, EPA-AA-SDSB 81-8
Technical Report
A Summary and Analysis of Comments Received in
Response to the EPA/NHTSA Information Request
Regarding the Effects of Test Procedure Changes
on Fuel Economy
by
James Hourihane,
Glenn D. Thompson
and
Edward LeBaron
November 1980
NOTICE
Technical Reports do not necessarily represent final EPA decisions
or positions. They are intended to present technical analysis of
issues using data which are currently available. The purpose in
the release of such reports is to facilitate the exchange of
technical information and to inform the public of technical devel-
opments which may form the basis for a final EPA decision, position
or regulatory action.
Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control-
-Office of Air, Noise and Radiation
U.S. Environmental Protection Agency
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CHAPTER 1
INTRODUCTION
This document presents, summarizes and analyzes vehicle
manufacturers' responses to the joint EPA/NHTSA request for in-
formation on the effects on fuel economy of changes made in the EPA
test procedures since 1975. The responses were solicited by
mailing the EPA/NHTSA questionaires dated on March 12, 1979 to the
vehicle manufacturers. Comments were received from Toyota,
Volkswagen, General Motors, Ford, Chrysler, and American Motors.
We would like to express our appreciation for the efforts required
of the manufacturers in the preparation of their very informative
comments. We hope that this analysis will be of corresponding
value to its readers.
This document is divided into eight chapters. Each of chap-
ters 2 through 8 discusses one of the seven subject categories of
the original questionnaire, namely: the fuel economy effects of
shift schedules, alternate dynamometer adjustments, accessories,
inertia weight changes, emission standards, a general category, and
light-duty truck road load.
Each chapter consists of a presentation of the EPA/NHTSA
introductory statement and questions posed to the manufacturers.
Each question is followed by a summary of the comments received
from the automobile manufacturers. In those areas where sufficient
information was made available to the EPA an analysis and a summary
of the issue are presented.
Summaries of the responses to each question by the individual
manufacturers are provided as appendices to this report.
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CHAPTER 2
SHIFT SCHEDULE MODIFICATIONS
I. Introductory
In 1975, EPA regulations provided that test vehicles with
manual transmissions would normally be shifted at 15, 25 and 40
mph. In order to provide more appropriate (representative) shift
schedules for unusual vehicles, the regulations also provided the
option of shifting at shift points recommended by the manufacturer.
On July 16, 1976 the 15, 25 and 40 mph default shift points
were deleted from the regulations and all vehicles shifted accor-
ding to their manufacturer's recommendation to the ultimate
purchaser. EPA soon began to receive shift point requests which
appeared to be selected primarily to minimize emissions or to
maximize fuel economy, and did not seem to reflect consumer
use of the vehicle. EPA investigated this problem and concluded
that many of the shift schedules requested by vehicle manufacturers
were unrepresentative of typical vehicle use.1/,2/
In order to ensure more representative shift schedules in the
future, EPA defined acceptable shift schedules in Advisory Circular
No. 72 which provides that the allowable shift schedules are either
the 15-25-40 mph schedule originally presented in the regulations,
a shift schedule developed by EPA which is based on a percentage of
the maximum recommended engine rpm, or any other recommended shift
schedule which is based on typical vehicle use data.
II. Summary of Comments
Question 1: "in 1974, and separately in 1975, what percentage
of your product line was represented by test vehicles shifted at
speeds other than the 15-25-40 mph schedule?"
N Answers: Five respondents stated that 100 percent of their
1974 product line was represented by test vehicles shifted at
15-25-40 mph. One respondent stated their test vehicles were not
shifted according to the 15-25-40 mph schedule.
Four of the respondents stated that 100 percent of their 1975
product line was represented by test vehicles shifted at 15-25-40
mph; the fifth respondent stated that all of their carlines and 93
percent of their trucklines were shifted using the 15-25-40 mph
schedule: the sixth stated that most of their vehicles were shifted
at speeds other than 15-25-40 mph.
Question 2: "For those vehicles shifted at other than the
15-25-40 mph schedule, what shift speed schedules were used?"
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Answers,: For 1974 only one respondent stated that shift
schedules other than the 15-25-40 mph schedule had been used.
Their shift schedules were:
18-40 mph (LDV),
18-30 mph (LOT),
and 18-30-40 mph (LDT)
For 1975, two respondents stated that alternate shift sched-
ules had been used. These schedules were as follows:
Vehicle Speed at Shift Points (mph)
lst/2nd 2nd/3rd 3rd/4th
10 20 40
20 30
20 35
20 20
20 30 40
10 15 30
20 25 30
25 25-40*
15 18-25* 40
* Shift whenever a cruise within the specified range has been
reached.
Question 3: "What data are available to indicate that those
1974 and 1975 alternate shift schedules were more representative of
consumer use than the 15-25-40 mph schedule?"
Answers; No respondents provided data to indicate that the
alternate shift schedules were more representative of consumer
use. Two of the respondents stated that in their owner's manuals,
they have advised their customers to use the alternative shift
schedules because: (1) they, "recognized the in-use fuel economy
improvement possible" or (2) "it is our obligation to recommend
customer operation of the vehicle that is both practical and
efficient." A third respondent stated that they recommended the
alternate shift points through the owner's manual because, "it was
appropriate for off-road" manual transmission type vehicles.
Question 4: "What shift schedule changes have been typically
used after 1975?"
Answers: One of the respondents indicated that they had used
alternate shift schedules but did not describe them numerically.
Another respondent stated that they did not deviate from the
15-25-40 mph shift schedule totally. A third noted that they had
deviated once and used a 15-25-30 mph shift schedule on two of
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their models. The last three respondents used one or more of the
following shift schedules:
a) 20-25 mph
b) 20-35 mph
c) 20-25-40 mph (shift whenever cruise speed has been
reached)
d) 5-15-25 mph
e) 10-15-30 mph
f) 10-20-30 tnph (shift directly to 4th gear once stabilized
at 25 mph)
g) 10-20-35 mph (shift directly to 4th gear
once stabilized at 25 mph)
h) 10-25-25-mph (shift directly to 4th gear once stabilized
at 25 mph)
i) 15-25-40 mph (shift directly to 4th gear once stabilized
at 25 mph)
j) 20-25-30 mph
k) 20-30-40 mph
1) 16-17-38 mph (based on RPM)
m) 13-^24-31 mph (based on a consumer survey)
n) 10-20-35-45 mph
o) 10-20-35-45* mph (*cruise = 25 mph)
p) 15-26-37-57 mph
q) 15-26-38-58 mph
r) 10-20-40 mph
s) 15/18-25/30 mph
t) 10/15-20/25-30 mph
Question 5: "What effect has the use of these post-1975 shift
changes had on specific fuel economies?"
Answers: One respondent stated that they had not determined
the effects of these changes on fuel economy. Another respondent
using a 1977 model year vehicle, compared the fuel economies
obtained with the 15-25-40 mph and an alternate shift schedule and
observed that their alternate shift schedule realized a city fuel
economy increase of 13 percent (3.0 mpg). A third stated that
one of their vehicles showed an 8 percent reduction in fuel economy
caused by the 1979 shift schedule restrictions. The fourth re-
spondent stated that tests performed with several vehicles using
their recommended and the EPA's (RPM method) shift schedules
resulted in city fuel economy losses of from 6.4 to 17.8 percent
(1.4 to 2.6 mpg). The last respondent stated that their 1979
certification program caused a reduction in measured fuel economy
of about 1.0 mpg (composite).
Question 6: "What effect has the use of these post-1975 shift
changes had on your corporate average fuel economy?"
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Answers: The responses of those commenters claiming an
effect on their CAFE are summarized in the following table.
Estimated CAFE Effect
Respondent LDV LPT
A 2% (0.40 mpg) 5%
B 0.06 mpg 0.13 mpg
C 0.08 mpg
D 0.30 mpg 0.60 mpg
Question 7: "What data can you present to indicate that these
post-1975 shift schedules are more representative of consumer
vehicle use than the 15-25-40 mph schedule?"
Answers: Two respondents stated that they had demon-
strated the representativeness of alternate shift schedules on
several of their models and supplied such findings to EPA. One of
these stated that they were conducting similar research on other
engine families.
