[Federal Register Volume 60, Number 25 (Tuesday, February 7, 1995)]
[Proposed Rules]
[Pages 7404-7424]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2833]




[[Page 7403]]

_______________________________________________________________________

Part IX





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 86



Proposed Regulations for Revisions to The Federal Test Procedure for 
Emissions From Motor Vehicles; Proposed Rule

  Federal Register / Vol. 60, No. 25 / Tuesday, February 7, 1995 / 
Proposed Rules   
[[Page 7404]] 

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 86

[FRL-5150-1]
RIN 2060-AE27


Proposed Regulations for Revisions to the Federal Test Procedure 
for Emissions From Motor Vehicles

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking (NRPM).

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SUMMARY: This notice proposes additions and revisions to the tailpipe 
emission portions of the Federal Test Procedure (FTP) for light-duty 
vehicles (LDVs) and light-duty trucks (LDTs). The primary new element 
of the proposal is a Supplemental Federal Test Procedure (SFTP) 
designed to address shortcomings with the current FTP in the 
representation of aggressive (high speed and/or high acceleration) 
driving behavior, rapid speed fluctuations, driving behavior following 
startup, air conditioning, and intermediate-duration periods where the 
engine is turned off. An element of the SFTP that also affects the 
conventional FTP is a new set of requirements designed to more 
accurately reflect real road forces on the test dynamometer. The Agency 
is also proposing new emission standards for the new control areas with 
a specified phase-in period for these standards. After complete fleet 
turnovers, the standards proposed today are estimated to reduce 
emissions from LDVs and LDTs by eight percent for non-methane 
hydrocarbons (NMHC), 18 percent for carbon monoxide (CO), and 14 
percent for oxides of nitrogen (NOX).

DATES: Written comments on this NPRM must be submitted on or before 30 
days after the public hearing date. The Agency will conduct a public 
hearing on this NPRM approximately March 24, 1995. The date of the 
public hearing will be published in a future Federal Register document.

ADDRESSES: Interested parties may submit written comments (in duplicate 
if possible) to Public Docket No. A-92-64, at: Air Docket Section, U.S. 
Environmental Protection Agency, 401 M Street SW, Washington, DC 20460. 
The public hearing will be held at a location to be published in a 
future Federal Register document.
    Materials relevant to this proposed rulemaking have been placed in 
Docket No. A-92-64. The docket is located at the above address in Room 
M-1500, Waterside Mall, and may be inspected weekdays between 8:30 a.m. 
and 5:30 p.m. A reasonable fee may be charged by EPA for copying docket 
materials.

FOR FURTHER INFORMATION CONTACT: John German, Certification Division, 
U.S. Environmental Protection Agency, National Vehicle and Fuel 
Emissions Laboratory, 2565 Plymouth Road, Ann Arbor, Michigan, 48105. 
Telephone (313) 668-4214.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Obtaining Copies of the Regulatory Language
II. Introduction
III. Proposal Requirements and Alternative Approaches
IV. Statutory Authority and Legal Analysis
V. The FTP Review Project and Areas of EPA Concern
VI. In-Use Behavior
VII. Representative Driving Cycles
VIII. Emission Inventory Assessments
IX. Cause and Control of Emissions
X. Other Options and Information Needed
XI. Environmental and Economic Impacts
XII. Public Participation
XIII. Administrative Designation
XIV. Regulatory Flexibility Act
XV. Reporting and Recordkeeping Requirement

I. Obtaining Copies of the Regulatory Language

    Electronic copies (on 3.5'' diskettes) of both the proposed 
regulatory language and the Support Document to the Proposed 
Regulations for Revisions to the Federal Test Procedure: Detailed 
Discussion and Analysis, Regulatory Impact Analysis (RIA), and 
Technical Reports may be obtained free of charge by visiting, calling, 
or writing the Environmental Protection Agency, Certification Division, 
2565 Plymouth Road, Ann Arbor, MI 48105, (313) 668-4384. Refer to 
Docket A-92-64. A copy is available for inspection in the docket (See 
ADDRESSES).
    The proposed regulatory language and the Support Document to the 
Proposed Regulations for Revisions to the Federal Test Procedure: 
Detailed Discussion and Analysis, RIA, and Technical Reports are also 
available electronically on the Technology Transfer Network (TTN). TTN 
is an electronic bulletin board system (BBS) operated by EPA's Office 
of Air Quality Planning and Standards. Users are able to access and 
download TTN files on their first call. The steps required to access 
information on this rulemaking are listed below. The service is free, 
except for the cost of the phone call.

TTN BBS: 919-541-5742 (1,200-14,400 bps, no parity, eight data bits, 
one stop bit)
Voice help: 919-541-5384
Internet address: TELNET ttnbbs.rtpnc.epa.gov Off-line: Mondays from 
8:00-12:00 Noon ET

1. Technology Transfer Network Top Menu:  GATEWAY TO TTN TECHNICAL 
AREAS (Bulletin Boards) (Command: T)
2. TTN TECHNICAL INFORMATION AREAS:  OMS--Mobile Sources Information 
(Command: M)
3. OMS BBS === MAIN MENU FILE TRANSFERS:  Rulemaking & Reporting 
(Command: K)
4. RULEMAKING PACKAGES: <1> [Light-Duty] (Command: 1)
5. Light-duty Rulemaking Area: File area #1 ... FTP Review (Command: 1)

    At this stage, the system will list all available FTP Review files. 
To download a file, select a transfer protocol which will match the 
terminal software on your computer, then set your own software to 
receive the file using that same protocol.
    If unfamiliar with handling compressed (that is, ZIP'd) files, go 
to the TTN top menu, System Utilities (Command: 1) for information and 
the necessary program to download in order to unZIP the files of 
interest after downloading to your computer. After getting the files 
you want onto your computer, you can quit TTN BBS with the oodbye 
command.

II. Introduction

    Automobiles are among the largest producers of hydrocarbons (HC), 
carbon monoxide (CO), and oxides of nitrogen (NOX), all of which 
have documented impacts on public health. Hydrocarbons and oxides of 
nitrogen contribute to the formation of ozone, a powerful oxidant which 
irritates the respiratory system and reduces lung function. Some 
studies indicate that ozone may permanently damage lung and other 
tissues. Elevated levels of CO decrease the ability of blood to 
transport oxygen throughout the body, which tends to exacerbate 
cardiovascular stress. High ambient levels of CO can also adversely 
affect the central nervous system, and the presence of CO in even 
moderate levels in the bloodstream may impact the health of fetuses and 
newborns.\1\ After complete turnover of the fleet, the Agency believes 
that the changes proposed today would result in an eight percent 
reduction in non-methane hydrocarbons (NMHC), an 18 percent reduction 
in CO, and a 14 percent reduction in NOX emissions from 
[[Page 7405]] automobiles during typical summertime ozone exceedance 
days.

    \1\Regulatory Impact Analysis for FTP Revisions, U.S. EPA, 
Office of Air and Radiation. Available in the public docket for 
review.
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    The Agency has established a number of emission standards for motor 
vehicles and engines, designed to control air pollution by reducing in-
use emissions from motor vehicles. Compliance with these standards is 
typically measured using a test procedure that simulates in-use 
driving. In 1990, Congress amended the Clean Air Act with passage of 
the Clean Air Act Amendments (hereafter, CAAA or Amendments) and 
required that EPA review these test procedures and revise them as 
appropriate to reflect in-use conditions. The Agency's review focused 
on the procedures for light-duty motor vehicles, especially the Federal 
Test Procedure (FTP), the procedure used to measure compliance with 
motor vehicle tailpipe and evaporative emission standards.
    The Agency, in conjunction with automobile manufacturers and 
California's Air Resources Board (CARB), conducted an extensive review 
of in-use driving behavior, obtaining a wealth of data on how cars are 
driven during trips, the length of trips, the length of time between 
trips, and so on.2 The Agency then generated representative 
driving cycles from the data and conducted emission testing to compare 
emissions over these cycles with emissions over driving cycles used in 
the FTP. These results confirmed that revisions to the FTP were needed, 
as significant emissions were seen under conditions not represented by 
the current FTP.

    \2\See the ``Federal Test Procedure Review Project: Preliminary 
Technical Report,'' EPA 420-R-93-007 and the Technical Reports for 
this rulemaking, both in the public docket, for descriptions of the 
surveys and data gathered.
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    The Agency sought an approach which would extend the level of 
control found under current FTP conditions across all in-use driving 
behavior. Thus, EPA developed various changes to the FTP, focusing on 
new driving cycles to add to the current FTP. The Agency also 
investigated possible control technologies that could be used to 
control emissions over these new compliance cycles. Today's proposal 
includes these various changes in the test procedure for tailpipe 
emissions, as well as the emission standards related to them.
    In developing new compliance cycles, EPA did not re-evaluate the 
stringency of current standards. Rather, EPA sought parity between the 
types and extent of controls that manufacturers currently employ to 
comply with existing FTP standards and those they would implement to 
comply across all driving behavior. Thus, EPA believes that 
manufacturers for the most part will comply by making simple changes to 
their existing calibration strategies.

                                                 BILLING CODE 6560-50-P
[[Page 7406]]

[GRAPHIC][TIFF OMITTED]TP07FE95.000


BILLING CODE 6560-50-C
[[Page 7407]]

    The FTP is the core procedure used to measure compliance with 
emission standards for light-duty vehicles (LDVs) and light-duty trucks 
(LDTs). The current version of the FTP (40 CFR 86.130-96) consists of a 
series of preparatory steps to ensure the vehicle has been properly 
preconditioned on the test fuel, periods when the engine is off between 
vehicle operation (called ``soaks''), and emission tests which measure 
tailpipe and evaporative emissions. Tailpipe emissions are measured 
while the vehicle is operated according to a specified driving cycle on 
a dynamometer. Figure 1 presents the Urban Dynamometer Driving 
Schedule, commonly referred to as the LA4. With the exception of 
running losses, which are measured during dynamometer operation, 
evaporative emissions are measured in a sealed enclosure while the 
vehicle is turned off. An additional cold temperature CO test procedure 
measures tailpipe emissions at 20 deg. F following a cold soak. By 
comparing the emission test results to emission standards applicable to 
a given vehicle class, combustion cycle, and motor fuel, EPA determines 
if the vehicle meets applicable certification or in-use 
requirements.3

    \3\The Agency has historically relied on emission performance 
standards because they directly limit production of exhaust 
constituents that affect attainment of the National Ambient Air 
Quality Standards, while providing maximum flexibility to the 
vehicle manufacturers in determining cost-effective compliance 
strategies. Other basic compliance program approaches include system 
performance standards, which set bounds on measurable performance 
parameters of the engine or emission control system rather than 
actual emission levels, and design standards, which prescribe 
primary design elements of the engine or control system.
---------------------------------------------------------------------------

    The current evaporative emission procedure, including refueling, 
and cold temperature CO test procedures were promulgated following 
passage of the Amendments. Thus, the test procedures in these rules 
were recently developed to reflect the actual current driving 
conditions under which motor vehicles are used (57 FR 31888; 58 FR 
16002). The Agency is not proposing to change these test procedures and 
the remainder of this section and the subsequent proposal focuses on 
the light-duty tailpipe emission testing procedures of the FTP.
    The FTP simulates on-road vehicle operation using a dynamometer in 
a laboratory test cell held between 68 deg. F and 86 deg. F. The 
vehicle is driven on the dynamometer over cycles that prescribe the 
vehicle operator's speed as a function of time. The method for 
measuring tailpipe emissions of HC, CO, and NOx requires filling a 
bag with exhaust drawn from the tailpipe and diluted with background 
air while the vehicle is driven over the appropriate cycle. The bagged 
sample is analyzed for the concentrations of exhaust constituents, 
which serve as inputs to subsequent emission compliance calculations. 
Additional procedures apply to the sampling of particulate matter from 
diesel-cycle vehicles and organic gases from alternative-fuel vehicles.

III. Proposal Requirements and Alternative Approaches

    Today's proposal deals primarily with five areas of driving 
behavior that have not previously been represented in the test 
procedure: aggressive driving behavior (such as high acceleration rates 
and high speeds); rapid speed fluctuations (microtransient driving 
behavior); start driving behavior; intermediate soak times (engine-off 
times between 10 minutes and 2 hours prior to vehicle start); and 
actual air conditioner (A/C) operation. The Agency is proposing new 
requirements for these areas, separate from the existing FTP 
requirements. Also included in this proposal are requirements to 
improve the simulation of actual road load forces4 across all 
speed ranges and to revise the criteria for allowable speed variation 
for a valid test, which would be applicable both to the new provisions 
proposed in this NPRM and the existing FTP.

