95-18255. Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines: Evaporative and Refueling Emission Regulations for Gasoline- and Methanol-Fueled Light-Duty Vehicles and Light-Duty Trucks and Heavy-Duty Vehicles; Technical ...  

  • [Federal Register Volume 60, Number 163 (Wednesday, August 23, 1995)]
    [Rules and Regulations]
    [Pages 43880-43907]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-18255]
    
    
    
    
    [[Page 43879]]
    
    _______________________________________________________________________
    
    Part III
    
    
    
    
    
    Environmental Protection Agency
    
    
    
    
    
    _______________________________________________________________________
    
    
    
    40 CFR Parts 9 and 86
    
    
    
    Control of Air Pollution From New Motor Vehicles and New Motor Vehicle 
    Engines: Evaporative and Refueling Emission Regulations for Gasoline- 
    and Methanol-Fueled Light-Duty Vehicles and Light-Duty Trucks and 
    Heavy-Duty Vehicles; Technical Amendments; Final Rule
    
    Federal Register / Vol. 60, No. 163 / Wednesday, August 23, 1995 / 
    Rules and Regulations 
    
    [[Page 43880]]
    
    
    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Parts 9 and 86
    
    [FRL-5258-7]
    RIN 2060-AF49
    
    
    Control of Air Pollution From New Motor Vehicles and New Motor 
    Vehicle Engines: Evaporative and Refueling Emission Regulations for 
    Gasoline- and Methanol-Fueled Light-Duty Vehicles and Light-Duty Trucks 
    and Heavy-Duty Vehicles; Technical Amendments
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Final rule; technical amendments.
    
    -----------------------------------------------------------------------
    
    SUMMARY: On March 24, 1993 EPA finalized a new test procedure to 
    measure evaporative emissions from motor vehicles. The amendments 
    contained in this document modify several of the test procedure's 
    tolerances, equipment specifications, and procedural steps.
        In compliance with the Paperwork Reduction Act, this document 
    announces that the information collection requirements contained in the 
    Evaporative Emissions Final Rule were approved by the Office of 
    Management and Budget on May 9, 1994.
        Also, this document incorporates by reference the California 
    Regulatory Requirements Applicable to the Evaporative Emissions Program 
    (January 4, 1995). EPA will accept test data developed using the 
    California procedure for demonstrating compliance with the 1996 model 
    year federal evaporative emissions requirement for purposes of 
    certification.
    
    DATES: The amendments to 40 CFR part 86 are effective October 23, 1995, 
    unless notice is received by September 22, 1995, that adverse or 
    critical comments will be submitted or that an opportunity to submit 
    such comments at a public hearing is requested. If the Agency receives 
    such comments or a request for a public hearing by September 22, 1995, 
    EPA will then publish a subsequent Federal Register document 
    withdrawing from this action only those items which are specifically 
    listed in those comments or in the request for a public hearing. See 
    Supplementary Information for further discussion on submission of 
    public comment.
        The incorporation by reference of the publications listed in the 
    regulations is approved by the director of the Federal Register as of 
    October 23, 1995.
        The information collection requirements contained in 40 CFR 86.096-
    7, 86.096-8, 86.096-9, 86.096-10, 86.096-14, 86.096-21, 86.096-23, 
    86.096-26, 86.096-30, 86.096-35, 86.097-9, 86.098-23, 86.099-8, 86.099-
    9, and 86.099-10, which were published at 58 FR 16002, March 24, 1993, 
    and the amendments to 40 CFR part 9 are effective August 23, 1995.
    
    ADDRESSES: Interested parties may submit written comments (in 
    duplicate, if possible) to Public Docket No. A-94-35 at Air Docket 
    Section, U.S. Environmental Protection Agency, First Floor, Waterside 
    Mall, Room M-1500, 401 M Street SW., Washington, DC 20460 (telephone 
    202-260-7548). Materials relevant to the evaporative emissions final 
    rule and this direct final rule are available for inspection in Public 
    Dockets A-89-18 and A-94-35 at the above address.
    
    FOR FURTHER INFORMATION CONTACT: Mr. Alan Stout, (313) 741-7805.
    
    SUPPLEMENTARY INFORMATION:
    
    Table of Contents
    
    I. Introduction
    II. Overview of Technical Amendments
    III. List of Changes to Test Procedures
    IV. Public Participation and Effective Date
    V. Paperwork Reduction Act
    VI. Administrative Designation
    VII. Regulatory Flexibility Act
    VIII. Unfunded Mandates Act
    IX. Judicial Review
    
    I. Introduction
    
        On March 24, 1993 the Environmental Protection Agency (EPA) 
    published a final rule establishing new requirements to test vehicles 
    for evaporative emissions (58 FR 16002), which will apply to new motor 
    vehicles beginning in model year 1996 according to a phased-in 
    compliance schedule. The procedure was amended with several corrections 
    and minor changes by a direct final rule, which was published June 28, 
    1993 (58 FR 34535). As EPA and manufacturers have come closer to 
    implementing the new test procedure, it has become clear that there are 
    several potential changes to the test procedure that would make testing 
    simpler, safer, and less resource-intensive. In addition, the Agency 
    wants to harmonize its evaporative emission test procedure with that of 
    the California Air Resources Board (CARB).
        EPA has worked closely with the California Air Resources Board and 
    manufacturers to identify all the changes to the test procedure 
    specifications that could improve the test without affecting test 
    stringency. The regulations contained in this document reflect these 
    discussions. This document is published as a direct final rule. In the 
    case of adverse comments received in response to this document by 
    September 22, 1995, EPA will remove from the regulations those 
    provisions that receive comment. EPA may, at its discretion, propose 
    such provisions in a future rulemaking action.
        A copy of this document 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. The service is free of charge, except for the cost of the 
    phone call. Users are able to access and download TTN files on their 
    first call using a personal computer and modem according to 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
    
        Users who have not called TTN previously will first be required to 
    answer some basic informational questions for registration purposes. 
    After completing the registration process, users must 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
    <1> Light Duty
    <7> File area #7. . . Evaporative Emissions
    
        At this point, the system will list all available files in the 
    chosen category in reverse chronological order with brief descriptions. 
    To download files, users must select a transfer protocol that is 
    supported by the terminal software on their own computer, then set 
    their own software to receive the file using that same protocol.
        If unfamiliar with handling compressed (i.e. ZIP'ed) files, users 
    should go to the TTN top menu, System Utilities (Command: 1) to 
    identify the program that must be downloaded to un-ZIP the files of 
    interest. After completing a session, users can quit the TTN BBS with 
    the  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. 
    
    [[Page 43881]]
    
    
    II. Overview of Technical Amendments
    
        In addition to the test procedure changes, EPA has in this rule 
    addressed the issue of reliance on CARB's test procedure (i.e., the 
    California Regulatory Requirements Applicable to the Evaporative 
    Emissions Program, January 4, 1995) for testing 1996 model year 
    vehicles for evaporative emissions. EPA is modifying the existing 
    evaporative emission regulations to accept manufacturers' data showing 
    compliance with CARB's 1996 model year certification requirements as 
    demonstration of compliance with the evaporative emissions portion of 
    the federal certification requirements for the 1996 model year. EPA's 
    confirmatory and in-use testing of 1996 model year vehicles certified 
    in this way will also rely on the CARB procedure for evaluating 
    compliance with test requirements. EPA's evaporative emission 
    regulations have been modified to incorporate by reference relevant 
    CARB regulations. EPA intends to evaluate CARB's pending technical 
    amendments, once finalized, and will approve use of the resulting 
    modified procedure for 1996 model year vehicles, provided the modified 
    procedure maintains at least the same level of control as CARB's 
    existing procedure.
        The more flexible arrangement for certifying 1996 model year 
    vehicles should have no negative air quality impact. Because of the 
    uncertainty surrounding EPA's technical amendments to the evaporative 
    emission test procedure, especially where they affect procurement of 
    test equipment, manufacturers have been constrained in their ability to 
    conduct testing according to federal specifications. Given the 
    direction CARB has taken with its own pending technical amendments, EPA 
    is confident that the CARB procedure will be as stringent, or nearly as 
    stringent, as the EPA procedure. Furthermore, since the enhanced test 
    requirements apply to only 20 percent of each manufacturer's 1996 model 
    year fleet, the air quality impact of any compromise in test stringency 
    would be very limited.
        Following promulgation of this rule and the pending changes to the 
    CARB procedure, the remaining differences of significance between EPA's 
    and CARB's evaporative emission test procedures are limited to the 
    specifications for temperatures and fuel volatility. EPA is pursuing a 
    test program to better understand the relative stringency of the two 
    sets of test conditions and to decide if data generated according to 
    the CARB test procedure will be acceptable for federal testing on a 
    long-term basis. The same information will be factored into the 
    decision related to carryover of data from the CARB test procedure for 
    federal certification in subsequent model years.
        The most significant changes to the test procedure fall into three 
    categories: (1) Control of fuel tank temperature and pressure during 
    running loss testing, (2) air circulation during the diurnal emission 
    test, and (3) a provision for a simplified procedure for generating 
    fuel temperature profiles for the running loss test. Each of these 
    areas is briefly described below.
        The issues of greatest concern relate to controlling fuel tank 
    temperature and pressure during the running loss test. These technical 
    amendments incorporate several changes to deal with these concerns. For 
    example, the procedure for outdoor testing to generate fuel temperature 
    profiles now allows the option of stabilizing vehicle and fuel 
    temperatures to 95  deg.F before driving. Also, determination of 
    compliance with the fuel tank pressure limit during driving on a 
    dynamometer would depend on control of vapor temperatures throughout 
    the running loss test; conversely, measurement of fuel tank pressure 
    and vapor temperature may be omitted at the discretion of those 
    responsible for testing. Another change allows temporary exceedances to 
    the fuel tank pressure limit during driving on a dynamometer to account 
    for potentially artificial tank heating effects in the laboratory. 
    Finally, equipment specifications related to heating and cooling the 
    vehicle's fuel tank have been broadened to increase the degree of 
    control that technicians have in controlling fuel tank temperatures.
        Another important issue was the requirement in the initial final 
    rule to maintain a specified wind speed underneath the vehicle during 
    diurnal emission testing. The regulations contain a new requirement to 
    control ambient temperatures underneath the test vehicle and allow an 
    option to use an established fan configuration to meet the required 
    wind speed specification (5 mph). This change provides an option to 
    comply with the wind speed requirement without measuring underbody air 
    velocity on every test.
        Also, EPA has included in the regulations a provision giving 
    general guidance for use of a heated wind tunnel for generating fuel 
    temperature profiles. Further work will be required in the 
    certification process to implement the policy; for example, to 
    determine what constitutes acceptable correlation between wind tunnel 
    and outdoor fuel temperature profiles, how often and on what vehicles 
    correlation would have to be demonstrated, and how fuel temperature 
    profiles could be carried over to subsequent model years.
        Manufacturers are required to submit either test data or an 
    engineering evaluation to demonstrate compliance with evaporative 
    emission standards at high altitudes. One manufacturer has expressed to 
    EPA its concern that a fuel temperature profile generated at low 
    altitude has limited applicability for testing at high altitude, which 
    causes difficulty in testing methanol-fueled vehicles. The existing 
    regulatory language for high-altitude requirements provides the Agency 
    limited discretion to adjust the test procedure to accommodate changes 
    related to fuel temperature profiles. EPA believes it is inappropriate 
    to address this issue in a direct final rulemaking, since any change 
    that cannot be accommodated under the Agency's existing discretion 
    would require a formal proposal and a period for public comment. EPA 
    encourages interested manufacturers to work with EPA's Certification 
    Division to resolve this issue.
        In addition to the changes to the evaporative emission test 
    procedure, these technical amendments include revised language related 
    to the test requirements for onboard refueling vapor recovery, 
    initially finalized April 6, 1994 (59 FR 16262), to clarify test 
    provisions and make typographical corrections.
    
    III. List of Changes to Test Procedures
    
        The following list describes the individual changes made to the 
    test procedure. Explanation and, where appropriate, EPA's 
    interpretation of the resulting regulatory language is provided.
    Vehicle Preconditioning
    
        1. Change initial soak to 6 hours minimum:
    
    --The procedure previously called for a 12-hour minimum soak before the 
    preconditioning drive, though EPA reserved the option of conducting 
    testing with only a 6-hour soak. The shorter soak time is sufficient to 
    stabilize the vehicle.
    
        2. Make the initial soak and refueling event optional for a second 
    test run on a vehicle (or optional for any SEA test):
    
    --Vehicles that have already been tested in the laboratory have been 
    sufficiently stabilized with respect to temperature and fuel effects.
    
        3. Require vehicles to be parked within 5 minutes after the 
    refueling procedure:
    
     
    [[Page 43882]]
    
    --The regulations previously required the test vehicle to be parked 
    within 5 minutes after completion of the preconditioning drive. Since 
    test vehicles must be refueled during the hour following the 
    preconditioning drive, the timing of the parking event is best 
    specified relative to completion of the refueling event.
    
        4. Precondition multiple canisters as a set unless they are 
    arranged in parallel:
    
    --While canisters configured in parallel should be preconditioned 
    individually, as the initial final rule required, EPA agrees that 
    evaporative canisters arranged in a series configuration should be 
    preconditioned as a set to best simulate normal vehicle operation.
    
        5. Add requirement to use a service port on evaporative canisters 
    (if so equipped) for loading and purging steps:
    
    --Provided that manufacturers install such service ports on their 
    production canisters, EPA agrees that it is appropriate to use the 
    ports for the preconditioning procedure.
    
        6. Allow replacement canister to collect vapors during canister 
    preconditioning:
    
    --The regulations have been modified to clarify that it is acceptable 
    to collect fuel tank vapors that may escape during the period that the 
    vehicle's canister is disconnected. This arrangement would provide a 
    safety benefit without affecting the condition of the test vehicle.
    
        7. Specify a representative vapor load to the canister for all 
    flexible-fueled and methanol-fueled vehicles:
    
    --The regulations previously called for representative vapor loading 
    for dedicated methanol-fueled vehicles only. A vehicle using any amount 
    of methanol should not have its canister loaded with pure butane, since 
    the engine's electronic controls depend on a vapor composition from the 
    canister being similar to that coming from the fuel tank. Using 
    repeated diurnal heat builds to precondition the canister for the two-
    day diurnal sequence would provide, by definition, a representative 
    vapor composition. EPA anticipates that the best way to conduct bench-
    loading for either test sequence would be to generate vapors from an 
    off-board fuel tank or other reservoir partially filled with the type 
    of fuel to be used in the subsequent test run.
    
        8. Delete parenthetical reference to volumetric flow rate 
    equivalent to 40 g/hr butane load:
    
    --The regulations previously provided a conversion of the mass flow 
    rate into volumetric units for the convenience of the reader. Because 
    this conversion is valid only at sea level, it has been deleted.
    
    Diurnal Emission Test
        9. Provide flexibility to satisfy 5-mph wind speed requirement near 
    tank with a demonstrated configuration:
    
    --This provision allows one to conduct diurnal emission tests without 
    routinely measuring wind speed under the fuel tank. Consistently using 
    a given fan configuration that has been demonstrated to satisfy the 
    wind speed requirement on the test vehicle or a broad range of vehicles 
    would be sufficient to show adequate airflow underneath the test 
    vehicle.
    
        10. Add undertank thermocouple for instantaneous and average 
    temperature tolerances and relax tolerance on sidewall temperatures to 
    5  deg.F:
    
    --The new requirement to measure air temperatures under the fuel tank 
    becomes the primary measurement for following the ambient fuel 
    temperature profile. The sidewall temperature measurement serves the 
    purpose of ensuring adequate air mixing in the enclosure and providing 
    a temperature measurement representative of the overall enclosure 
    volume (for calculation of mass emissions).
    
        11. Allow passive fixed-volume diurnal enclosures and change 
    pressure tolerance to 2 in. H2O:
    
    --The regulatory language has been broadened to accommodate a different 
    design of a fixed-volume diurnal enclosure and to match the 
    specifications in place for variable-volume enclosures.
    
        12. Delete maximum surface temperature:
    
    --EPA believes that the specified maximum surface temperature does not 
    affect the test vehicle or the emission measurement, and so can be 
    deleted without compromising test effectiveness.
    
    Hot Soak Test
    
        13. Allow a 7-minute interval before the hot soak test; add 
    language to encourage making this interval as short as possible; add 
    language to make sure fans are off at the end of the running loss test:
    
    --EPA continues to believe that the time between the running loss and 
    hot soak tests is very important for an accurate measurement of hot 
    soak emissions. EPA believes a relaxed time specification does not 
    compromise test stringency for several reasons. First, the language for 
    the hot soak tests for both test sequences specifies that the intent of 
    testing is to minimize the time before the hot soak test. Second, new 
    language specifying that fans must be turned off after the running loss 
    test should prevent technicians from artificially cooling the fuel 
    during the period between the test segments. Third, the vehicle 
    continues to operate at idle until just before entry into the hot soak 
    enclosure. Fourth, EPA may make an extra effort to minimize the time 
    interval before the hot soak measurement for its testing. Similarly, 
    EPA may conduct the hot soak test with no elapsed time between the end 
    of the running loss test and the beginning of the hot soak test by 
    making a continuous measurement of running loss and hot soak emissions 
    in a running loss enclosure.
    
        14. Delete maximum surface temperature:
    
    --EPA believes that the specified maximum surface temperature does not 
    affect the test vehicle or the emission measurement, and so can be 
    deleted without compromising test effectiveness.
    
    Running loss test
    
        15. Increase maximum flow rate for under-tank blower; increase 
    minimum temperature to 85  deg.F:
    
    --Increasing the maximum flow rate of the under-tank blower to 4,000 
    cubic feet per minute (cfm) increases the degree of flexibility 
    available for controlling fuel temperatures. The regulations provide 
    for a maximum flow rate of 6,000 cfm for exceptional circumstances. To 
    prevent a high flow rate of chilled air from condensing generated fuel 
    vapors, the minimum temperature of air from the blower was increased 
    from 70 deg. to 85  deg.F.
    
