[Federal Register Volume 65, Number 34 (Friday, February 18, 2000)]
[Rules and Regulations]
[Pages 8275-8280]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-1091]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 86

[FRL-6523-7]


Amendments to the Test Procedures for Heavy-Duty Engines, and 
Light-Duty Vehicles and Trucks and Amendments to the Emission Standard 
Provisions for Gaseous Fueled Vehicles and Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: On September 5, 1997 EPA promulgated a direct final rulemaking 
that amended several sections of the heavy-duty engine test procedure 
regulations. EPA also published a notice of proposed rulemaking 
proposing the same amendments. EPA noted that if adverse comments were 
received regarding any provisions, EPA would withdraw those provisions 
and comments would be addressed in a later final rule based on the 
proposed rule. Due to adverse comments that were received regarding 
three provisions, EPA issued a final rule on May 4, 1998 withdrawing 
those three provisions and indicated that they would be addressed in a 
separate action. Today, EPA is finalizing those three provisions with 
amendments, after taking into consideration comments received during 
the comment period and further discussions with heavy-duty engine and 
light-duty vehicle manufacturers.

EFFECTIVE DATE: March 20, 2000.

ADDRESSES: Materials relevant to this rulemaking are contained in 
Docket No. A-96-07, and are available for public inspection and 
photocopying between 8 a.m. and 5:30 p.m. Monday through Friday. EPA 
may charge a reasonable fee for copying docket materials.

FOR FURTHER INFORMATION CONTACT: Chuck Moulis, U.S. EPA, Engine 
Programs and Compliance Division, 2000 Traverwood Dr, Ann Arbor, MI 
48105. Telephone 734-214-4826.

SUPPLEMENTARY INFORMATION:

Table of Contents

I.  Regulatory Revisions
II.  Administrative Designation and Regulatory Analysis
III.  Regulatory Flexibility
IV.  Unfunded Mandates
V.  Paperwork Reduction Act
VI.  Submission to Congress and the General Accounting Office
VII.  Federalism
VIII.  Consultation and Coordination With Indian Tribal Governments
IX.  Protection of Children
X.  National Technology Transfer and Advancement Act
XI.  Copies of Rulemaking Documents

I. Regulatory Revisions

    On September 5, 1997, EPA published a direct final rule (62 FR 
47114) and accompanying notice of proposed rule (62 FR 46937) making 
amendments to the test procedures for heavy-duty engines and light duty 
vehicles and trucks. Although EPA believed that the action was non-
controversial, adverse comments were received from the Engine 
Manufacturers Association (EMA) and from the American Automobile 
Manufacturers Association (AAMA). As a result of receiving the adverse 
comments, EPA published a final rule (63 FR 24446) on May 4, 1998 that 
withdrew the three provisions on which adverse comments were received. 
After taking into consideration EMA and AAMA's comments and also 
discussing the issues and options, today's action addresses the three 
provisions. The paragraphs below describe the comments received for 
each issue, followed by EPA's response.

a. Cycle Verification at Idle Conditions

    Both of the comments received by EPA referred to changes made to 
Sec. 86.1333-90. In Sec. 86.1333-90 EPA provided a new requirement for 
cycle verification at idle conditions. The new requirement stated that 
for idle segments that are seven seconds or longer, the average 
feedback torque must fall within 10 ft-lb of the Curb Idle 
Transmission Torque (CITT). Both EMA and AAMA commented that current 
dynamometer systems utilized might not be capable of controlling torque 
to this specification and thus the time period might have to be 
lengthened or modifications made to dynamometer control systems. Both 
EMA and AAMA recommended to change the idle segment specification from 
seven to ten seconds. According to EMA and AAMA, such change would not 
impact emissions and would allow manufacturers to comply with the CITT 
requirements without having to make extensive modifications to engine 
dynamometers control systems.
    EPA agrees that making modifications to engine dynamometer systems 
to meet the proposed CITT requirements would be not only burdensome but 
also very costly. Furthermore, EPA agrees that increasing the idle 
segment length specification from seven to ten seconds will not impact 
emissions. Thus, EPA agrees with EMA and AAMA's recommendation and the 
final rule will apply the CITT requirement to segments of ten seconds 
or longer.