    \4\Road load forces refers to the force needed to overcome wind 
and tire resistance when driving at specific speeds.
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    As most of this proposal deals with areas that have not previously 
been regulated, the Agency is considering a broad range of alternative 
approaches and requests. Comment on the alternative approaches, as well 
as the central proposal, are requested. Depending on comments and data 
received and analyses conducted subsequent to today's proposals, EPA 
may include some of the alternatives, in whole or in part, in the final 
rule. Interested parties may also submit comments on alternatives not 
specifically identified or analyzed by EPA for this proposal.
    While both the central proposal and the alternatives are EPA's own 
design, they incorporate some concepts put forth both by the California 
Air Resources Board (CARB) and the Ad Hoc Panel on Revisions to the FTP 
(Ad Hoc Panel), a joint committee of the American Automobile 
Manufacturers Association (AAMA) and the Association of International 
Automobile Manufacturers (AIAM).
    The proposed additions and revisions to the tailpipe emission 
portions of the FTP would apply to all LDVs and LDTs, certifying on all 
current motor fuels. The proposed changes would apply to testing 
conducted during certification, Selective Enforcement Audits, and in-
use enforcement (recall). Adjustments are included to accommodate 
certain vehicle types, transmission types, and performance categories 
where the additions are not representative of in-use driving. The 
Agency solicits comments and data on the appropriate treatment of 
vehicles for which adjustments are allowed and the methods for making 
the adjustments.

A. Central Proposal

    The central proposal relies on a new Supplemental Federal Test 
Procedure (SFTP) that addresses various conditions under which vehicles 
are actually driven and used, which are not in the FTP. The SFTP 
includes three new driving cycles to represent (1) aggressive driving 
(as characterized by high speeds and/or high accelerations); (2) 
driving immediately following vehicle startup; and (3) microtransient 
driving (rapid speed fluctuations), which occur across the majority of 
the normal ranges of operating speeds and accelerations. The proposed 
SFTP incorporates conditions that are designed to more accurately 
reflect actual engine load due to A/C operation under typical ozone 
exceedance conditions. A new intermediate-duration (10- to 60-minute) 
soak period is also included.
    Two components of today's proposal have wider impacts than just the 
SFTP. The first is to more accurately simulate real on-road loads at 
the tire/dynamometer interface, which is an element of the proposal 
that affects dynamometer operation throughout both the FTP and SFTP. 
The second would remove language specifying ``minimal throttle 
movement'' when conducting emission tests and replace it with 
``appropriate throttle movement'' and require a specification of 
allowable speed variation, which also impacts both SFTP and FTP 
testing. The Agency is also requesting comment on whether the increased 
sophistication of vehicle computers necessitates replacing existing 
defeat device language with a requirement for proportional emission 
control under conditions not directly represented by the FTP and the 
SFTP.
    The proposed standards would apply for full useful life under 
section 202 of the Clean Air Act. The warranty provisions under section 
207 of the Clean Air Act also apply to this rulemaking. [[Page 7408]] 
    Supplementary Federal Test Procedure--The SFTP includes three 
single-bag emission test cycles: a hot stabilized 866 Cycle5 run 
with a new simulation of in-use A/C operation; a new Start Control 
Cycle (SC01, see figure 2) simulating driving with the new simulation 
of in-use A/C operation and proceeded by a soak period; and a new 
Aggressive Driving Cycle (US06, see figure 3) run in the hot stabilized 
condition. The cycles of the SFTP can be run as a sequence to save on 
preconditioning and setup time; however, separate runs of the cycles 
are permissible with the appropriate soak or preconditioning steps 
appended.

    \5\5 Refers to Bag 2 of the LA4, preceding the 10-minute hot 
soak, lasting 866 seconds.
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                                                 BILLING CODE 6560-50-P
[[Page 7409]]

[GRAPHIC][TIFF OMITTED]TP07FE95.001


[[Page 7410]]

[GRAPHIC][TIFF OMITTED]TP07FE95.002



BILLING CODE 6560-50-C
[[Page 7411]]

    Elements of the proposed A/C simulation for certification testing 
include, a 95 deg.F  5 deg.F test cell ambient temperature, 
A/C set to ``maximum A/C'' with interior air recirculation, high 
interior fan setting, coldest setting on the temperature slide, 
driver's window down, and front-end supplemental fan cooling. Although 
certification testing would occur at 95 deg., the compliance 
requirement would apply at less demanding temperatures as well. Thus, 
EPA confirmatory testing could take place at any point across the range 
68 deg.F to 95 deg.F. The compliance requirement would would The Agency 
proposes these conditions as a cost-effective surrogate for testing in 
a fully controlled environmental chamber set to simulate ozone-
exceedance conditions of ambient temperature, humidity, solar load, and 
pavement temperature, although the use of a fully controlled 
environmental chamber would be permitted.
    The required elements for the SC01 include the preconditioning, 
soak period, and compliance cycle requirements. Prior to the soak 
period, the vehicle is to be preconditioned to allow engine and 
catalyst temperatures to stabilize at typical warmed-up operating 
temperatures. The Agency believes that running the vehicle over EPA's 
Urban Dynamometer Driving Schedule (LA4) is adequate to achieve engine 
and catalyst stabilization regardless of the time period for which the 
vehicle was not operational prior to preconditioning. However, in the 
event the vehicle was shut off for less than two hours prior to 
preconditioning, the Agency believes that a 505 cycle is adequate for 
preconditioning the vehicle, although the 866 or the SC01 is also 
acceptable.
    Immediately following the preconditioning cycle, the vehicle will 
enter the soak period. Manufacturer testing of engine families required 
to comply with the intermediate soak requirements for certification or 
SEA testing must soak the vehicle for at least 60 minutes. EPA will 
have the option of testing any soak duration between 10 and 60 minutes 
for certification, SEA, and in-use testing. If the engine family is not 
required to meet the intermediate soak requirements, a 10-minute soak 
period is proposed. During this period, cooling fans directed at the 
vehicle are to be shut off. The vehicle may be removed from the 
dynamometer, provided the vehicle is not subjected to unrepresentative 
cooling of the engine or catalyst. Following the soak period, the 
vehicle will be run over the SC01 cycle using the proposed A/C 
simulation for proper representation of engine and catalyst warm-up and 
start driving.
    The US06 driving cycle is designed to be run in hot stabilized 
condition. High-volume exhaust flow for larger-displacement vehicles 
run on US06 dictates use of a larger-capacity constant volume sampler 
(CVS) than is needed for current FTP testing. The proposed A/C 
simulation is not required for this test cycle.
    The Agency proposes that manufacturers determine the appropriate 
shift points for their manual transmission applications and submit the 
shift schedules for EPA approval. In general, EPA will allow 
manufacturers to specify upshift points, but downshifting will not be 
permitted unless the vehicle is unable to stay within the driving 
tolerance on the speed trace in the existing gear.
    Hot stabilized condition is achieved by including several 
preconditioning options as part of the formal procedure immediately 
prior to the US06 Cycle. If the vehicle has undergone a soak of 2 hours 
or less, the preconditioning may be a 505 Cycle, the 866 Cycle, US06, 
or the SC01. Following longer soaks, the proposed preconditioning cycle 
is an LA4. For manufacturers who have concerns about fuel effects on 
adaptive memory systems, the proposal allows manufacturers, and upon 
manufacturer request, requires EPA to run the vehicle over the US06 
Cycle on the certification test fuel before entering the formal test 
procedure.
    The Agency proposes adjustments to the aggressive driving test 
cycle for all heavy light-duty trucks (HLDTs),6 and also, for some 
low- and high-performance LDVs and LDTs. The proposal calls for US06 
Cycle testing of HLDTs with the truck ballasted to curb weight plus 300 
lbs and the dynamometer inertia weight determined from this same basis, 
while FTP testing remains at Adjusted Loaded Vehicle Weight. The 
proposed US06 Cycle adjustments based on performance level are 
summarized in Table 1. For low performance vehicles, the inertia weight 
is adjusted by multiplying the original inertia weight by the 
adjustment factor which is equal to the ratio of the applicable 
performance cutoff and the W/P of the test vehicle. Where an adjustment 
factor is called for, it is applied dynamically by the dynamometer only 
during those portions of the US06 Cycle that are the most 
aggressive.7 No adjustment factors are proposed for mid-
performance (``normal'') vehicles. For high performance vehicles, the 
manufacturer must demonstrate stoichiometric control for wide-open 
throttle events of two seconds or less in order to ensure that these 
vehicles have aggressive driving emission control over similar vehicle 
operation as the rest of the fleet.

    \6\Light-duty trucks are divided into two weight categories 
known as light light-duty trucks (rated up through 6000-pounds Gross 
Vehicle Weight Rating (GVWR)) and heavy light-duty trucks (rated 
greater than 6000-pounds GVWR).
    \7\Refer to the Final Technical Report on Aggressive Driving 
Behavior for the Revised Federal Test Procedure Notice of Proposed 
Rulemaking for a detailed discussion of the points in the cycle 
where the proposed adjustments would be made.

                 Table 1.--Performance-Based Adjustments                
------------------------------------------------------------------------
  Transmission    Performance                                           
      type        (W/P range)                  Adjustment               
------------------------------------------------------------------------
manual.........  low            dynamic dynamometer inertia weight      
                 W/P>34          reduction.                             
                 normal         none.                                   
                 18 W/P 34                                              
                 high W/P<18    2 second stoich control.                
automatic......  low            dynamic dynamometer inertia weight      
                 W/P>31          reduction.                             
                 normal         none.                                   
                 18 W/P 31                                              
                 high           2 second stoich control.                
                 (W/P<18)                                               
------------------------------------------------------------------------

    Determining compliance with standards--With the exception of 
changes prompted by use of new dynamometers and an additional driver 
speed variation tolerance, no changes are proposed for the driving 
cycle of the conventional FTP. Similarly, EPA proposes to retain 
unchanged the method of calculating compliance with the existing FTP. 
However, an additional ``composite'' compliance calculation is proposed 
that brings together elements of the conventional FTP with results from 
the SFTP. In the composite calculation, emissions from the range of in-
use driving are appropriately weighted, summed, and compared to the 
proposed emission performance standards. For total hydrocarbon (THC), 
non-methane hydrocarbons (NMHC), organic material hydrocarbon 
equivalents (OMHCE), organic material non-methane hydrocarbon 
equivalents (OMNMHCE), and CO, the proposed standards are the same as 
the standards applicable under the conventional FTP; for NOX, an 
adjustment factor of 1.15 is applied to that standard to account for 
the emission response of vehicles to the new A/C test conditions. See 
the [[Page 7412]] Support Document to the Proposed Regulations for 
Revisions to the Federal Test Procedure: Detailed Discussion and 
Analysis for the specific numerical standards. Due to the absence of 
relevant test data on which to base a decision, no supplemental test 
procedures or standards are proposed for diesel particulate.
    Included in the composite calculation are a cold start bag (based 
on Bag 1 of the conventional FTP) and the three bags of the SFTP 
(called Bag 4, 5, and 6). The weighting factor for each of the four 
bags is adjusted as appropriate to reflect the proposed level of 
control for each type of driving in the SFTP. Because the exhaust 
constituents respond differently to the loads and speeds of the new 
SFTP cycles, the proposed levels of control and, thus, the weighting 
factors of the composite calculation differ somewhat for different 
pollutants. The proposed weighting factors are:

------------------------------------------------------------------------
                                                       Percentages      
                                               -------------------------
                                                  THC/NMHC     CO & NOX 
------------------------------------------------------------------------
Bag 1 (cold start from FTP)...................           21           15
Bag 4 (866 cycle from SFTP)...................           24           37
Bag 5 (SC01 from SFTP)........................           27           20
Bag 6 (US06 from SFTP)........................           28           28
------------------------------------------------------------------------

    The Agency is proposing that changes in the achievable levels of 
control over the SFTP tests would track changes in the underlying FTP 
standards and, thus, adoption of the central proposal would have the 
effect of automatically reducing the composite standards in step with 
any mandatory future declines in the FTP standards.8

    \8\The issue of what standards would apply in the context of a 
voluntary Federal low emission vehicle program will be determined in 
a separate rulemaking (60 FR 4712, January 24, 1995).
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    Flexibilities are proposed to allow manufacturers to reduce their 
testing burden, particularly during development testing. (See Support 
Document to the Proposed Regulations for Revisions to the Federal Test 
Procedure: Detailed Discussion and Analysis and Technical Reports for 
discussion.)9

    \9\Both the Support Document to the Proposed Regulations for 
Revisions to the Federal Test Procedure: Detailed Discussion and 
Analysis and the Technical Reports are in the public docket for 
review.
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    Emissions Standards and Phase-in--The Agency is proposing to phase 
in the proposed requirements for aggressive driving and air 
conditioning control prior to implementing the intermediate soak 
requirements. It is proposed that the standards apply to 40 percent of 
each manufacturer's combined production of LDVs and LDTs for the 1998 
model year, 80 percent in 1999, and 100 percent in 2000. Small volume 
manufacturers would not have to comply until the 2000 model year. All 
the proposed requirements would apply during this phase-in period, 
except that Bag 5 could be conducted with a 10-minute soak instead of 
the proposed 60-minute soak for control of intermediate soak emissions. 
The 60-minute soak would be required for all vehicles starting with 
model year 2001, including small volume manufacturers.
    The Agency is continuing to analyze the impact of this phase-in 
schedule, particularly when considered in conjunction with other 
recently promulgated rules (such as revisions to the evaporative test 
procedures) as well as potential future programs (such as voluntary 
Federal low emission vehicle standards). Comments are specifically 
requested (1) on the impact of this phase-in schedule when considered 
with other programs and (2) providing suggestions for other schedules 
which will coordinate programs more effectively. The Agency will review 
this information in developing the final rule to determine if a more 
logical coordination schedule is possible while maximizing the cost/
benefit effectiveness of this rule.
    The proposal recognizes that adoption of emission standards more 
stringent than current Federal Tier 1 standards will likely result in 
emission control strategies that reduce catalyst light-off 
times.10 This could have a significant impact on the costs and 
benefits of the intermediate soak requirement. As Tier 1 standards are 
the current legal requirement and the status of future standard changes 
is uncertain at this time, this proposal presumes Tier 1 applicability. 
The Agency invites comments and data addressing the cost/benefit 
implications of the proposed soak requirement under a Federal Tier 2 
(or equivalent) program.