        16. Define a tolerance for vapor temperature control, but make 
    measurement of vapor temperature and pressure in the tank optional 
    during lab driving:
    
    --Manufacturers have indicated to EPA that it is important to control 
    vapor temperatures during the running loss test, primarily to prevent 
    artificially high fuel tank pressures and vapor generation. EPA 
    believes it is appropriate to define a tolerance for controlling vapor 
    temperatures similar to that for controlling liquid fuel temperatures. 
    However, because of the technical difficulty of controlling vapor 
    temperatures during driving, the regulations provide the 
    
    [[Page 43883]]
    discretion for any laboratory testing to omit measurement of vapor 
    temperatures. EPA recognizes fuel tank pressure is very dependent on 
    vapor temperatures; therefore, vehicles must comply with the limit on 
    fuel tank pressures only if vapor temperatures are measured and 
    controlled to the specified profile. If a manufacturer chooses not to 
    develop a vapor temperature profile, compliance with the limit on fuel 
    tank pressure will be limited to the required outdoor driving.
    To address manufacturers' concern that vapor generation may be affected 
    by uncontrolled vapor temperatures, the regulations now state the 
    expectation that a facility be designed in a way that avoids 
    unrepresentative heating or cooling of the vapor space during the 
    running loss test. Also, in the case of EPA testing without measured 
    vapor temperatures, if a vehicle exceeds an emission standard, the 
    regulations provide manufacturers the opportunity to conduct subsequent 
    testing on that vehicle. If a manufacturer can show that the exceedance 
    is attributable to inadequate control of vapor temperatures, EPA will 
    invalidate its test run. To make such a demonstration, (1) a 
    manufacturer would be expected to conduct a complete test for 
    evaporative emissions, controlling vapor temperatures to the specified 
    tolerances; (2) the vehicle would have to meet the applicable standards 
    for running loss, hot soak and diurnal emissions; and (3) the 
    manufacturer would be expected to explain why the test facility for the 
    EPA test could have caused excessive vapor temperatures. To use this 
    provision, manufacturers would need to have developed a vapor 
    temperature profile prior to certification for the vehicle in question.
    
        17. Allow temporary exceedances of fuel tank pressure limit:
    
    --EPA is aware that characteristics of a laboratory's system for 
    managing fuel tank temperatures could cause the tank pressure during 
    driving on a dynamometer to show transient pressure behavior that does 
    not exist during on-road driving. In response, EPA has modified the 
    regulations to allow a vehicle to exceed the pressure limit for up to 
    10 percent of the total driving time during the running loss test.
    
        18. Require proportional-speed fan for cooling engine:
    
    --The fixed-speed fan originally specified in the regulations may in 
    some cases provide inadequate cooling for test vehicles. Additional 
    cooling capacity is needed because vehicles are operated on the 
    dynamometer with the hood closed or nearly closed. The regulations, as 
    amended by this final rule, now require a more complex fan; the new fan 
    is considerably more expensive, but does not compromise the 
    effectiveness of the test in any way. Because EPA believes that blowing 
    air underneath the test vehicle, past the engine and the fuel tank, is 
    the best primary source of heat for controlling fuel temperatures, the 
    original provision for this underbody blower is preserved as a 
    supplement to the proportional-speed fan.
    
        19. Allow manufacturers to start the test with fuel at less than 95 
     deg.F:
    
    --EPA recognizes that some future vehicles may be designed to keep fuel 
    temperatures below daily peak temperatures. The regulations now 
    describe what manufacturers must do to demonstrate the need for a 
    temperature offset (parking and driving on hot summer days), and set a 
    threshold of 3  deg.F as the minimum offset that must be demonstrated 
    to make use of this provision.
    
        20. Specify a 6-hour maximum soak before the running loss test; 
    limit the fuel heating rate to 5  deg.F per hour; and require 
    stabilized fuel temperatures for 1 hour before the running loss test:
    
    --The set of changes to the vehicle stabilization requirement provide 
    better control of fuel temperatures, and thus vapor generation, in the 
    time between the exhaust emission test and the running loss test. The 
    amended regulations provide for a faster heating rate or a longer 
    stabilization period for those vehicles that may have unusually cool 
    fuel following the exhaust emission test.
    
        21. Set average ambient temperature to 2  deg.F for the 
    running loss test:
    
    --This change resolves the inconsistency contained in EPA's original 
    regulations regarding specifications for an average ambient temperature 
    during the running loss test.
    
        22. Require ambient temperature measurement at the inlet to the 
    frontal fan; require sidewall temperature measurement for enclosure 
    testing only:
    
    --To clarify the original language, the regulations now specify that 
    temperature measurement upstream of the frontal fan is to be used for 
    demonstrating compliance with ambient temperature tolerances. In 
    enclosure testing, measurement of sidewall temperatures is also 
    required, but will likely be used only for calculation of mass 
    emissions.
    
        23. Allow direct tank heating for controlling fuel tank 
    temperatures:
    
    --The use of heat blankets or other direct methods of heating the fuel 
    tank during the running loss test may be needed for some vehicles whose 
    fuel temperatures cannot easily be controlled with circulating air. The 
    need to supplement the underbody blowers is most likely for designs in 
    which the fuel tank is isolated from the underbody in some way. This 
    provision gives EPA, manufacturers, and contract laboratories the 
    discretion to use direct tank heating if use of the specified fans is 
    insufficient to adequately control fuel temperatures. Direct tank 
    heating should be the exception and should be employed only after 
    attempting to control fuel temperatures with the specified fan 
    configuration. Also, the regulations add detailed cautionary language 
    to prevent the possibility of artificially increasing vapor generation 
    by this method.
    
        24. Allow use of a naturally aspirated running loss enclosure, if 
    it is shown to yield equivalent results:
    
    --EPA anticipates the possibility that running loss enclosures will 
    best be designed with a hybrid configuration; i.e., the test vehicle 
    would consume air from the enclosure ambient, with monitored makeup air 
    coming in through an orifice in a wall of the enclosure. The existing 
    language specifies that air be routed directly from outside the 
    enclosure into the engine's intake system. These technical amendments 
    allow use of a hybrid enclosure if testing shows that emission 
    measurement results are equivalent or superior to those from currently 
    specified enclosures.
    
        25. Correct reference to duration of driving schedule:
    
    --The original language incorrectly identified the duration of the 
    driving schedule for defining fuel temperature tolerances.
    
        26. Adjust densities for 68 deg. F ambient temperature for point-
    source calculations:
    
    --The original regulations inadvertently based densities on a 
    temperature of 74 deg. F. The corrected densities are hydrocarbons = 
    16.88 g/ft3; methanol = 37.71 g/ft3.
    
        27. Delete requirement for Type J thermocouple:
    
    --Though EPA expects to continue to depend on installation of Type J 
    thermocouples for confirmatory 
    
    [[Page 43884]]
    testing, this specification has been deleted from the regulations to 
    allow manufacturers to conduct their own testing using any temperature 
    sensor that meets the functional specifications for temperature 
    measurement.
    
    Procedure for generating fuel temperature profiles
    
        28. Add the option for developing vapor temperature profiles:
    
    --If manufacturers wish to develop vapor temperature profiles, 
    subsequent testing on those models may include measurement and control 
    of vapor temperatures according to the profile.
    
        29. Allow low-volatility fuel for generating profiles:
    
    --Manufacturers expressed a desire to have the flexibility to use a 
    test fuel with a different volatility than that specified for the 
    outdoor driving procedure; in particular, manufacturers wish to use 
    California's phase II reformulated gasoline. EPA has observed that 
    gasoline with lower volatility corresponds to slightly higher fuel 
    temperatures during driving. EPA therefore believes that using a fuel 
    such as California phase II reformulated gasoline, which has a lower 
    volatility than that of federal test fuel, would not sacrifice test 
    stringency. The new regulatory language is intended to allow use of 
    California's specified test fuel, even though other parameters besides 
    volatility fall outside the federal test fuel specifications.
    EPA will also accept demonstration of compliance with the fuel tank 
    pressure requirement using California phase II reformulated gasoline. 
    Using this fuel will cause somewhat lower fuel tank pressures, which 
    makes it easier to comply with the pressure limit. EPA believes this is 
    acceptable for a combination of reasons. First, vehicles tested on a 
    dynamometer to certify compliance with evaporative emission standards 
    will also demonstrate compliance with the fuel tank pressure 
    requirement, but with federal fuel. Also, because EPA may conduct its 
    own testing to measure pressure during outdoor driving, manufacturers 
    have no incentive to take advantage of the lower volatility fuel to 
    comply with the fuel tank pressure requirement.
    
        30. Change speed measurement accuracy to  1 mph:
    
    --Conventional equipment for measuring speeds during outdoor driving 
    cannot resolve speeds to the 0.1 mph tolerance originally 
    specified. Relaxing the accuracy to 1 mph would enable 
    manufacturers to use existing equipment and will not affect the 
    validity of the fuel temperature profiles.
    
        31. Allow fuel heating/stabilization up to 953 deg. F 
    before drive:
    
    --The regulations will continue to allow a 12-hour soak before starting 
    the outdoor drive, with no control of the fuel temperature during that 
    time. However, the regulations now include a provision to stabilize 
    fuel temperatures in a temperature-controlled environment before the 
    drive. When vehicles are stabilized in this way, manufacturers are 
    expected to attempt to start outdoor vehicle operation with fuel 
    temperatures at the nominal temperature of 95 deg. F. Manufacturers may 
    need to take steps to isolate the fuel tank from the pavement or other 
    heat sources and to begin the test drive as soon as possible after 
    exiting the enclosure.
    
        32. Specify 125 deg. F as minimum pavement temperature throughout 
    the outdoor drive:
    
    --EPA has learned that the requirement for pavement temperatures 
    staying 30 deg. F above ambient was sometimes difficult to meet, 
    because pavement temperatures might not increase fast enough to stay 
    30 deg. F ahead of increasing ambient temperatures. Since fuel 
    temperature is limited to a nominal starting point of 95 deg. F, fixing 
    the minimum pavement temperature at 125 deg. F satisfies EPA's desire 
    to keep the pavement temperature at least 30 deg. F above the initial 
    fuel temperature.
    
        33. Allow rolling fuel temperature profiles:
    
    --New language clarifies that manufacturers may use a rolling average 
    to derive fuel temperature profiles for testing.
    
        34. Add general provision for hot wind tunnel approach to 
    generating temperature profiles:
    
    --See Section II above.
    
        35. Add provision to allow temporary wind gusts:
    
    --Originally, wind speed was limited to a maximum of 15 mph throughout 
    the period of outdoor driving. EPA would like to avoid invalidating a 
    test run for occasional gusts of wind exceeding the 15 mph limit, since 
    fuel temperature profiles should be unaffected. To accommodate such a 
    situation, the regulations now allow wind speeds between 15 and 25 mph 
    for up to 5 percent of the total driving time.
    
        36. Allow small-volume manufacturers to use alternate methods to 
    generate profiles:
    
    --EPA realizes that small-volume manufacturers may not have the 
    resources to conduct a full test program according to the prescribed 
    procedure to establish fuel temperature profiles for their vehicles. 
    These manufacturers may use other means to generate fuel temperature 
    profiles, though EPA expects such profiles to be at least as stringent 
    as those that would be generated according to the full set of 
    specifications for outdoor testing.
    
        37. Allow the possibility of alternate methodologies for correcting 
    fuel temperature profiles:
    
    --One issue EPA has not resolved with manufacturers is the method of 
    correcting measured fuel temperature profiles to create a target 
    profile for running loss testing. EPA has agreed to add language to the 
    regulations allowing an alternate correction methodology, subject to 
    prior Agency approval. This change provides EPA the discretion to 
    accommodate a future resolution without requiring a subsequent change 
    to the regulations.
    
    Spitback Test
    
        38. Change refueling rate to 9.80.3 gallons per minute:
    
    --The changed refueling rate matches that used for the refueling 
    emission test. Specifying consistent refueling rates allows use of the 
    same equipment for the two procedures.
    
        39. Allow vehicle to be moved across lab with engine off:
    
    --Safety regulations at some facilities prevent driving a test vehicle 
    from the dynamometer to the refueling site. The test procedure 
    therefore now includes an allowance for moving the vehicle with the 
    engine off, without changing the time constraints.
    
        40. Add time specification for the period between the end of the 
    drive and the start of refueling (not just key-off):
    
    --This time specification was missing from the original test procedure.
    
    Equipment Calibration
    
        41. Add the option to use alternate calibration data:
    
    --The regulations have been modified to allow alternate calibration 
    techniques that are acceptable to EPA. Under the modified regulations, 
    EPA would approve use of the calibration methods currently required by 
    CARB for demonstrating compliance with equipment specifications for 
    federal testing.
    
    
    [[Page 43885]]
    
        42. Add the option to use new calibration procedures for pre-1996 
    testing:
    
    --Manufacturers may use their upgraded facilities to continue testing 
    according to the test procedure specified in Sec. 86.130-78.
    
    Miscellaneous
    
        43. Allow limited subtraction of nonfuel background emissions for 
    certification vehicles:
    
    --For certification vehicles only, manufacturers may conduct testing on 
    individual vehicles to quantify nonfuel background levels. Testing must 
    indicate the expected decay rate of the nonfuel emissions. In addition 
    manufacturers must indicate the primary source of the measured nonfuel 
    emissions. EPA will not approve use of a correction for nonfuel 
    emissions if (1) the emissions cannot be accounted for, (2) the source 
    can be easily removed, or (3) the rate of decay indicates a significant 
    potential for increased in-use emissions.
    This change is consistent with EPA's long-standing position that 
    nonfuel background emissions should be included in testing for 
    evaporative emissions. By making no provision to treat nonfuel 
    emissions separately for in-use vehicles, EPA maintains this 
    fundamental position. EPA believes that the provision for special 
    treatment of some certification vehicles gives manufacturers some 
    flexibility to simplify vehicle selection and preparation, without 
    compromising EPA's expectation that manufacturers prevent nonfuel 
    emissions from constituting a significant source of in-use emissions. 
    Moreover, EPA still expects manufacturers routinely to take basic steps 
    to minimize nonfuel emissions from certification vehicles, for example, 
    to use weathered vehicles.
    
        44. Allow continuous measurement of evaporative emissions 
    (hydrocarbon only):
    
    --At various points through the procedure, the language has been 
    revised to allow continuous emission measurement, rather than just 
    testing at the beginning and end of a sampling period. Continuous 
    measurement would make it possible to terminate a test, without making 
    it invalid, if the vehicle has exceeded the standard well before the 
    end of the test.
    
        45. Remove obsolete sections from the Code of Federal Regulations 
    (CFR):
    
    --Sections of title 40 part 86 of the CFR that affect only 1990 model 
    year and older vehicles will not be printed in future CFR publications.
    
        46. Change from ``alternate sampling systems'' to ``alternate 
    equipment or procedures'':
    
    --The revised language clarifies the meaning of this provision in 
    Sec. 86.106-96.
    
        47. Add simplified calculation for variable-volume enclosures for 
    diurnal emission testing:
    
    --Variable volume enclosures trap a fixed mass of air for the duration 
    of the test; therefore, the ideal gas law dictates that the ratio of 
    PV/T must remain constant during the test. Carrying this assumption 
    into the calculation of mass emissions allows one to omit separate 
    determination at the end of the test of pressure, temperature, and 
    volume in the enclosure.
    
        48. Revise the equation for calculating the mass of methanol 
    emissions:
    
    --The equation is simplified by eliminating the explicit temperature 
    correction for the enclosure volume (Vn) and sample volume 
    (Ve), and instead requires that the sample volumes be corrected 
    for changes in temperature, to be consistent with Vn, prior to 
    being used in the equation.
    
    Refueling Emission Test
    
        49. Allow road-speed modulated fan during vehicle operation:
    
    --EPA would like to allow the same road-speed modulated fans for engine 
    cooling during the refueling emission test that are specified for the 
    running loss test. Because these fans provide a better simulation of 
    on-road air cooling, the test vehicle's hood should be closed during 
    testing with these fans. If one continues to rely on the conventional 
    fixed-speed cooling fan, the test vehicle's hood should be left open to 
    increase the capacity for engine cooling.
    
    IV. Public Participation and Effective Date
    
        To prepare this final rule, EPA has worked actively with CARB and 
    the automobile manufacturers to reach a resolution on the many issues 
    involved. EPA twice distributed draft regulatory language for review 
    and met periodically with interested participants. EPA benefitted 
    greatly from this extensive interaction, so that the resulting set of 
    changes to the test procedure, reflecting this broad input, will 
    significantly improve EPA's and manufacturers' ability to conduct 
    testing more efficiently.
        The Agency is publishing this action as a direct final rule because 
    it views the changes as not affecting test stringency and anticipates 
    no adverse or critical comments. This action will become effective 
    unless the Agency receives notice that adverse or critical comments 
    will be submitted, or that a party requests the opportunity to submit 
    such oral comments pursuant to section 307(d)(5) of the Clean Air Act, 
    as amended. If such notice is received regarding a change to a 
    particular regulatory provision by September 22, 1995, EPA will 
    withdraw the provision in question before the effective date by 
    publishing a subsequent Federal Register document removing the 
    identified provision from the direct final rule.
    
    V. Paperwork Reduction Act
    
        EPA is amending the table of currently approved information 
    collection request (ICR) control numbers issued by the Office of 
    Management and Budget (OMB) for various regulations. The amendments in 
    this document update the table to accurately display those information 
    requirements promulgated under the Evaporative Emissions Final Rule 
    (March 24, 1993, 58 FR 16002). The affected regulations are codified at 
    40 CFR part 86, subpart A. EPA will continue to present OMB control 
    numbers in a consolidated table format to be codified in 40 CFR part 9 
    and in each CFR volume containing EPA regulations. The table lists the 
    section numbers with reporting and recordkeeping requirements, and the 
    current OMB control numbers. This display of the OMB control number and 
    its subsequent codification in the Code of Federal Regulations 
    satisfies the requirements of the Paperwork Reduction Act (44 U.S.C. 
    3501 et seq.) and OMB's implementing regulations at 5 CFR part 1320.
        This ICR was subject to public notice and comment prior to OMB 
    approval. As a result, EPA finds that there is ``good cause'' under 
    section 553(b)(B) of the Administrative Procedures Act (5 U.S.C. 
    553(b)(B)) to amend this table without additional notice and comment. 
    Due to the technical nature of the table, further notice and comment 
    would be unnecessary.
    
    VI. Administrative Designation
    
        Pursuant to Executive Order 12866 (58 FR 51735, October 4, 1993), 
    the Agency must determine whether a regulatory action is 
    ``significant'' and therefore subject to 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:
    
    
    [[Page 43886]]
    
        (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, the Agency has 
    determined that this direct final rule is not a ``significant 
    regulatory action.''
    VII. Regulatory Flexibility Act
    
        The Regulatory Flexibility Act of 1980 requires federal agencies to 
    examine significant adverse impacts of federal regulations on a 
    substantial number of small entities. The Agency believes that the 
    changes to the test requirements published in this final action are 
    unlikely to have a significant economic impact on a substantial number 
    of small entities. In fact, the revisions expand the flexibility of 
    small businesses required to comply with existing regulations.
    