Question 8: "What data can you present to demonstrate that
the fuel economy improvements obtained with the post-1975 shift
schedules were obtained in consumer use of the vehicles."
Answers: No data were presented in response to this ques-
tion. One respondent suggested that, "if the shift schedules were
optimized with respect to the EPA cycle, the f.uel economy for these
vehicles would be from 2 to 4.5 percent better than that obtained
with 'default1 shift schedule" and "since any survey of consumer
driving patterns is not likely to show shifting at the true optimum
the potential gain . . . would be some fraction of the 2 to 4.5
percent obtainable."
Another respondent stated, "we believe intuitively that our
consumers are witnessing the same comparative gain seen during
testing . . . cycles."
Question 9: "As more efficient automatic .transmissions are
phased in, what will the relationship between manual- and auto-
matic-equipped vehicles be with respect to EPA measured fuel
economy using 1975 and using post-1975 shift schedules?
Answers; Four respondents indicated that as automatic
transmissions become more efficient the fuel economy differential
obtained with automatic and manual transmissions will be reduced.
One of these specifically referred to small vehicles only. Another
indicated that post-1975 manual transmission equipped vehicles were
expected to achieve an average of 8 to 12 percent higher fuel
economies than their automatic transmission equipped vehicles and
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that in 1975 their manual transmission equipped vehicles had
achieved approximately 10 to 15 percent better fuel economies than
those with automatic transmissions.
The fifth respondent did not anticipate that the 10 percent
fuel economy advantage (combined city/highway) that manual shift
transmissions currently have over automatic transmissions would be
overcome in the foreseeable future.
Question 10: "What data can you present to indicate manual
transmissions will be more or less efficient in actual vehicles use
compared with more efficient automatic transmission?"
Answers; One respondent stated that, based on their 1974
study of executive lease vehicles (sub-compact imports and light-
duty trucks), manual transmission vehicles showed an average fuel
economy advantage of 11.5 percent over those with automatic trans-
missions. This respondent also stated that utilization of the
lockup torque converter is expected to improve the automatic
transmission's fuel economy by about 2 percent. "This improvement,
which occurs principally during highway operation, is expected to
reduce the 'in-use' benefits of manual transmissions to the general
driving public from about 10 to about 8 percent." The other five
respondents did not provide any actual vehicle use data.
Question 11: "Do you have any programs underway to optimize
automatic transmission shift schedules to the EPA test cycles? If
so, please describe."
Answers: One respondent stated that they had, "no program
underway to change schedules." Another stated that they, "have
developed a simulation model to obtain automatic transmission
optimized curves for better fuel economy for various driving
modes." A third respondent stated that they had no programs to
optimize automatic transmission shift schedules with respect to the
EPA test cycles, but instead that, "shift schedules are dictated by
customers acceptance of acceleration performance." The fourth
respondent stated that they, "are continuously working to improve
and optimize these transmissions and their shift schedules."
Question 12: The existing shift schedule restrictions allow
you to use any manual transmission shift schedule that you can
demonstrate is or will be in typical use. Do you intend to en-
courage your vehicle purchasers to use alternate shift schedules so
that those schedules can be used during fuel economy testing? Will
this action be accompanied by transmission changes, such as the use
of additional or wide ratio gears? What fuel economy benefits do
you expect?"
Answers: Three respondents noted that the use of alternate
shift schedules will not be encouraged to purchasers. One of the
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above respondents stated that they "are studying and planning to
use wide ratio gear sets in our future manual . . . transmis-
sions." The other three respondents stated that they intended to
encourage purchasers to use alternate shift schedules provided that
it improves fuel economy as well as performance. Two of these did
not indicate whether this action would be accompanied by trans-
mission changes. The third intends to pursue product design
improvements, such as wide ratio transmission gears and added that
"the potential fuel economy gains from manual transmission impro-
vements cannot be recognized with the current EPA certification
procedures."
III. Analysis
In response to the question about the shift schedules used in
the 1974 and 1975 exhaust emission and fuel economy tests, all
but one commenter stated that virtually all of their manual
transmission equipped vehicles were shifted according to the
standard EPA 15-25-40 mph shift schedule.
In 1975, the majority of a large and a small manufacturer's
vehicles were tested with shift schedules which deviated from the
15-25-40 mph shift schedule. Generally, the alternate schedules
requested shifts at higher speeds than the default shift schedules.
These higher speeds tended to occur on the 1st to 2nd and the 2nd
to 3rd gear changes. The prevailing requested shift point speeds
were 20 mph and 30 mph, respectively. No data were presented to
indicate that these shift speeds were more representative of
typical vehicle use than the 15-25-40 mph default schedule.
From 1976 through 1978 the number of alternate shift schedules
requested and used increased. These alternate schedules tended to
call for earlier (lower speed) shifting than the standard sched-
ule. The predominant speeds used for the 1st to 2nd, the 2nd to
3rd, and the 3rd to 4th gear changes were 10, 20, and 30 mph,
respectively.
The respondents stated that these alternate shift schedules
improved the measured fuel economies of specific light-duty vehi-
cles by amounts ranging from 0.2 to 2.6 mpg (6 to.18 percent). The
average effect was approximately 1.2 mpg. This effect, expressed
in terms of a change in mpg, is relatively large, primarily,
because manual transmissions are most frequently used in smaller,
more efficient, vehicles.
Although the effects of the shift schedule changes on specific
vehicles are significant, their effect on the corporate average
fuel economy is much smaller for most manufacturers because of the
small percentage of vehicles sold with manual transmissions.
Estimates of the effect on the CAFE of the alternate shift sche-
dules ranged from 0.06 to 0.13 mpg or approximately 0.3 to 0.6
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percent for light-duty vehicles. For light-duty trucks, the range
of the reported effect was 0.1 to 0.6 mpg. A computed arithmetic
average of the effect on the CAFE is about 0.2 mpg for both LDV and
LDT. This average is not sales weighted and is therefore signifi-
cantly affected by the small sales volume manufacturer whose
product line includes a large fraction of small manual transmission
vehicles.
Advisory Circular No. 72, introduced by EPA for the 1979 model
year, required that if an alternate shift schedule is to be used by
EPA the request for that schedule must be supported by data indi-
cating that the requested schedule is representative of typical
vehicle use. Two manufacturers responded that they had met this
criterion and have used alternate shift schedules for their 1979
and/or 1980 vehicles. (One of these requested an alternate shift
schedule for a turbo-charged vehicle. The requested speeds for
the 1st to 2nd and the 2nd to 3rd gear changes were 13 and 24 mph,
respectively. These were quite near the default, 15 and 25 mph,
speed points. The 3rd to 4th gear change occurs at a point when
the turbo-charger has a significant effect the shift speed and was
substantially reduced from 40 mph to 35 mph.)
No data were presented to indicate that the lower shift speeds
used between 1976 and 1978 were more representative of typical
in-use vehicles than either the higher shift speeds used in 1974
and 1975 or the default shift schedule.
Several manufacturers correctly stated.that the fuel economy
improvements obtained from 1976 through 1978 model years could also
be obtained by in-use vehicles. However, no data was presented to
substantiate that such shift related fuel economy benefits were
actually being obtained by vehicle consumers. One manufacturer
correctly stated that if the "shift schedules were optimized with
the EPA cycle, the fuel economy for these vehicles would be 2 to
4.5 percent better than the 'default' shift schedule" and "since
any survey on consumer driving patterns is not likely to show their
shifting at true optimum, the potential gain . . . would be some
fraction of 2 to 4.5 percent obtainable."
In regard to questions concerning the efficiency of automatic
versus manual transmissions, manufacturers stated that automatic
transmissions will continue to improve and that the fuel economy
disparity between vehicles with automatic and those with manual
transmissions will decrease from the 10 to 15 percent range to the
8 to 12 percent range. No manufacturer indicated that the fuel
efficiencies of improved automatic transmission equipped vehicles
would equal or exceed those of vehicles having manual transmis-
sions.
IV. Summary and Conclusions
In the 1974 model year few vehicles were tested using shift
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.schedule alternates, to the standard 15-25-40 mph schedule.. In 1975
their number and proportion increased. During the 1974 and 1975
model years the alternate shift points selected tended to be at
speeds higher than the 15-25-40 mph default schedule.
