 
    found in-use for at least 4 pipe diameters upstream to the inlet of the 
    beginning of the expansion section containing the aftertreatment 
    device. The exhaust backpressure or restriction shall follow the same 
    criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler 
    omitted). The catalyst container may be removed during all test 
    sequences prior to the practice cycle, and replaced with an equivalent 
    container having an inactive catalyst support.
        (i) The engine exhaust systems shall meet the following 
    requirements:
        (A) The total length of the tubing from the exit of the engine 
    exhaust manifold, turbocharger outlet or aftertreatment device to the 
    primary dilution tunnel shall not exceed 32 feet (9.8 m).
        (B) The initial portion of the exhaust system may consist of a 
    typical in-use (i.e., length, diameter, material, etc.) chassis-type 
    exhaust system.
        (C) The distance from the exhaust manifold flange(s) or 
    turbocharger outlet to any exhaust aftertreatment device shall be the 
    same as in the vehicle configuration or within the distance 
    specifications provided by the manufacturer.
        (D) For engines which are not equipped with exhaust aftertreatment 
    devices, all tubing in excess of 12 feet (3.7 m) from the exit of the 
    turbocharger or exhaust manifold shall be insulated. For engines 
    equipped with exhaust aftertreatment devices, all tubing after the 
    aftertreatment device which is in excess of 12 feet (3.7 m) shall be 
    insulated.
        (E) If the tubing is required to be insulated, the radial thickness 
    of the insulation must be at least 1.0 inch (25 mm). The thermal 
    conductivity of the insulating material must have a value no greater 
    than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700 
     deg.F (371  deg.C).
        (F) A smoke meter or other instrumentation may be inserted into the 
    exhaust system tubing. If this option is exercised in the insulated 
    portion of the tubing, then a minimal amount of tubing not to exceed 18 
    inches may be left uninsulated. However, no more than 12 feet (3.66 m) 
    of tubing can be left uninsulated in total, including the length at the 
    smoke meter.
    * * * * *
        39. Section 86.1327-98 is added to subpart N to read as follows:
    
    
    Sec. 86.1327-98  Engine dynamometer test procedures; overview.
    
        Section 86.1327-98 includes text that specifies requirements that 
    differ from Sec. 86.1327-96. Where a paragraph in Sec. 86.1327-96 is 
    identical and applicable to Sec. 86.1327-98, this may be indicated by 
    specifying the corresponding paragraph and the statement ``[Reserved]. 
    For guidance see Sec. 86.1327-96''.
        (a) through (d)(3) [Reserved]. For guidance see Sec. 86.1327-96.
        (d)(4) Additional accessories (e.g., oil cooler, alternators, air 
    compressors, etc.) may be installed or their loading simulated if 
    typical of the in-use application. This loading shall be parasitic in 
    nature and, if used, shall be applied during all engine testing 
    operations, including mapping. The accessory work performed shall not 
    be included in the integrated work used in emissions calculations.
        (d)(5) through (f) [Reserved]. For guidance see Sec. 86.1327-96.
        40. Section 86.1330-84 of subpart N is amended by revising 
    paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to 
    read as follows:
    
    
    Sec. 86.1330-84  Test sequence; general requirements.
    
    * * * * *
    
    [[Page 47131]]
    
        (b) * * *
        (1) The temperature of the CVS dilution air shall be maintained 
    above 68  deg.F (20  deg.C) for Otto cycle engines and between 68 
    deg.F and 86  deg.F (20  deg.C and 30  deg.C) for diesel cycle engines 
    throughout the test sequence, except as permitted by Sec. 86.1335-84.
        (2) For engines with auxiliary emission control devices which sense 
    or detect ambient air temperature and operate at 68  deg.F or higher, 
    the test cell ambient air temperature and the temperature of the engine 
    intake air shall be maintained at 77  deg.F 9  deg.F (25 
    deg.C 5  deg.C) throughout the test sequence. For engines 
    with auxiliary emission control devices which are temperature dependent 
    and operate at 68  deg.F or higher, the temperature of the engine 
    intake air shall be maintained at 77  deg.F 9  deg.F (25 
    deg.C 5  deg.C) throughout the test sequence.
    * * * * *
        (5) For engines equipped with an air-to-air intercooler (or any 
    other low temperature charge air cooling device) between the 
    turbocharger compressor and the intake manifold, the procedure for 
    simulating the device in the transient dynamometer test facilities 
    shall follow the SAE Recommended Practice J1937, ``Engine Testing with 
    Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
    * * * * *
        (f) Diesel-Fueled Engines only. (1)(i) Air inlet restriction shall 
    be set to a value midway between a clean filter and the maximum 
    restriction specified by the manufacturer. The exhaust restriction 
    normally shall be set at 80 percent of the manufacturer's recommended 
    maximum specified exhaust restriction. The manufacturer shall be liable 
    for emission compliance from the minimum in-use restrictions to the 
    maximum restrictions specified by the manufacturer for that particular 
    engine.
    * * * * *
        41. Section 86.1330-90 of subpart N is amended by revising 
    paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to 
    read as follows:
    
    
    Sec. 86.1330-90  Test sequence; general requirements.
    