    VIII. Unfunded Mandates Act
    
        Under section 202 of the Unfunded Mandates Reform Act of 1995, EPA 
    must prepare a budgetary impact statement to accompany any proposed or 
    final rule that includes a federal mandate with estimated costs to the 
    private sector of $100 million or more, or to state, local, or tribal 
    governments of $100 million or more in the aggregate. Under section 
    205, EPA must select the most cost-effective and least burdensome 
    alternative that achieves the objectives of the rule and is consistent 
    with statutory requirements. Section 203 requires EPA to establish a 
    plan for informing and advising any small governments that may be 
    significantly or uniquely impacted by the rule.
        EPA has determined that this direct final rule imposes no new 
    federal requirements and therefore does not include any federal mandate 
    with costs to the private sector or to state, local, or tribal 
    governments.
    
    IX. Judicial Review
    
        Under section 307(b) of the Clean Air Act, EPA hereby finds that 
    these regulations are of national applicability. Accordingly, judicial 
    review of this action is available only by filing a petition for review 
    in the United States Court of Appeals for the District of Columbia 
    Circuit within 60 days of publication. Under section 307(b)(2) of the 
    Act, the requirements that are the subject of this document may not be 
    challenged later in judicial proceedings brought by EPA to enforce 
    these requirements.
    
    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 vehicle pollution, Motor 
    vehicles, Reporting and recordkeeping requirements.
    
    40 CFR Part 600
    
        Administrative practice and procedures, Electric power, Energy 
    conservation, Fuel economy, Gasoline, Labeling, Motor vehicles, 
    Reporting and recordkeeping requirements.
    
        Dated: July 6, 1995.
    Carol M. Browner,
    Administrator.
    
        For the reasons set out in the preamble, title 40, chapter I, parts 
    9 and 86 of the Code of Federal Regulations, are amended as set forth 
    below.
    
    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.
    
        2. Section 9.1 is amended by removing from the table entries 
    86.078-7, 86.082-14, 86.084-5, 86.084-14, 86.084-26, 86.085-8--86.085-
    9, 86.085-21--86.085-25, 86.085-27--86.085-30, 86.085-35, 86.085-37--
    86.085-38, 86.087-21, 86.087-23, 86.087-25, 86.087-28, 86.087-30, 
    86.087-35, 86.088-21, 86.088-23, 86.088-25, 86.088-28, 86.088-30, 
    86.088-35, 86.090-7, 86.090-14--86.090-15, 86.090-23, 86.090-25--
    86.090-28, 86.090-30, 86.142-82, 86.144-78, 86.537-78, 86.542-78, 
    86.1310-84, 86.1310-88, 86.1335-84, 86.1341-84, 86.1342-84, 86.1344-84, 
    86.1344-88 and by adding new entries in numerical order under the 
    indicated heading to read as follows:
    
    
    Sec. 9.1  OMB approvals under the Paperwork Reduction Act.
    
    * * * * *
    
    ------------------------------------------------------------------------
                                                                 OMB control
                          40 CFR citation                            No.    
    ------------------------------------------------------------------------
                                                                            
                   *         *         *         *         *                
      Control of Air Pollution From New and In-Use Motor Vehicles and New   
     and In-Use Motor Vehicle Engines: Certification and Test Procedures    
                                                                            
                    *         *         *         *         *               
    86.085-37..................................................    2060-0104
                                                                            
                    *         *         *         *         *               
    86.090-14..................................................    2060-0104
                                                                            
                    *         *         *         *         *               
    86.090-25..................................................    2060-0104
    86.090-26..................................................    2060-0104
    86.090-27..................................................    2060-0104
                                                                            
                    *         *         *         *         *               
    86.096-7...................................................    2060-0104
    86.096-10..................................................    2060-0104
    86.096-14..................................................    2060-0104
    86.096-26..................................................    2060-0104
    86.096-30..................................................    2060-0104
    86.099-10..................................................    2060-0104
                                                                            
                    *         *         *         *         *               
    ------------------------------------------------------------------------
    
    PART 86--[AMENDED]
    
        3. The authority citation for part 86 continues to read as follows:
    
        Authority: Secs. 202, 203, 205, 206, 207, 208, 215, 216, 217, 
    and 301(a), Clean Air Act, as amended (42 U.S.C. 7521, 7522, 7524, 
    7525, 7541, 7542, 7549, 7550, 7552, and 7601(a)).
    
        4. Part 86 is amended by removing the following sections: 86.078-7, 
    86.081-8, 86.082-8, 86.082-14, 86.083-30, 86.084-5, 86.084-14, 86.084-
    15, 86.084-26, 86.085-8, 86.085-9, 86.085-10, 86.085-11, 86.085-21, 
    86.085-22, 86.085-23, 86.085-24, 86.085-25, 86.085-27, 86.085-28, 
    86.085-29, 86.085-30, 86.085-35, 86.085-38, 86.087-8, 86.087-9, 86.087-
    10, 86.087-21, 86.087-23, 86.087-25, 86.087-28, 86.087-29, 86.087-30, 
    86.087-35, 86.088-9, 86.088-11, 86.088-21, 86.088-23, 86.088-25, 
    86.088-28, 86.088-29, 86.088-30, 86.088-35, 86.090-7, 86.090-10, 
    86.090-11, 86.090-15, 86.090-23, 86.090-28, 86.090-29, 86.090-30, 
    86.090-35, 86.106-82, 86.109-82, 86.110-82, 86.111-82, 86.112-82, 
    86.116-82, 86.119-78, 86.126-78, 86.139-82, 86.142-82, 86.144-78, 
    86.401-78, 86.410-78, 86.509-78, 86.511-78, 
    
    [[Page 43887]]
    86.513-82, 86.516-78, 86.521-78, 86.526-78, 86.527-78, 86.535-78, 
    86.537-78, 86.540-78, 86.542-78, 86.544-78, 86.1309-84, 86.1310-84, 
    86.1310-88, 86.1311-84, 86.1335-84, 86.1341-84, 86.1342-84, 86.1344-84, 
    86.1344-88, 86.1501-84, 86.1504-84, 86.1506-84, 86.1513-84, 86.1513-87.
        5. Section 86.1 is amended by adding paragraph (b)(4) to read as 
    follows:
    
    
    Sec. 86.1  Reference materials.
    
    * * * * *
        (b) * * *
        (4) California regulatory requirements. The following table sets 
    forth California regulatory requirements that have been incorporated by 
    reference. The first column lists the name and date of the material. 
    The second column lists the sections of the part, other than Sec. 86.1, 
    in which the matter is referenced. The second column is presented for 
    information only and may not be all-inclusive. Copies of these 
    materials may be obtained from U.S. EPA, Office of Air and Radiation, 
    401 M Street, S.W., Washington, DC 20460.
    
    ------------------------------------------------------------------------
           Document No. and name               40 CFR part 86 reference     
    ------------------------------------------------------------------------
    California Regulatory Requirements   86.096-8; 86.096-9; 86.096-10.     
     Applicable to the Evaporative                                          
     Emissions Program, January 4, 1995.                                    
    ------------------------------------------------------------------------
    
    Subpart A--[Amended]
    
        6. Section 86.096-8 of subpart A is amended by revising paragraph 
    (b) introductory text and adding paragraph (b)(5)(iv) to read as 
    follows:
    
    
    Sec. 86.096-8  Emission standards for 1996 and later model year light-
    duty vehicles.
    
    * * * * *
        (b) Evaporative emissions from light-duty vehicles shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        (5) * * *
        (iv) For the 1996 model year, manufacturers may satisfy the testing 
    requirements for federal certification to the evaporative standards of 
    paragraph (b) of this section, except the fuel dispensing spitback 
    test, by presenting test results from the certification procedures 
    defined by the California Regulatory Requirements Applicable to the 
    Evaporative Emissions Program (January 4, 1995). These requirements 
    have been incorporated by reference (see Sec. 86.1).
    * * * * *
        7. Section 86.096-9 of subpart A is amended by revising paragraphs 
    (b) introductory text and (c) through (k), and adding paragraph 
    (b)(5)(iv) to read as follows:
    
    
    Sec. 86.096-9  Emission standards for 1996 and later model year light-
    duty trucks.
    
    * * * * *
        (b) Evaporative emissions from light-duty trucks shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        (5) * * *
        (iv) For the 1996 model year, manufacturers may satisfy the testing 
    requirements for federal certification to the evaporative standards of 
    paragraph (b) of this section, except the fuel dispensing spitback 
    test, by presenting test results from the certification procedures 
    defined by the California Regulatory Requirements Applicable to the 
    Evaporative Emissions Program (January 4, 1995). These requirements 
    have been incorporated by reference (see Sec. 86.1).
        (c) [Reserved]. For guidance see Sec. 86.094-9.
        (d) through (f) [Reserved].
        (g) through (k) [Reserved]. For guidance see Sec. 86.094-9.
        8. Section 86.096-10 of subpart A is amended by revising paragraph 
    (b) introductory text and adding paragraph (b)(5)(iv) to read as 
    follows:
    
    
    Sec. 86.096-10  Emission standards for 1996 and later model year Otto-
    cycle heavy-duty engines and vehicles.
    
    * * * * *
        (b) Evaporative emissions from heavy-duty vehicles shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        (5) * * *
        (iv) For the 1996 model year, manufacturers may satisfy the testing 
    requirements for federal certification to the evaporative standards of 
    paragraph (b) of this section, except the fuel dispensing spitback 
    test, by presenting test results from the certification procedures 
    defined by the California Regulatory Requirements Applicable to the 
    Evaporative Emissions Program (January 4, 1995). These requirements 
    have been incorporated by reference (see Sec. 86.1).
    * * * * *
        9. Section 86.096-11 of subpart A is amended by revising paragraph 
    (b)(5)(i) to read as follows:
    
    
    Sec. 86.096-11  Emission standards for 1996 and later model year diesel 
    heavy-duty engines and vehicles.
    
    * * * * *
        (b) * * *
        (5)(i) For vehicles with a Gross Vehicle Weight Rating of up to 
    26,000 lbs, the standards set forth in paragraphs (b)(3) and (b)(4) of 
    this section refer to a composite sample of evaporative emissions 
    collected under the conditions and measured in accordance with the 
    procedures set forth in subpart M of this part. For certification 
    vehicles only, manufacturers may conduct testing to quantify a level of 
    nonfuel background emissions for an individual test vehicle. Such a 
    demonstration must include a description of the source(s) of emissions 
    and an estimated decay rate. The demonstrated level of nonfuel 
    background emissions may be subtracted from emission test results from 
    certification vehicles if approved in advance by the Administrator.
    * * * * * 
    
    [[Page 43888]]
    
        10. Section 86.098-7 of subpart A is amended by adding paragraphs 
    (h)(1) through (h)(5) to read as follows:
    
    
    Sec. 86.098-7   Maintenance of records; submittal of information; right 
    of entry.
    
    * * * * *
        (h)(1) through (h)(5) [Reserved]. For guidance see Sec. 86.094-7.
    * * * * *
        11. Section 86.098-11 of subpart A is amended by revising paragraph 
    (b)(3)(iii)(A) to read as follows:
    
    
    Sec. 86.098-11   Emission standards for 1998 and later model year 
    diesel heavy-duty engines and vehicles.
    
    * * * * *
        (b) * * *
        (3) * * *
        (iii)(A) For vehicles with a Gross Vehicle Weight Rating of up to 
    26,000 lbs, the standards set forth in paragraph (b)(3) of this section 
    refer to a composite sample of evaporative emissions collected under 
    the conditions and measured in accordance with the procedures set forth 
    in subpart M of this part. For certification vehicles only, 
    manufacturers may conduct testing to quantify a level of nonfuel 
    background emissions for an individual test vehicle. Such a 
    demonstration must include a description of the source(s) of emissions 
    and an estimated decay rate. The demonstrated level of nonfuel 
    background emissions may be subtracted from emission test results from 
    certification vehicles if approved in advance by the Administrator.
    * * * * *
        12. Section 86.098-26 is amended by removing paragraphs 
    (a)(3)(i)(B) through (a)(3)(ii)(B) and adding paragraphs (a)(3)(i)(D) 
    through (a)(3)(ii)(B) to read as follows:
    
    
    Sec. 86.098-26   Mileage and service accumulation; emission 
    measurements.
    
    * * * * *
        (a)(3)(i)(D) through (a)(3)(ii)(B) [Reserved]. For guidance see 
    Sec. 86.094-26.
    * * * * *
        13. Section 86.099-8 of subpart A is amended by revising paragraph 
    (b) introductory text to read as follows:
    
    
    Sec. 86.099-8  Emission standards for 1999 and later model year light-
    duty vehicles.
    
    * * * * *
        (b) Evaporative emissions from light-duty vehicles shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        14. Section 86.099-9 of subpart A is amended by revising paragraph 
    (b) introductory text to read as follows:
    
    
    Sec. 86.099-9   Emission standards for 1999 and later model year light-
    duty trucks.
    
    * * * * *
        (b) Evaporative emissions from light-duty trucks shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        15. Section 86.099-10 of subpart A is amended by revising paragraph 
    (b) introductory text to read as follows:
    
    
    Sec. 86.099-10  Emission standards for 1999 and later model year Otto-
    cycle heavy-duty engines and vehicles.
    
    * * * * *
        (b) Evaporative emissions from heavy-duty vehicles shall not exceed 
    the following standards. The standards apply equally to certification 
    and in-use vehicles. The spitback standard also applies to newly 
    assembled vehicles. For certification vehicles only, manufacturers may 
    conduct testing to quantify a level of nonfuel background emissions for 
    an individual test vehicle. Such a demonstration must include a 
    description of the source(s) of emissions and an estimated decay rate. 
    The demonstrated level of nonfuel background emissions may be 
    subtracted from emission test results from certification vehicles if 
    approved in advance by the Administrator.
    * * * * *
        16. Section 86.099-11 of subpart A is amended by revising paragraph 
    (b)(3)(iii)(A) to read as follows:
    
    
    Sec. 86.099-11   Emission standards for 1999 and later model year 
    diesel heavy-duty engines and vehicles.
    
    * * * * *
        (b) * * *
        (3) * * *
        (iii)(A) For vehicles with a Gross Vehicle Weight Rating of up to 
    26,000 lbs, the standards set forth in paragraph (b)(3) of this section 
    refer to a composite sample of evaporative emissions collected under 
    the conditions and measured in accordance with the procedures set forth 
    in subpart M of this part. For certification vehicles only, 
    manufacturers may conduct testing to quantify a level of nonfuel 
    background emissions for an individual test vehicle. Such a 
    demonstration must include a description of the source(s) of emissions 
    and an estimated decay rate. The demonstrated level of nonfuel 
    background emissions may be subtracted from emission test results from 
    certification vehicles if approved in advance by the Administrator.
    * * * * *
    
    Subpart B--[Amended]
    
        17. Section 86.106-96 of subpart B is amended by revising paragraph 
    (a) introductory text to read as follows:
    
    
    Sec. 86.106-96   Equipment required; overview.
    
        (a) This subpart contains procedures for exhaust emission tests on 
    petroleum-fueled, natural gas-fueled, liquefied petroleum gas-fueled, 
    and methanol-fueled light-duty vehicles and light-duty trucks, and for 
    evaporative emission tests on gasoline-fueled, natural gas-fueled, 
    liquefied petroleum gas-fueled, and methanol-fueled light-duty vehicles 
    and light-duty trucks. Certain items of equipment are not necessary for 
    a particular test, e.g., evaporative enclosure when testing petroleum-
    fueled diesel vehicles. Alternate equipment, procedures, and 
    calculation methods may be used if shown to yield equivalent or 
    superior results, and if approved in advance by the Administrator. 
    Equipment required and specifications are as follows:
    * * * * *
        18. Section 86.107-96 of subpart B is amended by revising 
    paragraphs (a)(1) introductory text, (a)(1)(ii)(A), (a)(1)(ii)(B), 
    (a)(2), (a)(3)(i), (a)(3)(ii), (c)(1), (d), (e), and (f) to read as 
    follows:
    
    
    Sec. 86.107-96  Sampling and analytical systems; evaporative emissions.
    
        (a) Testing enclosures--(1) Diurnal emission test. The enclosure 
    shall be readily sealable, rectangular in shape, with space for 
    personnel access to all sides of the vehicle. When sealed, the 
    