From 1976 through 1978 there was a dramatic increase in the
use of alternate shift schedules, but the speeds used during
these years tended to be lower than the standard shift schedule.
Shifting at lower speeds reduces the engine speed and requires that
the engine produce a greater torque. Under conditions of light
engine loading, such as many portions of the EPA test cycle, these
changes in the engine operational state result in increased
engine efficiency.
The use of the requested alternate schedules in typical
vehicle operation was generally not substantiated. It appears that
many of these alternate shift schedules evolved primarily as a
means to improve the EPA measured fuel economy.
Estimates of the effect of alternate shift schedules on the
CAFE of various manufacturers ranged from approximately 0.1 mpg to
0.3 mpg. The variation in the magnitude of the effect primarily
reflects the proportion of manual transmission vehicles in product
lines of the various manufacturers.
Advisory Circular No. 72 requires that if an alternate shift
schedule is used by EPA, the manufacturer must demonstrate in some
fashion that this alternate schedule will be used in typical
vehicle operation. This Advisory Circular has greatly reduced the
use of alternate shift schedules, however, several manufacturers
have met this criterion and alternate shift schedules continue to
be used.
The option of an alternate shift schedule still exists and
this option is currently used to about the same extent that it was
during the 1974 and 1975 model years. Therefore, no reduction in
fuel economy can be claimed due to alternate shift schedules when
comparing "procedures utilized by the Administrator" in 1974 and
1975 versus those utilized at the present time. The recent change
in EPA regulations has not eliminated nor restricted the use of a
technology which would result in improved consumer fuel economy.
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CHAPTER 3
ALTERNATE DYNAMOMETER ADJUSTMENTS .
I. Introductory Statement
EPA has always provided the option that a manufacturer may
request, for specific vehicles, dynamometer adjustments which are
different from the values contained in EPA regulations. A request
for such alternate dynamometer power absorptions must be supported
by road test data demonstrating the appropriateness of the re-
quest. In 1975, the regulations implied that manifold pressure
measurements were the required method of generating acceptable road
load data. Later the manifold pressure approach was deleted and,
subsequently, the coastdown technique has become the prevalent
method of generating supporting data for alternate dynamometer
power absorption requests. An acceptable coastdown procedure,
which has been provided to the industry as an EPA Recommended
Practice, has been distributed as an Attachment to Advisory Cir-
cular No. 55B.
II. Summary of Comments .
Question 1: "To what extent were alternate dynamometer
adjustments (DPA) used in 1974, in 1975? To what extent are they
currently used?"
Answers; One respondent, a foreign manufacturer, noted that
they had used alternate DPAs on two out of nine 1974 models and
four out of nine 1975 models. All other respondents stated that
they had not used alternate DPAs in 1974 or 1975. In 1979 three
respondents noted that between 40 to 87 percent of their light-duty
vehicles used alternate DPAs. One of the respondents indicated
that all of their light-duty trucks used alternate DPAs, too. Four
respondents stated that they intend in 1980 to use the alternate
DPAs for between 75 and 100 percent of their light-duty vehicles.
Question 2: " To what extent has the increased use of alter-
nate dynamometer power absorptions improved your corporate average
fuel economy (CAFE) compared to the CAFE value that would be
obtained if: (1) dynamometer power absorptions from the equation
contained in the current regulations were used exclusively, (2)
dynamometer power absorptions from the inertial weight based table
of the 1975 regulations were used exclusively, or (3) the use of
alternate dynamometer power absorptions were restricted to the
extent they were used in 1974 or in 1975?"
Answers: Four respondents stated that the use of the alter-
nate DPA improved their light-duty vehicle CAFE compared to either
the equation or inertial weight-based table. One respondent
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commented that their LDT CAFE would improve if the 1975 inertial
weight-based table were used for these vehicles. The LDV CAFE
improvements claimed as a result of using the alternate DPA were:
(1) from 0.8 to 1.5 percent, that is, 0.2 to 0.4 mpg relative
to the frontal area equation, and (2) approximately 2.5 percent or
about 0.5 mpg relative to the inertial weight-based table.
Question 3: "To what extent does current EPA policy (ap-
plicable Advisory Circulars) on alternate dynamometer adjustment
restrict your ability to make improvements in vehicle fuel economy
which would be observed in consumer use of the vehicles? Please
describe."
Answers: One respondent stated that the current EPA policy on
alternate dynamometer adjustment does not inhibit their ability to
make improvements of fuel economy which may be observed in consumer
use. Another stated that they have not determined any such ef-
fect. The other four respondents stated that the current EPA
policy on alternate dynamometer adjustment has been restrictive in
improving their fuel economy in the following ways:
a. Additional and extensive testing requirements.
b. Not being credited for improvements of items,
such as optional mirrors, etc.
c. Requiring dynamometer settings to reflect a
33 percent option rate rather than the fifty
percent level.
d. Confirmation procedures inhibit the early imple=
mentation of improved product actions.
e. Late changes and interpretations of require-
ments.
Question 4: "Have the administrative procedures implemented
since 1975 become burdensome to the point that time and money
considerations preclude their use in some instances as compared to
using the standard Federal Register procedures? Provide details.
Answers: All of the respondents stated that the administra-
tive procedures implemented since 1975 have become burdensome but
did not preclude the use of the alternate dynamometer power adjust-
ments even though they recognized the time and expense penalty.
One respondent stated that if the "alternate horsepower values . .
. are close to frontal area numbers" the former values "are often
not submitted to EPA because of added burden resulting from con-
firmatory testing."
III. Analysis
Alternate dynamometer adjustments were only used by one small
manufacturer in 1974 and 1975. Therefore, strict interpretation of
"test procedures utilized by the Administrator in 1975" might
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preclude the use of alternate dynamometer adjustments by most
manufacturers, or restrict their use to a small percentage of the
vehicle fleet. However, this option is the method by which a
manufacturer obtains credit for aerodynamic and rolling resistance
improvements to a vehicle which improve its fuel economy during
consumer use.
Presently alternate dynamometer adjustments are widely used by
major manufacturers for nearly 100 percent of the test fleet.
.As a result of this use, LDV CAFE's have improved by about 0.3 mpg
compared with the results which would be obtained if current
vehicles were tested exclusively according to the 1975 inertia
weight-table, or the equation contained in the current regulations.
Some improvement of measured fuel economy might result if the
1975 table were retained for light-duty trucks. The truck question
is really not germane since the inappropriateness of the weight-
table for trucks was recognized before LDT fuel economy standards
were promulgated and these standards were adjusted to account for
the more realistic dynamometer adjustments which were anticipated
for LDT's. This is basis for Question 1 of Chapter 8, and is
discussed further under that question. .
Manufacturers did comment that current testing requirements
were somewhat burdensome, and therefore, alternate dynamometer
adjustments were only requested when significant benefits would
be obtained. One manufacturer commented that EPA policy prevents
credit for some improvements such as optional mirrors. However,
since a manufacturer has the option of testing multiple vehicles,
both for alternate dynamometer power absorptions and for fuel
economies, this response is really another version of the earlier
statement that alternate dynamometer power absorptions are used
only when sufficient benefit is obtained.
It should be noted that the use of alternate dynamometer power
absorptions is an optional procedure to be used at the discretion
of the manufacturer. When its use is elected the manufacturer
logically incurs the burden of supplying data to support the
requested alternate dynamometer power absorption. One manufacturer
specifically stated that confirmatory tests required by EPA to be
conducted by independent testing organization cost more than
$3,000.
This may well be too great a "burden" when the proposed
improvement is an optional mirror. It should be noted, however,
that all major manufacturers and many small manufacturers ex-
tensively use alternate dynamometer power absorptions.
IV. Summary and Conclusions
The use of alternate dynamometer power absorptions.currently
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yields approximately 0.3 rapg improvements in corporate average fuel
economies compared xvith those, which would be obtained using the
1975 inertial weight table. Although this option was not exten-
sively used in 1975, it is the only mechanism by which, a manu-
facturer receives fuel economy credit for improvements in vehicle
aerodynamics or tire rolling resistance and should be retained to
provide incentive in these areas.
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CHAPTER A
ACCESSORIES
I. Introductory Statement
"EPA now uses a carline/truckline designation rather than an
engine family designation for assigning accessory load. Addition-
ally, carline and truckline have been redefined to some degree.