b. Critical Flow Venturi

    In the September 5, 1997 final rule (62 FR 47114) EPA revised 
sections 86.119-90, 86.1319-84 and 86.1319-90 to require manufacturers 
to verify that the critical flow venturi is achieving critical flow 
when using a CFV-CVS sampling system during the emissions test. Both 
EMA and AAMA commented that, even though they agree with the technical 
merits of such requirement, more lead time would be needed to make the 
software and hardware changes necessary. Thus EMA and AAMA recommended 
that, in order to provide sufficient time for the implementation of 
this new requirement, that EPA provides an 18 month lead time.
    EPA recognizes that this new requirement will require software 
changes to current testing facilities and that more lead time would be 
needed to ensure that all the manufacturer's testing facilities comply 
at the same

[[Page 8276]]

time. Thus, EPA will not require that this provision be met until 
August 20, 2001 to allow manufacturers to make the software and 
hardware changes needed for compliance. EPA is not finalizing the 
change to Sec. 86.1319-84 because this section is not applicable to 
future model years.

c. Light-duty Diesel Cetane Number Specifications

    On August 21, 1990 (55 FR 34120), EPA promulgated a final rule that 
established new requirements related to the quality of diesel fuel. As 
part of that rule EPA changed the cetane number specification to 40-48 
and established a cetane index specification of 40-48. In the 1994 
Gaseous Fuels Rule (59 FR 48472), modifications to the section 
specifying certification fuel parameters for light-duty vehicles and 
trucks resulted in inadvertent changes to the cetane number 
specifications from 40-48 to 42-50. In the September 5, 1997 notice, 
EPA proposed to correct the light-duty diesel fuel cetane 
specifications contained in section 86.113-94. In its comments, AAMA 
expressed concern that proposed correction would not provide sufficient 
lead time for manufacturers to comply. In addition, they stated that 
since diesel hydrocarbon emissions are sensitive to cetane levels, 
changing the cetane level of the test fuel could cause in-use 
compliance issues in the future. EMA and AAMA recommended EPA to keep 
the current 42-50 cetane specification for light-duty certification 
fuel.
    EPA continues to believe that the current cetane number 
specification of 42-50 is not correct since it does not include fuels 
with cetane numbers/indices in the range of 40 to 42. Such fuels 
represent a significant portion of in-use fuels, and should be included 
as potential test fuels. EPA believes that it is necessary to change 
the specifications to include this lower range. However, EPA has 
analyzed the most recently available data for in-use fuels and has 
determined that fuels with cetane numbers/indices in the range of 48 to 
50 are also representative of in-use fuels. As a result, EPA is 
finalizing a broad specification that includes both fuels with cetane 
numbers/indices in the range of 40 to 42 and fuels with cetane numbers/
indices in the range of 48 to 50. EPA is applying this broad 
specification to both light-duty and heavy-duty fuels.

II. Administrative Designation and Regulatory Analysis

    Under Executive Order 12866, the Agency must determine whether this 
regulatory action is ``significant and therefore subject to Office of 
Management and Budget (OMB) review and the requirements of the 
Executive Order. The Order defines ``significant'' regulatory action as 
one that is likely to result in a rule that may:
    (1) have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local or tribal governments or communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Pursuant to the terms of Executive Order 12866, EPA has determined 
that this action is not a ``significant'' regulatory action within the 
meaning of the Executive Order an is therefore not subject to OMB 
review.

III. Regulatory Flexibility

    EPA has determined that it is not necessary to prepare a regulatory 
flexibility analysis in connection with this final rule. In support of 
its proposed rule entitled Control of Emissions of Air Pollution from 
Highway Heavy-Duty Engines (61 FR 33421, June 27, 1996), EPA 
characterized the heavy-duty engine manufacturing industry in Chapter 3 
of its Regulatory Impact Analysis (RIA). Based on that 
characterization, EPA has determined that this action will not have a 
significant impact on a substantial number of small entities.