    [[Page 43889]]
    enclosure shall be gas tight in accordance with Sec. 86.117-96. 
    Interior surfaces must be impermeable and nonreactive to hydrocarbons 
    (and to methanol, if the enclosure is used for methanol-fueled 
    vehicles). The temperature conditioning system shall be capable of 
    controlling the internal enclosure air temperature to follow the 
    prescribed temperature versus time cycle as specified in Sec. 86.133-96 
    and Appendix II of this part, within an instantaneous tolerance of 
    3.0 deg. F of the nominal temperature versus time profile 
    throughout the test, and an average tolerance of 2.0 deg. F over the 
    duration of the test (where the average is calculated using the 
    absolute value of each measured deviation). The control system shall be 
    tuned to provide a smooth temperature pattern that has a minimum of 
    overshoot, hunting, and instability about the desired long-term ambient 
    temperature profile. Interior surface temperatures shall not be less 
    than 40 deg. F at any time during the diurnal emission test. To 
    accommodate the volume changes due to enclosure temperature changes, 
    either a variable-volume or fixed-volume enclosure may be used for 
    diurnal emission testing:
    * * * * *
        (ii) Fixed-volume enclosure. * * *
        (A) The enclosure shall be equipped with a mechanism to maintain a 
    fixed internal air volume. This may be accomplished either by 
    withdrawing air at a constant rate and providing makeup air as needed, 
    or by reversing the flow of air into and out of the enclosure in 
    response to rising or falling temperatures. If inlet air is added 
    continuously throughout the test, it should be filtered with activated 
    carbon to provide a relatively low and constant hydrocarbon level. Any 
    method of volume accommodation shall maintain the differential between 
    the enclosure internal pressure and the barometric pressure to a 
    maximum value of 2.0 inches of water.
        (B) The equipment shall be capable of measuring the mass of 
    hydrocarbon and methanol (if the enclosure is used for methanol-fueled 
    vehicles) in the inlet and outlet flow streams with a resolution of 
    0.01 gram per hour. A bag sampling system may be used to collect a 
    proportional sample of the air withdrawn from and admitted to the 
    enclosure. Alternatively, the inlet and outlet flow streams may be 
    continuously analyzed using an on-line FID analyzer and integrated with 
    the flow measurements to provide a continuous record of the mass 
    hydrocarbon and methanol removal.
        (2) Running loss test. The enclosure shall be readily sealable, 
    rectangular in shape, with space for personnel access to all sides of 
    the vehicle. When sealed, the enclosure shall be gas tight in 
    accordance with Sec. 86.117-96. The enclosure may be equipped with a 
    personnel door, provided that the enclosure can still meet the 
    requirements of Sec. 86.117-96 with the door installed. Interior 
    surfaces must be impermeable and nonreactive to hydrocarbons and to 
    methanol (if the enclosure is used for methanol-fueled vehicles). 
    Interior surface temperatures shall not be less than 40 deg. F. If a 
    running loss enclosure meets all the requirements of paragraph (a)(1) 
    of this section, it may be used as a diurnal evaporative emission 
    enclosure. The enclosure must contain a dynamometer that meets the 
    requirements of Sec. 86.108. Provisions shall be made to remove exhaust 
    gases from the enclosure. During the running loss test, ambient 
    temperatures must be maintained at 955 deg. F 
    (952 deg. F on average). An air or oxygen cylinder with an 
    attached self-contained breathing apparatus may be provided for the 
    vehicle operator. The air required for vehicle operation shall be 
    provided by one of the following methods:
        (i) The running loss enclosure may be equipped to supply air to the 
    vehicle, at a temperature of 955 deg. F, from sources 
    outside of the running loss enclosure directly into the operating 
    engine's air intake system. Supplemental air requirements (e.g., for an 
    air pump) shall be supplied by drawing air from the engine intake 
    source.
        (ii) If it is shown to yield equivalent or superior results, the 
    running loss enclosure may be designed with an air makeup system that 
    brings outside air into the enclosure to accommodate the aspiration 
    needs of the engine and any auxiliary devices. The makeup air shall be 
    monitored to establish the background hydrocarbon levels (or 
    hydrocarbon and methanol, levels, if applicable) of the makeup air. A 
    filter may be used to provide dry air with a stable concentration of 
    background hydrocarbon. The makeup-air vent shall be readily sealable 
    for calibration of the enclosure and other purposes. For calculation of 
    running loss emissions, it may be assumed that the hydrocarbon and 
    methanol concentration in the air consumed by the vehicle is the same 
    as that of the rest of the air in the enclosure.
        (3) Hot soak test. * * *
        (i) If the hot soak test is conducted in the same enclosure as the 
    immediately preceding running loss test, interior surface temperatures 
    shall not be below 70 deg. F for the last 55 minutes of the hot soak 
    test.
        (ii) If the hot soak test is not conducted in the same enclosure as 
    the immediately preceding running loss test, interior surface 
    temperatures shall not be below 70 deg. F for the duration of the hot 
    soak test.
    * * * * *
        (c) Evaporative emission hydrocarbon and methanol data recording 
    system.
        (1) The electrical output of the FID used for measuring 
    hydrocarbons (or hydrocarbons plus methanol, as appropriate) shall be 
    recorded at least at the initiation and termination of each running 
    loss and hot soak test, and at least at the initiation and termination 
    of the enclosure sampling period(s) for the diurnal emission test, as 
    described in Sec. 86.133. The recording may be taken by means of a 
    strip chart potentiometric recorder, by use of an on-line computer 
    system or other suitable means. In any case, the recording system must 
    have operational characteristics (signal-to-noise ratio, speed of 
    response, etc.) equivalent to or better than those of the signal source 
    being recorded, and must provide a permanent record of results. The 
    record shall show a positive indication of the initiation and 
    completion of each hot soak, running loss, or diurnal emission test 
    (including initiation and completion of sampling period(s)), along with 
    the time elapsed during each soak.
    * * * * *
        (d) Fuel temperature control system. Fuel temperatures of the test 
    vehicle shall be controlled, as specified in Sec. 86.134(g)(1)(xv), 
    with the following combination of fans. The control system shall be 
    tuned and operated to provide a smooth and continuous fuel temperature 
    profile that is representative of the on-road temperature profile. The 
    running loss test configuration should be designed to avoid heating or 
    cooling the fuel tank's vapor space in a way that would cause vapor 
    temperature behavior to be unrepresentative of the vehicle's on-road 
    profile.
        (1) A vehicle cooling fan shall discharge air to the front of the 
    vehicle. The fan shall be a road-speed modulated fan that is controlled 
    to a discharge velocity that follows the dynamometer roll speed, at 
    least up to speeds of 30 mph, throughout the driving cycle. If a 
    warning light or gauge indicates that the vehicle's engine coolant has 
    overheated, subsequent test runs on the vehicle must include a vehicle 
    cooling fan that follows the dynamometer roll speed at all speeds 
    throughout the test cycle. The fan may direct airflow to both the 
    
    [[Page 43890]]
    vehicle radiator air inlet(s) and the vehicle underbody.
        (2) An additional fan may be used to discharge airflow from the 
    front of the vehicle directly to the vehicle underbody to control fuel 
    temperatures. Such a fan shall provide a total discharge airflow not to 
    exceed 8,000 cfm.
        (3) Additional fans may be used to route heating or cooling air 
    directly at the bottom of the vehicle's fuel tank. The air supplied to 
    the tank shall be between 85 deg. and 160 deg. F, with a total 
    discharge airflow not to exceed 4,000 cfm. For exceptional 
    circumstances, manufacturers may direct up to 6,000 cfm at the bottom 
    of the fuel tank with the advance approval of the Administrator.
        (4) Direct fuel heating may be needed for canister preconditioning, 
    as specified in Sec. 86.132(j)(2). Also, under exceptional 
    circumstances in which airflow alone is insufficient to control fuel 
    temperatures during the running loss test, direct fuel tank heating may 
    be used (see Sec. 86.134-96(g)(1)(xv)). The heating system must not 
    cause hot spots on the tank wetted surface that could cause local 
    overheating of the fuel. Heat must not be applied directly to the 
    tank's vapor space, nor to the liquid-vapor interface.
        (e) Temperature recording system. A strip chart potentiometric 
    recorder, an on-line computer system, or other suitable means shall be 
    used to record enclosure ambient temperature during all evaporative 
    emission test segments, as well as vehicle fuel tank temperature during 
    the running loss test. The recording system shall record each 
    temperature at least once every minute. The recording system shall be 
    capable of resolving time to 15 s and capable of resolving 
    temperature to 0.75 deg. F (0.42 deg. C). The 
    temperature recording system (recorder and sensor) shall have an 
    accuracy of 3 deg. F (1.7 deg. C). The recorder 
    (data processor) shall have a time accuracy of 15 s and a 
    precision of 15 s. Enclosures shall be equipped with two 
    ambient temperature sensors, connected to provide one average output, 
    located 3 feet above the floor at the approximate mid-length of each 
    side wall of the enclosure and within 3 to 12 inches of each side wall. 
    For diurnal emission testing, an additional temperature sensor shall be 
    located underneath the vehicle to provide a temperature measurement 
    representative of the air temperature under the fuel tank. For running 
    loss testing, an ambient temperature sensor shall be located at the 
    inlet to the fan that provides engine cooling. Manufacturers shall 
    arrange that vehicles furnished for testing at federal certification 
    facilities be equipped with temperature sensors for measurement of fuel 
    tank temperatures. Vehicles shall be equipped with two temperature 
    sensors installed to provide an average liquid fuel temperature. The 
    temperature sensors shall be placed to measure the temperature at the 
    mid-volume of the liquid fuel at a fill level of 40 percent of nominal 
    tank capacity. An additional temperature sensor may be placed to 
    measure vapor temperatures approximately at the mid-volume of the vapor 
    space, though measurement of vapor temperatures is optional during the 
    running loss test. In-tank temperature sensors are not required for the 
    supplemental two-diurnal test sequence specified in Sec. 86.130-96.
        (f) Pressure recording system. A strip chart potentiometric 
    recorder, an on-line computer system, or other suitable means, shall be 
    used to record the enclosure gage pressure for any testing in an 
    enclosure, as well as the vehicle's fuel tank pressure during the 
    running loss test and the outdoor driving procedure specified in 
    Sec. 86.129-94(d). Fuel tank pressure measurement and recording 
    equipment are optional during the running loss test. The recording 
    system shall record each pressure at least once every minute. The 
    recording system shall be capable of resolving time to 15 s 
    and capable of resolving pressure to 0.1 inches of water. 
    The pressure recording system (recorder and sensor) shall have an 
    accuracy of 1.0 inch of water. The recorder (data 
    processor) shall have a time accuracy of 15 s and a 
    precision of 15 s. The pressure transducer shall be 
    installed to measure the pressure in the vapor space of the fuel tank.
    * * * * *
        19. Section 86.107-98 of subpart B is amended by revising paragraph 
    (e)(1) to read as follows:
    
    
    Sec. 86.107-98  Sampling and analytical system.
    
    * * * * *
        (e) Temperature recording system--(1) For all emission testing. A 
    strip chart potentiometric recorder, an on-line computer system, or 
    other suitable means shall be used to record enclosure ambient 
    temperature during all evaporative emission test segments, as well as 
    vehicle fuel tank temperature during the running loss test. The 
    recording system shall record each temperature at least once every 
    minute. The recording system shall be capable of resolving time to 
    15 s and capable of resolving temperature to 
    0.75 deg. F (0.42 deg. C). The temperature 
    recording system (recorder and sensor) shall have an accuracy of 
    3 deg. F (1.7 deg. C). The recorder (data 
    processor) shall have a time accuracy of 15 s and a 
    precision of 15 s. Enclosures shall be equipped with two 
    ambient temperature sensors, connected to provide one average output, 
    located 3 feet above the floor at the approximate mid-length of each 
    side wall of the enclosure and within 3 to 12 inches of each side wall. 
    For diurnal emission testing, an additional temperature sensor shall be 
    located underneath the vehicle to provide a temperature measurement 
    representative of the temperature of the air under the fuel tank. For 
    running loss testing, an ambient temperature sensor shall be located at 
    the inlet to the fan that provides engine cooling. Manufacturers shall 
    arrange that vehicles furnished for testing at federal certification 
    facilities be equipped with temperature sensors for measurement of fuel 
    tank temperature. Vehicles shall be equipped with 2 temperature sensors 
    installed to provide an average liquid fuel temperature. The 
    temperature sensors shall be placed to measure the temperature at the 
    mid-volume of the liquid fuel at a fill level of 40 percent of nominal 
    tank capacity. An additional temperature sensor may be placed to 
    measure vapor temperatures approximately at the mid-volume of the vapor 
    space, though measurement of vapor temperatures is optional during the 
    running loss test. In-tank temperature sensors are not required for the 
    supplemental two-diurnal test sequence specified in Sec. 86.130-96 or 
    for the refueling test specified in Sec. 86.151-98.
    * * * * *
        20. Section 86.117-96 of subpart B is amended by revising the 
    introductory text and paragraphs (a)(1)(ii), (a)(1)(iii), (a)(7), (b), 
    (c) heading, (c)(1) introductory text, (c)(1)(iv), (c)(1)(v), 
    (c)(1)(vii), (d)(1) introductory text and equation, (d)(1)(v), and 
    (e)(1)(iii), adding paragraph (d)(3), and removing and reserving 
    paragraphs (d)(1)(iii) and (d)(1)(iv) to read as follows:
    
    
    Sec. 86.117-96   Evaporative emission enclosure calibrations.
    
        The calibration of evaporative emission enclosures consists of 
    three parts: initial and periodic determination of enclosure background 
    emissions (hydrocarbons and methanol); initial determination of 
    enclosure internal volume; and periodic hydrocarbon and methanol 
    retention check and calibration. Methanol measurements may be omitted 
    if methanol-fueled vehicles will not be tested in the evaporative 
    enclosure. Alternate calibration methods may be used if 
    
    [[Page 43891]]
    shown to yield equivalent or superior results, and if approved in 
    advance by the Administrator; specifically, more extreme temperatures 
    may be used for determining calibration without affecting the validity 
    of test results.
        (a) Initial and periodic determination of enclosure background 
    emissions. * * *
        (1) * * *
        (ii) Fixed-volume enclosures may be operated with inlet and outlet 
    flow streams either closed or open; if inlet and outlet flow streams 
    are open, the air flowing into and out of the enclosure must be 
    monitored in accordance with Sec. 86.107-96(a)(1)(ii)(B). Ambient 
    temperatures shall be maintained at 963 deg. F throughout 
    the 4-hour period.
        (iii) For running loss enclosures ambient temperatures shall be 
    maintained at 953 deg. F throughout the 4-hour period. For 
    running loss enclosures designed with a vent for makeup air, the 
    enclosure shall be operated with the vent closed.
    * * * * *
        (7) Allow the enclosure to stand undisturbed for four hours.
    * * * * *
        (b) Initial determination of enclosure internal volume. Prior to 
    its introduction into service the enclosure internal volume shall be 
    determined by the following procedure:
        (1) Carefully measure the internal length, width and height of the 
    enclosure, accounting for irregularities (such as braces) and calculate 
    the internal volume. For variable-volume enclosures, latch the 
    enclosure to a fixed volume when the enclosure is held at a constant 
    temperature; this nominal volume shall be repeatable within 
    0.5 percent of the reported value.
        (2) [Reserved].
        (3) [Reserved].
        (c) Hydrocarbon and methanol (organic gas) retention check and 
    calibration. * * *
        (1) An enclosure to be used for the diurnal emission test (see 
    Sec. 86.133-96) shall be calibrated according to the following 
    procedure. Calibration for hydrocarbon and methanol may be conducted 
    simultaneously or in sequential test runs.
    * * * * *
        (iv) [Reserved].
        (v) Turn on the ambient temperature control system (if not already 
    on) and adjust it for an initial temperature of 96 deg. F (36 deg. C). 
    On variable-volume enclosures, latch the enclosure to the appropriate 
    volume position for the set temperature. On fixed-volume enclosures 
    close the outlet and inlet flow streams.
    * * * * *
        (vii) Inject into the enclosure 2 to 6 grams of pure methanol at a 
    temperature of at least 150 deg. F (65 deg. C) and/or 2 to 6 grams of 
    pure propane. The injected quantity may be measured by volume flow or 
    by mass measurement. The method used to measure the quantity of 
    methanol and propane shall have an accuracy of 0.2 percent 
    of the measured value (less accurate methods may be used with the 
    advance approval of the Administrator).
    * * * * *
        (d) Calculations. (1) The calculation of net methanol and 
    hydrocarbon mass change is used to determine enclosure background and 
    leak rate. It is also used to check the enclosure volume measurements. 
    The methanol mass change is calculated from the initial and final 
    methanol samples, the net withdrawn methanol (in the case of diurnal 
    emission testing with fixed-volume enclosures), and initial and final 
    temperature and pressure according to the following equation:
    [GRAPHIC][TIFF OMITTED]TR23AU95.000
    
    Where:
    * * * * *
        (iii) [Reserved].
        (iv) [Reserved].
        (v) VE=Volume of sample withdrawn, ft3. Sample volumes 
    must be corrected for differences in temperature to be consistent with 
    determination of Vn, prior to being used in the equation.
    * * * * *
        (3) For variable-volume enclosures, defined in 
    Sec. 86.107(a)(1)(i), the following simplified form of the hydrocarbon 
    mass change equation may be used:
    [GRAPHIC][TIFF OMITTED]TR23AU95.001
    
        (e) Calibration of equipment for point-source testing of running 
    losses. * * *
        (1) * * *
        (iii) Operate the vapor sampling system in the normal manner and 
    release a known quantity of pure propane into the most frequently used 
    fuel vapor collector during the sampling period (approximately 5 
    minutes).
    * * * * *
        21. Section 86.129-94 of subpart B is amended by revising 
    paragraphs (d)(1), (d)(2)(iii), (d)(3)(ii), (d)(3)(iii), (d)(4)(i), 
    (d)(4)(ii), (d)(4)(iii), (d)(7)(iii), and (d)(7)(iv) and adding 
    paragraph (d)(7)(v) to read as follows:
    
    
    Sec. 86.129-94   Road load power, test weight, inertia weight class 
    determination, and fuel temperature profile.
    
    * * * * *
        (d) Fuel temperature profile--(1) General requirements. (i) To be 
    tested for running losses, as specified in Sec. 86.134, a vehicle must 
    have a fuel temperature profile. The following procedure is used to 
    generate the fuel temperature profile, which serves as a target for 
    controlling fuel temperatures during the running loss test. This 
    profile represents the fuel temperature change that occurs during on-
    road driving. If a vehicle has more than one fuel tank, a profile shall 
    be established for each tank. Manufacturers may also simultaneously 
    generate a profile for vapor temperatures.
        (ii) If a manufacturer uses a vehicle model to develop a profile to 
    represent multiple models, the vehicle model selected must have the 
    greatest expected fuel temperature increase during driving of all those 
    models it represents. Also, manufacturers must select test vehicles 
    