Other than this no apparent changes have been made in the EPA test
procedure which would affect the simulation of vehicle acces-
sories ."
II. Summary of Comments
Question 1: "Has the carline/truckline approach for assigning
accessory load had an effect on your corporate average fuel econ-
omy? How? To what extent?"
Answers: All of the respondents except two, claimed that
switching from the engine family approach to the carline/truckline
approach did not affect or had no significant effect on their
CAFE. One of the two dissenters stated that the 1980 accessory
selection rule, which determines the 33 percent option criterion by
carline, caused their effective test weight to increase slightly
and coupled with "some resultant additional power absorber penal-
ties" resulted in a 0.1 mpg decline in the 1980 CAFE for their
carlines and a 0.3 mpg CAFE decline for their trucklines. The
other dissenting respondent claimed that the switch from engine
family accessory loading to truckline accessory loading in 1980 had
reduced the fuel economy of their 2-wheel drive' truck fleet by 0.1
mpg.
Question 2: "Do you believe that there have been other
changes made in the EPA test procedure which affect the simulation
of the load imposed on the engine by vehicle acessories? What
changes? What effect?"
Answers; None of the respondents were aware of any other
changes in the EPA test procedure that have affected accessory load
simulat ion.
Question 3: "There appears to be an increasing use of acces-
sories, such as air conditioners, in small vehicles. Is the
current EPA simulation of air conditioning (10 percent increase in
the dynamometer power absorption) adequate since such smaller
vehicles generally have reduced dynamometer power absorptions?"
Answers: Most respondents stated that the current 10 percent
increase in the power absorption of the dynamometer to simulate the
fuel economy effect of air conditioning was appropriate for both
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large and small vehicles. One non-concurring respondent commented
that the current EPA simulation of air conditioning results in a
1.7 percent fuel economy penalty for large vehicles and a 2.3
percent fuel economy penalty for small vehicles and, therefore,
small vehicles are more heavily penalized. Another respondent
concurred with this observation but also commented that this was
appropriate since the fuel economy effect of air conditioning was
greatest on the smaller, typically lower power-to-weight ratio
vehicles.
One respondent commented that their subcorapacts are penalized
relative to the larger vehicles since their average air condition-
ing installation rate (48.7%) is less than that of larger cars,
i.e., compact (75.3%), intermediate (80.2%), and full-size cars
(95.6%). Yet EPA treats all of the classes equally since in all
instances the installation rate exceeds 33 percent.
Question 4: "What would be the effect on your corporate
average fuel economy of a more realistic simulation of the air
conditioning load."
Answers: Three of the respondents stated that the current
simulation of air conditioning load is probably reasonable and
"realistic" as an average annual effect. Four respondents indi-
cated improvement of this procedure would add "to further compli-
cation to test procedures" and one stated that the cost impact of
the procedures would be prohibitive.
With regard to the fuel economy effect of operating vehicle
air conditioners, one respondent stated that their vehicles exper-
ienced a 5 to 10 percent fuel economy penalty. Another stated that
using vehicle air conditioning under FTP ambient conditions would
result in about a 9 percent fuel economy penalty.
In comparison, three respondents stated that the 10 percent
increase in the power absorption (PAU) setting used by EPA to
simulate vehicle air conditioning resulted in approximately 2 to 4
percent fuel economy loss for their smaller vehicles and only 2
percent or less for their larger ones.
Question 5: "What would be the effect of- a more realistic
simulation of other engine driven accessories which are not fully
utilized in the EPA test procedure (power steering;, engine cooling
fan, electrical system load) on your corporate average fuel
economy?"
Answers: Two respondents stated that they had neither con-
ducted any studies nor collected any data on the effect of the
simulation of other engine-driven accessories on their corporate
average fuel economy. One 'respondent stated that a more realistic
simulation of power steering (movement of the steering wheel back
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and forth, to activate the system) .would have a negl igible. effect on
fuel economy. Another suggested that, at straight ahead driving,
the EPA measured fuel economy is slightly better than consumer
use. One respondent claimed that operation of the electrical
systems would reduce fuel economy.
Quest ion 6: "Has the lack of accurate representation of
accessory loading precluded or inhibited your development of more
efficient accessories or accessory drives?"
Answers: All respondents commented that whether or not
accessory loading is realistically represented, this would not
preclude or inhibit the development of more efficient accessories
in order to improve consumer fuel economy.
III. Analysis
The manufacturers unanimously concurred that the change from
engine to carline/truckline classification was the only change in
the EPA procedure which has affected the treatment of accessories.
Most manufacturers stated that switching from engine family to
the carline approach for assigning accessory load had no signifi-
cant effect on their LDV CAFE. However, one manufacturer did claim
the change reduced their 1980 CAFE 0.1 mpg. In the case of the
change from engine family to truckline for assigning accessory
loads, two manufacturers commented that this change caused a
negative effect of 0.1 mpg to 0.3 mpg on their truckline CAFE. A
detailed explanation of how this occurred was not provided, however
reference was made to an earlier more detailed" .submission to DOT.
It is important to understand how fuel economy could be
affected by this change in EPA regulations. Consider, for example,
light-duty trucks. Previously, vans and pick-up trucks would have
been grouped together in a single engine family. If there were
equal sales of trucks and vans and, for example, 50 percent of all
vans were equipped with air conditioning but only 10 percent of the
pick-ups were air conditioned, then air conditioning would be
present on only 30 percent of the trucks in the engine family and
EPA would have considered a non-air conditioned vehicle as appro-
priate to represent the sales fleet.
At the present time, EPA separates sales by truckline into
pick-up trucks and vans. If a van were selected as the test
vehicle, then, since 50 percent of these vehicles were equipped
with air conditioning the vehicle would be tested as an air con-
ditioned vehicle. Consequently, the vehicle would be tested with a
10 percent greater dynamometer power absorption and possibly at an
increased test weight resulting from the additional weight of
the air conditioner.
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In all instances it should be noted that, as a result of the
change to carline/truckline, the selected vehicle was always tested
in a manner more appropriate for the carline/truckline repre-
sented. Furthermore, a manufacturer who believes that the selected
test vehicle does not adequately represent the product line, has
the option of supplying additional test data or additional test
vehicles.
In response to the question regarding the appropriateness of
the current air conditioner simulation, particularly with respect
to smaller vehicles, the general comment was that the current 10
percent increase in dynamometer power absorption was appropriate
to simulate the average annual effect of air conditioning for all
vehicle sizes. However, no reference to any data or detailed study
was provided.
One manufacturer did comment that the selection criteria (air
conditioner simulation if more than 33 percent of carline is
equipped with air conditioners) tended to penalize subcompacts more
heavily than other vehicle categories. This was so because al-
though air conditioners were sold on only slightly more than 40
percent of their subcompact vehicles, they were installed on
virtually all full-sized vehicles, and the same percentage dyna-
mometer adjustment penalty applied to the test vehicle representing
the subcompact vehicles as was applied to the full-sized test
vehicle.
Most manufacturers concurred that the 10 percent increase in
dynamometer adjustment used by EPA to simulate the effect of air
conditioners caused a 2 to 4 percent decrease in measured vehicle
fuel economy. EPA estimates of the effect of air conditioner
simulation are generally in the lower portion of this range.3/
In response to a question on the effects of more accurate air
conditioner simulation most manufacturers protested that this could
be prohibitively complex and expensive. One manufacturer did
comment that actual use of air conditioners reduced vehicle fuel
economy by 5 to 10 percent, and therefore, more accurate simulation
of actual use would have a similar effect.
One approach, generally not considered, would be for EPA to
accurately simulate actual air conditioner use. Then consumers
could be presented with a much more significant estimate of the
cost in fuel economy, of air conditioning and would have greater
incentive to choose more fuel efficient vehicles. Also with
this approach, the air conditioning penalty could be applied to
whatever percentage of vehicles were actually sold with air condi-
tioning, thus eliminating the manufacturers objections that all
classes of vehicles, in which more than 33 percent were equipped
with air conditioning, are tested equally. This approach would
require some additional testing to accurately assess the actual
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effect of the air conditioner. This testing would not necessarily
be prohibitively expensive since air conditioners are probably
similar enough over a large segment of any manufacturer's product
line that few vehicles would have to be tested.