    * * * * *
        (b) * * *
        (1) The temperature of the CVS dilution air shall be maintained at 
    greater than 68  deg.F (20  deg.C) for Otto cycle engines and between 
    68  deg.F and 86  deg.F (20  deg.C and 30  deg.C) for diesel cycle 
    engines throughout the test sequence, except as permitted by 
    Sec. 86.1335-84.
        (2) For engines with auxiliary emission control devices which sense 
    or detect ambient air temperature and operate at 68  deg.F or higher, 
    the test cell ambient air temperature and the temperature of the engine 
    intake air shall be maintained at 77  deg.F 9  deg.F (25 
    deg.C 5  deg.C) throughout the test sequence. For engines 
    with auxiliary emission control devices which are temperature dependent 
    and operate at 68  deg.F or higher, the temperature of the engine 
    intake air shall be maintained at 77  deg.F 9  deg.F (25 
    deg.C 5  deg.C) throughout the test sequence.
    * * * * *
        (5) For engines equipped with an air-to-air intercooler (or any 
    other low temperature charge air cooling device) between the 
    turbocharger compressor and the intake manifold, the procedure for 
    simulating the device in the transient dynamometer test facilities 
    shall follow the SAE Recommended Practice J1937, ``Engine Testing with 
    Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
    * * * * *
        (f) Petroleum-fueled and methanol-fueled diesel engines. (1)(i) Air 
    inlet restriction shall be set to a value midway between a clean filter 
    and the maximum restriction specified by the manufacturer. The exhaust 
    restriction normally shall be set at 80 percent of the manufacturer's 
    recommended maximum specified exhaust restriction. The manufacturer 
    shall be liable for emission compliance from the minimum in-use 
    restrictions to the maximum restrictions specified by the manufacturer 
    for that particular engine.
    * * * * *
        42. Section 86.1333-90 of subpart N is amended by revising 
    paragraphs (c), (d) introductory text, (d)(1), (d)(2), (e)(2) and 
    removing paragraphs (d)(3) and (d)(4) to read as follows:
    
    
    Sec. 86.1333-90  Transient test cycle generation.
    
    * * * * *
        (c) Engine speed and torque shall be recorded at least once every 
    second during the cold start test and hot start test. The torque and 
    rpm feedback signals may be filtered.
        (d) Idle Speed Enhancement Devices (e.g. cold idle, alternator 
    idle, etc.). The zero percent speed specified in the engine dynamometer 
    schedules (appendix I (f)(1), (f)(2), or (f)(3) to this part) shall be 
    superseded by proper operation of the engine's idle speed enhancement 
    device.
        (1) During idle speed enhancement device operation, a manual 
    transmission engine shall be allowed to idle at whatever speed is 
    required to target a feedback torque equal to zero (using, for example, 
    clutch disengagement, speed to torque control switching, software 
    overrides, etc.) at those points in appendix I (f)(1), (f)(2), or 
    (f)(3) to this part where both reference speed and reference torque are 
    zero percent values. For each idle segment that is seven seconds or 
    longer, the average feedback torque must be within 10 ft-
    lbs of zero. To allow for transition, up to the first four seconds may 
    be deleted from each idle segment calculation.
        (2) During idle speed enhancement device operation, an automatic 
    transmission engine shall be allowed to idle at whatever speed is 
    required to target a feedback torque equal to CITT (see (e)(2) of this 
    section for definition of CITT) at those points in appendix I (f)(1), 
    (f)(2), or (f)(3) to this part where both reference speed and reference 
    torque are zero percent values. For each idle segment that is seven 
    seconds or longer, the average feedback torque must be within 
    10 ft-lbs of CITT. To allow for transition, up to the first 
    four seconds may be deleted from each idle segment calculation.
        (e) * * *
        (2) All zero-percent speed, zero-percent torque points (idle 
    points) shall be modified to zero percent speed, Curb Idle Transmission 
    Torque (CITT), except as permitted in Sec. 86.1337-90(a)(9). Also, all 
    points with speed equal to or less than zero percent and torque less 
    than CITT shall be modified to CITT. Motoring torque shall remain 
    unchanged. In order to provide a smooth torque transition, all 
    consecutive torque points that are between 0 and CITT shall be changed 
    to CITT if the first of these is preceded or the last of these is 
    succeeded by idle points. The manufacturer's specified CITT shall be 
    based upon that value observed in typical applications at the mean of 
    the manufacturers' specified idle speed range at stabilized temperature 
    conditions.
    * * * * *
        43. Section 86.1334-84 of subpart N is amended by revising 
    paragraph (a)(2) to read as follows:
    
    
    Sec. 86.1334-84  Pre-test engine and dynamometer preparation.
    