    \10\Time required for the catalyst to reach the temperature 
needed to sustain significant catalytic activity.
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    Each of the test cycles is run on a system providing accurate 
replication of real road load forces at the interface between drive 
tires and the dynamometer over the full speed range. In addition, the 
new US06 cycle requires significantly higher power absorption capacity, 
due to the higher power requirements of this aggressive driving cycle. 
While EPA intends to use a large-diameter single-roll dynamometer with 
electronic control of power absorption to meet these requirements for 
both the new SFTP and current FTP testing, any system would be allowed 
that yields equivalent or superior test results.
    The improved road load simulation and the new criteria for 
allowable speed variation for FTP compliance determination are proposed 
to be implemented in the 1998 model year. Manufacturers could elect to 
use improved road load simulations prior to 1998, at their option.
    The Agency is also proposing a minor procedural change that would 
remove the current 5500-pound test weight cap, to be implemented in the 
1998 model year with the improved road load simulations.

B. Alternative Approaches

    As indicated, EPA is considering a number of alternatives to 
critical elements of the central proposal. The following provides a 
summary of the most important of these alternatives. A full discussion 
of all the options and alternatives considered is found in the Support 
Document to the Proposed Regulations for Revisions to the Federal Test 
Procedure: Detailed Discussion and Analysis.
    In determining compliance with the emission standards, EPA is 
considering two alternatives to the proposed FTP/SFTP composite and the 
related standards: (1) promulgating three separate sets of standards, 
one set each for aggressive driving, post-soak startup emissions, and 
A/C impacts; and (2) promulgating a single set of standards, based on a 
simple weighted average of separate standards for each control area. 
Both of these alternatives would use the same cycles and test 
procedures as the composite approach of the central proposal. However, 
instead of weighing them with Bag 1 of the FTP and using bag weights to 
help establish appropriate compliance procedures and standards, the 
alternative approaches would establish emission standards specifically 
for each new control area.
    The Agency did not select either of these alternatives as the 
central proposal because of difficulties encountered in determining the 
appropriate amount of in-use compliance margin to allow when 
establishing emission standards. Also, the proposed concept of indexing 
the SFTP standards to any future changes in FTP standards probably 
would not work with either of the two alternatives. If data are 
submitted that could help establish appropriate in-use margins, EPA 
would reevaluate the most appropriate compliance structure and, if 
[[Page 7413]] appropriate, may select one of the alternatives in the 
final rule.
    The Agency is also considering the alternative of establishing a 
single standard for NMHC+NOX, instead of separate standards, and 
invites comments on the cost and emission impacts of this alternative.
    One issue was identified too late for EPA to properly evaluate it. 
Concern was raised that the proposed level of CO control may 
significantly interfere with the ability for vehicles to comply with 
the proposed level of NOX control. Should further data and 
analyses substantiate that tradeoffs between CO and NOX control 
would preclude meeting the proposed level of NOX control, EPA 
would consider reducing the stringency of the CO standards for the new 
control areas in the final rule.
    On October 20, 1994, EPA representatives received a joint vehicle 
manufacturer proposal from the Ad Hoc Panel that addressed emissions 
arising from aggressive driving and A/C operation and proposed emission 
standards for each of these two areas. The Agency has not had 
sufficient time to fully analyze the concepts offered by the panel or 
to incorporate the manufacturer proposal as an explicit, complete 
alternative to the primary Agency proposal presented today. 
Nevertheless, the manufacturers' specific proposals fall within the 
scope of the options and alternatives discussed by EPA in today's 
notice. The Agency has submitted materials supplied by the panel on 
October 20, 1994, to the rulemaking docket.11 Analysis of these 
elements by the Agency, as well as any related material supplied in the 
future, will also be docketed. In order that the Agency may make the 
most informed and appropriate judgments in any final rulemaking, EPA 
encourages interested persons and organizations to evaluate and comment 
upon these materials.

    \11\Ad Hoc Panel, ``Industry Proposal on FTP Revisions,'' 
October 20, 1994.
---------------------------------------------------------------------------

    In the area of A/C emission control, EPA is considering an 
alternative to the proposed test simulation of A/C operation, as well 
as the alternative of requiring A/C testing across the cold start (that 
is, Bag 1 of the FTP). The alternative A/C simulation would leave the 
A/C off in the test cell, but would increase the dynamometer load curve 
across the range of vehicle speeds to reflect the additional load 
imposed by an A/C compressor during ozone exceedance conditions.12

    \12\The Ad Hoc Panel has submitted a proposed methodology for 
such a dynamometer simulation of A/C load, dubbed ``Nissan II.'' 
Manufacturers are pursuing additional refinements to address 
potential concerns with the approach, such as the ability to 
simulate air compressor cycling and A/C loads at idle, which cannot 
be simulated on a dynamometer.
---------------------------------------------------------------------------

    In the intermediate soak area, the effect on in-use emissions of 
the alternatives depends on future changes to the stringency of the FTP 
standards, the control strategies manufacturers would employ to meet 
such future standards, and the impacts those strategies might have on 
post-soak emissions. Because these are not known, alternatives might 
include exemption from aspects of the soak requirement or total 
deletion of the soak requirement.

IV. Statutory Authority and Legal Analysis

    The promulgation of these regulations is authorized by sections 
202, 206, 208, and 301 of the Clean Air Act (CAA or the Act) as amended 
by the Clean Air Act Amendments of 1990 (42 U.S.C. 7521, 7525, 7542, 
and 7601). Section 206(h) of the Act requires EPA to ``review and 
revise as necessary--the testing of motor vehicles and motor vehicle 
engines to insure that vehicles are tested under circumstances which 
reflect the actual current driving conditions under which motor 
vehicles are used, including conditions relating to fuel, temperature, 
acceleration, and altitude.'' Congress mandated that EPA exercise its 
authority under section 206(a) of the Act, giving broad authority to 
determine appropriate test procedures, consistent with the broad 
direction of section 206(h), to determine appropriate changes to 
reflect real world conditions.
    Although the text of the statute and the legislative history do not 
provide explicit criteria or intent for this review, EPA believes the 
primary concern of Congress is having test procedures for LDVs and LDTs 
reflect in-use conditions in order to obtain better in-use emission 
control. This flows from the basic purpose of test procedures--to 
measure compliance with the emission standards--and from standards 
designed to obtain in-use emission reductions. Therefore, EPA made this 
the primary concern and objective.
    A more detailed analysis of the statute, the scope of EPA's 
authority, and interpretation of how best to exercise EPA's discretion 
under section 206(h) are found in the Support Document to the Proposed 
Regulations for Revisions to the Federal Test Procedure: Detailed 
Discussion and Analysis.

V. The FTP Review Project and Areas of EPA Concern

    In response to the review requirement of the CAAA, EPA initiated 
the FTP Review Project (the FTP Review) in November 1990. The first 
action of the project team was to perform an initial review of existing 
information to identify elements of the current FTP that might be of 
concern (justifying additional focus) and others that might not justify 
concern at this time.
    Of immediate concern to EPA was representativeness of the driving 
cycle used in the current FTP, the ``LA4'' or ``Urban Dynamometer 
Driving Schedule,'' especially in the area of aggressive driving 
behavior.13 It was clear that the LA4 maximum speed of 57 mph 
excluded a significant fraction of higher-speed, in-use 
operation.14 Similarly, EPA suspected that an important fraction 
of in-use accelerations were more severe than those found in the LA4. A 
1990 CARB study found much higher emissions, particularly for CO, 
during operation at high acceleration rates relative to those seen 
during FTP-level accelerations.

    \13\In this report, ``driving behavior'' refers to the 
measurable consequences of the operator's action on the accelerator 
pedal, including vehicle speed, throttle variation, acceleration, 
and power.
    \14\Details about the development of the LA4 driving cycle can 
be found in an SAE paper, ``Development of the Federal Urban Driving 
Schedule,'' Ronald E. Kruse and Thomas A. Huls, EPA, 1973, #730553.
---------------------------------------------------------------------------