As for other engine-driven accessories, some manufacturers
suggested that although the power steering and electrical systems
may cause a reduction in measured fuel economy any effect would be
small compared to that of air conditioning.
Finally, manufacturers commented that, even though not cred-
ited in the EPA test procedure, the efficiency of engine acces-
sories will continue to be improved to provide improved consumer
fuel economy. In this regard however, it should be noted that
although DOT has projected significant consumer fuel economy
improvements through improved accessory drive mechanisms, such
drives, which would show little benefit on the EPA test procedure,
do not seem to be actively considered by manufacturers.
IV. Summary
The change in assigning accessory load from engine to carline/
truckline families could have had an effect on measured CAFEs.
Only one manufacturer claimed such an effect for its LDV CAFE while
two manufacturers claimed their LDT CAFEs were affected. This
change was made' to improve the accuracy of the simulation of the
represented vehicles and has resulted in more accurate testing of
the represented production vehicles. Additionally, it should be
noted that manufacturers have the option of submitting additional
test data or additional test vehicles if they, wish more accurate
representation of their entire product line.' The use of this
option would tend to eliminate any CAFE effects of the EPA change
to carline/truckline.
The air conditioner simulation currently used by EPA under-
states the fuel consumption effects of actual air conditioner use.
This simulation may be appropriate to predict the national aggre-
gate effect of annual air conditioner use, however, no detailed
study has been made to confirm this.
In general, the manufacturers have commented that more fuel
efficient accessories and accessory drives are being developed to
improve consumer fuel economy even though little benefit is ob-
tained from the effort in the EPA tests. However, little evidence
of significant improvement in these areas has been seen.
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CHAPTER 5
INERTIA WEIGHT CHANGES
I. Introductory Statement
"Beginning with the 1980 model year, EPA reduced the incre-
ments of simulated inertia by approximately a factor of two (from
500 pounds to 250 pounds for vehicles over 4,000 pounds). This
change was made to provide more accurate simulation of the test
vehicle weight."
II. Summary of Comments
Question 1: "If the current test weight increments were
applied first to the 1974 test vehicle fleet, then to the 1975 test
vehicle fleet, what percentage of those vehicles would have been
tested.at higher simulated inertia? At lower simulated inertia?"
Answers: If the current inertia weight increments had been
applied to the 1974 and 1975 fleets, the percentage of the vehicles
that would have been tested at the lower and at the higher simu-
lated inertias are as follows:
In the case of the 1974 test fleet (no responses from the major
manufacturers):
Respondent
A
B
Vehicles (%)
Tested at the
Higher Inertia
27
50
100
11
Vehicles (%)
Tested at the
Lower Inertia
9
0
0
11
Remarks
LDT (Family 1)
LOT (Family 2)
In the case of the 1975 test fleet:
Respondent
A
B
C
D
Vehicles (%)
Tested at the
Higher Inertia
0
24
75
28
19
Vehicles (%)
Tested at the
Lower Inertia
0
0
0
31
18
Remarks
LDT
LDV
LDT
Note: Response D represents the greatest number of sales by a
major manufacturer.
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Question 2: "If. the current test vehicle fleet were tested
using the pre-1979 inertia increments, what percentage of vehicles
would be tested at the higher simulated inertia? At the lower
simulated inertia?"
Answers: With regard to the current test vehicle fleet, the
percentage of vehicles that would have been tested at the higher
and the lower simulated inertia categories are as follows:
Respondent
A
B
C
Vehicles (%)
Tested at the
Higher Inertia
0
9
10
0
3
21
Vehicles (%)
Tested at the
Lower Inertia
100
31
40
60
75
17
Remarks
LDT
LDV
LDT
LDV
One respondent stated that if their 1979 model year fleet were
tested according to the 1980 test procedure, their fleet average
test weight would increase 112 pounds.
Question 3: "What additional improvements in the EPA measured
fuel economies would have been obtained if this change in EPA
inertia categories had not been made? What data exists to indicate
that these EPA measured fuel economy improvements would have been
realized by the consumer use?"
Answers: Five of the six respondents stated that the change
in inertial weight increments resulted in a reductions in mea-
sured fuel economies of from 0.1 to 0.3 mpg. The sixth stated that
their answers to the question were "undertermined."
Only two respondents directly addressed the second part of the
question, both stated that the change would not be detectable to
the consumer.
Question 4: "What was the average difference between produc-
tion vehicle weights and the EPA simulated vehicle weights deter-
mined under the 1980 procedures? Under the pre-1980 procedures?"
Answers: Only one respondent provided data. Under the
pre-1980 model year regulation, the production vehicle weight was
greater than the EPA simulated vehicle weight by 27.9 pounds.
Under the 1980 regulation the production vehicle weight is 4.2
pounds less than the EPA simulated vehicle weight.
Question 5: "Are the above claimed effects permanent or
If transitory, what percentage of your fleet is
for how long? Please explain your answer."
trans itory?
affected and
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Answers: Four respondents stated that the effects were
permanent. One stated that the fuel economy loss would eventually
level off and the sixth stated that the effects were transitory
because the sensitivity of fuel economy is anticipated to be
changeable depending on future design modifications.
III. Analysis
If the 1979 inertia simulation weights were applied to the
1974 and 1975 test vehicles, there would have been little net
effect. As one commenter observed, "As of 1975, the actual weights
of ... passenger cars and light trucks were more or less randomly
distributed within each inertia weight category."
As vehicle downsizing occurred manufacturers directed their
goals toward the EPA inertia categories, and consequently in 1979
vehicles tended to be grouped near the upper regions of the cate-
gories. This motivated EPA to decrease the test weight category
increments and, thereby, to improve the accuracy of the simulation
of the vehicle road experience during the EPA tests. As expected,
this frequently reduced the measured vehicle fuel economy for
current vehicles. Most commenters expressed the opinion that the
resulting decrease in 1980 corporate average fuel economy was
approximately 0.2 mpg.
This decrease in corporate average fuel economy was a result
of improved test accuracy and did not affect in-use vehicle fuel
consumption. This position is supported by comments indicating
that the average difference between the vehicle design and the EPA
tests weights significantly decreased in 1980 and also by comments
stating that the in-use.vehicle fuel consumption would be un-
changed.
Most commenters objected to the change to smaller inertial
weight increments on the basis that this change eliminated some of
the gains in measured fuel economy which were made in the 1977 and
1978 model years. While these gains may not have represented real
progress in reduction of in-use fuel consumption, they were,
nevertheless, used in the progress of establishing fuel economy
standards for future model year vehicles.
Several manufacturers commented that the changes in inertial
weight increments had a permanent effect on measured fuel econ-
omies, but others stated that the effect was transistory. It is
more logical to consider the effect transistory since any losses
can be recovered in future weight reduction programs, since a
manufacturer would receive credit for smaller increments of
weight reduction. Therefore, benefits may be obtained from design
refinements rather than major redesign efforts.
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IV. Summary and Conclusions
In 1979 EPA reduced the increments of simulated vehicle weight
used during the EPA fuel economy test for the purpose of improving
the accuracy of the simulation of the vehicle road experience
during the EPA tests.
This change reduced the measured fuel economy of many 1980
model year test vehicles because these vehicles tended to fall near
the upper bounds of the previous test weight categories. The
reduction in the test weight increments would have had little
effect if applied to the 1975 test fleet. Therefore, this change
in test procedure yields results which are equivalent to those
obtained from the test procedure used in 1975.
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CHAPTER 6
EMISSION STANDARD MODIFICATIONS
I. Introductory Statement
In other areas of this questionnaire it is important that the
issue of test procedure changes is not confused with comments
related to emission standards. However, since some manufacturers
may wish to comment in issues related to emission standards the
following questions are presented.
II. Summary of Comments
Question 1; "Has the imposition of the 1981 emission stan-
dards (0.41 g/mi HC, 3.4 g/mi CO, and 1.0 g/mi NOx) inhibited the
development of alternate engines and control strategies relative to
conventional spark ignition (SI) engines?"