        (a) * * *
        (2) Following any practice runs or calibration procedures, the 
    engine shall be cooled per Sec. 86.1335-90.
        44. Section 86.1335-90 of subpart N is revised to read as follows:
    
    
    Sec. 86.1335-90  Cool-down procedure.
    
        (a) This cool-down procedure applies to Otto-cycle and diesel 
    engines.
        (b) Engines may be soaked at ambient conditions. No substances or 
    fluids may
    
    [[Page 47132]]
    
    be applied to the engine's internal or external surfaces except for 
    water and air as prescribed in paragraphs (c) and (d) of this section.
        (c) For water-cooled engines, two types of cooling are permitted:
        (1) Water may be circulated through the engine's water coolant 
    system.
        (i) The coolant may be flowed in either direction and at any 
    desired flow rate. The thermostat may be removed or blocked open during 
    the cool-down but must be restored before the exhaust emissions test 
    begins.
        (ii) The temperature of the circulated or injected water shall be 
    at least 10  deg.C (50  deg.F). In addition, the temperature of the 
    cooling water shall not exceed 30  deg.C (86  deg.F) during the last 30 
    minutes of the cool-down.
        (iii) Only water, including the use of a building's standard water 
    supply, or the coolant type that is already in the engine (per 
    Sec. 86.1327-90(e)) is permitted for cool-down purposes.
        (2) Flows of air may be directed at the exterior of the engine.
        (i) The air shall be directed essentially uniformly over the 
    exterior surface of the engine at any desired flow rate.
        (ii) The temperature of the cooling air shall not exceed 86  deg.F 
    (30  deg.C) during the last 30 minutes of the cool-down, but may be 
    less than 68  deg.F (20  deg.C) at any time.
        (d) For air-cooled engines, only cooling as prescribed in paragraph 
    (c)(2) of this section is permitted.
        (e)(1) The cold cycle exhaust emission test may begin after a cool-
    down only when the engine oil and water temperatures are stabilized 
    between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C) for a minimum 
    of fifteen minutes.
        (i) These temperature measurements are to be made by temperature 
    measurement devices immersed in the sump oil and in the thermostat 
    housing or cylinder head cooling circuit, the sensor parts of which are 
    not in contact with any engine surface.
        (ii) The flow of oil and water shall be shut off during this 
    measurement. Air flow, except as necessary to keep the cell temperature 
    between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C), shall be 
    shut off. No engine oil change is permitted during the test sequence.
        (2) Direct cooling of engine oil through the use of oil coolers or 
    heat exchangers is permitted. The cold cycle emission test may begin 
    only when the requirements in paragraph (e)(1)(ii) are met.
        (3) Any other means for the direct cooling of the engine oil must 
    be approved in advance by the Administrator.
        (f)(1) The cold cycle exhaust emission test for engines equipped 
    with exhaust aftertreatment devices may begin after a cool-down only 
    when the aftertreatment device is 77  deg.F 9  deg.F (25 
    deg.C 5  deg.C), in addition to the temperature 
    restrictions in paragraph (e) of this section. For catalysts, this 
    temperature must be measured at the outlet of the catalyst bed.
        (2) Exhaust aftertreatment device cool-down may be accomplished in 
    whatever manner and using whatever coolant deemed appropriate by proper 
    engineering judgment. The aftertreatment device, engine, and exhaust 
    piping configurations shall not be separated, altered, or moved in any 
    way during the cool-down.
        (g) For engines with auxiliary emission control devices which are 
    temperature dependent, the cold start shall not begin until the 
    temperature readings of the auxiliary emission control devices are 
    stable at 77  deg.F 9  deg.F (25  deg.C 5 
    deg.C).
        (h) At the completion of the cool-down all of the general 
    requirements specified in Sec. 86.1330, the oil temperature 
    specification set forth in paragraph (e) of this section, and the 
    catalyst temperature specifications in paragraph (f) of this section 
    must be met before the cold cycle exhaust emission test may begin.
        45. Section 86.1337-90 of subpart N is amended by revising 
    paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23), 
    and (a)(26), and by removing paragraph (a)(10)(iii), to read as 
    follows:
    
    
    Sec. 86.1337-90  Engine dynamometer test run.
    
        (a) * * *
        (9) As soon as it is determined that the engine is started, start a 
    ``free idle'' timer. Allow the engine to idle freely with no-load for 
    24 1 seconds. This idle period for automatic transmission 
    engines may be interpreted as an idle speed in neutral or park. All 
    other idle conditions shall be interpreted as an idle speed in gear. It 
    is permissible to lug the engine down to curb idle speed during the 
    last 8 seconds of the free idle period for the purpose of engaging 
    dynamometer control loops.
        (10) * * *
        (i) During diesel particulate sampling it must be demonstrated that 
    the ratio of main tunnel flow to particulate sample flow does not 
    change by more than 5.0 percent of its set point value 
    (except for the first 10 seconds of sampling).
    