    [[Page 43892]]
    with any available vehicle options that increase fuel temperatures 
    during driving (for example, any feature that limits underbody 
    airflow).
        (iii) Manufacturers may conduct testing to develop fuel temperature 
    profiles in a laboratory setting, subject to approval by the 
    Administrator. The laboratory facility should simulate outdoor testing 
    to reproduce fuel and vapor temperature behavior over the specified 
    driving schedule. The design of the laboratory facility should include 
    consideration of any parameters that may affect fuel temperatures, such 
    as solar loading, pavement heat, and relative wind velocities around 
    and underneath the test vehicle. Indoor testing to develop the fuel 
    temperature profiles must be conducted with little or no vehicle-
    specific adjustment of laboratory parameters. Manufacturers would need 
    to maintain an ongoing demonstration of correlation between laboratory 
    and outdoor measurement of fuel temperatures. Specifically, fuel 
    temperatures and pressures from indoor driving should be at least as 
    high as measured when driving outdoors according to the procedures 
    described in this section.
        (iv) Small-volume manufacturers, as defined in Sec. 86.094-
    14(b)(1), may use an alternate method for generating fuel temperature 
    profiles, subject to the approval of the Administrator.
        (v) The Administrator may conduct testing to establish any 
    vehicle's temperature profiles or to verify compliance with fuel tank 
    pressure requirements.
        (2) * * *
        (iii) The data recording system described in paragraph (d)(2)(ii) 
    of this section shall be capable of resolving time to 1 s, 
    capable of resolving temperature to 2 deg. F, capable of 
    resolving pressure to 1.0 inch of water, and capable of 
    resolving speed to 1 mph. The temperature and pressure 
    signals shall be recorded at intervals of up to 1 minute; speed signals 
    shall be recorded at intervals of up to 1 second.
        (3) * * *
        (ii) Wind conditions shall be calm to light with maximum wind speed 
    of 15 mph. In the case of temporary gusting, wind speeds between 15 and 
    25 mph may occur for up to 5 percent of the total driving time without 
    invalidating the data collection. Wind speed shall be measured and 
    recorded in regular intervals of at least once per minute. Measure wind 
    speed with the following requirements (based on Federal Standard for 
    Siting Meteorological Sensors at Airports, FCM-S4-1987). The site 
    should be relatively level, but small gradual slopes are acceptable. 
    The sensor shall be mounted 30 to 33 feet (9 to 10 meters) above the 
    average ground height within a radius of 500 feet (150 meters). The 
    sensor height shall not exceed 33 feet, except as necessary to be at 
    least 15 feet (5 meters) above the height of any obstruction (e.g. 
    vegetation, buildings, etc.) within a 500 foot (150 meter) radius. An 
    object is considered to be an obstruction if the included lateral angle 
    from the sensor to the ends of the object is 10 degrees or more.
        (iii) Road surface temperature shall be at least 125  deg.F 
    throughout the driving period. Pavement temperature shall be measured 
    and recorded in regular intervals of at least once per minute. The 
    track temperature may be measured with an embedded sensor, a portable 
    temperature probe, or an infrared pyrometer that can provide an 
    accuracy of 2  deg.F. Temperatures must be measured on a 
    surface representative of the surface where the vehicle is driven.
    * * * * *
        (4) Profile determination procedure. (i) Drain the fuel tank(s) and 
    fill with test fuel to the ``tank fuel volume'' defined in Sec. 86.082-
    2. The test fuel should meet the specifications of Sec. 86.113, except 
    that fuel with a lower volatility may be used, subject to Administrator 
    approval. Manufacturers using a lower volatility fuel must generate a 
    vapor temperature profile for demonstrating compliance with the limit 
    on fuel tank pressure during the running loss test (see Sec. 86.134-
    96).
        (ii) The vehicle shall be moved to the location where the data is 
    to be collected. It may be driven a maximum distance of 5 miles and may 
    also be transported by other means. The vehicle shall be stabilized by 
    one of the following methods:
        (A) The vehicle shall be parked for a minimum of 12 hours in an 
    open area on a surface that is representative of the test road, without 
    any artificial heating or cooling of the fuel. The orientation of the 
    front of the vehicle during parking (e.g., N, SW, etc.) shall be 
    documented.
        (B) The vehicle may be soaked in a temperature-controlled 
    environment to stabilize fuel temperatures. Before starting the drive, 
    the vehicle shall be stabilized with fuel temperatures 95 3 
     deg.F for at least one hour. The fuel temperature may not exceed 98 
    deg.F at any time before the beginning of the driving schedule, during 
    which only whole-vehicle heating and cooling may be used to control 
    fuel temperatures. If a manufacturer uses the provisions of paragraph 
    (d)(7)(v) of this section to establish a lower initial fuel temperature 
    for the running loss test, the fuel in the test vehicle may not be 
    stabilized at a temperature higher than the newly established initial 
    fuel temperature.
        (iii) Once the ambient conditions specified in paragraph (d)(3) of 
    this section are met and the vehicle has been stabilized according to 
    paragraph (d)(4)(ii) of this section, the vehicle's engine may be 
    started. The vehicle's air conditioning system (if so equipped) shall 
    be set to the ``normal'' air conditioning mode and adjusted to the 
    minimum discharge air temperature and high fan speed. Vehicles equipped 
    with automatic temperature controlled air conditioning systems shall be 
    set to operate in ``automatic'' temperature and fan modes with the 
    system set at 72  deg.F.
    * * * * *
        (7) * * *
        (iii) If all these requirements are met, the following calculations 
    shall be performed to determine a profile for liquid fuel temperatures 
    and, if applicable, for vapor temperatures:
    
    Ti,profile=Ti-To.
    
    Where:
    
        (A) Ti,profile=the series of temperatures that comprise the 
    relative temperature profile.
        (B) Ti=the series of observed liquid fuel or vapor 
    temperatures during the drive.
        (C) To=the liquid fuel or vapor temperature observed at the 
    start of the specified driving schedule.
        (iv) The relative temperature profile consists of the set of 
    temperatures at each 1-minute interval. If temperatures are sampled 
    more frequently than once per minute, the temperature data points may 
    represent a rolling average of temperatures sampled for up to one-
    minute intervals. If multiple valid test runs are conducted for any 
    model, then all the collected data shall be used to calculate a 
    composite profile, based on the average temperatures at each point. The 
    absolute temperature profile is determined by adding 95  deg.F (35 
    deg.C) to each point of the relative profile. Other methodologies for 
    developing corrected liquid fuel and vapor space temperature profiles 
    may be used if demonstrated to yield equivalent results and approved in 
    advance by the Administrator.
        (v) Manufacturers may use a lower initial fuel temperature for the 
    running loss test, if approved in advance by the Administrator. To 
    demonstrate the need for such an adjustment, manufacturers would be 
    expected to determine the maximum fuel temperature experienced by a 
    vehicle during an extended park or after driving one UDDS cycle when 
    exposed to the ambient conditions described in paragraph (d)(3) of this 
    section. To use this provision, 
    
    [[Page 43893]]
    manufacturers would have to show maximum fuel temperatures no greater 
    than 92  deg.F.
        22. Section 86.130-96 of subpart B is amended by revising figure 
    B96-10 at the end of the section and adding paragraph (e) to read as 
    follows:
    
    
    Sec. 86.130-96  Test sequence; general requirements.
    
    * * * * *
        (e) If tests are invalidated after collection of emission data from 
    previous test segments, the test may be repeated to collect only those 
    data points needed to complete emission measurements. Compliance with 
    emission standards may be determined by combining emission measurements 
    from different test runs. If any emission measurements are repeated, 
    the new measurements supersede previous values.
    
    BILLING CODE 6560-50-P
          
    
    [[Page 43894]]
        [GRAPHIC][TIFF OMITTED]TR23AU95.008
        
    
    
    BILLING CODE 6560-50-C
    
    [[Page 43895]]
    
        23. Section 86.131-96 of subpart B is amended by revising paragraph 
    (d) to read as follows:
    
    
    Sec. 86.131-96  Vehicle preparation.
    
    * * * * *
        (d) For vehicles to be tested for running loss emissions, prepare 
    the fuel tank(s) for measuring and recording the temperature and 
    pressure of the fuel tank as specified in Sec. 86.107-96 (e) and (f). 
    Measurement of vapor temperature is optional during the running loss 
    test. If vapor temperature is not measured, fuel tank pressure need not 
    be measured.
    * * * * *
        24. Section 86.132-96 of subpart B is amended by revising 
    paragraphs (c), (f), (h) introductory text, (h)(1)(i), (h)(2), (j) 
    introductory text, (j)(1) introductory text, (j)(1)(i), and (j)(1)(vi) 
    to read as follows:
    
    
    Sec. 86.132-96  Vehicle preconditioning.
    
    * * * * *
        (c)(1) Gasoline- and methanol-fueled vehicles shall be soaked for 
    at least 6 hours after being refueled. Petroleum-fueled diesel vehicles 
    and gaseous-fueled vehicles shall be soaked for at least 1 hour after 
    being refueled. Following this soak period, the test vehicle shall be 
    placed, either by being driven or pushed, on a dynamometer and operated 
    through one Urban Dynamometer Driving Schedule (UDDS), specified in 
    Sec. 86.115 and Appendix I of this part.
        (2) Once a test vehicle has completed the refueling and vehicle 
    soak steps specified in paragraphs (b) and (c)(1) of this section, 
    these steps may be omitted in subsequent testing with the same vehicle 
    and the same fuel specifications, provided the vehicle remains under 
    laboratory ambient temperature conditions for at least 6 hours before 
    starting the next test. In such cases, each subsequent test shall begin 
    with the preconditioning drive specified in this paragraph. The test 
    vehicle may not be used to set dynamometer horsepower.
    * * * * *
        (f)(1) Gasoline- and methanol-fueled vehicles. After completion of 
    the preconditioning drive, the vehicle shall be driven off the 
    dynamometer. The vehicle's fuel tank(s) shall be drained and then 
    filled with test fuel, as specified in Sec. 86.113, to the ``tank fuel 
    volume'' defined in Sec. 86.082-2. The vehicle shall be refueled within 
    1 hour after completion of the preconditioning drive. The fuel cap(s) 
    shall be installed within 1 minute after refueling. The vehicle shall 
    be parked within five minutes after refueling.
        (2) Petroleum-fueled diesel vehicles. Within five minutes after 
    completion after the preconditioning drive, the vehicle shall be driven 
    off the dynamometer and parked.
        (3) Gaseous-fueled vehicles. After completion of the 
    preconditioning drive, the vehicle shall be driven off the dynamometer. 
    Vehicle fuel tanks shall be refilled with fuel that meets the 
    specifications in Sec. 86.113. Fuel tanks shall be filled to a minimum 
    of 75% of service pressure for natural gas-fueled vehicles or a minimum 
    of 75% of available fill volume for liquefied petroleum gas-fueled 
    vehicles. Prior draining of the fuel tanks is not called for if the 
    fuel in the tanks already meets the specifications in Sec. 86.113. The 
    vehicle shall be parked within five minutes after refueling, or, in the 
    absence of refueling, within five minutes after completion of the 
    preconditioning drive.
    * * * * *
        (h) During the soak period for the three-diurnal test sequence 
    described in Sec. 86.130-96, evaporative canisters, if the vehicle is 
    so equipped, shall be preconditioned according to the following 
    procedure. For vehicles with multiple canisters in a series 
    configuration, the set of canisters must be preconditioned as a unit. 
    For vehicles with multiple canisters in a parallel configuration, each 
    canister must be preconditioned separately. If production evaporative 
    canisters are equipped with a functional service port designed for 
    vapor load or purge steps, the service port shall be used during 
    testing to precondition the canister. In addition, for model year 1998 
    and later vehicles equipped with refueling canisters, these canisters 
    shall be preconditioned for the three-diurnal test sequence according 
    to the procedure in paragraph (j)(1) of this section. If a vehicle is 
    designed to actively control evaporative or refueling emissions without 
    a canister, the manufacturer shall devise an appropriate 
    preconditioning procedure, subject to the approval of the 
    Administrator.
        (1)(i) Prepare the evaporative emission canister for the canister 
    purging and loading operation. The canister shall not be removed from 
    the vehicle, unless access to the canister in its normal location is so 
    restricted that purging and loading can only reasonably be accomplished 
    by removing the canister from the vehicle. Special care shall be taken 
    during this step to avoid damage to the components and the integrity of 
    the fuel system. A replacement canister may be temporarily installed 
    during the soak period while the canister from the test vehicle is 
    preconditioned.
    * * * * *
        (2) For methanol-fueled and flexible-fueled vehicles, canister 
    preconditioning shall be performed with a fuel vapor composition 
    representative of that which the vehicle would generate with the fuel 
    mixture used for the current test. Manufacturers shall develop a 
    procedure to precondition the evaporative canister, if the vehicle is 
    so equipped, for the different fuel. The procedure shall represent a 
    canister loading equivalent to that specified in paragraph (h)(1) of 
    this section and shall be approved in advance by the Administrator.
    * * * * *
        (j) For the supplemental two-diurnal test sequence described in 
    Sec. 86.130-96, one of the following methods shall be used to 
    precondition evaporative canisters during the soak period specified in 
    paragraph (g) of this section. For vehicles with multiple canisters in 
    a series configuration, the set of canisters must be preconditioned as 
    a unit. For vehicles with multiple canisters in a parallel 
    configuration, each canister must be preconditioned separately. In 
    addition, for model year 1998 and later vehicles equipped with 
    refueling canisters, these canisters shall be preconditioned for the 
    supplemental two-diurnal test sequence according to the procedure in 
    paragraph (j)(1) of this section. Canister emissions are measured to 
    determine breakthrough. Breakthrough is here defined as the point at 
    which the cumulative quantity of hydrocarbons emitted is equal to 2 
    grams.
        (1) Butane loading to breakthrough. The following procedure 
    provides for emission measurement in an enclosure. Breakthrough may 
    also be determined by measuring the weight gain of an auxiliary 
    evaporative canister connected downstream of the vehicle's canister, in 
    which case, the following references to the enclosure can be ignored. 
    The auxiliary canister shall be well purged prior to loading. If 
    production evaporative canisters are equipped with a functional service 
    port designed for vapor load or purge steps, the service port shall be 
    used during testing to precondition the canister.
        (i) Prepare the evaporative/refueling emission canister for the 
    canister loading operation. The canister shall not be removed from the 
    vehicle, unless access to the canister in its normal location is so 
    restricted that purging and loading can only reasonably be accomplished 
    by removing the canister from the vehicle. Special care shall be 
    
    [[Page 43896]]
    taken during this step to avoid damage to the components and the 
    integrity of the fuel system. A replacement canister may be temporarily 
    installed during the soak period while the canister from the test 
    vehicle is preconditioned.
    * * * * *
        (vi)(A) For gasoline-fueled vehicles, load the canister with a 
    mixture composed of 50 percent butane and 50 percent nitrogen by volume 
    at a rate of 40 grams butane per hour.
        (B) For methanol-fueled and flexible-fueled vehicles, canister 
    preconditioning shall be performed with a fuel vapor composition 
    representative of that which the vehicle would generate with the fuel 
    mixture used for the current test. Manufacturers shall develop a 
    procedure to precondition the evaporative canister, if the vehicle is 
    so equipped, for the different fuel.
    * * * * *
        25. Section 86.133-96 of subpart B is amended by revising 
    paragraphs (c), (h), and (i)(5) to read as follows:
    
    
    Sec. 86.133-96  Diurnal emission test.
    
    * * * * *
        (c) The test vehicle shall be exposed to ambient temperatures 
    cycled according to the profile specified in Sec. 86.133 and Appendix 
    II of this part.
        (1) Temperatures measured with the underbody temperature sensor 
    shall follow the profile with a maximum deviation of 3 deg. F at any 
    time and an average temperature deviation not to exceed 2 deg. F, where 
    the average deviation is calculated using the absolute value of each 
    measured deviation. In addition, the temperature from the sidewall 
    temperature sensors shall follow the profile with a maximum deviation 
    of 5 deg. F at any time.
        (2) Ambient temperatures shall be measured at least every minute. 
    Temperature cycling shall begin when time=0 minutes, as specified in 
    paragraph (i)(5) of this section.
    * * * * *
        (h) Prior to sampling for emissions and throughout the period of 
    cycled ambient temperatures, the mixing fan(s) shall circulate the air 
    at a rate of 0.80.2 cfm per cubic foot of ambient volume. 
    The mixing fan(s), plus any additional fans if needed, shall also 
    maintain a minimum wind speed of 5 mph (8 km/hr) under the fuel tank of 
    the test vehicle. The Administrator may adjust fan speed and location 
    to ensure sufficient air circulation around the fuel tank. The wind 
    speed requirement may be satisfied by consistently using a fan 
    configuration that has been demonstrated to maintain a broad 5-mph air 
    flow in the vicinity of the vehicle's fuel tank, subject to 
    verification by the Administrator.
        (i) * * *
        (5) Within 10 minutes of closing and sealing the doors, analyze 
    enclosure atmosphere for hydrocarbons and record. This is the initial 
    (time=0 minutes) hydrocarbon concentration, CHCi, required in 
    Sec. 86.143. Hydrocarbon emissions may be sampled continuously during 
    the test period.
    * * * * *
        26. Section 86.134-96 of subpart B is amended by revising 
    paragraphs (a), (f), (g)(1)(v), (g)(1)(vii), (g)(1)(viii), (g)(1)(xii) 
    introductory text, (g)(1)(xii)(A), (g)(1)(xiv), (g)(1)(xv), 
    (g)(1)(xvi), (g)(2)(v), (g)(2)(vii), (g)(2)(x), and (g)(2)(xii) and 
    adding paragraphs (g)(1)(xx)(C) and (g)(2)(xv) to read as follows:
    
    
    Sec. 86.134-96  Running loss test.
    
        (a) Overview. Gasoline- and methanol-fueled vehicles are to be 
    tested for running loss emissions during simulated high-temperature 
    urban driving; this test is not required for gaseous-fueled vehicles. 
    During operation, tank temperatures are controlled according to a 
    prescribed profile to simulate in-use conditions. If the vehicle is 
    determined to have exceeded the standard before the end of the running 
    loss test, the test may be terminated without invalidating the data. 
    The test can be run either in a sealed enclosure or with the point-
    source method, as specified in paragraph (g) of this section. 
    Measurement of vapor temperature is optional during the running loss 
    test; however, if testing by the Administrator shows that a vehicle has 
    exceeded an emission standard without measurement of vapor 
    temperatures, the manufacturer may, utilizing its own resources, 
    conduct subsequent testing on that vehicle to determine if the 
    exceedance is attributable to inadequate control of vapor temperatures.
    * * * * *
        (f) Temperature stabilization. Immediately after the hot transient 
    exhaust emission test, the vehicle shall be soaked in a temperature 
    controlled area for a maximum of 6 hours until the fuel temperature is 
    stabilized. The fuel may be heated or cooled to stabilize fuel 
    temperatures, but the fuel heating rate must not exceed 5 deg. F in any 
    1-hour interval during the soak period. A manufacturer may use a faster 
    heating rate or a longer period for stabilizing fuel temperatures if 
    the needed heating cannot be easily accomplished in the 6-hour period, 
    subject to Administrator approval.
        (1) Fuel temperatures must be held at 95 3 deg. F for 
    at least one hour before the start of the running loss test.
        (2) If a vehicle's fuel temperature profile has an initial 
    temperature lower than 95 deg. F, as described in Sec. 86.129-
    94(d)(7)(v), the fuel in the test vehicle must be stabilized to within 
    3 deg. F of that temperature for at least one hour before the start of 
    the running loss test.
        (g) Running loss test. * * *
        (1) Enclosure method. * * *
        (v) Fans shall be positioned as described in Secs. 86.107-96 (d) 
    and (h).
    * * * * *
        (vii) Connect the air intake equipment to the vehicle, if 
    applicable. This connection shall be made to minimize leakage.
        (viii) The temperature and pressure recording systems shall be 
    started. Measurement of vapor temperature is optional during the 
    running loss test. If vapor temperature is not measured, fuel tank 
    pressure need not be measured.
    * * * * *
        (xii) When the ambient temperature is 955 deg. F 
    (353 deg. C) and the fuel has been stabilized according to 
    paragraph (f) of this section, the running loss test may begin. Measure 
    the initial ambient temperature and pressure.
        (A) Analyze enclosure atmosphere for hydrocarbons and record. This 
    is the initial (time=0 minutes) hydrocarbon concentration, CHCi, 
    required in Sec. 86.143. Hydrocarbon emissions may be sampled 
    continuously during the test period.
    * * * * *
        (xiv) The ambient temperature shall be maintained at 
    955 deg. F (952 deg. F on average) during the 
    running loss test, measured at the inlet to the cooling fan in front of 
    the vehicle; it shall be recorded at least every 60 seconds.
        (xv) The fuel temperature during the dynamometer drive shall be 
    controlled to match the fuel tank temperature profile determined in 
    Sec. 86.129. Measured fuel temperatures must be within 
    3 deg. F of the target profile throughout the test run. 
    Vapor temperatures, if measured, must be within 5 deg. F of 
    the target profile during the first 4186 seconds of the running loss 
    test, and within 3 deg. F for the remaining 120 seconds of 
    the test run. For any vehicle complying with the test standards, vapor 
    temperatures may be higher than the specified tolerances without 
    invalidating test results. For testing by the Administrator, vapor 
    temperatures may be lower than the specified tolerances without 
    invalidating test results. If the test vehicle has more than one fuel 
    tank, the temperatures for both fuel tanks shall 
    
    [[Page 43897]]
    follow the target profiles determined in Sec. 86.129. The control 
    system shall be tuned and operated to provide smooth and continuous 
    tank temperature profiles that are representative of the on-road 
    profiles.
        (xvi) Tank pressure shall not exceed 10 inches of water at any time 
    during the running loss test unless a pressurized system is used and 
    the manufacturer demonstrates that vapor would not be vented to the 
    atmosphere upon fuel cap removal. A vehicle may exceed the pressure 
    limit for temporary periods during the running loss test, up to 10 
    percent of the total driving time, provided that the vehicle has 
    demonstrated conformance with the pressure limit during the entire 
    outdoor driving period specified in Sec. 86.129. Measurement of fuel 
    tank pressures will be considered valid only if vapor temperatures are 
    measured and controlled to the tolerances specified in paragraph 
    (g)(1)(xv) of this section.
    * * * * *
        (xx) * * *
        (C) Turn off all the fans specified in Sec. 86.107-96(d). Also, the 
    time that the vehicle's engine compartment cover is open for removal of 
    air intake equipment, if applicable, shall be minimized to avoid loss 
    of heat from the engine compartment.
    * * * * *
        (2) Point-source method. * * *
        (v) Fans shall be positioned as described in Sec. 86.107-96(d).
    * * * * *
        (vii) The temperature and pressure recording systems shall be 
    started. Measurement of vapor temperature is optional during the 
    running loss test. If vapor temperature is not measured, fuel tank 
    pressure need not be measured.
    * * * * *
        (x) The ambient temperature shall be maintained at 
    955 deg. F (952 deg. F on average) during the 
    running loss test, measured at the inlet to the cooling fan in front of 
    the vehicle; it shall be recorded at least every 60 seconds.
    * * * * *
        (xii) The tank pressure requirements described in paragraph 
    (g)(1)(xvi) of this section apply also to running loss testing by the 
    point source method.
    * * * * *
        (xv) At the end of the running loss test, turn off all the fans 
    specified in Sec. 86.107-96(d).
    * * * * *
        27. Section 86.138-90 of subpart B is amended by revising paragraph 
    (b) to read as follows:
    
    
    Sec. 86.138-90  Hot soak test.
    