Answers: The respondents stated that the imposition of the
1981 emission standards has inhibited the development of alternate
engines and control strategies in two ways. Three respondents
stated that the development efforts to meet the 1981 emission
standards, as well as the current fuel economy standards, have
diverted their capital and manpower resources from the alternate
engine programs. Four respondents stated that they have been
devoting resources in the development or improvement of
alternate engines but were having difficulty meeting the 1981
emission standards with them.
The diesel engine was frequently mentioned as an example of
an attractive alternate engine, at least from the fuel economy
standpoint, however, several manufacturers commented that current
technology on diesel engines could not simultaneously meet the 1.0
g/mi NOx standard and the proposed particulate standard.
Question 2: "On September 19, 1978, EPA distributed a draft
Advisory Circular with regard to emissions at temperatures and
operating conditions typical of the urban environment, such as
vehicle operation at 50°F, but not specifically evaluated by the
FTP. What effect would this draft Advisory Circular have on your
present corporate average fuel economy? What effect would it have
on your future ability to improve fuel economy as measured on the
EPA tests and in consumer use? In particular, what would be the
effect of this draft Advisory Circular on the use of electronics
and on the use of other new types of fuel economy improvement
technology such as turbocharging, and variable displacement en-
gines? What data are available to support your response?
Answers: The majority of respondents stated that they did
not have sufficient data available to assess the potential effect
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this Advisory Circular might have, or that the application of the
Advisory Circular was. not sufficiently clear to allow an assessment
of the effect.
Three respondents did state that fuel economy would decrease
with decreased ambient temperature. One of these cited a study
conducted by the Canadian government.
Question 3: "What effect did the change by Congress of the
1978 light-duty Vehicle Emission Standards (0.41 g/mi HC, 3.4 g/mi
CO, and 0.4 g/mi NOx) to 0.41 g/mi HC for 1980, 3.4 g/mi CO for
1981 (with possible waiver to 7.0 g/mi), and 1.0 NOx for 1981 have
on your 1978 through 1985 corporate average fuel economies? Please
answer separately for conventional SI engines, stratified charge SI
engines and diesel engines."
Answers: Two respondents indicated that the relaxation of the
emission standards by Congress had a positive effect on fuel
economy when compared to the effect which would have been obtained
if the original more stringent standards had remained. One re-
spondent stated that the relaxation of standards avoided a fuel
economy penalty of 5 percent in model year 1980 and.3 percent for
subsequent model years. Three other respondents stated that they
were unable to assess the magnitude of the effects.
One respondent stated that failure to grant a 1980 model year
NOx waiver or the promulgation of stringent particulate standards
may preclude the inclusion of the diesel engine in their corporate
fleet. The anticipated effect of this loss on CAFE would be 0.4
mpg in the 1982 model year and 0.8 mpg in the 1985 model year.
Question 4: "Are any synergistic effects present when simul-
taneous changes are made in emissions standards and test proce-
dures, which do not occur when one of those factors is changed
alone? Explain."
Answers: One respondent stated that they do not believe that.
there are inherent synergistic effects, three respondents indicated
that this was undetermined, and two indicated that an antagonistic
effect was evident, primarily because of leadtime constraints.
III. Analysis
This area of the questionnaire addressed the effects of
emission standards on the development of alternate engines. An
analysis of this section of the questionnaire responses has not
been provided since the main EPA concern herein is with the effects
on fuel economy of changes in test procedure and also because very
little alternate information in this area is available.
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IV. Summary
Since no analysis of this section of the questionnaire was
made the following statements, a condensation of the received
comments, are not necessarily indicative of EPA conclusions.
Most respondents commented that the current emission standards
inhibit the development of alternate engines or control strategies
either because of the demands on their resources of meeting the
standards with conventional engines or because of the cost or
because of the uncertainty of meeting current standards with
alternate engines.
With regard to the effects of a proposed Advisory Circular on
measuring fuel emissions and fuel economy under conditions not
specifically evaluated by the current test procedure: most manu-
facturers commented that the effects of the application of this
Advisory Circular were undetermined.
According to the majority of respondents, the relaxation of
the NOx emission standard by Congress from 0.4 g/mi to 1.0 g/mi and
the postponement of the HC and CO statutory standards resulted in
fuel economy gains compared to fuel economies obtainable under the
original more stringent standards. One respondent stated that this
relaxation of the standards avoided a fuel economy penalty of 3 to
5 percent. Most of the respondents did not quantify the effect.
Several manufacturers commented that there is an antagonistic
effect when both emission standards and test procedures are changed
simultaneously because of generally inadquate leadtimes. Other
commenters indicated that no synergistic effects were experienced.
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CHAPTER 7
GENERAL QUESTIONS
I. Introductory Statement
"The following questions are not within the previous [or
subsequent] question groups. However, since they address areas
where some changes may have occurred, your comments are reques-
ted."
II. Summary of Comments and Analysis
In this chapter the summary of the comments, the analysis, and
any conclusions are presented after each individual question since
the questions are not grouped by subject.
Question 1; "Emissions and fuel economy tests are performed
on vehicles which are specially prepared by the manufacturer for
these tests. Would there be an effect on your corporate average
fuel economy if production vehicles were randomly selected for fuel
economy testing? What effect do you estimate?"
Answers: Two respondents stated that there would be little or
no effect on their CAFE. Two respondents believed that the pro-
duction vehicle would have a higher fuel economy than its proto-
type. Others responded that the difference would be unpredictable
and the procedure impractical.
Analysis: EPA tests have indicated that in some instances
production vehicles appear to obtain lower fuel economies than
their prototypes tested during the certification process. _4/, 5_/
Question 2: "What data can you present to indicate that the
fuel economy improvements measured on the EPA tests have also
occurred in consumer vehicle use?"
Answers: Some respondents stated that consumer in-use fuel
economy is lower than the fuel economy measured by the EPA test
procedure. One respondent stated, that this discrepancy is de-
creasing. Two others stated that the EPA's fuel economy data is
closely representative of the actual fuel consumption of in-use
vehicles. Two manufacturers did not provide data.
Analysis: Investigations by EPA concur that, in general, fuel
economy improvements measured according to the EPA test procedure
also occur in consumer vehicle use. However, EPA and DOE observa-
tions indicate that the difference between in-use fuel economy and
that measured by EPA is increasing. One manufacturer concurred
with this EPA observation and commented that while their fuel
economy shortfall has increased over the years, their fuel con-
sumption shortfall has remained constant at 0.01 gal/mi.
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Question 3: "Prior to the 1975 model year, all EPA fuel
economy measurements were conducted on vehicles selected by. EPA.
Many of these selected vehicles were "worst case1 offenders from an
exhaust emission standpoint. Did these vehicles also tend to be
the 'worst case1 vehicles from a fuel economy standpoint? Since
1975, EPA has allowed testing of vehicles selected by the manufac-
turer in the fuel economy program. To what extent has your corpor-
ate average fuel economy been improved since 1975 by the addition
of these potentially favorable test vehicles?"
Answers: The general consensus among the commenters was that
"worst case" emissions vehicles tended to be "worst case" fuel
economy vehicles.
Most respondents stated that the inclusion of the fuel economy
data vehicles had improved their CAFE between 0.06 to 0.17 mpg in
1979.
Analys is: No detailed data were presented to confirm the
stated CAFE benefits of using voluntary data vehicles. It is noted
that this option has been used primarily on an "as needed" basis.
That is, if a manufacturer was able to meet the CAFE standards
without using voluntary data vehicles there was little incentive to
submit such data. Consequently this option will probably be used
more extensively used as the CAFE standards become more stringent.
Question 4: "How does EPA selection process for fuel economy
testing influence a manufacturer's capability to improve its
corporate average fuel economy? How does it influence your poten-
tial to make future improvements in fuel economy?"
Answers: Three of the respondents had no direct comment and a
fourth did not know. The fifth respondent had no major objection
to the EPA selection criteria. One respondent stated that the
running change fuel economy data requirements limited their ability
to incorporate fuel economy improvements. Another stated that the
EPA selection process influenced future improvements based on
volume considerations.
An a1y s i s: No data or information requiring analysis was
presented.
