Proposed Regulations for Revisions to the Federal Test Procedure
for Emissions From Motor Vehicles
[Federal Register: February 7, 1995]
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).
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
Technology Transfer Network Top Menu: <T> GATEWAY TO TTN TECHNICAL
AREAS (Bulletin Boards) (Command: T)
TTN TECHNICAL INFORMATION AREAS: <M> OMS--Mobile Sources Information
(Command: M)
OMS BBS === MAIN MENU FILE TRANSFERS: <K> Rulemaking & Reporting
(Command: K)
RULEMAKING PACKAGES: <1> [Light-Duty] (Command: 1)
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 <G>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 NOXemissions from
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.
The Agency has established a number of emission standards for motor
vehicles and engines, designed to control air pollution by reducing inuse
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.<SUP>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.
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
<GRAPHIC><TIFF>TP07FE95.000
BILLING CODE 6560-50-C
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.<SUP>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 NOXrequires 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 forces<SUP>4 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.
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 inuse
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.
Supplementary Federal Test Procedure--The SFTP includes three
single-bag emission test cycles: a hot stabilized 866 Cycle<SUP>5 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.
BILLING CODE 6560-50-P
<GRAPHIC><TIF1>TP07FE95.001
<GRAPHIC><TIF2>TP07FE95.002
BILLING CODE 6560-50-C
Elements of the proposed A/C simulation for certification testing
include, a 95 deg.F <plus-minus> 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 ozoneexceedance
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),<SUP>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.<SUP>7 No adjustment factors are proposed for midperformance
(``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
W/P>34 reduction.
normal none.
18 W/P 34
W/P>31 reduction.
normal none.
18 W/P 31
(W/P<18)
Percentages
-------------------------
THC/NMHC CO & NOX
Data/Sec
Jerk Change in power
---------------------------------------------------
Mean of the Mean of the
values (mph/ deviation values deviation
sec) (mph/sec) (mph<SUP>2/sec) (mph<SUP>2/sec)
Driving
Driving NMHC CO NOX
mi.
NMHC (g/ CO(g/ NO<INF>X(g/
Control area mi) mi) mi)
Control area NMHC CO NOX
Light-Duty Fleet
tpsd tpsd tpsd
Annual cost Cost/vehicle
($ million) ($)
NMHC CO NOX Total
![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}