        Note: For double dilution operation, sample flow is the net 
    difference between the flow rate through the sample filters and the 
    secondary dilution air flow rate.
    
        (ii) Record the average temperature and pressure at the gas 
    meter(s) or flow instrumentation inlet, where needed to calculate flow. 
    If the set flow rate cannot be maintained because of high particulate 
    loading on the filter, the test shall be terminated. The test shall be 
    rerun using a lower flow rate and/or a larger diameter filter.
        (11) Begin the transient engine cycles such that the first non-idle 
    record of the cycle occurs at 25 1 seconds. The free idle 
    time is included in the 25 1 seconds.
    * * * * *
        (13) Immediately after the engine is turned off, turn off the 
    engine cooling fan(s) if used, and the CVS blower (or disconnect the 
    exhaust system from the CVS). As soon as possible, transfer the ``cold 
    start cycle'' exhaust and dilution air bag samples to the analytical 
    system and process the samples according to Sec. 86.1340. A stabilized 
    reading of the exhaust sample on all analyzers shall be obtained within 
    20 minutes of the end of the sample collection phase of the test. 
    Analysis of the methanol and formaldehyde samples shall be obtained 
    within 24 hours of the end of the sample collection period. For 
    petroleum-fueled and methanol-fueled diesel engines, carefully remove 
    the filter holder from the sample flow apparatus, and remove each 
    particulate sample filter from its holder and invert the secondary 
    filter and place it stain side to stain side on top of the primary 
    filter. Place the filter pair in a petri dish and cover.
    * * * * *
        (23) Allow the engine to idle freely with no-load for 24 
    1 seconds. The provisions and interpretations of paragraph 
    (a)(9) of this section apply.
    * * * * *
        (26) As soon as possible, transfer the ``hot start cycle'' exhaust 
    and dilution air bag samples to the analytical system and process the 
    samples according to Sec. 86.1340. A stabilized reading of the exhaust 
    sample on all analyzers shall be obtained within 20 minutes of the end 
    of the sample collection phase of the test. Analyze the methanol and 
    formaldehyde samples within 24 hours. (If it is not possible to perform 
    analysis within 24 hours, the samples should be stored in a cold 
    (approximately 0 deg.C) dark environment until analysis can be 
    performed). For petroleum-fueled and methanol-fueled diesel engines, 
    carefully remove the assembled filter holder from the sample flow lines 
    and remove each particulate sample filter from its holder and invert 
    the secondary filter and place it stain side to stain side on top of 
    the primary filter. Place the filter pairs in a clean petri dish and
    
    [[Page 47133]]
    
    cover as soon as possible. Within 1 hour after the end of the hot start 
    phase of the test, transfer the particulate filters to the weighing 
    chamber for post-test conditioning.
    * * * * *
        46. Section 86.1337-96 of subpart N is amended by revising 
    paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23), 
    and (a)(26), and by removing paragraph (a)(10)(iii) to read as follows:
    
    
    Sec. 86.1337-96  Engine dynamometer test run.
    
        (a) * * *
        (9) As soon as it is determined that the engine is started, start a 
    ``free idle'' timer. Allow the engine to idle freely with no-load for 
    241 seconds. This idle period for automatic transmission 
    engines may be interpreted as an idle speed in neutral or park. All 
    other idle conditions shall be interpreted as an idle speed in gear. It 
    is permissible to lug the engine down to curb idle speed during the 
    last 8 seconds of the free idle period for the purpose of engaging 
    dynamometer control loops.
        (10) * * *
        (i) During diesel particulate sampling it must be demonstrated that 
    the ratio of main tunnel flow to particulate sample flow does not 
    change by more than 5.0 percent of its set point value 
    (except for the first 10 seconds of sampling). For double dilution 
    operation, sample flow is the net difference between the flow rate 
    through the sample filters and the secondary dilution air flow rate.
        (ii) Record the average temperature and pressure at the gas 
    meter(s) or flow instrumentation inlet, where needed to calculate flow. 
    If the set flow rate cannot be maintained because of high particulate 
    loading on the filter, the test shall be terminated. The test shall be 
    rerun using a lower flow rate and/or a larger diameter filter.
        (11) Begin the transient engine cycles such that the first non-idle 
    record of the cycle occurs at 251 seconds. The free idle 
    time is included in the 251 seconds.
    * * * * *
        (13) Immediately after the engine is turned off, turn off the 
    engine cooling fan(s) if used, and the CVS blower (or disconnect the 
    exhaust system from the CVS). As soon as possible, transfer the ``cold 
    start cycle'' exhaust and dilution air bag samples to the analytical 
    system and process the samples according to Sec. 86.1340. A stabilized 
    reading of the exhaust sample on all analyzers shall be obtained within 
    20 minutes of the end of the sample collection phase of the test. 
    Analysis of the methanol and formaldehyde samples shall be obtained 
    within 24 hours of the end of the sample collection period. For 
    petroleum-fueled and methanol-fueled diesel engines, carefully remove 
    the filter holder from the sample flow apparatus, remove each 
    particulate sample filter from its holder and invert the secondary 
    filter and place it stain side to stain side on top of the primary 
    filter. Place the filter pair in a petri dish and cover.
    * * * * *
        (23) Allow the engine to idle freely with no-load for 
    241 seconds. The provisions and interpretations of 
    paragraph (a)(9) of this section apply.
    * * * * *
        (26) As soon as possible, transfer the ``hot start cycle'' exhaust 
    and dilution air bag samples to the analytical system and process the 
    samples according to Sec. 86.1340. A stabilized reading of the exhaust 
    sample on all analyzers shall be obtained within 20 minutes of the end 
    of the sample collection phase of the test. Analyze the methanol and 
    formaldehyde samples within 24 hours. (If it is not possible to perform 
    analysis within 24 hours, the samples should be stored in a cold 
    (approximately 0  deg.C) dark environment until analysis can be 
    performed). For petroleum-fueled and methanol-fueled diesel engines, 
    carefully remove the assembled filter holder from the sample flow lines 
    and remove each particulate sample filter from its holder and invert 
    the secondary filter and place it stain side to stain side on top of 
    the primary filter. Place the filter pairs in a clean petri dish and 
    cover as soon as possible. Within 1 hour after the end of the hot start 
    phase of the test, transfer the particulate filters to the weighing 
    chamber for post-test conditioning.
    * * * * *
        47. Section 86.1338-84 of subpart N is revised to read as follows:
    