Question 5: "It has been an EPA practice that if laboratory
test results for.a particular vehicle were within 10 percent of the
manufacturer's data for the same vehicle, EPA would use the EPA
data. Recently, however, EPA has used discretionary administrative
actions to select 'official1 test results upon which the corporate
average fuel economy is calculated. Has this improved or dimin-
ished your corporate average fuel economy? To what extent?"
Answers: The majority commented that the selection of "offi-
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cial" test results by EPA had decreased their CAFEs between 0.03 to
0.07 mpg. One respondent stated that this change had not had a
significant impact on their fleet average fuel economy.
Analysis: It should be noted that the vehicles which are
selected for confirmatory testing are those for which the most
questionable data have been submitted. Consequently, it is not
surprising that the discretionary administrative selection of the
"official" result leads to a slight reduction in measured CAFE.
Question 6: "The EPA test is conducted with Indolene Clear
test fuel having an octane rating of nearly 98 RON. Typical
unleaded fuel in the marketplace has an octane rating of 93 RON.
To what extent is your corporate average fuel economy improved by
the use of higher octane fuel during fuel economy testing. What
effect does this difference have on consumer use fuel economy,
wherein spark timing retardation may be necessary to avoid objec-
tionable or harmful detonation? How has the Octane Requirement
Increase (ORI) rating of your engines changed with the switch to
unleaded fuel?"
Answers: Most respondents indicated that the use of 98 RON
Indolene Clear test fuel had little or no effect on fuel economy
compared to the use of 93 RON fuel. One respondent indicated that
there would be an improvement in fuel economy with 98 RON fuel for
vehicles which were equipped with knock sensors. They, however,
did not have any of these vehicles and could present no data. One
respondent submitted data which showed no significant difference
between the fuel economies of knock sensor equipped vehicles using
Indolene Clear or 91 RON test fuels. Addressing the question of
spark retardation, most respondents claimed little effect on in-use
fuel economy. All respondents indicated that their ORI is slightly
higher for unleaded fuels compared to leaded fuels.
Analysis: Based on the comments received in response to this
question there should be little or no objection to a proposed
change in the test fuel specifications to require a more repre-
sentative RON fuel.
Question 7: "Certification tests are performed on vehicles
with a nominal accumulated distance of 4,000 miles. What was the
actual average accumulated distance of the vehicles used in your
1975 test program and in your 1979 test program? Would you favor
some other distance for certification testing?"
Answers: Three respondents stated that their average certifi-
cation test vehicle mileage was 4,000 +_ 250 miles for both the 1975
and 1979 test programs. Another claimed that their average ac-
cumulated mileages were 4,300 miles in 1975 and 4,800 miles in
1979. A fifth responded that the accumulated mileages of their
certification vehicles were 4,160 j+ 150 miles in 1975 and 4,020 _+_
175 miles in 1979. ~
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One respondent suggested that the accumulated distance should
be reduced to 2,000 miles or less for certification testing and a
correction factor be applied on the CAFE. Another suggested that
3,800 to 4,800 miles would be a practical range. The remaining
respondent favored retaining the 4,000 J^ 250 miles accumulated
distance specification.
Analysis: The major concern is that higher mileage vehicles,
with their attendent better fuel economics, may be used for certi-
fication or fuel economy test vehicles and particularly as running
change vehicles. Apparently, this is not a problem if one assumes
that the responses from the commenters are representative of all
manufacturers. This assumption should be verified from the EPA
data base.
Question 8: "Front-wheel drive is becoming an increasingly
popular engineering option for producing space-efficient vehicles.
Front wheel drive vehicles typically have a higher percentage of
their curb weight on the driving wheels than do their rear wheel
drive counterparts. What effect does this have on the simulated
road load curve and hence, fuel economy? To what extent are
alternate dynamometer power absorptions requested for your front-
wheel drive vehicles? To what extent does this affect their
measured fuel economy and benefit your corporate average fuel
economy? How is the air conditioning affected by these alternate
dynamometer adjustments and how does this effect your corporate
average fuel economy?
Answers: Most respondents indicated that front wheel drive
vehicles were at a disadvantage when using the frontal area equa-
tion for dynamometer power adjustments because the greater curb
weight on the drive wheels causes an increase in the tire energy
dissipation on the dynamometer. All respondents stated that they
use alternate (coastdown) dynamometer power absorptions on their
front wheel drive vehicles. Several respondents stated that this
significantly improved the measured fuel economy of the vehicle.
One manufacturer stated that their CAFE may have increased by up to
one percent through the use of this option.
Analysis: As the respondents commented, alternate dynamometer
power absorptions are being used extensively for front wheel drive
vehicles. This is because of the relatively high tire energy
dissipation associated with the weighted drive axles. This re-
sulted in some very low dynamometer power absorption requests. One
particular concern which was not directly addressed by the corn-
mentors is the meaningfulness of the air conditioner simulation for
front wheel drive vehicles. The air conditioner simulation used in
the EPA tests is simply an additional dynamometer loading equal to
10 percent of the basic dynamometer adjustment. Therefore, in the
case of front wheel drive vehicles the additional incremental
loading used to simulate air conditioning is generally less than
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th at which would be applied to similar conventional front engine,
rear wheel drive vehicles. Consequently, the effect of air condi-
tioning on the fuel economy would be smaller on front wheel drive
vehicles than on conventional drive vehicles. The concern is that
this underestimation may be a contributing factor in the increasing
sales of air conditioners on small vehicles.
Question 9: "The oil industry has recently developed new
engine lubricants which incorporate either lower viscosity or
additives to reduce friction. What would be the effect on your
average fuel economy if these oils were approved for use? To what
extent have they penetrated the replacement oil market? To what
extent would the fuel economy of in-use vehicles be improved by the
use of these oils.
Answers: Three respondents, through speculation or testing,
claimed that certification vehicles would experience 0.5 to 3.0
percent fuel economy improvements. One respondent stated, however,
that there would be no advantage in the use of "slippery oils."
Two respondents stated that in-use vehicles would experience fuel
economy improvements equal to or greater than those determined by
the EPA test.
Only one respondent made a statement regarding the market
penetration of the improved oils. This manufacturer reported that
there are 19 low friction engine oils on the market in the U.S. and
Canada.
Analysis: The fuel economy effects of "slippery oils" men-
tioned by the respondents are in agreement with values generally
reported in the literature. In regard to the question of the
market penetration of such oils, the desired information was the
sales volume penetration of the market. We are concerned that the
use of such oils during the EPA tests would be unrepresentative of
typical use until the sales of these oils represent a significant
percentage of automotive lubricant sales.
Question 10: "What effects have the EPA changes in dyna-
mometer calibration (electronic feedback dynamometer control system
and changes made to support automatic control features) had on your
corporate average fuel economy?"
Answers: Two respondents claimed that there has been a loss
in fuel economy because of changes in dynamometer procedure. One
respondent estimated a 0.3 mpg loss in their CAFE. Another re-
spondent stated that there was no significant effect on their
CAFE. One respondent specifically claimed that changes in the PAU
exponent and in the use of the vehicle factor potentiometer caused
a loss of about 0.1 mpg in their 1980 "CAFE.
Analysis: A change in the application of the vehicle factor
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potentiometer was -made in 1980 which might have had an effect on
measured fuel economy. This practice has since been discontinued.
Question 11: "What effect has the change from 55 to 75 grains
in the average humidity level at the EPA test facility had on your
corporate average fuel economy?"
Answers: "Three respondents stated or expected that there
would be a decrease in fuel economy due to the change in the
average humidity level. One respondent claimed that their CAFE
loss was 0.14 mpg and two respondents claimed losses between 0.7
and 1.5 percent.
Analysis: In April 1976 EPA changed its average laboratory
humidity from approximately 55 grains of water per pound of air to
75 grains. This change was made to reduce the magnitude of the
humidity correction factors applied in the calculation of the NOx
emissions. This reduction was desirable to improve the accuracy of
vehicle NOx emissions estimates.
EPA concurs that this change would, in general, be expected to
decrease the measured fuel economy of a vehicle since the com-
bustible portion of the incoming fuel-air mixture would be reduced
and the vehicle would, thus, tend toward enriched operation. This
is, however, dependent on the "calibration" of the vehicle. For
1975 through 1978 model vehicles, the theoretically anticipated
enrichment effect would probably result in some loss of fuel
economy. However, for 1979 and later model year vehicles using
fuel system feedback technology, this enrichment condition would be
sensed and the fuel delivery compensated. Alternately, when
vehicles are "calibrated" for the increased humidity test condition
the amount of EGR might be reduced resulting in fuel economy
improvements under some operating conditions.