IV. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a written statement to accompany any rule where the 
estimated costs to State, local, or tribal governments, or to the 
private sector will be $100 million or more in any one year. Under 
section 205, EPA must select the most cost-effective and least 
burdensome alternative that achieves the objective of the rule and that 
is consistent with statutory requirements. Section 203 requires EPA to 
establish a plan for informing and advising any small governments that 
may be significantly and uniquely impacted by the rule. EPA has 
determined that the costs to State, local, or tribal governments, or 
the private sector, from this rule will be less than $100 million.

V. Paperwork Reduction Act

    The technical amendments promulgated by this action do not create 
or change the information collection burden under the provisions of the 
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The Office of 
Management and Budget (OMB) has previously approved the information 
collection requirements already contained in all the Part 86 sections 
amended by this action and has assigned OMB control numbers 2060-0104 
and 2060-0064.

VI. Submission to Congress and the General Accounting Office

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a report which includes a copy of the rule, to 
each House of Congress and to the Comptroller General of the United 
States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives and the Comptroller General of the General Accounting 
Office prior to publication of this rule in the Federal Register. This 
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

VII. Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    Under Section 6 of Executive Order 13132, EPA may not issue a 
regulation that has federalism implications, that imposes substantial 
direct compliance costs, and that is not required by statute, unless 
the Federal government provides the funds necessary to pay the direct 
compliance costs incurred by State and local governments, or EPA 
consults with State and local officials early in the process of 
developing the proposed regulation. EPA also may not issue a regulation 
that has federalism

[[Page 8277]]

implications and that preempts State law, unless the Agency consults 
with State and local officials early in the process of developing the 
proposed regulation.
    This final rule does not have federalism implications. It will not 
have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. This rule only revises the 
emissions testing requirements that are part of EPA's existing 
regulation of new motor vehicles and new motor vehicle engines and only 
affects the manufacturers of such vehicles and engines. Thus, the 
requirements of section 6 of the Executive Order do not apply to this 
rule.

VIII. Consultation and Coordination With Indian Tribal Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of Indian tribal governments ``to provide meaningful 
and timely input in the development of regulatory policies on matters 
that significantly or uniquely affect their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. Accordingly, the requirements 
of section 3(b) of Executive Order 13084 do not apply to this rule.

IX. Protection of Children

    Executive Order 13045, entitled ``Protection of Children from 
Environmental Health Risks and Safety Risks'' (62FR19885, April 23, 
1997) applies to any rule that: (1) is determined to be ``economically 
significant'' as defined under Executive Order 12866, and (2) concerns 
an environmental health or safety risk that EPA has reason to believe 
may have a disproportionate effect on children. If the regulatory 
action meets both criteria, the Agency must evaluate the environmental 
health or safety effects of the planned rule on children, and explain 
why the planned regulation is preferable to other potentially effective 
and reasonably feasible alternatives considered by the Agency.
    EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that are based on health or safety risks, such that 
the analysis required under section 5-501 of the Order has the 
potential to influence the regulation. This rule is not subject to 
Executive Order 13045 because it does not establish an environmental 
standard intended to mitigate health or safety risks.

X. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law. 104-113, section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless doing so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    EPA has continued to incorporate ASTM test methods in this rule. 
EPA is not aware of any voluntary consensus standards which are 
inconsistent with the regulations promulgated in this rule.

XI. Copies of Rulemaking Documents

    Electronic copies of the preamble and the regulatory text of this 
rule are available via the Internet on the Office of Mobile Sources 
(OMS) Home Page (http://www.epa.gov/oms). This service is free of 
charge, except for any cost you already incur for Internet 
connectivity. The official Federal Register version is made available 
on the day of publication on the primary Web site (http://www.epa.gov/docs/fedrgstr/EPA-AIR/).
    Please note that due to differences between the software used to 
develop the documents and the software into which the documents may be 
downloaded, changes in format, page length, etc., may occur.