    
    Sec. 86.1338-84  Emission measurement accuracy.
    
        (a) Measurement accuracy--Bag sampling. (1) Good engineering 
    practice dictates that exhaust emission sample analyzer readings below 
    15 percent of full scale chart deflection should generally not be used.
        (2) Some high resolution read-out systems such as computers, data 
    loggers, etc., can provide sufficient accuracy and resolution below 15 
    percent of full scale. Such systems may be used provided that 
    additional calibrations of at least 4 non-zero nominally equally spaced 
    points, using good engineering judgement, below 15 percent of full 
    scale are made to ensure the accuracy of the calibration curves.
        (3) The following procedure shall be followed:
        (i) Span the analyzer using a calibration gas that meets the 
    accuracy requirements of Sec. 86.1314-84(f)(2), is within the operating 
    range of the analyzer and at least 90% of full scale.
        (ii) Generate calibration data over the full concentration range at 
    a minimum of 6, approximately equally spaced, points (e.g. 15, 30, 45, 
    60, 75 and 90 percent of the range of concentrations provided by the 
    gas divider). If a gas divider or blender is being used to calibrate 
    the analyzer and the requirements of paragraph (a)(2) of this section 
    are met, verify that a second calibration gas with a concentration 
    between 10 and 20 percent of full scale can be named within 2 percent 
    of its certified concentration. If more calibration points are needed 
    to meet the requirements of paragraph (a)(2) of this section, continue 
    with paragraph (a)(3)(iii) of this section.
        (iii) If a gas divider or blender is being used to calibrate the 
    analyzer, input the value of a second calibration gas (a span gas may 
    be used for calibrating a CO2 analyzer) having a named 
    concentration between 10 and 20 percent of full scale. This gas shall 
    be included on the calibration curve. Continue adding calibration 
    points by dividing this gas until the requirements of paragraph (a)(2) 
    of this section are met.
        (iv) Fit a calibration curve per Secs. 86.1321 through 86.1324 for 
    the full scale range of the analyzer using the calibration data 
    obtained with both calibration gases.
        (b) Measurement accuracy--Continuous sampling. (1) Analyzers used 
    for continuous analysis must be operated such that the measured 
    concentration falls between 15 and 100 percent of full scale chart 
    deflection. Exceptions to these limits are:
        (i) Analyzer response less than 15 percent or more than 100 percent 
    of full scale may be used if automatic range change circuitry is used 
    and the limits for range changes are between 15 and 100 percent of full 
    scale chart deflection;
        (ii) Analyzer response less than 15 percent of full scale may be 
    used if one of the following is true:
        (A) Alternative (a)(2) of this section is used to ensure that the 
    accuracy of the calibration curve is maintained below 15 percent; or
        (B) The full scale value of the range is 155 ppm (C) or less.
        (iii) Analyzer response over 100% of full scale may be used if it 
    can be shown that readings in this range are accurate.
        (iv) The HC and CO readings are allowed to ``spike'' above full 
    scale of the analyzer's maximum operating range for a maximum 
    accumulation of 5
    
    [[Page 47134]]
    
    seconds. These analyzer readings shall default to the maximum readable 
    value during this time.
        (c) If a gas divider is used, the gas divider shall conform to the 
    accuracy requirements specified in Sec. 86.1314-84(g), and shall be 
    used according to the procedures contained in (a) and (b) of this 
    section.
        48. Section 86.1339-90 of subpart N is revised to read as follows:
    
    
    Sec. 86.1339-90  Particulate filter handling and weighing.
    