    One possible explanation for these emission increases is that the 
engines were not calibrated for emission control during the higher 
engine loads associated with aggressive driving, as these loads are not 
encountered during current FTP testing. However, insufficient data 
existed at the time to quantify the in-use frequency of aggressive 
driving events or the actual emission impacts. There were also 
concerns, based on engineering judgment, about other aspects of driving 
behavior that were not represented in the current test procedures for 
which no data existed. Thus, the Agency concluded that further 
information was necessary to properly represent actual driving 
conditions. In collaboration with key stakeholders, EPA began extensive 
research into driving behavior and conditions and their emission 
implications.
    During the course of the research a number of other concerns with 
the current FTP were identified, including two additional concerns with 
the LA4 representation of in-use driving behavior. The first concern 
was start driving behavior; that is, behavior immediately following 
vehicle startup [[Page 7414]] and initial idle. The LA4 cycle used in 
the current FTP brings the most aggressive operation close to the 
beginning of the cycle; driving survey data suggest this is atypical of 
in-use operation. The second concern was microtransient behavior (rapid 
speed fluctuations). In-use driving survey data contains more frequent 
speed fluctuations than the FTP.
    The Agency identified concerns about four additional elements of 
the FTP: The duration of the soaks; the representation of A/C load; 
representation of additional loads on the engine due to factors such as 
road grade, extra cargo, or trailer towing; and the adequacy of the 
dynamometer specification for representation of real road load.
    With respect to soaks, EPA sought to determine if significant 
levels of emissions are missed by the current FTP because only very 
short- and long-duration soaks are reflected in the current structure. 
One related hypothesis was that the much faster cooling rate of 
catalysts compared to engines might lead to excessive emissions during 
intermediate-duration soaks.
    Several aspects of the A/C load simulation were problematic. The 
current FTP adds load as a percentage of the base road load horsepower 
curve, which means the FTP A/C load decreases with decreasing speed, 
while real A/C system loads relative to road load horsepower are 
highest at low speed. Also, vehicles with different base horsepower 
curves end up with different FTP A/C load simulations, even if they 
have identical A/C systems. Additionally, the Agency believes that the 
current method significantly under-represents the magnitude of in-use 
A/C loads. As in the case of aggressive driving behavior, incorrect 
representation of A/C loads during the FTP risks incorrect simulation 
of the emissions these loads would generate from an engine in-use.
    Road grade, vehicle towing, and cargo also represent a load effect 
on the engine. The 300-pound passenger-plus-cargo allowance on the FTP 
is clearly unrepresentative for some driving situations, especially for 
trucks, and the absence of road grade or vehicle towing simulations on 
the FTP means these actual in-use loads are not a factor determining 
emission standards or compliance with those standards.
    Three aspects of the current FTP dynamometer configuration have the 
potential to misrepresent the actual road load experienced by vehicles 
in-use. First, the shape of the speed/load curve on current 
certification dynamometers is fixed and cannot be changed; the 
magnitude of the speed/load curve is adjusted by periodically 
calibrating the dynamometer at a single speed (currently, 50 mph). As a 
consequence, loads at speeds other than the calibration point can be 
misrepresented. Second, current FTP dynamometers cradle the vehicle 
drive wheels between two small (8.65-inch) rolls. Heating effects and 
pinching of the tire result in an unrepresentative simulation of road 
``surface.'' Third, the dynamometer rolls are currently uncoupled and 
the front roll (which bears the power absorber) spins somewhat more 
slowly than the rear (which provides the vehicle speed signal); this 
tends to bias the system towards underloading the vehicle.
    The Agency analyzed three other elements of the FTP and believes 
revising the current procedures is unnecessary at this time. The first 
such area was the altitude of testing. Given that EPA has the authority 
to perform vehicle testing at any altitude, and it currently exercises 
that authority, the Agency is not proposing to supplement by further 
regulation the altitude testing flexibility in current law. While it is 
possible that driving behavior may differ at high altitudes, EPA 
believes that any emission controls required for aggressive driving 
will also be effective during high altitude driving.
    A second element which EPA did not pursue beyond the initial 
evaluation was test fuels. In-use fuels have a wide range of 
properties. This specification for fast fuel allowance for a range of 
fuels (40 CFR 86.113-94) appear to provide EPA with the flexibility to 
use a variety of test fuels ranging from an average in-use fuel to some 
of the less typical in-use fuels with qualities that could effect 
emissions. Significant differences, with potentially large emissions 
implications, do appear to exist between average in-use gasoline and 
the gasoline (indolene) typically purchased by both EPA and industry 
for certification testing. After evaluating approaches to addressing 
this situation, EPA concluded that changes to the regulations are not 
necessarily required, since the current regulations provide the 
flexibility needed to address those situations where the use of 
indolene may not be representative. In addition, various programs to 
address in-use fuel qualities are still under consideration. If a 
decision is ultimately made to change the certification fuel 
regulations, it may be best to do so along with changes to the 
specifications for in-use fuels.
    Finally, EPA believes that it is unnecessary to further address the 
direct impacts of ambient temperature on FTP tailpipe emissions in this 
proposal. At the time the Amendments were adopted, the FTP evaluated 
tailpipe emissions performance in the midrange of temperature (68 deg. 
F to 86 deg. F), but omitted both cold and hot temperature testing. The 
emission concern following cold temperature soaks and during cold 
temperature operation is increased CO emissions. This concern was 
addressed through EPA's Cold Temperature CO rulemaking (57 FR 31888). 
The direct emission impact during hot temperature operation is 
increased fuel evaporation. Ambient temperature should not otherwise 
affect tailpipe emissions, as the engine and combustion temperature are 
not affected in any significant way by temperatures hotter than 86 deg. 
F. This concern was addressed through the Agency's Evaporative 
Emissions rulemaking (58 FR 16002). Ambient temperature also produces 
indirect emission effects through increased operation of the vehicle A/
C, affecting the load on the engine. This indirect aspect of 
temperature was addressed in EPA's detailed review of the FTP and is 
reflected in today's proposal.
    The FTP Review project team found that existing information was 
clearly inadequate for evaluating potential revisions to the test 
procedures. Consequently, a number of new data gathering and analytical 
efforts were undertaken in connection with the project. In several of 
these efforts, EPA resources were supplemented by significant 
cooperative investments from other sources, including the American 
Automobile Manufacturers Association (AAMA), the Association of 
International Automobile Manufacturers (AIAM), and the California Air 
Resources Board (CARB). These studies provided EPA with unprecedented 
data on which to base its comparative review with the FTP and to 
construct the options presented in today's proposal.

VI. In-Use Behavior

    The first critical need in reviewing the FTP was a current database 
on in-use driving and vehicle soak behavior. The Agency collaborated 
with AAMA, AIAM, and CARB over the spring and summer of 1992 to conduct 
surveys of in-use driving and soak behavior in four major U.S. cities.

A. In-Use Driving Behavior

    Instrumented vehicle surveys and/or chase car studies were 
conducted in Baltimore, Maryland; Spokane, Washington; Atlanta, 
Georgia; and Los Angeles, California. In May of 1993, EPA published its 
initial conclusions regarding aggressive driving behavior in the 
``Federal Test Procedure Review Project: Preliminary Technical 
Report.''15 These conclusions were largely based on the Baltimore 
instrumented vehicle survey data. Subsequent analysis has found the 
larger three-city instrumented vehicle results to be consistent with 
the Baltimore-only results. The three-city analysis showed that nearly 
13 percent of vehicle operation, on a time-wrighted basis, occurs at 
combinations of speed and acceleration that fall outside the matrix of 
speeds and accelerations found on the LA4 driving cycle. The maximum 
observed in-use speed was 95.5 mph, compared to the LA4 maximum speed 
of 56.7 mph, and slightly more than seven percent of in-use vehicle 
operation time was spent at speeds greater than 60 mph. Average speed 
from the three-city in-use data was 25.9 mph compared to 19.6 mph over 
the LA4. [[Page 7415]] 

    \15\U.S. Environmental Protection Agency, Federal Test Procedure 
Review Project: Preliminary Technical Report, EPA 420-R-93-007, 
Office of Air and Radiation, May 1993.
---------------------------------------------------------------------------

    Specific power is also useful when analyzing aggressive driving 
behavior.16 Measures of power also indicated that in-use driving 
behavior was more aggressive than reflected in the LA4. Specific power 
in the three-city sample ranged up to 723 mph\2\/sec and averaged 47.0 
mph\2\/sec. The LA4 has maximum power of 192 mph\2\/sec and an average 
of 38.6 mph\2\/sec.

    \16\The power needed from an engine to move a vehicle is 
proportional to both the vehicle speed and the acceleration rate. 
Neither variable, by itself, is a good measure of the load placed on 
the engine. The joint distribution of speed and acceleration is 
probably the best measure, but it must be examined in three 
dimensions, which is difficult to visualize and comprehend. The 
concept of specific power provides a two-dimensional measure which 
is roughly equal to 2*speed*acceleration and has the units of 
mph\2\/sec.
---------------------------------------------------------------------------

    The Agency analyzed the in-use survey data to determine how the 
above findings on speeds, accelerations, and power measures were 
affected by other factors, including vehicle type (car/truck), 
transmission type, vehicle performance level, time of day, and day of 
the week. The first three vehicle-related factors are reflected in 
today's proposal. The discussion of the analysis and findings are in 
the Support Document to the Proposed Regulations for Revisions to the 
Federal Test Procedure: Detailed Discussion and Analysis and the 
Technical Reports.
    The Agency also examined start driving behavior as represented by 
the instrumented vehicle survey data. The Agency determined that the 
start driving (operation following the initial idle and before coolant 
temperature exceeded 140 deg. F) in the survey data generally did not 
exceed 240 seconds. Further analysis showed that the speeds of start 
driving did not change substantially following soaks of different 
durations, but they did differ from those found in hot stabilized 
driving. The results for in-use initial idle time and start driving are 
different than the representation of these elements in the FTP. The LA4 
cycle has atypical high speeds over the first four minutes of a vehicle 
trip. On the other hand, the LA4 has substantially less aggressive 
accelerations than the first 80 seconds or so of typical in-use start 
driving, while it is substantially over-aggressive when compared to the 
succeeding 160 seconds. For initial idles, the FTP presumes 20-second 
durations for both cold and hot starts, whereas the in-use averages 
from EPA's data were 28 seconds for cold starts and only 12 seconds for 
hot starts.
    The previous discussion of in-use speeds and accelerations presents 
a snapshot of driving behavior. Although the acceleration measure, 
which looks at the change in speed from one second to the next, 
partially characterizes the transient nature of driving, other measures 
expand the time interval to examine the rapid fluctuations in speed, or 
microtransients. One measure, referred to as jerk, is equal to the 
change in acceleration. A related measure is the second-to-second 
change in specific power. Conceptually, this measure captures the 
change in the power requirement imposed by the driving behavior.
    The Agency used the three-parameter instrumented vehicle data from 
Baltimore, Spokane, and Atlanta,17 to calculate these 
microtransient measures for in-use driving behavior and compared the 
results to the LA4's representation. The measures of jerk and change in 
power are shown in Table 2.

    \17\See the Technical Reports for a full description and 
analysis of this data.

 Table 2.--Measures of Microtransient Driving From Instrumented Vehicle 
                                Data/Sec                                
------------------------------------------------------------------------
                                Jerk                 Change in power    
                     ---------------------------------------------------
                      Mean of the               Mean of the             
       Source           absolute     Standard     absolute     Standard 
                      values (mph/  deviation      values     deviation 
                          sec)      (mph/sec)    (mph2/sec)   (mph2/sec)
------------------------------------------------------------------------
In-use driving......         0.47         0.89        20.48        34.36
LA4.................         0.36         0.63        14.96        22.96
------------------------------------------------------------------------

For both jerk and change in power, the mean of the absolute values were 
used in order to look at both the positive and negative values (the 
mean of the signed values of jerk is always equal to zero). The in-use 
means were higher than those for the LA4, indicating larger in-use 
changes in acceleration and power, as well as reflecting, in part, the 
LA4's acceleration rate cutoff of 3.3 mph/sec and the maximum speed of 
57 mph. The standard deviations of jerk and change in power are 
probably a better measure of microtransient behavior. Again, in-use 
data show larger values for both measures. The greater variation around 
the mean demonstrated by the in-use data suggests that the LA4 does not 
adequately represent the microtransient nature of in-use driving 
behavior.

B. Soak Behavior

    The survey data were also analyzed to determine the frequencies at 
which soaks of different durations occurred in-use. The Agency found 
that soaks of less than 10 minutes and greater than 8 hours occur with 
the highest frequencies in use. However, EPA also found that a 
significant portion of in-use soaks are of intermediate duration. For 
example, nearly 40 percent of all soaks in the Baltimore survey data 
were between 10 minutes and 2 hours. Given that the current FTP employs 
only two soaks (the 10-minute hot soak and the 12- to 36-hour cold 
soak) to represent the range of soaks in-use, EPA was concerned that 
the current FTP might not adequately control for emissions following 
these intermediate-duration soaks.

C. Air Conditioning

    A number of variables affect the range of A/C usage, particularly 
temperature, sun load, and humidity, all of which [[Page 7416]] vary by 
season, time of day, and geographic location. Given that the overall 
goal of the Act is to help bring localities and regions into compliance 
with the National Ambient Air Quality Standards (NAAQS), the Agency 
chose to focus attention on the contribution of A/C to vehicle 
emissions during typical high ozone situations. Analyses of ozone 
exceedances revealed that ozone exceedances typically occur on days 
with a mean ambient temperature of 95  deg.F, 30-40 percent relative 
humidity, and limited cloud cover.
    In August and September 1994, the Agency conducted an instrumented 
vehicle study in Phoenix, Arizona. Preliminary analyses of the survey 
data indicate that the average A/C usage was 77 percent for days that 
reached a peak temperature between 90  deg.F and 100  deg.F. The A/C 
compressor was actually engaged 61 percent of the total time (see 
Technical Reports and the Support Document to the Proposed Regulations 
for Revisions to the Federal Test Procedure: Detailed Discussion and 
Analysis for full analysis). The high use of A/C in ozone exceedance 
conditions makes the accurate simulation of A/C during the FTP more 
important.

D. Additional Elements Affecting Engine Load

    A comprehensive evaluation of additional elements affecting engine 
load would require surveys of the frequency of occurrence of the 
elements in-use, as well as evaluation of interactive effects with 
driving behavior. For road grade, a 1980 EPA report18 indicated 
that positive road grades average 1.66 percent nationally and that 
roughly six percent of national VMT is spent on grades of four percent 
or higher. The Agency sought to supplement this information with 
driving behavior data over road grade, gathered during the chase car 
portion of the in-use driving surveys. Unfortunately, problems with 
noise and insufficient resolution on the measure of grade rendered the 
data inadequate, and no alternative data source was available. In 
addition, EPA was unable to conduct in-use surveys in the areas of 
passenger/cargo loading and trailer towing, due to the scope and nature 
of the necessary survey instrument. As a consequence, EPA has 
insufficient data for use in evaluating the additional elements 
affecting engine load that were originally identified as areas of 
concern.