List of Subjects in 40 CFR Part 86

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Labeling, Motor vehicle pollution, 
Reporting and recordkeeping requirements.

    Dated: January 10, 2000.
Carol M Browner,
Administrator.

    For the reasons set forth in the preamble, part 86 of chapter I of 
title 40 of the Code of Federal Regulations is amended as follows:

PART 86--CONTROL OF EMISSIONS FROM NEW AND IN--USE HIGHWAY VEHICLES 
AND ENGINES

    1. The authority citation for part 86 continues to read as follows:

    Authority: 42 U.S.C. 7401-7671q.

Subpart B--[Amended]

    2. Section 86.113-94 is amended by revising the table in paragraph 
(b)(2) to read as follows:


Sec. 86.113-94  Fuel specifications.

* * * * *
    (b) * * *
    (2) * * *

----------------------------------------------------------------------------------------------------------------
               Item                                             ASTM test method No.            Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane number.....................                            D 613                     40-50
Cetane index......................                            D 976                     40-50
Distillation range:
  IBP.............................   deg.F                    D 86                      340-400
                                    ( deg.C)                                            (171.1-204.4)
  10 pct. point...................   deg.F                    D 86                      400-460

[[Page 8278]]

 
                                    ( deg.C)                                            (204.4-237.8)
  50 pct. point...................   deg.F                    D 86                      470-540
                                    ( deg.C)                                            (243.3-282.2)
  90 pct. point...................   deg.F                    D 86                      560-630
                                    ( deg.C)                                            (293.3-332.2)
  EP..............................   deg.F                    D 86                      610-690
                                    ( deg.C)                                            (321.1-365.6)
Gravity...........................   deg.API                  D 287                     32-37
Total sulfur......................  pct.                      D 2622                    0.03-0.05
Hydrocarbon composition:
  Aromatics, minimum..............  pct.                      D 1319                    27
  Paraffins, Naphthenes, Olefins..                            D 1319                    1
Flashpoint, min...................   deg.F                    D 93                      130
                                    ( deg.C)                                            (54.4)
Viscosity.........................  centistokes               D 445                     2.0-3.2
----------------------------------------------------------------------------------------------------------------
[1] Remainder.

* * * * *

    3. Section 86.119-90 is amended by revising paragraph (b)(3) and 
adding paragraph (b)(8) to read as follows:


Sec. 86.119-90  CVS calibration.

* * * * *
    (b) * * *
    (3) Measurements necessary for flow calibration are as follows:

                                                              Calibration Data Measurements
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Parameter                                   Symbol                              Units                           Tolerances
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected)........  Pb........................................  Inches Hg (kPa).........  .01 in Hg (.034
                                                                                                                kPa)
Air temperature, flowmeter.............  ETI.......................................   deg.F ( deg.C).........  .25 deg.F (.14
                                                                                                                deg.C)
Pressure depression upstream of LFE....  EPI.......................................  Inches H2O (kPa)........  .05 in H2O (.012
                                                                                                                kPa)
Pressure drop across LFE matrix........  EDP.......................................  Inches H2O (kPa)........  .005 in H2O (.001
                                                                                                                kPa)
Air flow...............................  Qs........................................  Ft3/min. (m3/min,)......  .5 pct
CFV inlet depression...................  PPI.......................................  Inches fluid (kPa)......  .13 in fluid (.055 kPa)
CFV outlet pressure....................  PPO.......................................  Inches Hg (kPa).........  0.05 in. Hg (0.17
                                                                                                                kPa)1
Temperature at venturi inlet...........  Tv........................................   deg.F ( deg.C).........  0.5 deg.F (0.28
                                                                                                                deg.C)
Specific gravity of manometer fluid      Sp. Gr....................................  ........................  .........................................
 (1.75 oil).
--------------------------------------------------------------------------------------------------------------------------------------------------------
1 Requirement begins August 20, 2001.