        (a) At least 1 hour before the test, place a filter pair in a 
    closed (to eliminate dust contamination) but unsealed (to permit 
    humidity exchange) petri dish and place in a weighing chamber meeting 
    the specifications of Sec. 86.1312 for stabilization.
        (b) At the end of the stabilization period, weigh each filter pair 
    on a balance having a precision of 20 micrograms and a readability of 
    10 micrograms. This reading is the tare weight of the filter pair and 
    must be recorded (see Sec. 86.1344(e)(18)).
        (c) The filter pair shall then be stored in a covered petri dish or 
    a sealed filter holder, either of which shall remain in the weighing 
    chamber until needed for testing.
        (d) If the filter pair is not used within 1 hour of its removal 
    from the weighing chamber, it must be re-weighed before use. This limit 
    of 1 hour may be replaced by an 8-hour limit if either of the following 
    three conditions are met:
        (1) A stabilized filter pair is placed and kept in a sealed filter 
    holder assembly with the ends plugged; or
        (2) A stabilized filter pair is placed in a sealed filter holder 
    assembly, which is then immediately placed in a sample line through 
    which there is no flow; or
        (3) A combination of the conditions specified in paragraphs (d) (1) 
    and (2) of this section.
        (e) After the emissions test, remove the filters from the filter 
    holder and place them face to face in a covered but unsealed petri 
    dish. They must then be conditioned in the weighing chamber for at 
    least one hour. The filters are then weighed as a pair. This reading is 
    the gross weight of the filters (Pf) and must be recorded (see 
    Sec. 86.1344-90(e)(19)).
        (f) The net particulate weight (Pf) on each filter pair is the 
    gross weight minus the tare weight. Should the sample on the filters 
    (exhaust or background) contact the petri dish or any other surface, 
    the test is void and must be rerun.
        (g) Static neutralizers shall be used on petri dishes in accordance 
    with good engineering judgement.
        49. Section 86.1341-90 of subpart N is amended by revising 
    paragraphs (b), (c) and (d) and removing paragraphs (e) through (h) to 
    read as follows:
    
    
    Sec. 86.1341-90  Test cycle validation criteria.
    
        (a) * * *
        (b) Brake horsepower-hour calculation. (1) Calculate the brake 
    horsepower-hour for each pair of engine feedback speed and torque 
    values recorded. Also calculate the reference brake horsepower-hour for 
    each pair of engine speed and torque reference values. Calculations 
    shall be to five significant digits.
        (2) In integrating the reference and the feedback horsepower-hour, 
    all negative torque values shall be set equal to zero and included. If 
    integration is performed at a frequency of less than 5 Hz, and if 
    during a given time segment, the torque value changes from positive to 
    negative or negative to positive, then the negative portion must be 
    computed by linear interpolation and set equal to zero and the positive 
    portion included. The same methodology shall be used for integrating 
    both reference and actual brake horsepower-hour.
        (c) Regression line analysis to calculate validation statistics. 
    (1) Linear regressions of feedback value on reference value shall be 
    performed for speed, torque and brake horsepower on 1 Hz data after the 
    feedback shift has occurred (see paragraph (a) of this section). The 
    method of least squares shall be used, with the best fit equation 
    having the form:
    
    y=mx+b
    
    Where:
    
    y = The feedback (actual) value of speed (rpm), torque (ft-lbs), or 
    brake horsepower.
    m = Slope of the regression line.
    x = The reference value (speed, torque, or brake horsepower).
    b = The y-intercept of the regression line.
    
        (2) The standard error of estimate (SE) of y on x and the 
    coefficient of determination (r2) shall be calculated for 
    each regression line.
        (3) For a test to be considered valid, the criteria in Figure N90-
    11 must be met for both cold and hot cycles individually. Point 
    deletions from the regression analyses are permitted where noted in 
    Figure N90-11.
    
                                                                          Figure N90-11                                                                     
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Speed                                    Torque                          BHP             
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Regression Line Tolerances                                                               
                                                                                                                                                            