    \18\18 U.S. Environmental Protection Agency, Passenger Car Fuel 
Economy: EPA and Road, EPA# 460/3-80-010, September 1980, p. 119.
---------------------------------------------------------------------------

VII. Representative Driving Cycles

    In order to evaluate the emission impacts of in-use driving and 
soak behavior, EPA designed three driving cycles that were 
representative of the in-use survey results, using segments of actual 
in-use driving survey data. Concurrently, EPA determined weighting 
factors to reflect the fraction of in-use operation represented by each 
cycle; these factors are used to properly weight the emissions from the 
cycles when doing an emission assessment.
    The Agency developed separate cycles for start driving and 
aggressive driving. The Agency chose to develop individual cycles 
rather than a single ``representative'' cycle in order to evaluate 
EPA's areas of concern independently. This is most critical in the case 
of aggressive driving where both capturing the diversity of aggressive 
driving behavior and representing it proportionally in a single cycle 
covering all in-use operation would lead to a very long cycle.
    The Start Cycle (ST01) represents three successive 80-second 
segments of in-use driving immediately following the initial idle. 
Testing using ST01 allowed separate determination of start driving 
emissions; ST01 was also used to quantify the emissions effects of 
varying soak duration.
    The second cycle, characterizing aggressive driving, was the 
Representative Non-LA4 Cycle (REP05). This cycle targeted speeds and 
accelerations, as well as microtransient effects, not covered by the 
current LA4.
    To complete the representation of in-use driving behavior for 
emission assessment purposes, a third cycle, the Remnant Cycle, was 
developed to characterize in-use driving behavior not represented by 
either the ST01 or REP05.
    The Agency used the same basic cycle development methodology for 
each of the three representative cycles. A full discussion of the 
methodology used, the composition of each cycle, and how it compares to 
the cycle in the FTP is found in the Technical Reports.
    It seemed clear from the in-use survey data that rapid speed 
fluctuations, including ones not well represented on the LA4, could be 
found in all types of in-use vehicle operation. The Agency's use of 
actual microtrips as the building blocks for the three representative 
cycles directly incorporated such microtransient driving behavior into 
all three cycles.
    The Agency has assumed that driving behavior is not affected 
significantly by A/C operation and that the representative driving 
cycles developed from the in-use driving survey data are equally 
applicable to testing with the A/C system on and off. In fact, even 
though the Atlanta driving survey was the only one of the three surveys 
conducted during the summer, that city had the most aggressive driving 
of the three cities. Thus, it does not seem likely that A/C operation 
could have a significant impact on driving behavior. Nonetheless, the 
Agency welcomes data and comments on the relationship between A/C 
operation and driving behavior.

VIII. Emission Inventory Assessments

    An assessment of emissions from four areas for potential emission 
control was conducted using the representative test cycles developed 
from the survey data. A full description of the test programs and the 
results can be found in the Technical Reports. The following summarizes 
the conclusions for each area considered.

A. In-Use Driving Behavior

    The FTP Review's emission assessment of in-use driving behavior was 
based on a vehicle emission test program conducted cooperatively by 
EPA, CARB, AAMA, and AIAM during 1993 and early 1994 (referred to 
subsequently as the Non-LA4 Emissions Test Program).19

    \19\EPA's assessment was limited to EPA's and AAMA/AIAM data. 
Due to differences in testing hardware, CARB's emission results were 
not directly comparable.
---------------------------------------------------------------------------

    On the basis of the EPA data, the project team concluded that the 
LA4 under-predicts actual in-use hot stabilized emissions by 0.043 g/mi 
NMHC, 2.8 g/mi CO, and 0.083 g/mi NOX on current technology, 
properly operating vehicles.20 These numbers do not have any 
direct bearing on the FTP standards; they are simply an estimate of the 
additional amount such vehicles actually emit in-use, compared to the 
FTP test results.

    \20\These estimates are only for the emission under-prediction 
related to driving behavior. Other factors such as soak are 
addressed in the sections to follow.
---------------------------------------------------------------------------

    Table 3 shows the percentage contribution to the in-use emission 
increase from the Start (ST01), Remnant, and aggressive (REP05) driving 
cycles, weighted by their respective proportion of in-use driving. As 
expected, the aggressive driving of REP05 contributed significantly to 
the difference. More surprisingly, however, significant contributions 
to the increase also came from the Start and Remnant Cycles, 
particularly for NMHC and NOX.

                                                                        
[[Page 7417]]                                                           
  Table 3.--Contributions to the In-Use g/mi Increase by Three Types of 
                                 Driving                                
------------------------------------------------------------------------
             Driving                    NMHC          CO          NOX   
------------------------------------------------------------------------
All (In-Use Increase)............  0.043 g/mi...  2.784 g/mi  0.083 g/  
                                                               mi.      
Start............................  30.2%........  17.1%.....  23.0%.    
Remnant..........................  33.8%........  25.0%.....  45.6%.    
Aggressive.......................  36.0%........  57.8%.....  31.4%.    
------------------------------------------------------------------------

    The AAMA/AIAM portion of the program was conducted in late 1993 and 
early 1994. This 26-vehicle, 8-manufacturer program included hot 
stabilized testing with REP05, the 505, and the 866, but none with the 
Remnant or Start Cycles; thus, a complete assessment of in-use hot 
stabilized driving could not be conducted with the manufacturers' data. 
Nevertheless, comparisons were made between the EPA and manufacturer 
program results for REP05 as well as the difference between REP05 
emissions and hot stabilized LA4 emissions. In looking at the emission 
difference between REP05 and hot LA4, the LDV and light light-duty 
truck (LLDT) average for the EPA tested vehicles was 0.04 g/mi while it 
was 0.06 g/mi for the vehicles tested by the manufacturers. The CO 
emissions tracked better, with the REP05 and hot LA4 difference of 5.71 
g/mi for EPA and 5.32 g/mi for the manufacturer tests. The manufacturer 
testing showed a much larger NOX differential. The NOX 
difference between REP05 and hot LA4 was 0.25 g/mi for the 
manufacturers' testing while only 0.09 g/mi for EPA testing. The NMHC 
and CO differences are primarily among the LLDTs while the NOX 
difference was found in LDVs and LLDTs. The Agency did not test any 
heavy light-duty trucks (HLDTs); however, the manufacturers' results 
showed these vehicles as having the largest grams per mile increases 
from hot LA4 to REP05. This comparison suggests that EPA's emission 
assessment should provide a reasonable, if not conservative, estimate 
of in-use emissions.

B. Intermediate Soaks

    The Agency conducted the assessment of in-use emissions following 
intermediate soaks using data from EPA's Soak/Start Test Program, 
conducted in two phases between July 1993 and June 1994. The testing 
represented the soaks observed in the driving survey data. The primary 
cycles used to measure post-soak emission levels for the emission 
assessment were variations of EPA's representative Start Cycle (ST01).
    Post-soak emissions in the Soak/Start Test Program, measured over 
the ST01 cycle, increased steadily and sharply as soak duration was 
incremented between 10 minutes and 60 minutes. The average ST01 
emissions for all vehicles tested for NMHC, CO, and NOX were 
higher following the 60-minute soak than they were for the 10-minute 
soak by factors of seven, two, and four, respectively. The increases 
were significant in absolute terms as well; for example, the average 
NMHC emissions on three Tier 1 vehicles went from about 0.05 g/mi 
following the 10-minute soak to over 0.50 g/mi following the 60-minute 
soak. The rate of increase moderated with soaks longer than 60 minutes, 
such that emissions of all constituents following a 2-hour soak were 
within 50 percent of cold soak levels. The subset of Tier 1 vehicles in 
the EPA program showed similar percentage increases as a function of 
soak duration relative to the Tier 0 vehicles, although the average 
emission levels of these vehicles were lower than the Tier 0 vehicles.

C. In-Use Air Conditioner Operation

    The Agency conducted three test programs and participated 
cooperatively with AIAM and AAMA in an additional test program during 
late 1993 and early 1994 with the purpose of assessing in-use emissions 
due to A/C operation. Detailed descriptions of all of these programs 
and the results are contained in the Support Document to the Proposed 
Regulations for Revisions to the Federal Test Procedure: Detailed 
Discussion and Analysis.
    The first test program compared emissions during the current FTP A/
C simulation to emissions obtained with the A/C actually operating and 
confirmed that the current A/C simulation method significantly under-
represents the actual load of the A/C on the engine.21

    \21\In fact, the Agency believes that the effect on emission 
values of the additional ten percent dynamometer road load 
horsepower is negligible and unobservable within the range of 
current test-to-test variability.
---------------------------------------------------------------------------

    The second test program went beyond the current FTP by testing A/C 
impacts over the three representative cycles (REP05, ST01, Remnant) as 
well as over the LA4. As in the first program, results from this 
testing demonstrated an overall increase in actual emissions with the 
A/C operating. In particular, the magnitude of the NOX increase in 
both programs was much larger than expected and caused the Agency to 
focus further research and analysis on the effects of A/C operation on 
NOX emissions.
    The third test program was very similar to the second but was 
designed to collect second-by-second emissions and vehicle operating 
data. Analysis of these data indicated that the significant A/C-related 
emission impacts were occurring during idles and accelerations; on the 
LA4, ST01, and Remnant cycles the combination of idles and 
accelerations accounted for more than 80 percent of the total observed 
NOX increase. As was the case in the previous program, the overall 
increases in NOX were heavily weighted towards the moderate and 
lower speed driving of the ST01, Remnant, and LA4 cycles, although some 
increases were seen on the REP05 cycle.
    A detriment of these test programs is that they did not adequately 
or fully represent the actual conditions under which A/C systems are 
likely to be operated. To test vehicles under an accurate simulation of 
environmental conditions and vehicle speed, an emission testing program 
(referred to as the AC Rochester [ACR] test program) was conducted by 
vehicle manufacturers in a sophisticated environmental test 
facility.22 The Agency and manufacturers cooperatively defined for 
the testing a set of environmental and meteorological parameters to 
represent a typical ozone nonattainment day.

    \22\This program was developed as a cooperative effort between 
EPA and manufacturers with funding from manufacturers.
---------------------------------------------------------------------------

    Eight vehicles certified to the EPA's Tier 1 emission standards 
with HFC-134a A/C refrigerant systems were tested in the program. Once 
again, the effects of A/C operation were most pronounced on the 
moderate-to-lower speed cycles. On a hot, stabilized LA4, the average 
increases were 0.011 g/mi for NMHC, 0.3 g/mi for CO, and 0.205 g/mi for 
NOX. The increases observed on the REP05 cycle were smaller than 
on the LA4, but still noteworthy due to the performance of several of 
the vehicles, causing the Agency some concern about the impact of A/C 
operation during aggressive driving behavior. Fuel economy decreased by 
about 13 percent on the REP05 with the A/C operating, substantially 
less than the 20 percent reduction on the LA4, further indicating that 
the A/C load as a proportion of total load tends to diminish as speeds 
and accelerations increase. [[Page 7418]] 

D. Additional Elements Contributing to Engine Load

    As part of the Non-LA4 Emission Test Program, EPA conducted an 
evaluation of emission impacts from road grade by simulating a two 
percent grade through increased inertia weight at the dynamometer 
during testing of three vehicles over the three representative cycles. 
The road grade effect, weighted by the percentages of the driving types 
in-use, showed a consistent HC increase of 0.04 g/mile, a highly 
variable CO increase averaging 3.2 g/mile, and a NOX increase (due 
largely to one vehicle) of 0.19 g/mi. Due to the absence of 
comprehensive in-use survey information, EPA did not calculate 
adjustments to these numbers to reflect in-use frequency of grade or 
modifications to driving behavior over grades.

IX. Cause and Control of Emissions

    Three candidate areas for emission control are aggressive driving 
behavior, intermediate soak periods, and A/C operation. Microtransient 
driving behavior carries over and is addressed withing these candidate 
areas. The following discusses each of these areas, the causes of 
emission, and potential strategies for controlling the emission.

A. Aggressive Driving Emissions

    Both agencies and the vehicle manufacturers anticipated that a 
primary cause of higher emissions during aggressive operation would be 
``commanded enrichment,'' which is done by programming the vehicle's 
computer to change the air/fuel ratio to the rich side (more fuel for 
the same air) of stoichiometric operation, typically in response to 
high loads on the engine. Aggressive driving, positive road grade, 
increased vehicle loading, and air conditioning operation all generate 
increased load on the engine. Further, the effect of these factors are 
cumulative. Manufacturers currently employ commanded enrichment in 
essentially all applications when high load at the engine (regardless 
of the source) is detected, both to provide increased power and to cool 
the engine or catalyst.
    Using data from EPA's Non-LA4 Test Program, supplemented by AAMA/
AIAM data,23 the Agency concluded elevated HC and CO emissions 
during aggressive driving are due primarily to enrichment, both 
commanded and transient. High NOX emissions during aggressive 
driving, EPA believes, are due both to an increase in engine out 
NOX (from higher temperatures) and to relatively poor catalytic 
conversion. Poor catalytic conversion is due to lean events resulting 
from erratic A/F control and to an A/F control strategy which is not 
biased rich. The Agency also recognizes that catalyst breakthrough is a 
potential contributor to CO and NOX emissions during aggressive 
driving.