    * * * * *
        (b) The enclosure doors shall be closed and sealed within two 
    minutes of engine shutdown and within seven minutes after the end of 
    the exhaust emission test. The steps after the end of the driving cycle 
    should be done as quickly as possible to minimize the time needed to 
    start the hot soak test.
    * * * * *
        28. Section 86.138-96 of subpart B is amended by revising 
    paragraphs (a)(2), (b)(2)(v)(A), and (b)(2)(viii) to read as follows:
    
    
    Sec. 86.138-96  Hot soak test.
        (a) * * *
        (2) Gaseous-fueled vehicles. Since gaseous-fueled vehicles are not 
    required to perform a running loss test, the hot soak test shall be 
    conducted within seven minutes after completion of the hot start 
    exhaust test.
        (b) * * *
        (2) * * *
        (v) * * *
        (A) Analyze the enclosure atmosphere for hydrocarbons and record. 
    This is the initial (time = 0 minutes) hydrocarbon concentration, 
    CHCi, required in Sec. 86.143. Hydrocarbon emissions may be 
    sampled continuously during the test period.
    * * * * *
        (viii) The vehicle shall enter the enclosure; the enclosure doors 
    shall be closed and sealed within 2 minutes of engine shutdown and 
    within seven minutes after the end of the running loss test.
    * * * * *
        29. Section 86.143-96 of subpart B is amended by revising 
    paragraphs (b)(1)(i) introductory text and equation, (b)(1)(i)(D), 
    (b)(2)(i)(B), and (b)(2)(ii)(B), adding paragraph (b)(1)(iii), and 
    removing and reserving paragraphs (b)(1)(i)(C) and (b)(1)(i)(E) to read 
    as follows:
    
    
    Sec. 86.143-96  Calculations; evaporative emissions.
    
    * * * * *
        (b) * * *
        (1) * * *
        (i) Methanol emissions:
        [GRAPHIC][TIFF OMITTED]TR23AU95.002
        
    Where:
    * * * * *
        (C) [Reserved].
        (D) VE=Volume of sample withdrawn, ft\3\. Sample volumes must 
    be corrected for differences in temperature to be consistent with 
    determination of Vn, prior to being used in the equation.
        (E) [Reserved].
    * * * * *
        (iii) For variable-volume enclosures, defined in 
    Sec. 86.107(a)(1)(i), the following simplified form of the hydrocarbon 
    mass change equation may be used:
    [GRAPHIC][TIFF OMITTED]TR23AU95.003
    
        (2) * * *
        (i) * * *
        (B) CH3OH= 37.71 g/ft\3\, density of pure vapor at 
    68 deg. F.
    * * * * *
        (ii) * * *
        (B) HC= 16.88 g/ft\3\, density of pure vapor at 
    68 deg. F (for hydrogen to carbon ratio of 2.3).
    * * * * *
        30. Section 86.146-96 of subpart B is amended by revising 
    paragraphs (f), (i)(1), and (i)(2) to read as follows:
    
    [[Page 43898]]
    
    
    
    Sec. 86.146-96  Fuel dispensing spitback procedure.
    
    * * * * *
        (f) Following the preconditioning drive, the vehicle shall be moved 
    or driven at minimum throttle to the refueling area.
    * * * * *
        (i) * * *
        (1) The fueling operation shall be started within 4 minutes after 
    the vehicle is turned off and within 8 minutes after completion of the 
    preconditioning drive. The average temperature of the dispensed fuel 
    shall be 655 deg. F (183 deg. C).
        (2) The fuel shall be dispensed at a rate of 9.80.3 
    gallons/minute (37.11.1 L/min) until the automatic shutoff 
    is activated.
    * * * * *
        31. Section 86.152-98 of subpart B is amended by revising paragraph 
    (a) to read as follows:
    
    
    Sec. 86.152-98  Vehicle preparation; refueling test.
    
        (a) Provide additional fittings and adapters, as required, to 
    accommodate a fuel drain at the lowest point possible in the tank(s) as 
    installed on the vehicle. The canister shall not be removed from the 
    vehicle, unless access to the canister in its normal location is so 
    restricted that purging and loading can only reasonably be accomplished 
    by removing the canister from the vehicle. Special care shall be taken 
    during this step to avoid damage to the components and the integrity of 
    the fuel system. A replacement canister may be temporarily installed 
    during the soak period while the canister from the test vehicle is 
    preconditioned.
    * * * * *
        32. Section 86.153-98 is amended by revising paragraphs (a) and 
    (c)(2) to read as follows:
    
    
    Sec. 86.153-98  Vehicle and canister preconditioning; refueling test.
    
        (a) Vehicle and canister preconditioning. Vehicles and vapor 
    storage canisters shall be preconditioned in accordance with the 
    preconditioning procedures for the supplemental two-diurnal evaporative 
    emissions test specified in Sec. 86.132-96 (a) through (j). For 
    vehicles equipped with non-integrated refueling emission control 
    systems, the canister must be loaded using the method involving butane 
    loading to breakthrough (see Sec. 86.132-96(j)(1)).
    * * * * *
        (c) * * *
        (2) To provide additional opportunity for canister purge, conduct 
    additional driving on a dynamometer, within one hour of completion of 
    the hot start exhaust test, by operating the test vehicle through one 
    UDDS, a 2 minute idle, two NYCCs, another 2 minute idle, another UDDS, 
    then another 2 minute idle (see Sec. 86.115-78 and Appendix I of this 
    part). Fifteen seconds after the engine starts, place the transmission 
    in gear. Twenty seconds after the engine starts, begin the initial 
    vehicle acceleration of the driving schedule. The transmission shall be 
    operated according to the specifications of Sec. 86.128-79 during the 
    driving cycles. The vehicle's air conditioner (if so equipped) shall be 
    turned off. Ambient temperature shall be controlled as specified in 
    Sec. 86.151-98. It is not necessary to monitor and/or control in-tank 
    fuel temperatures.
        (i) The fixed-speed fan specified in Sec. 86.135-94(b) may be used 
    for engine cooling. If a fixed-speed fan is used, the vehicle's hood 
    shall be opened.
        (ii) Alternatively, the roadspeed-modulated fan specified in 
    Sec. 86.107-96(d)(1) may be used for engine cooling. If a road-speed 
    modulated fan is used, the vehicle's hood shall be closed.
    * * * * *
        33. Section 86.154-98 is amended by revising paragraph (e)(3) to 
    read as follows:
    
    
    Sec. 86.154-98  Measurement procedure; refueling test.
    
    * * * * *
        (e) * * *
        (3) An electrical ground shall be attached to the vehicle. The 
    vehicle fuel filler cap shall be removed and the enclosure door shall 
    be closed and sealed within two minutes of cap removal. The FID (or 
    HFID) trace shall be allowed to stabilize.
    * * * * *
    
    Subpart G--[Amended]
    
        34. Section 86.608-90 of subpart G is amended by revising paragraph 
    (a)(2)(ii) to read as follows:
    
    
    Sec. 86.608-90  Test procedures.
    
        (a) * * *
        (2) * * *
        (ii) The manufacturer may measure the temperature of the test fuel 
    at other than the approximate mid-volume of the fuel tank, as specified 
    in Sec. 86.131-96(a) with only a single temperature sensor, and may 
    drain the test fuel from other than the lowest point of the tank, as 
    specified in Sec. 86.131-96(b), provided an equivalent method is used. 
    Equivalency documentation shall be maintained by the manufacturers and 
    shall be made available to the Administrator upon request. 
    Additionally, for any test vehicle that has remained under laboratory 
    ambient temperature conditions for at least 6 hours prior to testing, 
    the vehicle soak described in Sec. 86.132-96(c) may be eliminated upon 
    approval of the Administrator. In such cases, the vehicle shall be 
    operated through the preconditioning drive described in Sec. 86.132-
    96(c) immediately following the fuel drain and fill procedure described 
    in Sec. 86.132-96(b).
    * * * * *
        35. Section 86.608-98 of subpart G is amended by revising paragraph 
    (a)(2)(ii) to read as follows:
    
    
    Sec. 86.608-98  Test procedures.
    
        (a) * * *
        (2) * * *
        (ii) The manufacturer may measure the temperature of the test fuel 
    at other than the approximate mid-volume of the fuel tank, as specified 
    in Sec. 86.131-96(a) with only a single temperature sensor, and may 
    drain the test fuel from other than the lowest point of the tank, as 
    specified in Sec. 86.131-96(b) and Sec. 86.152-98(a), provided an 
    equivalent method is used. Equivalency documentation shall be 
    maintained by the manufacturers and shall be made available to the 
    Administrator upon request. Additionally, for any test vehicle that has 
    remained under laboratory ambient temperature conditions for at least 6 
    hours prior to testing, the vehicle soak described in Sec. 86.132-96(c) 
    may be eliminated upon approval of the Administrator. In such cases, 
    the vehicle shall be operated through the preconditioning drive 
    described in Sec. 86.132-96(c) immediately following the fuel drain and 
    fill procedure described in Sec. 86.132-96(b).
    * * * * *
    Subpart M--[Amended]
    
        36. Section 86.1207-96 of subpart M is amended by revising 
    paragraphs (a)(1) introductory text, (a)(1)(ii)(A), (a)(1)(ii)(B), 
    (a)(2), (a)(3)(i), (a)(3)(ii), (c)(1), (d), (e), and (f) to read as 
    follows:
    
    
    Sec. 86.1207-96  Sampling and analytical systems; evaporative 
    emissions.
    
        (a) Testing enclosures--(1) Diurnal emission test. The enclosure 
    shall be readily sealable, rectangular in shape, with space for 
    personnel access to all sides of the vehicle. When sealed, the 
    enclosure shall be gas tight in accordance with Sec. 86.1217-96. 
    Interior surfaces must be impermeable and nonreactive to hydrocarbons 
    (and to methanol, if the enclosure is used for methanol-fueled 
    vehicles). The temperature conditioning system shall 
    
    [[Page 43899]]
    be capable of controlling the internal enclosure air temperature to 
    follow the prescribed temperature versus time cycle as specified in 
    Sec. 86.1233-96 and Appendix II of this part, within an instantaneous 
    tolerance of 3.0  deg.F of the nominal temperature versus 
    time profile throughout the test, and an average tolerance of 2.0 
    deg.F over the duration of the test (where the average is calculated 
    using the absolute value of each measured deviation). The control 
    system shall be tuned to provide a smooth temperature pattern that has 
    a minimum of overshoot, hunting, and instability about the desired 
    long-term ambient temperature profile. Interior surface temperatures 
    shall not be less than 40  deg.F at any time during the diurnal 
    emission test. To accommodate the volume changes due to enclosure 
    temperature changes, either a variable-volume or fixed-volume enclosure 
    may be used for diurnal emission testing:
    * * * * *
        (ii) Fixed-volume enclosure. * * *
        (A) The enclosure shall be equipped with a mechanism to maintain a 
    fixed internal air volume. This may be accomplished either by 
    withdrawing air at a constant rate and providing makeup air as needed, 
    or by reversing the flow of air into and out of the enclosure in 
    response to rising or falling temperatures. If inlet air is added 
    continuously throughout the test, it should be filtered with activated 
    carbon to provide a relatively low and constant hydrocarbon level. Any 
    method of volume accommodation shall maintain the differential between 
    the enclosure internal pressure and the barometric pressure to a 
    maximum value of 2.0 inches of water.
        (B) The equipment shall be capable of measuring the mass of 
    hydrocarbon and methanol (if the enclosure is used for methanol-fueled 
    vehicles) in the inlet and outlet flow streams with a resolution of 
    0.01 gram per hour. A bag sampling system may be used to collect a 
    proportional sample of the air withdrawn from and admitted to the 
    enclosure. Alternatively, the inlet and outlet flow streams may be 
    continuously analyzed using an on-line FID analyzer and integrated with 
    the flow measurements to provide a continuous record of the mass 
    hydrocarbon and methanol removal.
        (2) Running loss test. The enclosure shall be readily sealable, 
    rectangular in shape, with space for personnel access to all sides of 
    the vehicle. When sealed, the enclosure shall be gas tight in 
    accordance with Sec. 86.1217-96. The enclosure may be equipped with a 
    personnel door, provided that the enclosure can still meet the 
    requirements of Sec. 86.1217-96 with the door installed. Interior 
    surfaces must be impermeable and nonreactive to hydrocarbons and to 
    methanol (if the enclosure is used for methanol-fueled vehicles). 
    Interior surface temperatures shall not be less than 40  deg.F. If a 
    running loss enclosure meets all the requirements of paragraph (a)(1) 
    of this section, it may be used as a diurnal evaporative emission 
    enclosure. The enclosure must contain a dynamometer that meets the 
    requirements of Sec. 86.1208. Provisions shall be made to remove 
    exhaust gases from the enclosure. During the running loss test, ambient 
    temperatures must be maintained at 955  deg.F 
    (952  deg.F on average). An air or oxygen cylinder with an 
    attached self-contained breathing apparatus may be provided for the 
    vehicle operator. The air required for vehicle operation shall be 
    provided by one of the following methods:
        (i) The running loss enclosure may be equipped to supply air to the 
    vehicle, at a temperature of 955 deg. F, from sources 
    outside of the running loss enclosure directly into the operating 
    engine's air intake system. Supplemental air requirements (e.g., for an 
    air pump) shall be supplied by drawing air from the engine intake 
    source.
        (ii) If it is shown to yield equivalent or superior results, the 
    running loss enclosure may be designed with an air makeup system that 
    brings outside air into the enclosure to accommodate the aspiration 
    needs of the engine and any auxiliary devices. The makeup air shall be 
    monitored to establish the background hydrocarbon levels (or 
    hydrocarbon and methanol, levels, if applicable) of the makeup air. A 
    filter may be used to provide dry air with a stable concentration of 
    background hydrocarbon. The makeup-air vent shall be readily sealable 
    for calibration of the enclosure and other purposes. For calculation of 
    running loss emissions, it may be assumed that the hydrocarbon and 
    methanol concentration in the air consumed by the vehicle is the same 
    as that of the rest of the air in the enclosure.
        (3) Hot soak test. * * *
        (i) If the hot soak test is conducted in the same enclosure as the 
    immediately preceding running loss test, interior surface temperatures 
    shall not be below 70 deg. F for the last 55 minutes of the hot soak 
    test.
        (ii) If the hot soak test is not conducted in the same enclosure as 
    the immediately preceding running loss test, interior surface 
    temperatures shall not be below 70 deg. F for the duration of the hot 
    soak test.
    * * * * *
        (c) Evaporative emission hydrocarbon and methanol data recording 
    system. (1) The electrical output of the FID used for measuring 
    hydrocarbons (or hydrocarbons plus methanol, as appropriate) shall be 
    recorded at least at the initiation and termination of each running 
    loss and hot soak test, and at least at the initiation and termination 
    of the enclosure sampling period(s) for the diurnal emission test, as 
    described in Sec. 86.1233. The recording may be taken by means of a 
    strip chart potentiometric recorder, by use of an on-line computer 
    system or other suitable means. In any case, the recording system must 
    have operational characteristics (signal-to-noise ratio, speed of 
    response, etc.) equivalent to or better than those of the signal source 
    being recorded, and must provide a permanent record of results. The 
    record shall show a positive indication of the initiation and 
    completion of each hot soak, running loss, or diurnal emission test 
    (including initiation and completion of sampling period(s)), along with 
    the time elapsed during each soak.
    * * * * *
        (d) Fuel temperature control system. Fuel temperatures of the test 
    vehicle shall be controlled, as specified in Sec. 86.1234(g)(1)(xv), 
    with the following combination of fans. The control system shall be 
    tuned and operated to provide a smooth and continuous fuel temperature 
    profile that is representative of the on-road temperature profile. The 
    running loss test configuration should be designed to avoid heating or 
    cooling the fuel tank's vapor space in a way that would cause vapor 
    temperature behavior to be unrepresentative of the vehicle's on-road 
    profile.
        (1) A vehicle cooling fan shall discharge air to the front of the 
    vehicle. The fan shall be a road-speed modulated fan that is controlled 
    to a discharge velocity that follows the dynamometer roll speed, at 
    least up to speeds of 30 mph, throughout the driving cycle. If a 
    warning light or gauge indicates that the vehicle's engine coolant has 
    overheated, subsequent test runs on the that vehicle must include a 
    vehicle cooling fan that follows the dynamometer roll speed at all 
    speeds throughout the test cycle. The fan may direct airflow to both 
    the vehicle radiator air inlet(s) and the vehicle underbody.
        (2) An additional fan may be used to discharge airflow from the 
    front of the vehicle directly to the vehicle underbody to control fuel 
    temperatures. 
    