                                                       Petroleum-fueled and methanol-fueled diesel engines                                                  
    Standard error of estimate (SE) of Y    100 rpm...........................................  13 pct. of power map maximum   8 pct. of power map maximum  
     on X.                                                                                       engine torque                  BHP.                        
    Slope of the regression line, m.......  0.970 to 1.030....................................  0.83-1.03 (hot), 0.77-1.03     0.89-1.03 (hot), 0.87-1.03   
                                                                                                 (cold)                         (cold).                     
    Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.8800 (hot), \1\ 0.8500   \1\ 0.9100.                  
                                                                                                 (cold).                                                    
    Y intercept of the regression line, b.  50 rpm................................  15 ft-lb.........  5.0 BHP.         
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Gasoline-fueled and methanol-fueled Otto-cycle engines                                                 
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    Standard error of estimate (SE) of Y    100 rpm...........................................  10% (hot), 11% (cold) of       5% (hot), 6% (cold) of power 
     on X.                                                                                       power map max. engine torque.  map maximum BHP.            
    Slope of the regression line, m.......  0.980 to 1.020....................................  0.92-1.03 (hot), 0.88-1.03     0.93-1.03 (hot), 0.89-1.03   
                                                                                                 (cold)                         (cold).                     
    Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.9300 (hot), \1\ 0.9000   \1\ 0.9400 (hot), \1\ 0.9300 
                                                                                                 (cold)                         (cold).                     
    Y intercept of the regression line, b.  25 (hot), 40 (cold).......  4% (hot), 2.0% (hot), 5 (cold) of power map    minus>2.5% (cold) of power  
                                                                                                 max. engine torque.            map BHP.                    
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    \1\ Minimum.                                                                                                                                            
    
    
    [[Page 47135]]
    
    
               Permitted Point Deletions From Regression Analysis           
    ------------------------------------------------------------------------
                     Condition                      Points to be deleted    
    ------------------------------------------------------------------------
    1. Wide Open Throttle and Torque Feedback   Torque, and/or BHP.         
     < torque="" reference.="" 2.="" closed="" throttle,="" not="" an="" idle="" point,="" torque,="" and/or="" bhp.="" torque="" feedback=""> Torque Reference.                                    
    3. Closed Throttle, Idle Point, and Torque  Speed, and/or BHP.          
     Feedback = CITT (10 ft-lb).                                
                                                                            
      For the purposes of this discussion:                                  
                                                                            
      An Idle Point is defined as a point having a Normalized Reference     
    Torque of 0 and a Normalized Reference Speed of 0 and an engine tested  
    as having a manual transmission has a CITT of 0. Point deletion may be  
    applied either to the whole or to any part of the cycle.                
    ------------------------------------------------------------------------
    
        (4)(i) For petroleum-fueled and methanol-fueled diesel engines, the 
    integrated brake horsepower-hour for each cycle (cold and hot start) 
    shall be between -15 percent and +5 percent of the integrated brake 
    horsepower-hour for the reference cycle, or the test is void.
        (ii) For gasoline-fueled and methanol-fueled Otto-cycle engines, 
    the integrated brake horsepower-hour of the feedback cycle shall be 
    within 5 percent of the integrated brake horsepower-hour of the 
    reference cycle for the cold cycle, or the test is void. The tolerance 
    for the hot cycle shall be 4 percent.
        (5) If a dynamometer test run is determined to be statistically or 
    experimentally void, corrective action shall be taken. The engine shall 
    then be allowed to cool (naturally or forced) and the dynamometer test 
    rerun per Sec. 86.1337 or be restarted at Sec. 86.1336-84(e).
        (d) For petroleum-fueled and methanol-fueled diesel engines, all 
    reference torque values specified (in paragraph (f)(2) of appendix I to 
    this part) as ``closed throttle'' shall be deleted from the calculation 
    of cycle torque and power validation statistics.
        50. Section 86.1341-98 is added to subpart N and reads as follows:
    
    
    Sec. 86.1341-98  Test cycle validation criteria.
    
        Section 86.1341-98 includes text that specifies requirements that 
    differ from Sec. 86.1341-90. Where a paragraph in Sec. 86.1341-90 is 
    identical and applicable to Sec. 86.1341-98, this may be indicated by 
    specifying the corresponding paragraph and the statement ``[Reserved]. 
    For guidance see Sec. 86.1341-90''
        (a) Through (b)(2) [Reserved]. For guidance see Sec. 86.1341-90.
        (b)(3) All feedback torques due to accessory loads, either actual 
    or simulated as defined in Sec. 86.1327-90 (d)(4), shall be excluded 
    from both cycle validation and the integrated work used for emissions 
    calculations.
        (4) For reference idle portions of the cycle where CITT is not 
    applied, use measured torque values for cycle validation and the 
    reference torque values for calculating the brake horsepower-hour value 
    used in the emission calculations. For reference idle portions of the 
    cycle where CITT is applied, use measured torque values for cycle 
    validation and calculating the brake horsepower-hour value used in the 
    emission calculations.
        (c) Through (d) [Reserved]. For guidance see Sec. 86.1341-90.
        51. Section 86.1342-90 of subpart N is amended by removing 
    paragraphs (h)(2)(i), (h)(2)(ii), (h)(2)(iii), (h)(2)(iv), (h)(2)(v), 
    (h)(2)(vi), (h)(2)(vii) and adding paragraph (i) to read as follows:
    
    
    Sec. 86.1342-90  Calculations; exhaust emissions.
    