    \23\AAMA/AIAM spotlighted commanded enrichment by retesting a 
portion of the vehicles in their test program in a stoichiometric 
configuration, as well as in the ``production'' configuration and 
provided second-by-second data acquisition capability for emissions 
and a variety of engine and emission control parameters, allowing 
fine scrutiny of individual driving events.
---------------------------------------------------------------------------

    The Agency considered five strategies that manufacturers might 
employ for addressing the causes of high emissions from aggressive 
driving: improved control of the A/F ratio (fuel control) through 
calibration; improved fuel control by upgrading fuel injection systems 
to sequential firing; upgrading to electronic throttle control; 
improvements to catalyst design; and reapplication or refinement of 
conventional NOX emission control systems. These strategies are 
discussed in detail in the Technical Reports.
    Of these strategies, the various recalibration options appeared to 
be the least costly, because each of the remaining strategies involved 
per-vehicle hardware modifications. In addition, data from the Non-LA4 
test program indicated that recalibrations would probably control the 
vast majority of aggressive driving emissions.

B. Intermediate Soak Periods

    The Agency examined the causes of post-soak emissions using data 
from the EPA Soak/Start Test Program and a preliminary program called 
the Albany Cooldown Study that gathered real-world engine and catalyst 
cooldown profiles. The data from these programs indicated that 
increased emissions following intermediate soaks arise in three ways:
     Rapid catalyst cooldown following keyoff,
     Slow catalyst thermal recovery following a restart, and
     Manufacturer calibration strategies in response to the 
startup condition.
    The Agency data indicate the catalyst cools to below the 
temperature needed to sustain significant catalytic activity (``light-
off'' temperature) within 20-30 minutes of vehicle shutoff, while the 
engine is still near its normal operating temperature. Data also 
indicated a significant delay in achieving light-off temperature upon 
restart, apparently due to the cool initial temperature of the engine-
out exhaust. Because tailpipe emissions increase dramatically when the 
catalyst is below light-off temperatures, the relatively long delay in 
achieving light-off results in disproportionately high emission 
increases over intermediate soaks.
    The current FTP provides no incentive for manufacturers to retard 
the rapid cooldown of the catalyst during intermediate soaks. In 
addition, testing found differences in engine-out emissions determined 
by the manufacturer's calibration strategy upon restart. Following 
intermediate-duration soaks, one vehicle had a lean calibration 
strategy which increased NOX emissions. Here again, the test 
results indicate that significant emissions may be occurring in-use 
because of a lack of incentive for manufacturers to optimize startup 
calibrations following intermediate soaks.
    In general, strategies for reducing post-intermediate soak 
emissions are catalyst-based and either focus on the retarding of 
catalyst cooldown through insulation after the vehicle is shut off or 
the enhancement of catalyst light-off upon restart.
    Of the potential approaches considered for control of intermediate 
soaks, EPA is focusing on catalyst insulation as the primary control 
strategy. Use of insulation results in greater emission reductions over 
intermediate soaks than strategies which focus on improving catalyst 
light-off through conventional means and provides more cost-effective 
emission benefits than advanced cold start approaches. Although 
intermediate soak emissions will likely be reduced to some extent due 
to directional improvements in cold start performance, EPA believes 
that on Tier 1 vehicles intermediate soak emissions will continue to be 
relatively significant because the primary cause of intermediate soak 
emissions--rapid cooling of the catalyst--will remain unaddressed. 
Because insulation directly addresses catalyst cooldown, EPA 
anticipates that this approach will incur significant emission 
reductions over intermediate soaks on Tier 1 vehicles, including those 
which will incidentally reduce intermediate soak emissions through 
improved cold start performance.

C. Air Conditioner Operation

    The Agency focused on the NOX impacts from A/C use because of 
the large observed increases. The increases in tailpipe NOX with 
the A/C operating seen in the ACR Test Program could clearly be linked 
to large increases observed in engine out NOX, which are probably 
caused primarily by higher combustion temperatures due to the 
additional load of the A/C system. Tailpipe NOX can be improved by 
[[Page 7419]] increasing NOX conversion efficiency in the catalyst 
or decreasing engine out NOX. Control strategies include improving 
control of the A/F ratio, eliminating the lean-on-cruise calibration 
strategy, adjusting spark timing, adding or enhancing EGR systems 
strategic cycling of the A/C compressor, and improving catalysts to 
enhance NOX conversion efficiency.
    The testing at ACR confirmed that HC and CO were also impacted by 
A/C operation. The Agency believes that these HC and CO increases are 
related to the increased load on the engine triggering additional 
periods of commanded enrichment when the A/C is on. The Agency believes 
that the control strategies for HC and CO discussed in ``IX.A. 
Aggressive Driving Emissions'' will eliminate HC and CO emissions 
increases due to A/C operation as well as during aggressive driving.

X. Options Considered and Information Needed

    The following outlines the options which EPA has considered in 
developing today's proposal and issues on which more information is 
needed. As has been indicated, EPA and other stakeholders conducted 
extensive research and examined many options. While today's proposal 
selects the approach EPA felt would provide the most emission benefits 
feasible, in developing the final rule EPA will reconsider each of the 
options in terms of new research and data submitted. The Agency 
welcomes comments and additional data on these and any other points. A 
full discussion of these issues and a detailed analysis of each option 
is found in the Support Document to the Proposed Regulations for 
Revisions to the Federal Test Procedure: Detailed Discussion and 
Analysis.

A. Affecting Aggressive Driving Cycle

    The Agency evaluated three basic options for establishing standards 
and vehicle testing aimed at controlling emissions from aggressive 
driving. Two options were based on emission performance standards with 
compliance measured using a test cycle, and one option was based on a 
performance standard using the A/F ratio with a related test procedure.
    The Agency was guided by seven criteria in evaluating the options. 
First, EPA sought an option that would lead to control of emissions 
over the broad range of aggressive driving behavior found in the in-use 
driving survey data. Second, due to the non-linear nature of HC and CO 
emission increase during enrichment, a high priority was to ensure 
sufficient content from the highest-emission operating modes to prompt 
manufacturers to employ appropriate control strategies, including 
curtailing commanded enrichment. Third, the Agency sought consensus 
with CARB, to avoid duplicate or incompatible test requirements. 
Fourth, EPA sought to reasonably account for technical concerns raised 
by vehicle manufacturers, particularly manufacturer comment on the 
necessity of some commanded enrichment events to avoid elevated 
catalyst temperature levels from in-use operation leading to catalyst 
deterioration.24 Fifth, EPA sought to pursue cost saving elements 
like reduction in test time where practical. Sixth, the Agency sought 
practical control of microtransient behavior, a candidate area of 
control that spans all driving. Finally, EPA favored strategies to 
control aggressive driving emissions that would also address the 
potentially significant (but unquantified) emissions from other engine 
load factors like road grade.

    \24\The relationship between curtailing commanded enrichment and 
catalyst deterioration is addressed in the discussion of feasibility 
in the Technical Report.
---------------------------------------------------------------------------

    A full analysis of each option, how it was evaluated, how the level 
of emission control was determined, and the feasibility of the approach 
is in the Support Document to the Proposed Regulations for Revisions to 
the Federal Test Procedure: Detailed Discussion and Analysis and 
Technical Reports and comment on the analysis is welcome. Comment is 
specifically solicited on the following items:
     Comment is requested on the need to allow some commanded 
enrichment events during the USO6 Cycle to avoid elevated catalyst 
temperature levels from in-use operation leading to catalyst 
deterioration.
     The Agency is proposing that US06 HC and NMHC emissions be 
controlled to the same gram-per-mile emission levels currently achieved 
on the second bag of the FTP. US06 CO and NOX emissions are 
proposed to be controlled to overall FTP emission levels. These 
proposals are based upon the Agency's analyses of the potential control 
technology and their related costs and emission reductions, which are 
described in detail in the Technical Reports. Comments and additional 
data addressing these proposed levels of control are solicited. 
Additional information and data are also requested about the potential 
tradeoffs between NOX and CO control during aggressive driving, 
and on the impact such tradeoffs could have on the appropriate level of 
CO control.
     Although concern has been expressed that removal of 
commanded enrichment could impose a 2 percent to 10 percent power 
penalty, EPA believes power enrichment would not be precluded outright 
by this proposal, but rather curtailed only within the durations and 
speed-acceleration combinations found in the US06 cycle. Thus, the 
Agency has concluded on the basis of available data that compliance 
with the US06 standard should have a negligible effect on vehicle 
performance. Additional data on the effect on vehicle performance under 
this proposal is requested.
     The Agency has proposed adjustments to the US06 for all 
HLDTs and some LDVs and LDTs. These include a change in determing 
inertia weight for HLDTs, dynamic load adjustment for low-performance 
vehicles, and demonstration of stoichiometric control for wide-open 
throttle events for high-performance vehicles. Comments and data are 
solicited on the appropriateness of these adjustments and of the 
weight-to-power cutpoints. Of special concern is the possible unfair 
advantage the proposed high performance cut-off may provide to vehicles 
in the 18-21 W/P range.
     The Agency has proposed a W/P-based measure for the 
performance cutoffs after also considering the alternative performance 
criteria based on a vehicle's acceleration time from zero to 60 mph. 
The Agency rejected the zero to 60 time approach on the basis of 
practical problems related to establishing appropriate cutoff points 
and a standardized procedure for determining zero to 60 times. The 
Agency solicits comments on the proposed method for making vehicle 
performance adjustments, as well as input on alternatives, including 
the one discussed above.

B. Affecting Start Driving Cycle and Intermediate Soak

    The compliance program approach evaluated for intermediate soaks 
and start driving was an emission performance standard applied to the 
results of testing over an emission control cycle following a soak 
period of intermediate duration. As with control program approaches for 
aggressive driving emissions, EPA believes that an emission performance 
standard provides the most direct method of controlling the emissions 
arising during the particular type of vehicle operation. Given the 
particular causes of high emissions in this case, use of design 
standards or system performance [[Page 7420]] standards would be 
particularly complex and restrictive of the manufacturers' options.
    The Agency developed a new Start Control Cycle (SC01) to be used 
for controlling emissions following intermediate soaks. Initial idles 
and start driving are addressed in SC01 by incorporating the EPA Start 
Cycle (ST01) in its entirety. The balance of SC01 is composed of two 
microtrips of moderate driving, selected from the in-use survey 
database in order to bring the total distance of the new control cycle 
up to match the 3.6-mile distance of the 505 Cycle; the resulting cycle 
is 568 seconds long.25, 26

    \25\The severity of one SC01 acceleration was artificially 
modified to be less severe than in the original microtrip. This 
preserved the design objectives of matching the 505 trip distance 
and reflecting moderate, rather than aggressive driving. The 
representative level of microtransient behavior in the cycle was 
unaffected by this change.
    \26\Analysis of the two microtrips used to complete SC01 shows 
higher power levels than the comparable portion of the 505. The 
Agency plans to replace these microtrips with those which match 
power levels of the 505 more closely. The completed cycle, known as 
SC02, will replace SC01 and serve the same purpose.
---------------------------------------------------------------------------

    A full analysis of the approaches and issues considered, how each 
was evaluated, how the level of emission control was determined, and 
the feasibility of the proposed approach is in the Support Document to 
the Proposed Regulations for Revisions to the Federal Test Procedure: 
Detailed Discussion and Analysis and Technical Reports and comment on 
the analysis is welcome. Comment is specifically solicited on the 
following items:
     The Agency believes that manufacturers should be able to 
control emissions on the SC01 cycle following a soak of from 10- to 60-
minutes to the same gram-per-mile emission levels currently achieved on 
the third bag of the FTP. Comment on the appropriateness of this level 
of standard and method for determining compliance is requested.
     The Agency believes that internal catalyst insulation does 
not pose a temperature-based feasibility problem for underbody 
catalysts.27 However, EPA had insufficient data to reach a firm 
view on this issue for the small number of Tier 1 vehicles which might 
need to insulate close-coupled catalysts. Thus, EPA solicits comments 
or data on the temperature-based feasibility of insulation for close-
coupled catalysts.