    [[Page 43900]]
    Such a fan shall provide a total discharge airflow not to exceed 8,000 
    cfm.
        (3) Additional fans may be used to route heating or cooling air 
    directly at the bottom of the vehicle's fuel tank. The air supplied to 
    the tank shall be between 85 deg. and 160 deg. F, with a total 
    discharge airflow not to exceed 4,000 cfm. For exceptional 
    circumstances, manufacturers may direct up to 6,000 cfm at the bottom 
    of the fuel tank with the advance approval of the Administrator.
        (4) Direct fuel heating may be needed for canister preconditioning, 
    as specified in Sec. 86.1232(j)(2). Also, under exceptional 
    circumstances in which airflow alone is insufficient to control fuel 
    temperatures during the running loss test, direct fuel tank heating may 
    be used (see Sec. 86.1234-96(g)(1)(xv)). The heating system must not 
    cause hot spots on the tank wetted surface that could cause local 
    overheating of the fuel. Heat must not be applied directly to the 
    tank's vapor space, nor to the liquid-vapor interface.
        (e) Temperature recording system. A strip chart potentiometric 
    recorder, an on-line computer system, or other suitable means shall be 
    used to record enclosure ambient temperature during all evaporative 
    emission test segments, as well as vehicle fuel tank temperature during 
    the running loss test. The recording system shall record each 
    temperature at least once every minute. The recording system shall be 
    capable of resolving time to 15 s and capable of resolving 
    temperature to 0.75 deg. F (0.42 deg. C). The 
    temperature recording system (recorder and sensor) shall have an 
    accuracy of 3 deg. F (1.7 deg. C). The recorder 
    (data processor) shall have a time accuracy of 15 s and a 
    precision of 15 s. Enclosures shall be equipped with two 
    ambient temperature sensors, connected to provide one average output, 
    located 3 feet above the floor at the approximate mid-length of each 
    side wall of the enclosure and within 3 to 12 inches of each side wall. 
    For diurnal emission testing, an additional temperature sensor shall be 
    located underneath the vehicle to provide a temperature measurement 
    representative of the air temperature under the fuel tank. For running 
    loss testing, an ambient temperature sensor shall be located at the 
    inlet to the fan that provides engine cooling. Manufacturers shall 
    arrange that vehicles furnished for testing at federal certification 
    facilities be equipped with temperature sensors for measurement of fuel 
    tank temperatures. Vehicles shall be equipped with two temperature 
    sensors installed to provide an average liquid fuel temperature. The 
    temperature sensors shall be placed to measure the temperature at the 
    mid-volume of the liquid fuel at a fill level of 40 percent of nominal 
    tank capacity. An additional temperature sensor may be placed to 
    measure vapor temperatures approximately at the mid-volume of the vapor 
    space, though measurement of vapor temperatures is optional during the 
    running loss test. In-tank temperature sensors are not required for the 
    supplemental two-diurnal test sequence specified in Sec. 86.1230-96.
        (f) Pressure recording system. A strip chart potentiometric 
    recorder, an on-line computer system, or other suitable means, shall be 
    used to record the enclosure gage pressure for any testing in an 
    enclosure, as well as the vehicle's fuel tank pressure during the 
    running loss test and the outdoor driving procedure specified in 
    Sec. 86.1229-85(d). Fuel tank pressure measurement and recording 
    equipment are optional during the running loss test. The recording 
    system shall record each pressure at least once every minute. The 
    recording system shall be capable of resolving time to 15 s 
    and capable of resolving pressure to 0.1 inches of water. 
    The pressure recording system (recorder and sensor) shall have an 
    accuracy of 1.0 inch of water. The recorder (data 
    processor) shall have a time accuracy of 15 s and a 
    precision of 15 s. The pressure transducer shall be 
    installed to measure the pressure in the vapor space of the fuel tank.
    * * * * *
        37. Section 86.1217-96 of subpart M is amended by revising the 
    introductory text and paragraphs (a)(1)(ii), (a)(1)(iii), (a)(7), (b), 
    (c) heading, (c)(1) introductory text, (c)(1)(v), (c)(1)(vii), (d)(1) 
    introductory text and equation, (d)(1)(v), and (e)(1)(iii), adding 
    paragraphs (d)(1)(xiii), (d)(1)(xiv), and (d)(3), and removing and 
    reserving paragraphs (c)(1)(iv), (d)(1)(iii) and (d)(1)(iv) to read as 
    follows:
    Sec. 86.1217-96  Evaporative emission enclosure calibrations.
    
        The calibration of evaporative emission enclosures consists of 
    three parts: initial and periodic determination of enclosure background 
    emissions (hydrocarbons and methanol); initial determination of 
    enclosure internal volume; and periodic hydrocarbon and methanol 
    retention check and calibration. Methanol measurements may be omitted 
    if methanol-fueled vehicles will not be tested in the evaporative 
    enclosure. Alternate calibration methods may be used if shown to yield 
    equivalent or superior results, and if approved in advance by the 
    Administrator; specifically, more extreme temperatures may be used for 
    determining calibration without affecting the validity of test results.
        (a) Initial and periodic determination of enclosure background 
    emissions. * * *
        (1) * * *
        (ii) Fixed-volume enclosures may be operated with inlet and outlet 
    flow streams either closed or open; if inlet and outlet flow streams 
    are open, the air flowing into and out of the enclosure must be 
    monitored in accordance with Sec. 86.107-96(a)(1)(ii)(B). Ambient 
    temperatures shall be maintained at 963 deg. F throughout 
    the 4-hour period.
        (iii) For running loss enclosures ambient temperatures shall be 
    maintained at 953 deg. F throughout the 4-hour period. For 
    running loss enclosures designed with a vent for makeup air, the 
    enclosure shall be operated with the vent closed.
    * * * * *
        (7) Allow the enclosure to stand undisturbed for four hours.
    * * * * *
        (b) Initial determination of enclosure internal volume. Prior to 
    its introduction into service the enclosure internal volume shall be 
    determined by the following procedure:
        (1) Carefully measure the internal length, width and height of the 
    enclosure, accounting for irregularities (such as braces) and calculate 
    the internal volume. For variable-volume enclosures, latch the 
    enclosure to a fixed volume when the enclosure is held at a constant 
    temperature; this nominal volume shall be repeatable within 
    0.5 percent of the reported value.
        (2) [Reserved].
        (3) [Reserved].
        (c) Hydrocarbon and methanol (organic gas) retention check and 
    calibration. * * *
        (1) An enclosure to be used for the diurnal emission test (see 
    Sec. 86.1233-96) shall be calibrated according to the following 
    procedure. Calibration for hydrocarbon and methanol may be conducted 
    simultaneously or in sequential test runs.
    * * * * *
        (iv) [Reserved].
        (v) Turn on the ambient temperature control system (if not already 
    on) and adjust it for an initial temperature of 96 deg. F (36 deg. C). 
    On variable-volume enclosures, latch the enclosure to the appropriate 
    volume position for the set temperature. On fixed-volume enclosures 
    close the outlet and inlet flow streams.
    * * * * * 
    
    [[Page 43901]]
    
        (vii) Inject into the enclosure 2 to 6 grams of pure methanol at a 
    temperature of at least 150 deg. F (65 deg. C) and/or 2 to 6 grams of 
    pure propane. The injected quantity may be measured by volume flow or 
    by mass measurement. The method used to measure the quantity of 
    methanol and propane shall have an accuracy of 0.2 percent 
    of the measured value (less accurate methods may be used with the 
    advance approval of the Administrator).
    * * * * *
        (d) Calculations. (1) The calculation of net methanol and 
    hydrocarbon mass change is used to determine enclosure background and 
    leak rate. It is also used to check the enclosure volume measurements. 
    The methanol mass change is calculated from the initial and final 
    methanol samples, the net withdrawn methanol (in the case of diurnal 
    emission testing with fixed-volume enclosures), and initial and final 
    temperature and pressure according to the following equation:
    [GRAPHIC][TIFF OMITTED]TR23AU95.004
    
    Where:
    * * * * *
        (iii) [Reserved].
        (iv) [Reserved].
        (v) VE=Volume of sample withdrawn, ft3. Sample volumes 
    must be corrected for differences in temperature to be consistent with 
    determination of Vn, prior to being used in the equation.
    * * * * *
        (xiii) MCH3OH,out=mass of methanol exiting the enclosure, in 
    the case of fixed-volume enclosures for diurnal emission testing, 
    g.
        (xiv) MCH3OH,in=mass of methanol entering the enclosure, in 
    the case of fixed-volume enclosures for diurnal emission testing, 
    g.
    * * * * *
        (3) For variable-volume enclosures, defined in 
    Sec. 86.1207(a)(1)(i), the following simplified form of the hydrocarbon 
    mass change equation may be used:
    [GRAPHIC][TIFF OMITTED]TR23AU95.005
    
        (e) Calibration of equipment for point-source testing of running 
    losses. * * *
        (1) * * *
        (iii) Operate the vapor sampling system in the normal manner and 
    release a known quantity of pure propane into the most frequently used 
    fuel vapor collector during the sampling period (approximately 5 
    minutes).
    * * * * *
        38. Section 86.1229-85 of subpart M is amended by revising 
    paragraphs (d)(1), (d)(2)(iii), (d)(3)(ii), (d)(3)(iii), (d)(4)(i), 
    (d)(4)(ii), (d)(4)(iii), (d)(7)(iii), and (d)(7)(iv) and adding 
    paragraph (d)(7)(v) to read as follows:
    
    
    Sec. 86.1229-85  Dynamometer load determination and fuel temperature 
    profile.
    
    * * * * *
        (d) Fuel temperature profile--(1) General requirements. (i) To be 
    tested for running losses, as specified in Sec. 86.1234, a vehicle must 
    have a fuel temperature profile. The following procedure is used to 
    generate the fuel temperature profile, which serves as a target for 
    controlling fuel temperatures during the running loss test. This 
    profile represents the fuel temperature change that occurs during on-
    road driving. If a vehicle has more than one fuel tank, a profile shall 
    be established for each tank. Manufacturers may also simultaneously 
    generate a profile for vapor temperatures.
        (ii) If a manufacturer uses a vehicle model to develop a profile to 
    represent multiple models, the vehicle model selected must have the 
    greatest expected fuel temperature increase during driving of all those 
    models it represents. Also, manufacturers must select test vehicles 
    with any available vehicle options that increase fuel temperatures 
    during driving (for example, any feature that limits underbody 
    airflow).
        (iii) Manufacturers may conduct testing to develop fuel temperature 
    profiles in a laboratory setting, subject to approval by the 
    Administrator. The laboratory facility should simulate outdoor testing 
    to reproduce fuel and vapor temperature behavior over the specified 
    driving schedule. The design of the laboratory facility should include 
    consideration of any parameters that may affect fuel temperatures, such 
    as solar loading, pavement heat, and relative wind velocities around 
    and underneath the test vehicle. Indoor testing to develop the fuel 
    temperature profiles must be conducted with little or no vehicle-
    specific adjustment of laboratory parameters. Manufacturers would need 
    to maintain an ongoing demonstration of correlation between laboratory 
    and outdoor measurement of fuel temperatures. Specifically, fuel 
    temperatures and pressures from indoor driving should be at least as 
    high as measured when driving outdoors according to the procedures 
    described in this section.
        (iv) Small-volume manufacturers, as defined in Sec. 86.094-
    14(b)(1), may use an alternate method for generating fuel temperature 
    profiles, subject to the approval of the Administrator.
        (v) The Administrator may conduct testing to establish any 
    vehicle's temperature profiles or to verify compliance with fuel tank 
    pressure requirements.
        (2) * * *
        (iii) The data recording system described in paragraph (d)(2)(ii) 
    of this section shall be capable of resolving time to 1 s, 
    capable of resolving temperature to 2 deg. F, capable of 
    resolving pressure to 1.0 inch of water, and capable of 
    resolving speed to 1 mph. The temperature and pressure 
    signals shall be recorded at intervals of up to 1 minute; speed signals 
    shall be recorded at intervals of up to 1 second.
        (3) * * *
        (ii) Wind conditions shall be calm to light with maximum wind speed 
    of 15 mph. In the case of temporary gusting, wind speeds between 15 and 
    25 mph may occur for up to 5 percent of the total driving time without 
    invalidating the data collection. Wind speed shall be measured and 
    recorded in regular intervals of at least once per minute. Measure wind 
    speed with the following 
    
    [[Page 43902]]
    requirements (based on Federal Standard for Siting Meteorological 
    Sensors at Airports, FCM-S4-1987). The site should be relatively level, 
    but small gradual slopes are acceptable. The sensor shall be mounted 30 
    to 33 feet (9 to 10 meters) above the average ground height within a 
    radius of 500 feet (150 meters). The sensor height shall not exceed 33 
    feet, except as necessary to be at least 15 feet (5 meters) above the 
    height of any obstruction (e.g. vegetation, buildings, etc.) within a 
    500 foot (150 meter) radius. An object is considered to be an 
    obstruction if the included lateral angle from the sensor to the ends 
    of the object is 10 degrees or more.
        (iii) Road surface temperature shall be at least 125 deg. F 
    throughout the driving period. Pavement temperature shall be measured 
    and recorded in regular intervals of at least once per minute. The 
    track temperature may be measured with an embedded sensor, a portable 
    temperature probe, or an infrared pyrometer that can provide an 
    accuracy of 2 deg. F. Temperatures must be measured on a 
    surface representative of the surface where the vehicle is driven.
    * * * * *
        (4) Profile determination procedure. (i) Drain the fuel tank(s) and 
    fill with test fuel to the ``tank fuel volume'' defined in Sec. 86.082-
    2. The test fuel should meet the specifications of Sec. 86.1213, except 
    that fuel with a lower volatility may be used, subject to Administrator 
    approval. Manufacturers using a lower volatility fuel must generate a 
    vapor temperature profile for demonstrating compliance with the limit 
    on fuel tank pressure during the running loss test (see Sec. 86.1234-
    96).
        (ii) The vehicle shall be moved to the location where the data is 
    to be collected. It may be driven a maximum distance of 5 miles and may 
    also be transported by other means. The vehicle shall be stabilized by 
    one of the following methods:
        (A) The vehicle shall be parked for a minimum of 12 hours in an 
    open area on a surface that is representative of the test road, without 
    any artificial heating or cooling of the fuel. The orientation of the 
    front of the vehicle during parking (e.g., N, SW, etc.) shall be 
    documented.
        (B) The vehicle may be soaked in a temperature-controlled 
    environment to stabilize fuel temperatures. Before starting the drive, 
    the vehicle shall be stabilized with fuel temperatures 
    953 deg. F for at least one hour. The fuel temperature may 
    not exceed 98 deg. F at any time before the beginning of the driving 
    schedule, during which only whole-vehicle heating and cooling may be 
    used to control fuel temperatures. If a manufacturer uses the 
    provisions of paragraph (d)(7)(v) of this section to establish a lower 
    initial fuel temperature for the running loss test, the fuel in the 
    test vehicle may not be stabilized at a temperature higher than the 
    newly established initial fuel temperature.
        (iii) Once the ambient conditions specified in paragraph (d)(3) of 
    this section are met and the vehicle has been stabilized according to 
    paragraph (d)(4)(ii) of this section, the vehicle's engine may be 
    started. The vehicle's air conditioning system (if so equipped) shall 
    be set to the ``normal'' air conditioning mode and adjusted to the 
    minimum discharge air temperature and high fan speed. Vehicles equipped 
    with automatic temperature controlled air conditioning systems shall be 
    set to operate in ``automatic'' temperature and fan modes with the 
    system set at 72 deg. F.
    * * * * *
        (7) * * *
        (iii) If all these requirements are met, the following calculations 
    shall be performed to determine a profile for liquid fuel temperatures 
    and, if applicable, for vapor temperatures: Ti,profile=Ti-
    To.
    
    Where:
    
        (A) Ti,profile=the series of temperatures that comprise the 
    relative temperature profile.
        (B) Ti=the series of observed liquid fuel or vapor 
    temperatures during the drive.
        (C) To=the liquid fuel or vapor temperature observed at the 
    start of the specified driving schedule.
        (iv) The relative temperature profile consists of the set of 
    temperatures at each 1-minute interval. If temperatures are sampled 
    more frequently than once per minute, the temperature data points may 
    represent a rolling average of temperatures sampled for up to one-
    minute intervals. If multiple valid test runs are conducted for any 
    model, then all the collected data shall be used to calculate a 
    composite profile, based on the average temperatures at each point. The 
    absolute temperature profile is determined by adding 95 deg. F (35 deg. 
    C) to each point of the relative profile. Other methodologies for 
    developing corrected liquid fuel and vapor space temperature profiles 
    may be used if demonstrated to yield equivalent results and approved in 
    advance by the Administrator.
        (v) Manufacturers may use a lower initial fuel temperature for the 
    running loss test, if approved in advance by the Administrator. To 
    demonstrate the need for such an adjustment, manufacturers would be 
    expected to determine the maximum fuel temperature experienced by a 
    vehicle during an extended park or after driving one UDDS cycle when 
    exposed to the ambient conditions described in paragraph (d)(3) of this 
    section. To use this provision, manufacturers would have to show 
    maximum fuel temperatures no greater than 92 deg. F.
        39. Section 86.1230-96 of subpart M is amended by revising figure 
    M96-1 at the end of the section and adding paragraph (e) to read as 
    follows:
    
    
    Sec. 86.1230-96  Test sequence; general requirements.
    
    * * * * *
        (e) If tests are invalidated after collection of emission data from 
    previous test segments, the test may be repeated to collect only those 
    data points needed to complete emission measurements. Compliance with 
    emission standards may be determined by combining emission measurements 
    from different test runs. If any emission measurements are repeated, 
    the new measurements supersede previous values.
    
    BILLING CODE 6560-50-P
    
    [[Page 43903]]
    [GRAPHIC][TIFF OMITTED]TR23AU95.009
    
    
    
    BILLING CODE 6560-50-C
    
    [[Page 43904]]
    
        40. Section 86.1231-96 of subpart M is amended by revising 
    paragraph (d) to read as follows:
    
    
    Sec. 86.1231-96  Vehicle preparation.
    
    * * * * *
        (d) For vehicles to be tested for running loss emissions, prepare 
    the fuel tank(s) for measuring and recording the temperature and 
    pressure of the fuel tank as specified in Sec. 86.1207-96 (e) and (f). 
    Measurement of vapor temperature is optional during the running loss 
    test. If vapor temperature is not measured, fuel tank pressure need not 
    be measured.
    * * * * *
        41. Section 86.1232-96 of subpart M is amended by revising 
    paragraphs (c), (f), (h) introductory text, (h)(1)(i), (h)(2), (j) 
    introductory text, (j)(1) introductory text, (j)(1)(i), and (j)(1)(vi) 
    to read as follows:
    
    
    Sec. 86.1232-96  Vehicle preconditioning.
    