    * * * * *
        (i) For dilute sampling systems which require conversion of as-
    measured dry concentrations to wet concentrations, the following 
    equation shall be used for any combination of bagged, continuous, or 
    fuel mass-approximated sample measurements (except for CO measurements 
    made through conditioning columns, as explained in paragraph (d)(3) of 
    this section):
    
    Wet concentration = Kw  x  dry concentration.
    
    Where:
    
        (1)(i) For English units,
    
    Kw = 1-(/200)  x  CO2e(')-((1.608  x  
    H)/(7000 + 1.608  x  H))
    
        See paragraph (d)(1) of this section for  values.
        (ii) For SI units,
    
    Kw = 1-(/200)  x  CO2e(')-((1.608  x  
    H)/(1000 + 1.608  x  H))
    
        See paragraph (d)(1) of this section for  values.
    
    (2) CO2e(') = either CO2e or CO2e' as 
    applicable.
    (3)(i) H = Absolute humidity of the CVS dilution air, in grains (grams) 
    of water per lb (kg) of dry air.
    
        (ii) For English units,
    
    H ' = [(43.478)Ri'  x  Pd']/
    [PB-(Pd'  x  Ri'/100)]
    
        (iii) For SI units,
    
    H' = [(6.211)Ri'  x  Pd']/
    [PB-(Pd'  x  Ri'/100)]
    (4) Ri = Relative humidity of the CVS dilution air, in 
    percent.
    (5) Pd = Saturated vapor pressure, in mm Hg (kPa) at the 
    ambient dry bulb temperature of the CVS dilution air.
    (6) PB = Barometric pressure, mm Hg (kPa).
    
        52. Section 86.1342-94 is amended by revising paragraphs (e) 
    through (h) and adding paragraph (i) to read as follows:
    
    
    Sec. 86.1342-94  Calculations; exhaust emissions.
    
    * * * * *
        (e) Through (i) [Reserved]. For guidance see Sec. 86.1342-90.
        53. Section 86.1343-88 is amended by revising the introductory text 
    of paragraph (b), redesignating paragraphs (b)(2)(i) through (b)(2)(v) 
    as paragraphs (b)(2)(ii) through (b)(2)(vi) respectively and by adding 
    a new paragraph (b)(2)(i) to read as follows:
    
    
    Sec. 86.1343-88  Calculations; particulate exhaust emissions.
    
    * * * * *
        (b) The mass of particulate for the cold-start test and the hot-
    start test is determined from the following equation:
    * * * * *
        (2)(i)(A) For a CFV-CVS: Vmix = Total dilute exhaust 
    volume corrected to standard conditions (293  deg.K (20  deg.C) and 
    101.3 kPa (760 mm Hg)), cubic feet per test phase.
        (B) For a PDP-CVS:
        [GRAPHIC] [TIFF OMITTED] TR05SE97.006
        
    in SI units,
    [GRAPHIC] [TIFF OMITTED] TR05SE97.007
    
    Where:
    * * * * *
        \1\ Closed throttle motoring.
    ---------------------------------------------------------------------------
    
        \1\  
    
    ---------------------------------------------------------------------------
    
    [[Page 47136]]
    
        53. Appendix I to part 86 is amended by revising the footnote to 
    the table in paragraph (f)(2) to read as follows:
    
    Appendix I to Part 86--Urban Dynamometer Schedules
    
    * * * * *
        (f)(1) * * *
        (2) * * *
    
    * * * * *
    [FR Doc. 97-23352 Filed 9-4-97; 8:45 am]
    BILLING CODE 6560-50-P
    
    
    

Document Information

Effective Date:
1/5/1998
Published:
09/05/1997
Department:
Environmental Protection Agency
Entry Type:
Rule
Action:
Direct final rule.
Document Number:
97-23352
Dates:
This rule will be effective January 5, 1998 unless notice is received by October 6, 1997 that adverse or critical comments will be submitted on a specific element of this rule. If such comments are received, then EPA will publish a subsequent document in the Federal Register withdrawing any regulation for which adverse or critical comments were made.
Pages:
47114-47136 (23 pages)
Docket Numbers:
FRL-5881-3
PDF File:
97-23352.pdf
Supporting Documents:
» Legacy Index for Docket A-96-07
» Amendments to the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and Amendments to the Emission Standard Provisions for Gaseous Fueled Vehicles and Engines
» Direct Final Rule Amending the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and the Amending of Emission Standard Provisions for Gaseous Fueled Vehicles and Engines [A-96-07-V-A-1]
» Proposed Amendments to the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and Proposed Amendments to the Emission Standard Provisions for Gaseous Fueled Vehicles and Engines [A-96-07-III-A-1]
CFR: (59)
40 CFR 86.1314)
40 CFR 86.1327-90(e))
40 CFR 86.1344-90(e)(19))
40 CFR 86.1327-84(f)(2)
40 CFR 86.1310(b)(3)(vii)(A)
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