    \27\Per vehicles with both under-body and close-coupled 
catalysts, EPA anticipates that only the underfloor catalyst would 
need to be insulated.
---------------------------------------------------------------------------

     The Agency believes that application of catalyst 
insulation as a strategy for control of emissions following 
intermediate soaks is feasible. Data and comments are solicited on the 
feasibility of catalyst insulation and its impact on catalyst operation 
and durability.
     Comments are solicited on strategies to mitigate 
temperature increases in the catalyst brought about by insulation (such 
as moving the catalyst further downstream and subsequently conserving 
exhaust heat ahead of the catalyst to not impair cold start 
performance, or switching to more temperature-resistant noble metals 
like palladium), as well as spinoff effects of such strategies.
     The Agency believes it is necessary to move forward with 
an intermediate soak standard either if a significant proportion of 
vehicles are certified to Tier 1 standards for a significant time 
period following implementation or if it is cost effective and feasible 
to pursue control over intermediate soaks on vehicles certified to the 
lower standards. The Agency requests comment on the issues of cost-
effectiveness and feasibility of an intermediate soak requirement on 
vehicles certified to lower emission standards.
     Criteria are being considered to permit manufacturers to 
forego the data submittal requirement for SC01 testing following a 60-
minute soak on an engine family basis, allowing manufacturers to reduce 
the SFTP soak duration to 10 minutes. Under this option, manufacturers 
would be allowed to submit a technical justification demonstrating that 
an engine family would clearly pass the intermediate soak requirement. 
The Agency solicits comment on this option and potential criteria for 
granting such a waiver.

C. Affecting Air Conditioner Operation

    The Agency analyzed several possible approaches to compliance 
testing designed to control emissions due to
A/C operation. These options hinged on determination of two important 
elements--the choice of a control cycle and the choice of a methodology 
for simulating A/C operation over that cycle. The Agency pursued a 
control program for A/C-on emissions that utilized an emission 
performance standard rather than other control options.
    A full analysis of each option considered, how it was evaluated, 
how the level of emission control was determined, and the feasibility 
of the approach is in the Support Document to the Proposed Regulations 
for Revisions to the Federal Test Procedure: Detailed Discussion and 
Analysis and Technical Reports and comment on the analysis is welcome. 
Comment is specifically solicited on the following items:
     The control cycle for A/C-related emissions being proposed 
is the 866 plus SC01. While the Agency believes these are the best 
cycles for A/C control, comments are solicited on the possibility of 
substituting the 505 component of the LA4 for SC01. Comments are also 
solicited on whether full A/C simulation should be added to the US06 
cycle.
     A cold start test is not included in today's proposal, but 
the Agency does believe that it may be appropriate to return to this 
issue with respect to future technologies and future test procedures 
and emission standards. The Agency specifically solicits comments on 
this issue.
     Independent from determining the appropriate control 
cycles for testing, the Agency evaluated three principle options for 
simulating A/C operation on a given test cycle.28 The Agency 
requests comment on the potential applicability of each option and the 
various methods of implementing each option, whether any specific 
method should be retained as an option in the final rule to allow for 
its future development and use by petitioning for Agency approval. The 
``Nissan-II'' approach is currently being evaluated by a consortium of 
auto manufacturers and the Agency expects to review and evaluate the 
data as soon as it becomes available. The Agency specifically requests 
comments and data that would allow a better evaluation of this approach 
and its viability, as well as suggested improvements that would 
alleviate the Agency's concerns, as detailed in the Support Document to 
the Proposed Regulations for Revisions to the Federal Test Procedure: 
Detailed Discussion and Analysis.

    \28\The three options--bench testing, dynamometer simulation, 
and running test with A/C on--are discussed in more detail in the 
Support Document to the Proposed Regulations for Revisions to the 
Federal Test Procedure: Detailed Discussion and Analysis and the 
Final Technical Report on Air Conditioning for the Federal Test 
Procedure Revisions Notice of Proposed Rulemaking U. S. 
Environmental Protection Agency.
---------------------------------------------------------------------------

     The Agency has estimated that vehicles can maintain 
existing NMHC and CO emission levels with the A/C turned on. For 
NOX, the Agency believes that 25 percent of the NOX increase 
with the A/C engaed is likely to be unavoidable without increasing the 
stringency of the current NOX standard, but is proposing to 
control the other 75 percent. The Agency requests comments on the 
feasibility of this proposed level of control and the technology 
implications of controlling to this level.
[[Page 7421]]

D. Affecting Whole Proposal

    The Agency evaluated four different options to translate the 
proposed level of emission control for US06, intermediate soak, and A/C 
into compliance procedures and appropriate emission standards. The 
first option would set stand-alone standards for each control area. 
Compliance procedures and standards would be established individually 
for aggressive and microtransient driving behavior, A/C, and 
intermediate soaks. The second option would combine the three non-FTP 
areas of control into a single standard. The third option would 
establish a composite standard based on results drawn from both the 
SFTP and the FTP. While the basic concept is similar to the second 
option, the approach is specifically structured to directly implement 
the proposed level of control for each area using bag weights and to 
preserve the existing FTP compliance margins. The fourth option 
considered by EPA would replace the current FTP with an entirely new 
FTP that reflects, as accurately as possible, actual driving behavior.
    A full analysis of each option, how it was evaluated, and the 
feasibility of each approach is in the Support Document to the Proposed 
Regulations for Revisions to the Federal Test Procedure: Detailed 
Discussion and Analysis. Comment on the analysis is welcome. Comments 
are specifically solicited on the following issues which relate to all 
cycles in the SFTP or changes to the FTP.
     Use of a composite non-FTP emission standard was chosen as 
the central approach chosen instead of using individual stand-alone 
standards, a single combined stand-alone standard, a replacement FTP, 
or some other option not considered. Stand-alone standards or a single 
combined stand-alone standard were not chosen primarily because of the 
lack of data to determine appropriate compliance margins and the 
difficulty in determining a single emission level given the disparity 
in emission levels from vehicle to vehicle. Replacing the current FTP 
at this time was not chosen primarily because revising the existing FTP 
would potentially impact the stringency of more stringent emission 
standards currently being considered for different parts of the 
country, such as the California LEV and ULEV standards, efforts by the 
Northeast states to adopt California requirements, and voluntary 49-
state emissions standards (``FEDLEV''). Additional information and data 
are requested on the use of any of these approaches. Comments 
concerning stand-alone standards, or the simple average of the 
composite standards, should include consideration of how to set 
appropriate standards for both intermediate and full useful 
life.29 Durability procedures for new stand-alone standards should 
also be addressed.

    \29\Tier 1 standards were set for two points in the useful life 
of a vehicle--50,000 miles (intermediate) and 100,000 miles (full).
---------------------------------------------------------------------------

     Because replacing the FTP would offer better assurances of 
in-use emission control and would simplify the test procedure, EPA 
believes it makes sense in the long term to consolidate all the test 
requirements into a revised FTP. However, to avoid jeopardizing work on 
more stringent emission standards and to avoid delaying implementation 
of today's proposal, EPA believes it is better to incorporate 
consolidation of the FTP with future consideration of tighter federal 
standards. Comments are solicited on when consolidation should occur.
     Under the non-FTP composite approach, the bag weights for 
each cycle are selected to mirror the proposed level of control 
determined using the in-use driving survey data. (A discussion of the 
proposed level of control for each pollutant and how it was determined 
can be found in the Final Technical Report on Aggressive Driving 
Behavior for the Revised Federal Test Procedure Notice of Proposed 
Rulemaking). Comments are requested on the method used to select each 
weighting factor or the weighting given to each bag when determining 
compliance with the composite non-FTP emission standards.
      Emission standards are proposed to be set at current Tier 
1 FTP levels, with an adjustment made for NOX, and are tied to 
future changes in the FTP standards. Comments on tying the non-FTP 
composite standards to FTP standards, the method used for determining 
the standards, the NoX adjustment provided, or the need for other 
adjustments are requested.
     The Agency considered separating LDVs and LDTs but 
determined driving behavior was similar between these classes. Some 
adjustments are provided in the proposal for specific vehicle types, 
transmission types, and performance rating. Comments on the method used 
for determining these adjustments, the need for other adjustments, or 
other related issues are welcome.
     Very little emission data currently exists on emission 
impacts using fuels other than gasoline during the SFTP. Because of 
this, EPA considered exempting alternative- and/or diesel-fueled 
vehicles from the SFTP requirements, but decided such vehicles would be 
able to comply. Information and data related to applying today's 
proposal to alternative- and diesel-fueled vehicles are welcome.
     The Agency is asking for comments on whether or not it 
would be appropriate to establish a single NMHC+NOX standard for 
stand-alone A/C or soak/start requirements or for the proposed 
composite standards. Comments are also solicited on both the potential 
emission impacts and cost implications of this proposed alternative.
     Comments are requested on the benefits and feasibility of 
the proposed phase-in schedule from MY1998 to 2001. The Agency is 
particularly interested in data and comments on how potential concerns 
with higher catalyst temperatures should influence lead time, as well 
as how these concerns should be balanced with the objective to obtain 
the emission benefits under this rulemaking as quickly as possible. If 
it appears that wholesale elimination of commanded enrichment with 
short lead time could introduce unanticipated problems with catalyst 
deterioration, EPA may elect to spread the implementation of the 
requirements over a longer period in the final rule. Another option 
might be to set an intermediate standard level for the initial phase-
in. Comments are solicited on the relative benefits and costs of an 
intermediate standard compared to a phase-in directly to the final 
standards.
     Today's proposal provides two blanket, automatic 
substitutions from the SFTP to the FTP to reduce testing costs and time 
for manufacturers. No substitution of FTP bags into the SFTP 
calculation is allowed. Flexibility in preconditioning is also provided 
in the proposal. If stand-alone standards are promulgated, EPA is 
considering an exemption from the intermediate soak requirements. 
Comments on any of these aspects or related matters are requested.
     Today's proposal will improve the accuracy of the 
dynamometer simulation of actual on-road operation during vehicle 
testing. In addition, the change in dynamometers to improve accuracy 
also allows modifying the equivalent test weight requirements to remove 
the cap. Comments are solicited on these changes.
     Comments are specifically solicited on the need for 
additional lead time to implement the new road load requirements in 
terms of the dynamometer changes. If data and additional information 
submitted supports longer lead times, the Agency may elect to phase in 
the FTP under the same phase-in schedule used for the new SFTP 
requirements. Under this alternative, any engine family included in the 
SFTP phase-in would also use the improved road load simulations for FTP 
testing. To minimize the laboratory burden of maintaining two different 
sets of dynamometers, EPA would like to couple any phase-in of the new 
road load requirements with procedures allowing an electric dynamometer 
to simulate the existing dynamometer load. Comments addressing new road 
load lead time should also comment on how such a simulation could be 
incorporated.
     Changes to allow ``appropriate'' throttle action and new 
speed tolerance criteria are included in today's proposal. For each 
test cycle, a range of acceptable speed variation is created using the 
DPWRSUM30 variable. Each driving cycle has a unique value of 
DPWRSUM, which is compared to the DPWRSUM calculated from the driver's 
trace (what the vehicle actually drove) to determine a valid test. 
Comments are solicited on these aspects of today's proposal, 
specifically on the proper method for setting the lower DPWRSUM 
threshold for a valid test. [[Page 7422]] 

    \30\DPWRSUM is the sum in the change in power, a statistic which 
is derived from the vehicle speed.
---------------------------------------------------------------------------

XI. Environmental and Economic Impacts

    To estimate the emission reductions associated with the proposal, 
the expected lifetime emission reductions were determined per vehicle 
sold after implementation of the proposed regulations. Baseline 
emissions are taken from the extensive test programs conducted by the 
Agency and the original equipment manufacturers in support of the FTP 
Review Project, as discussed earlier. The weighted averages of the 
emission results of these test vehicles over the various new test 
procedures constitute the baseline emissions used in this analysis.

A. Emission Reductions

    The emission reductions used in this analysis were calculated by 
subtracting the proposed level of control for each control area from 
the baseline test vehicle emissions. These test vehicle reductions were 
then weight averaged to simulate the reductions associated with the 
actual in-use vehicle fleet mix. It should be noted that the test 
results were derived for an average vehicle with a 50,000 mile catalyst 
and do not include any allowance for in-use compliance margins. Thus, 
the emission benefits calculated here are likely to be understated.
    The average emission factor impacts per vehicle associated with the 
proposed regulations are shown in Table 4. The calculated results for 
A/C control listed in Table 4 include a factor to account for driving 
with the A/C ``on'' versus driving with it ``off.'' A recent survey of 
actual A/C operation in Phoenix, AZ found that the compressor was 
engaged about 61 percent of the time during typical ozone exceedance 
days. Thus, the estimated g/mi reduction from A/C control was 
multiplied by 0.61 for inclusion in Table 4.

         Table 4.--Average Emission Factor Reduction Per Vehicle        
------------------------------------------------------------------------
                                               NMHC (g/  CO(g/    NOX(g/
                 Control area                    mi)      mi)      mi)  
------------------------------------------------------------------------
High speed/accel.............................    0.055     2.39    0.062
Soak/start...................................    0.022     0.02    0.037
Air conditioning.............................    0.000     0.00     0.91
------------------------------------------------------------------------

    These emission reduction numbers constitute the emission reductions 
associated with the proposed requirements in g/mi. These g/mi values 
were converted into the estimated lifetime emission reduction per 
vehicle using assumptions about average annual mileage accumulation 
rates, a discount rate of seven percent, and estimated survival rates. 
The results are listed in Table 5; a detailed discussion of the 
methodology can be found in the Regulatory Impact Analysis.