* * * * *
    (8) Calculation of a parameter for monitoring sonic flow in the CFV 
during exhaust emissions tests:
    (i) Option 1. (A) CFV pressure ratio. Based upon the calibration 
data selected to meet the criteria for paragraphs (d)(7) (iv) and (v) 
of this section, in which Kv is constant, select the data 
values associated with the calibration point with the lowest absolute 
venturi inlet pressure. With this set of calibration data, calculated 
the following CFV pressure ratio limit, Prratio-lim:
[GRAPHIC] [TIFF OMITTED] TR18FE00.022



Where:

Pin-cal = Venturi inlet pressure (PPI in absolute pressure 
units), and

Pout-cal = Venturi outlet pressure (PPO in absolute pressure 
units), measured at the exit of the venturi diffuser outlet.

    (B) The venturi pressure ratio (Prratio-i) during all 
emissions tests must be less than, or equal to, the calibration 
pressure ratio limit (Prratio-lim) derived from the CFV 
calibration data, such that:
[GRAPHIC] [TIFF OMITTED] TR18FE00.023



Where:
Pin-i and Pout-i are the venturi inlet and outlet 
pressures, in absolute pressure units, at each i-th interval during the 
emissions test.

    (ii) Option 2. Other methods: With prior Administrator approval, 
any other method may be used that assure that the venturi operates at 
sonic conditions during emissions tests, provided the method is based 
upon sound engineering principles.
* * * * *

Subpart N--[Amended]

    4. Section 86.1313-98 is amended by revising Table N98-2 in 
paragraph (b)(2) to read as follows:


Sec. 86.1313-98  Fuel specifications.

* * * * *
    (b)(2) * * *

                                                 Table.--N 98-2
----------------------------------------------------------------------------------------------------------------
             Item                                       ASTM test method No.      Type 1-D          Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number.................                         D 613                             40-54             40-50
Cetane Index..................                         D 976                             40-54             40-50
Distillation range:
  IBP.........................   deg.F                 D 86                            330-390           340-400

[[Page 8279]]

 
                                ( deg.C)                                         (165.6-198.9)     (171.1-204.4)
  10 pct. point...............   deg.F                 D 86                            370-430           400-460
                                ( deg.C)                                         (187.8-221.1)     (204.4-237.8)
  50 pct. point...............   deg.F                 D 86                            410-480           470-540
                                ( deg.C)                                         (210.0-248.9)     (243.3-282.2)
  90 pct. point...............   deg.F                 D 86                            460-520           560-630
                                ( deg.C)                                         (237.8-271-1)     (293.3-332.2)
  EP..........................   deg.F                 D 86                            500-560           610-690
                                ( deg.C)                                         (260.0-293.3)     (321.1-365.6)
Gravity.......................   deg.API               D 287                             40-44             32-37
Total sulfur..................  pct.                   D 2622                        0.03-0.05         0.03-0.05
Hydrocarbon composition:
  Aromatics, minimum..........  pct.                   D 5186                                8                27
  Paraffins, Naphthenes,                               D 1319                                1                 1
   Olefins.
Flashpoint, min...............   deg.F                 D 93                                120               130
                                ( deg.C)                                                (48.9)            (54.4)
Viscosity.....................  centistokes            D 445                           1.6-2.0          2.0-3.2
----------------------------------------------------------------------------------------------------------------
1 Remainder.

* * * * *
    5. Section 86.1319-90 is amended by revising paragraph (d)(3) and 
adding paragraph (d)(8) to read as follows:


Sec. 86.1319-90  CVS calibration.