    * * * * *
        (c) Gasoline- and methanol-fueled vehicles shall be soaked for at 
    least 6 hours after being refueled. Gaseous-fueled vehicles shall be 
    soaked for at least 1 hour after being refueled. Following this soak 
    period, the test vehicle shall be placed, either by being driven or 
    pushed, on a dynamometer and operated through one Heavy-Duty Vehicle 
    Urban Dynamometer Driving schedule, specified in Sec. 86.1215 and 
    Appendix I of this part. Once a test vehicle has completed the 
    refueling and vehicle soak steps specified in paragraphs (b) and (c) of 
    this section, these steps may be omitted in subsequent testing with the 
    same vehicle and the same fuel specifications, provided the vehicle 
    remains under laboratory ambient temperature conditions for at least 6 
    hours before starting the next test. In such cases, each subsequent 
    test shall begin with the preconditioning drive specified in this 
    paragraph. The test vehicle may not be used to set dynamometer 
    horsepower.
    * * * * *
        (f)(1) Gasoline- and methanol-fueled vehicles. After completion of 
    the preconditioning drive, the vehicle shall be driven off the 
    dynamometer. The vehicle's fuel tank(s) shall be drained and then 
    filled with test fuel, as specified in Sec. 86.1213, to the ``tank fuel 
    volume'' defined in Sec. 86.082-2. The vehicle shall be refueled within 
    1 hour after completion of the preconditioning drive. The fuel cap(s) 
    shall be installed within 1 minute after refueling. The vehicle shall 
    be parked within five minutes after refueling.
        (2) Gaseous-fueled vehicles. After completion of the 
    preconditioning drive, the vehicle shall be driven off the dynamometer. 
    Vehicle fuel tanks shall be refilled with fuel that meets the 
    specifications in Sec. 86.1213. Fuel tanks shall be filled to a minimum 
    of 75% of service pressure for natural gas-fueled vehicles or a minimum 
    of 75% of available fill volume for liquefied petroleum gas-fueled 
    vehicles. Prior draining of the fuel tanks is not called for if the 
    fuel in the tanks already meets the specifications in Sec. 86.1213. The 
    vehicle shall be parked within five minutes after refueling, or, in the 
    absence of refueling, within five minutes after completion of the 
    preconditioning drive.
    * * * * *
        (h) During the soak period for the three-diurnal test sequence 
    described in Sec. 86.1230-96, evaporative canisters, if the vehicle is 
    so equipped, shall be preconditioned according to the following 
    procedure. For vehicles with multiple canisters in a series 
    configuration, the set of canisters must be preconditioned as a unit. 
    For vehicles with multiple canisters in a parallel configuration, each 
    canister must be preconditioned separately. If production evaporative 
    canisters are equipped with a functional service port designed for 
    vapor load or purge steps, the service port shall be used during 
    testing to precondition the canister. In addition, for model year 1998 
    and later vehicles equipped with refueling canisters, these canisters 
    shall be preconditioned for the three-diurnal test sequence according 
    to the procedure in paragraph (j)(1) of this section. If a vehicle is 
    designed to actively control evaporative or refueling emissions without 
    a canister, the manufacturer shall devise an appropriate 
    preconditioning procedure, subject to the approval of the 
    Administrator.
        (1)(i) Prepare the evaporative emission canister for the canister 
    purging and loading operation. The canister shall not be removed from 
    the vehicle, unless access to the canister in its normal location is so 
    restricted that purging and loading can only reasonably be accomplished 
    by removing the canister from the vehicle. Special care shall be taken 
    during this step to avoid damage to the components and the integrity of 
    the fuel system. A replacement canister may be temporarily installed 
    during the soak period while the canister from the test vehicle is 
    preconditioned.
    * * * * *
        (2) For methanol-fueled and flexible-fueled vehicles, canister 
    preconditioning shall be performed with a fuel vapor composition 
    representative of that which the vehicle would generate with the fuel 
    mixture used for the current test. Manufacturers shall develop a 
    procedure to precondition the evaporative canister, if the vehicle is 
    so equipped, for the different fuel. The procedure shall represent a 
    canister loading equivalent to that specified in paragraph (h)(1) of 
    this section and shall be approved in advance by the Administrator.
    * * * * *
        (j) For the supplemental two-diurnal test sequence described in 
    Sec. 86.1230-96, one of the following methods shall be used to 
    precondition evaporative canisters during the soak period specified in 
    paragraph (g) of this section. For vehicles with multiple canisters in 
    a series configuration, the set of canisters must be preconditioned as 
    a unit. For vehicles with multiple canisters in a parallel 
    configuration, each canister must be preconditioned separately. In 
    addition, for model year 1998 and later vehicles equipped with 
    refueling canisters, these canisters shall be preconditioned for the 
    supplemental two-diurnal test sequence according to the procedure in 
    paragraph (j)(1) of this section. Canister emissions are measured to 
    determine breakthrough. Breakthrough is here defined as the point at 
    which the cumulative quantity of hydrocarbons emitted is equal to 2 
    grams.
        (1) Butane loading to breakthrough. The following procedure 
    provides for emission measurement in an enclosure. Breakthrough may 
    also be determined by measuring the weight gain of an auxiliary 
    evaporative canister connected downstream of the vehicle's canister, in 
    which case, the following references to the enclosure can be ignored. 
    The auxiliary canister shall be well purged prior to loading. If 
    production evaporative canisters are equipped with a functional service 
    port designed for vapor load or purge steps, the service port shall be 
    used during testing to precondition the canister.
        (i) Prepare the evaporative/refueling emission canister for the 
    canister loading operation. The canister shall not be removed from the 
    vehicle, unless access to the canister in its normal location is so 
    restricted that purging and loading can only reasonably be accomplished 
    by removing the canister from the vehicle. Special care shall be taken 
    during this step to avoid damage to the components and the integrity of 
    the fuel system. A replacement canister may be temporarily installed 
    during the soak period while the canister from the test vehicle is 
    preconditioned.
    * * * * * 
    
    [[Page 43905]]
    
        (vi)(A) For gasoline-fueled vehicles, load the canister with a 
    mixture composed of 50 percent butane and 50 percent nitrogen by volume 
    at a rate of 40 grams butane per hour.
        (B) For methanol-fueled and flexible-fueled vehicles, canister 
    preconditioning shall be performed with a fuel vapor composition 
    representative of that which the vehicle would generate with the fuel 
    mixture used for the current test. Manufacturers shall develop a 
    procedure to precondition the evaporative canister, if the vehicle is 
    so equipped, for the different fuel.
    * * * * *
        42. Section 86.1233-96 of subpart M is amended by revising 
    paragraphs (c), (h), and (i)(5) to read as follows:
    
    
    Sec. 86.1233-96  Diurnal emission test.
    
    * * * * *
        (c) The test vehicle shall be exposed to ambient temperatures 
    cycled according to the profile specified in Sec. 86.1233 and Appendix 
    II of this part.
        (1) Temperatures measured with the underbody temperature sensor 
    shall follow the profile with a maximum deviation of 3 deg. F at any 
    time and an average temperature deviation not to exceed 2 deg. F, where 
    the average deviation is calculated using the absolute value of each 
    measured deviation. In addition, the temperature from the sidewall 
    temperature sensors shall follow the profile with a maximum deviation 
    of 5 deg. F at any time.
        (2) Ambient temperatures shall be measured at least every minute. 
    Temperature cycling shall begin when time=0 minutes, as specified in 
    paragraph (i)(5) of this section.
    * * * * *
        (h) Prior to sampling for emissions and throughout the period of 
    cycled ambient temperatures, the mixing fan(s) shall circulate the air 
    at a rate of 0.80.2 cfm per cubic foot of ambient volume. 
    The mixing fan(s), plus any additional fans if needed, shall also 
    maintain a minimum wind speed of 5 mph (8 km/hr) under the fuel tank of 
    the test vehicle. The Administrator may adjust fan speed and location 
    to ensure sufficient air circulation around the fuel tank. The wind 
    speed requirement may be satisfied by consistently using a fan 
    configuration that has been demonstrated to maintain a broad 5-mph air 
    flow in the vicinity of the vehicle's fuel tank, subject to 
    verification by the Administrator.
        (i) * * *
        (5) Within 10 minutes of closing and sealing the doors, analyze 
    enclosure atmosphere for hydrocarbons and record. This is the initial 
    (time=0 minutes) hydrocarbon concentration, CHCi, required in 
    Sec. 86.1243. Hydrocarbon emissions may be sampled continuously during 
    the test period.
    * * * * *
        43. Section 86.1234-96 of subpart M is amended by revising 
    paragraphs (a), (f), (g)(1)(v), (g)(1)(vii), (g)(1)(viii), (g)(1)(xii) 
    introductory text, (g)(1)(xii)(A), (g)(1)(xiv), (g)(1)(xv), 
    (g)(1)(xvi), (g)(2)(v), (g)(2)(vii), (g)(2)(x), and (g)(2)(xii) and 
    adding paragraphs (g)(1)(xx)(C) and (g)(2)(xv) to read as follows:
    
    
    Sec. 86.1234-96  Running loss test.
    
        (a) Overview. Gasoline- and methanol-fueled vehicles are to be 
    tested for running loss emissions during simulated high-temperature 
    urban driving; this test is not required for gaseous-fueled vehicles. 
    During operation, tank temperatures are controlled according to a 
    prescribed profile to simulate in-use conditions. If the vehicle is 
    determined to have exceeded the standard before the end of the running 
    loss test, the test may be terminated without invalidating the data. 
    The test can be run either in a sealed enclosure or with the point-
    source method, as specified in paragraph (g) of this section. 
    Measurement of vapor temperature is optional during the running loss 
    test; however, if testing by the Administrator shows that a vehicle has 
    exceeded an emission standard without measurement of vapor 
    temperatures, the manufacturer may, utilizing its own resources, 
    conduct subsequent testing on that vehicle to determine if the 
    exceedance is attributable to inadequate control of vapor temperatures.
    * * * * *
        (f) Temperature stabilization. Immediately after the hot transient 
    exhaust emission test, the vehicle shall be soaked in a temperature 
    controlled area for a maximum of 6 hours until the fuel temperature is 
    stabilized. The fuel may be heated or cooled to stabilize fuel 
    temperatures, but the fuel heating rate must not exceed 5 deg. F in any 
    1-hour interval during the soak period. A manufacturer may use a faster 
    heating rate or a longer period for stabilizing fuel temperatures if 
    the needed heating cannot be easily accomplished in the 6-hour period, 
    subject to Administrator approval.
        (1) Fuel temperatures must be held at 953 deg. F for at 
    least one hour before the start of the running loss test.
        (2) If a vehicle's fuel temperature profile has an initial 
    temperature lower than 95 deg. F, as described in Sec. 86.1229-
    85(d)(7)(v), the fuel in the test vehicle must be stabilized to within 
    3 deg. F of that temperature for at least one hour before the start of 
    the running loss test.
        (g) Running loss test. * * *
        (1) Enclosure method. * * *
        (v) Fans shall be positioned as described in Secs. 86.1207-96 (d) 
    and (h).
    * * * * *
        (vii) Connect the air intake equipment to the vehicle, if 
    applicable. This connection shall be made to minimize leakage.
        (viii) The temperature and pressure recording systems shall be 
    started. Measurement of vapor temperature is optional during the 
    running loss test. If vapor temperature is not measured, fuel tank 
    pressure need not be measured.
    * * * * *
        (xii) When the ambient temperature is 955 deg. F 
    (353 deg. C) and the fuel has been stabilized according to 
    paragraph (f) of this section, the running loss test may begin. Measure 
    the initial ambient temperature and pressure.
        (A) Analyze enclosure atmosphere for hydrocarbons and record. This 
    is the initial (time=0 minutes) hydrocarbon concentration, CHCi, 
    required in Sec. 86.1243. Hydrocarbon emissions may be sampled 
    continuously during the test period.
    * * * * *
        (xiv) The ambient temperature shall be maintained at 
    955 deg. F (952 deg. F on average) during the 
    running loss test, measured at the inlet to the cooling fan in front of 
    the vehicle; it shall be recorded at least every 60 seconds.
        (xv) The fuel temperature during the dynamometer drive shall be 
    controlled to match the fuel tank temperature profile determined in 
    Sec. 86.1229. Measured fuel temperatures must be within 
    3 deg. F of the target profile throughout the test run. 
    Vapor temperatures, if measured, must be within 5 deg. F of 
    the target profile during the first 4186 seconds of the running loss 
    test, and within 3 deg. F for the remaining 120 seconds of 
    the test run. For any vehicle complying with the test standards, vapor 
    temperatures may be higher than the specified tolerances without 
    invalidating test results. For testing by the Administrator, vapor 
    temperatures may be lower than the specified tolerances without 
    invalidating test results. If the test vehicle has more than one fuel 
    tank, the temperatures for both fuel tanks shall follow the target 
    profiles determined in Sec. 86.1229. The control system shall be tuned 
    and operated to provide smooth and continuous tank temperature profiles 
    that are representative of the on-road profiles.
        (xvi) Tank pressure shall not exceed 10 inches of water at any time 
    during 
    
    [[Page 43906]]
    the running loss test unless a pressurized system is used and the 
    manufacturer demonstrates that vapor would not be vented to the 
    atmosphere upon fuel cap removal. A vehicle may exceed the pressure 
    limit for temporary periods during the running loss test, up to 10 
    percent of the total driving time, provided that the vehicle has 
    demonstrated conformance with the pressure limit during the entire 
    outdoor driving period specified in Sec. 86.1229. Measurement of fuel 
    tank pressures will be considered valid only if vapor temperatures are 
    measured and controlled to the tolerances specified in paragraph 
    (g)(1)(xv) of this section.
    * * * * *
        (xx) * * *
        (C) Turn off all the fans specified in Sec. 86.1207-96(d). Also, 
    the time that the vehicle's engine compartment cover is open for 
    removal of air intake equipment, if applicable, shall be minimized to 
    avoid loss of heat from the engine compartment.
    * * * * *
        (2) Point-source method. * * *
        (v) Fans shall be positioned as described in Sec. 86.1207-96(d).
    * * * * *
        (vii) The temperature and pressure recording systems shall be 
    started. Measurement of vapor temperature is optional during the 
    running loss test. If vapor temperature is not measured, fuel tank 
    pressure need not be measured.
    * * * * *
        (x) The ambient temperature shall be maintained at 
    955 deg. F (952 deg. F on average) during the 
    running loss test, measured at the inlet to the cooling fan in front of 
    the vehicle; it shall be recorded at least every 60 seconds.
    * * * * *
        (xii) The tank pressure requirements described in paragraph 
    (g)(1)(xvi) of this section apply also to running loss testing by the 
    point source method.
    * * * * *
        (xv) At the end of the running loss test, turn off all the fans 
    specified in Sec. 86.1207-96(d).
    * * * * *
        44. Section 86.1238-90 of subpart M is amended by revising 
    paragraph (i) to read as follows:
    
    
    Sec. 86.1238-90  Hot soak test.
    
    * * * * *
        (i) The enclosure doors shall be closed and sealed within two 
    minutes of engine shutdown and within seven minutes after the end of 
    the exhaust emission test. The steps after the end of the driving cycle 
    should be done as quickly as possible to minimize the time needed to 
    start the hot soak test.
    * * * * *
        45. Section 86.1238-96 of subpart M is amended by revising 
    paragraphs (a)(2), (b)(2)(v)(A), and (b)(2)(viii) to read as follows:
    
    
    Sec. 86.1238-96  Hot soak test.
    
        (a) * * *
        (2) Gaseous-fueled vehicles. Since gaseous-fueled vehicles are not 
    required to perform a running loss test, the hot soak test shall be 
    conducted within seven minutes after completion of the hot start 
    exhaust test.
        (b) * * *
        (2) * * *
        (v) * * *
        (A) Analyze the enclosure atmosphere for hydrocarbons and record. 
    This is the initial (time = 0 minutes) hydrocarbon concentration, 
    CHCi, required in Sec. 86.1243. Hydrocarbon emissions may be 
    sampled continuously during the test period.
    * * * * *
        (viii) The vehicle shall enter the enclosure; the enclosure doors 
    shall be closed and sealed within 2 minutes of engine shutdown and 
    within seven minutes after the end of the running loss test.
    * * * * *
        46. Section 86.1243-96 of subpart M is amended by revising 
    paragraphs (b)(1)(i) introductory text and equation, (b)(1)(i)(D), 
    (b)(2)(i)(B), and (b)(2)(ii)(B), adding paragraph (b)(1)(iii), and 
    removing and reserving paragraphs (b)(1)(i)(C) and (b)(1)(i)(E) to read 
    as follows:
    
    
    Sec. 86.1243-96  Calculations; evaporative emissions.
    
    * * * * *
        (b) * * *
        (1) * * *
        (i) Methanol emissions:
        [GRAPHIC][TIFF OMITTED]TR23AU95.006
        
    Where:
    * * * * *
        (C) [Reserved].
        (D) VE=Volume of sample withdrawn, ft3. Sample volumes 
    must be corrected for differences in temperature to be consistent with 
    determination of Vn, prior to being used in the equation.
        (E) [Reserved].
    * * * * *
        (iii) For variable-volume enclosures, defined in 
    Sec. 86.1207(a)(1)(i), the following simplified form of the hydrocarbon 
    mass change equation may be used:
    [GRAPHIC][TIFF OMITTED]TR23AU95.007
    
        (2) * * *
        (i) * * *
        (B) CH3OH= 37.71 g/ft3, density of pure vapor at 
    68 deg. F.
    * * * * *
        (ii) * * *
        (B) HC= 16.88 g/ft3, density of pure vapor at 
    68 deg. F (for hydrogen to carbon ratio of 2.3).
    * * * * *
        47. Section 86.1246-96 of subpart M is amended by revising 
    paragraphs (f), (i)(1), and (i)(2) to read as follows:
    
    
    Sec. 86.1246-96  Fuel dispensing spitback procedure.
    
    * * * * *
        (f) Following the preconditioning drive, the vehicle shall be moved 
    or driven at minimum throttle to the refueling area.
    * * * * *
        (i) * * *
    
    [[Page 43907]]
    
        (1) The fueling operation shall be started within 4 minutes after 
    the vehicle is turned off and within 8 minutes after completion of the 
    preconditioning drive. The average temperature of the dispensed fuel 
    shall be 655 deg. F (183 deg. C).
        (2) The fuel shall be dispensed at a rate of 9.80.3 
    gallons/minute (37.11.1 l/min) until the automatic shutoff 
    is activated.
    * * * * *
    [FR Doc. 95-18255 Filed 8-22-95; 8:45 am]
    BILLING CODE 6560-50-P