  Table 5.--Discounted Lifetime Emission Reductions Pounds Per Vehicle  
------------------------------------------------------------------------
                 Control area                    NMHC      CO      NOX  
------------------------------------------------------------------------
US06.........................................     10.1      441     11.4
Soak/start...................................      4.1        4      6.8
Air conditioning.............................      0.0        0     16.9
                                              --------------------------
    Total....................................     14.2      445     35.1
------------------------------------------------------------------------

    The tons per summer day emission reductions in various years as a 
result of the proposed test procedure modifications were estimated 
using vehicle miles traveled (VMT) for different model year vehicles 
during each year of interest, the emission factor reductions shown in 
Table 4, and the proposed phase-in schedule. These calculations are 
show in Appendix B of the Regulatory Impact Analysis (RIA) and are 
summarized in Table 5. The percent reduction columns in Table 6 compare 
these estimated tons per summer day (tpsd) emission reductions to the 
baseline emissions for the light-duty fleet (cars and trucks). 
Calculations for these percentage reductions are shown in Appendix C of 
the RIA.

  Table 6.--Fleet Emission Reductions in Tons/Summer Day and Percent of 
                            Light-Duty Fleet                            
------------------------------------------------------------------------
                                  NMHC            CO            NOX     
                            --------------------------------------------
                              tpsd     %     tpsd     %     tpsd     %  
------------------------------------------------------------------------
2005.......................     404      4   12655     11    1000      9
2010.......................     577      6   18047     15    1427     12
2015.......................     694      7   21717     17    1717     14
2020.......................     765      8   23938     18    1892     14
------------------------------------------------------------------------

B. Economic Impact

    The proposed additions to emission test procedures will impose 
several costs on the original equipment manufacturers. These costs 
include added hardware for improved emission control and associated 
development and redesign costs, improved engine control calibrations, 
and increased costs associated with the certification process including 
durability data vehicle testing and reporting.
    The cost estimates correspond to costs incurred by the manufacturer 
in complying with the proposed requirements. These costs can be divided 
into fixed and variable costs. Fixed costs are those costs made prior 
to vehicle production and are relatively [[Page 7423]] independent of 
production volumes. The fixed costs considered in this analysis are 
those for engine control recalibration, vehicle redesign, mechanical 
integrity testing on redesigned engine families, certification 
durability demonstration, annual certification costs, and test facility 
upgrades and construction. Variable costs are costs for the necessary 
emission control hardware and are, by nature, directly dependent on 
production volume. Table 7 presents a summary of the cost estimates 
calculated by the Agency. Discussion of the assumptions and data 
included in these estimates can be found in the RIA.

                   Table 7.--Regulatory Cost Estimates                  
------------------------------------------------------------------------
                                               Annual cost  Cost/vehicle
                                               ($ million)       ($)    
------------------------------------------------------------------------
US06........................................          16.8          1.12
Soak/start..................................   139.4-187.0    9.30-12.47
A/C.........................................          18.3          1.22
    Totals..................................   174.5-222.1   11.63-14.81
------------------------------------------------------------------------

C. Cost-Effectiveness

    The cost-effectiveness estimate represents the expected cost per 
ton of pollutant reduced. The costs presented in Table 7 are not 
necessarily equally spread among the three pollutant emissions (NMHC, 
CO, and NOX). Since the requirements associated with A/C are 
targeted for NOX control, all costs associated with A/C have been 
allocated to NOX. For US06, the costs associated with each area 
have been allocated equally across each pollutant. As the CO reduction 
from soak/start is minimal, the costs associated with soak/start have 
been split equally between NMHC and NOX. Table 8 contains the per 
vehicle cost allocation to each pollutant within each control area.

                  Table 8.--Cost Allocation ($/vehicle)                 
------------------------------------------------------------------------
                       NMHC         CO          NOX           Total     
------------------------------------------------------------------------
US06 costs.......          0.37      0.37          0.37             1.12
Soak/start costs.     4.65-6.23      0.00     4.65-6.23       9.30-12.47
A/C Costs........          0.00      0.00          1.22             1.22
    Total........     5.02-6.61      0.37     6.24-7.83      11.63-14.81
------------------------------------------------------------------------

    Dividing the costs shown in Table 8 by the lifetime emission 
reductions shown in Table 5, gives the cost-effectiveness estimates 
shown in Table 9.

             Table 9.--Cost-Effectiveness Estimates ($/Ton)             
------------------------------------------------------------------------
              Control area                   NMHC       CO        NOx   
------------------------------------------------------------------------
US06....................................          74       2          65
Soak/start..............................   2291-3072      NA   1362-1827
A/C.....................................          NA      NA         153
    Total...............................     707-930       2     355-445
------------------------------------------------------------------------

D. Consumer Impacts

    Two impacts on value to the consumer not included in the above 
estimates are potential savings associated with reduced fuel 
consumption and impact on the horsepower output of some vehicle 
engines. As previously discussed, EPA expects manufacturers to 
eliminate or greatly reduce the amount of commanded enrichment 
currently used in order to meet the NMHC and CO standards for the US06 
control cycle. Due to the lower fuel consumption associated with 
stoichiometric air/fuel control as compared to commanded enrichment, 
this action will result both in a small improvement in fuel economy and 
a small loss in horsepower output. The Agency approximated the fuel 
economy benefit by determining how much extra fuel is used during 
commanded enrichment operating modes and the in-use incidence of these 
commanded enrichment operating modes. The result was an estimated 0.51 
percent reduction in fuel consumption. Using this fuel consumption 
reduction and multiplying it by the miles driven in a given year, the 
appropriate survival rate and a seven percent discount factor, results 
in an estimated lifetime fuel economy savings of $16.56, based on a 
gasoline cost of $0.80 per gallon, excluding state and federal 
taxes.31 A more detailed discussion of fuel economy cost savings 
can be found in the RIA for this rule.

    \31\From Cost Projections, FFA, 1992, updated from DOE/EIA 
Monthly Energy Review, May 1994, and DOT/FHA. According to FHA, 
average sales-weighted state taxes for gasoline were 18.54 cents in 
June 1994. Federal tax is 18.4 cents.
---------------------------------------------------------------------------

    Accompanying the lost horsepower output will be the potential for 
some consumers to consider such affected vehicles as having less value. 
The Agency does not believe that this lost value will be noticed by 
most consumers, as the horsepower loss is quite small, but acknowledges 
its potential effect nonetheless. Due to the difficult nature of trying 
to quantify a cost associated with reduced power output, or reduced 0 
to 60 mph acceleration time, etc., the Agency has not been able to 
quantify the loss in consumer value. However, the Agency believes that 
this cost should be roughly negated by the associated savings in fuel 
expenses. Comments and data are solicited on ways to quantify the 
consumer value of the power loss.
    The Agency does not anticipate that today's proposal will have any 
impact on Inspection/Maintenance programs.

XII. Public Participation

A. Comments and the Public Docket

    The Agency welcomes comments on all aspects of this proposed 
rulemaking. All comments, with the exception of proprietary 
information, should be directed to the EPA Air Docket Section, Docket 
No. A-92-64 (see ADDRESSES). Commenters who wish to submit proprietary 
information for consideration should clearly separate such information 
from other comments by:
     Labeling proprietary information ``Confidential Business 
Information'' and
     Sending proprietary information directly to the contact 
person listed (see FOR FURTHER INFORMATION CONTACT) and not to the 
public docket.
    This will help ensure that proprietary information is not 
inadvertently placed in the docket. If a commenter wants 
[[Page 7424]] EPA to use a submission labeled as confidential business 
information as part of the basis for the final rule, then a 
nonconfidential version of the document, which summarizes the key data 
or information, should be sent to the docket.
    Information covered by a claim of confidentiality will be disclosed 
by EPA only to the extent allowed and by the procedures set forth in 40 
CFR part 2. If no claim of confidentiality accompanies the submission 
when it is received by EPA, the submission may be made available to the 
public without notifying the commenters.

B. Public Hearing

    Anyone wishing to present testimony about this proposal at the 
public hearing (see DATES) should, if possible, notify the contact 
person (see FOR FURTHER INFORMATION CONTACT) at least seven days prior 
to the day of the hearing. The contact person should be given an 
estimate of the time required for the presentation of testimony and 
notification of any need for audio/visual equipment. A sign-up sheet 
will be available at the registration table the morning of the hearing 
for scheduling those who have not notified the contact earlier. This 
testimony will be scheduled on a first-come, first-served basis, and 
will follow the testimony that is arranged in advance.
    The Agency recommends that approximately 50 copies of the statement 
or material to be presented be brought to the hearing for distribution 
to the audience. In addition, EPA would find it helpful to receive an 
advance copy of any statement or material to be presented at the 
hearing at least one week before the scheduled hearing date. This is to 
give EPA staff adequate time to review such material before the 
hearing. Such advance copies should be submitted to the contact person 
listed.
    The official records of the hearing will be kept open for 30 days 
following the hearing to allow submissions of rebuttal and 
supplementary testimony. All such submittals should be directed to the 
Air Docket, Docket No. A-92-64 (see ADDRESSES).
    The hearing will be conducted informally, and technical rules of 
evidence will not apply. Written transcripts of the hearing will be 
made and a copy thereof placed in the docket. Anyone desiring to 
purchase a copy of the transcript should make individual arrangements 
with the court reporter recording the proceeding.

XIII. Administrative Designation

    Under Executive Order 12866 (58 FR 51735), the Agency must 
determine whether the regulatory action is ``significant'' and 
therefore subject to OMB review and the requirements of the Executive 
Order. The Order defines a ``significant regulatory action'' as one 
that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Pursuant to the terms of Executive Order 12866, it has been 
determined that this rule is a ``significant regulatory action'' 
because of annual impacts on the economy that are likely to exceed $100 
million. As such, this action was submitted to OMB for review. Changes 
made in response to OMB suggestions or recommendations will be 
documented in the public record.

XIV. Regulatory Flexibility Act

    The Regulatory Flexibility Act of 1990 requires federal agencies to 
identify potentially adverse impacts of federal regulations upon small 
entities. In instances where significant impacts are possible on a 
substantial number of these entities, agencies are required to perform 
a Regulatory Flexibility Analysis (RFA).
    The Agency has determined that this action will not have a 
significant impact on a substantial number of small entities. This 
regulation will affect only manufacturers of motor vehicles, a group 
which does not contain a substantial number of small entities.
    Therefore, as required under section 605 of the Regulatory 
Flexibility Act, 5 U.S.C. 601 et. seq., I certify that this regulation 
does not have a significant impact on a substantial number of small 
entities.

XV. Reporting and Recordkeeping Requirement

    The information collection requirements in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An 
Information Collection Request document has been prepared by EPA (ICR 
No. 2060-0104) and a copy may be obtained from Sandy Farmer, 
Information Policy Branch, EPA, 401 M St., SW (Mail Code 2136), 
Washington, DC 20460 or by calling (202) 260-2740.
    The information collection burden associated with this rule 
(testing, record keeping and reporting requirements) is estimated to 
average 566 hours annually for a typical manufacturer. However, the 
hours spent annually on information collection activities by a given 
manufacturer depends upon manufacturer-specific variables, such as the 
number of engine families, production changes, emissions defects, and 
so forth. The burden estimate includes such things as reviewing 
instructions, searching existing data sources, setting up and 
maintaining equipment, performing emission testing, gathering and 
maintaining data, performing analyses, and reviewing and submitting 
information.
    Send comments regarding the burden estimate or any other aspect of 
this collection of information, including suggestions for reducing this 
burden to Chief, Information Policy Branch, EPA, 401 M St., SW (Mail 
Code 2136), Washington, DC 20460 and to the Office of Information and 
Regulatory Affairs, Office of Management and Budget, Washington, DC 
20503, and marked ``Attention: Desk Officer for EPA.'' The final rule 
will respond to any OMB or public comments on the information 
collection requirements contained in this proposal.

List of Subjects in 40 CFR Part 86

    Administrative practice and procedure, Air pollution control, 
Confidential business information, Environmental protection, Gasoline, 
Imports, Labelling, Motor vehicles, Motor vehicle pollution, Reporting 
and recordkeeping requirements.

    Dated: January 31, 1995.
Carol M. Browner,
Administrator.
[FR Doc. 95-2833 Filed 2-6-95; 8:45 am]
BILLING CODE 6560-50-P