* * * * *
    (d) * * *
    (3) Measurements necessary for flow calibration are as follows:

                                          Calibration Data Measurements
----------------------------------------------------------------------------------------------------------------
            Parameter                     Symbol                Units             Sensor-readout tolerances
----------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected).  Pb                      in Hg (kPa)......  .01 in Hg (.034 kPa).
Air temperature, into flowmeter.  ETI                      deg.F ( deg.C)..  0.5  deg.F (.28  deg.C).
Pressure drop between the inlet   EDP                     Inches H2O (kPa).  0.05 in H2O (.012 kPa).
Air flow........................  Qs                      Ft3/min. (m3/min)  .5 % of NBS ``true''
                                                                              value.
CFV inlet depression............  PPI                     Inches fluid       .13 in fluid (.055 kPa).
CFV outlet pressure.............  PPO                     Inches Hg (kPa)..  .05 in Hg (.17 kPa) 1.
Temperature at venturi inlet....  Tv                       deg.F ( deg.C)..  4.0  deg.F (2.22  deg.C).
Specific gravity of manometer     Sp. Gr
 fluid (1.75 oil).
----------------------------------------------------------------------------------------------------------------
1 Requirement begins August 20, 2001.

* * * * *
    (8) Calculation of a parameter for monitoring sonic flow in the CFV 
during exhaust emissions tests:
    (i) Option 1. (A) CFV pressure ratio. Based upon the calibration 
data selected to meet the criteria for paragraphs (d)(7)(iv) and (v) of 
this section, in which Kv is constant, select the data 
values associated with the calibration point with the lowest absolute 
venturi inlet pressure. With this set of calibration data, calculated 
the following CFV pressure ratio limit, Prratio-lim:
      
    [GRAPHIC] [TIFF OMITTED] TR18FE00.024
    

Where:
Pin-cal = Venturi inlet pressure (PPI in absolute pressure 
units), and
Pout-cal = Venturi outlet pressure (PPO in absolute pressure 
units), measured at the exit of the venturi diffuser outlet.

    (B) The venturi pressure ratio (Prratio-i) during all 
emissions tests must be less than, or equal to, the calibration 
pressure ratio limit (Prratio-lim) derived from the CFV 
calibration data, such that:
[GRAPHIC] [TIFF OMITTED] TR18FE00.025



Where:
Pin-i and Pout-i are the venturi inlet and outlet 
pressures, in absolute pressure units, at each i-th interval during the 
emissions test.

    (ii) Option 2. Other methods: With prior Administrator approval, 
any other method may be used that assure that the venturi operates at 
sonic conditions during emissions tests, provided the method is based 
upon sound engineering principles.
* * * * *

    6. Section 86.1333-90 is amended by revising paragraph (d) to read 
as follows:


Sec. 86.1333-90  Transient test cycle generation.

* * * * *
    (d) Idle Speed Enhancement Devices (e.g. cold idle, alternator 
idle, etc.). For an engine equipped with an idle speed enhancement 
device, the zero percent speed specified in the engine dynamometer 
schedules (appendix I (f)(1), (f)(2), or (f)(3) to this part) does not 
apply. The idle speed shall be the speed that results from the proper 
operation of the engine's idle speed enhancement device.
    (1) During idle speed enhancement device operation, a manual 
transmission engine shall be allowed to idle at whatever speed is 
required to target a feedback torque equal to zero (using, for example, 
clutch disengagement, speed to torque control switching, software 
overrides, etc.) at those points in appendix I(f)(1), (f)(2), or (f)(3) 
to this part where both reference speed and reference torque are zero 
percent values. For each idle segment that is ten

[[Page 8280]]

seconds or longer, the average feedback torque must be within 
10 ft-lbs of zero. To allow for transition, up to the first 
four seconds may be deleted from each idle segment calculation.
    (2) During idle speed enhancement device operation, an automatic 
transmission engine shall be allowed to idle at whatever speed is 
required to target a feedback torque equal to CITT (see paragraph 
(e)(2) of this section for definition of CITT) at those points in 
appendix I(f)(1), (f)(2), or (f)(3) to this part where both reference 
speed and reference torque are zero percent values. For each idle 
segment that is ten seconds or longer, the average feedback torque must 
be within 10 ft-lbs of CITT. To allow for transition, up to 
the first four seconds may be deleted from each idle segment 
calculation.
* * * * *
[FR Doc. 00-1091 Filed 2-17-00; 8:45 am]
BILLING CODE 6560-50-P