Although above analysis is speculative in nature, it indicates
that there is reason to believe that little or no fuel economy
degradation need be anticipated for current or future vehicles
using sensor-feedback technologies. The analysis indicates the
inappropriateness of a too general application of fuel economy
"correction factors" which are based on previous technology to
current or future vehicle technologies.
It should also be noted that the higher test humidity condi-
tions were chosen as standard conditions before 1975. This is
evident since the NOx correction factor in the EPA exhaust emissions
calculations has used 75 grains of water per pound of air as the
standard condition from very early in the regulations. The only
change made was to cause the actual test conditions to correspond
to the theoretical standard condition of the calculations. This
change was made as soon as the Ann Arbor facility could consis-
tently and accurately maintain the higher humidity.
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Ouestion 12: "What effect has the change from the use of the
1 nom inal'vehicle distance traveled per testto the 'actual'
measured vehicle distance traveled had on your corporate average
fuel economy? What effect will this change have on your ability to
improve your corporate average fuel economy as you shift to vehi-
cles of lower power-to-weight ratios?"
Answers: Five respondents indicated that their fuel economy
was decreased by using the actual distance traveled instead of the
nominal test distance. The estimates of the magnitude of the loss
ranged from 0.25 to 0.60 percent of the measured CAFE; that is a
loss of about 0.05 to 0.12 mpg.
Four respondents stated that this loss may be even greater in
future model years because of an anticipated decrease in the
power-to-weight ratios of future vehicles.
An a I y s i s : Although it is apparent that differences between
the actual and nominal mileages driven during specific FTP and HFET
driving cycles will be reflected, on a percentage difference basis,
in emission rate and fuel consumption rate changes these differ-
ences are randomly distributed, and this average is quite small.
Using 1978 and 1979 certification test data EPA compared the actual
and nominal miles driven during each of the three FTP cycle phases
and the HFET cycle.6/ The largest average decrements in apparent
"fuel economy" were obtained during the second 'stabilized',
portion of the FTP. For the 1978 and 1«79 model year certification
fleets these "second bag" differences were -0.13 and -0.51 percent,
respectively. These differences were partially compensated for
during the transient portions of the FTP so that differences in the
full FTP mean differences were about 0.}4 percent in 1978 and -0.21
percent in 197C>. If the FTP and HFET distances are combined in a
55:4-5 ratio, the differences of the average combined distances
become 0.28 and -0.04 percent for 1978 and 1979 respectively.
Thus, the use of actual rather than nominal driving distances
in 1978 led to approximately 0.28 percent (0.5 mpg) increase in
1978 and an approximately O.OA. percent (0.01 mpg) decrease in the
average apparent fuel economy compared to estimates based on the
nominal 7.5 mile distance used previous to the 1978 model year.
When vehicles cannot follow the EPA driving cycle a signifi-
cant decrease in measured fuel economy occurs if the actual rather
than the nominal distance traveled i.s used in the fuel economy
calculation. However, very few, if any, vehicles tested today are
unable to follow the EPA speed-time cycles. If future vehicles are
unable to follow the cycle, it is illogical to credit these
vehicles with inappropriate fuel economies based on distances
not actually traveled.
Question 13: "What will be the effect of a requirement to
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couple the front and rear rolls of twin-roll dynamometers on
measured fuel economy and on your corporate average fuel economy?
Answers: Two respondents stated that they had not determined
this effect. The other respondents indicated that this coupling of
the rolls would decrease their CAFE. Only one respondent gave
estimated data, reporting an approximately 8 percent decrease in
urban fuel economy and a 6 percent decrease in highway fuel econ-
omy. This respondent also reported estimated increases in HC, CO,
and NOx.
Analys i s: A recent EPA investigation has shown that coupling
the dynamometer rolls greatly reduces an existing error in the
velocity simulation of the vehicle during fuel economy measure-
ments. EPA measurements indicate that the elimination of this
velocity error results in a decrease in measured fuel economy of 3
to 5 percent .J?y
Question 14: "Do you know of any procedural changes other
than those listed in previous questions which have already affected
your corporate average fuel economy, or have increased or dimin-
ished your potential to make future improvements?"
Answers: Recalibration requirements of Advisory Circular No.
24-2 and lack of sufficient, leadtime for instituting procedural
changes were cited as factors inhibiting manufacturers from making
fuel economy improvements. One manufacturer specifically claimed
that the requirements of A/C No. 24-2 had caused them to recali-
brate certain electronic control systems and reduced the fuel
economy benefit of their lean cruise control system.
Analys is: Advisory Circular No. 24-2 merely provides an
optional objective criteria to the manufacturers to assist them and
EPA in evaluating any auxilliary emissions control devices which
may be questioned as a "defeat device." A/C No. 24-2 does not
supercede the original criteria, but merely provides additional
optional objective criteria to the to the manufacturer and, there-
fore, the arguments that it has resulted in reduced fuel economy
do not seem valid.
One change which was made and not explicitly mentioned, but
was included in tabulations of changes since 1975 was the change in
the value of the CO density used in the fuel economy calcula-
tions. On November 14, 1978 the EPA changed the value from 51.85
g/cu.ft to 51.81 g/cu.ft. This increases the measured fuel economy
by slightly less than 0.08 percent.
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CHAPTER 8
LIGHT-DUTY TRUCK ROAD LOAD
I. Introductory Statement:
"In establishing the light-duty truck fuel economy standards
for model years 1979 through 1981, NHTSA allowed an 8 percent
fuel economy penalty for a procedural change in establishing road
load horsepower for light-duty trucks."
II. Summary of Comments
Question 1: "Was the adjustment appropriate? If not, what
should it be? What data are available to support your position?"
Answers: Most respondents stated that the 8 percent adjust-
ment provided by NHTSA to compensate for the 1979 increase in the
dynamometer power absorption used for light-duty trucks was appro-
priate. One manufacturer stated that the effect on their light-
duty CAFE was actually 7 percent while another manufacturer claimed
the effect was 10 percent.
Several manufacturers commented that the more stringent
light-duty truck exhaust emission standards introduced in 1979
resulted in an additional 5 to 8 percent fuel economy penalty which
was not considered by NHTSA.
Question 2: "When computing the above adjustment, alternate
dynamometer power absorption requests were not considered. Should
such alternate dynamometer power absorptions be allowed?"
Answers: Four respondents stated that the alternate dyna-
mometer power absorption requests should be allowed because this is
the only incentive for manufacturers to make improvements in
vehicle aerodynamics.
Question 3: "To what extent do. you anticipate using alternate
dynamometer power absorptions?"
Answers: Five respondents indicated they planned to use the
alternate settings. Two indicated they would apply it to all
vehicles for which it would be beneficial. Only one respondent did
not anticipate using the alternate settings.
Question 4: "Should the 8 percent correction factor be
reduced to account for any reduction in the actual anticipated test
dynamometer power absorptions?"
Answers: The general response was that the 8 percent value
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should not be reduced. One manufacturer provided the rationale
that since their data were included in developing the revised
dynamometer power absorptions, and that no benefit would have been
obtained in 1979 for alternate dynamometer power absorptions.
Therefore, any use of alternate dynamometer power absorptions
represented improvements in the vehicles since the 1979 model
year.
III. Analysis
Most manufacturers considered the 8 percent fuel economy
adjustment to be appropriate for the change made in the dynamometer
power absorption table. Most manufacturers stated, however, that
they do not often use this table but rely strongly on alternate
dynamometer power absorption requests. Consequently, on the
average, light-duty trucks are not being subjected to nearly as
great a change in the dynamometer power absorption as was assumed
when the 8 percent fuel economy adjustment was provided. There-
fore, an adjustment was provided for an effect which did not occur,
at least not to the extent presumed.
One manufacturer did comment that the 8 percent was appro-
priate, since the reductions in dynamometer loadings which have
resulted from alternate dynamometer power absorption requests
represented recent vehicle improvements for which credit should be
provided. No details of the "improvements" were provided and few
recent changes have been noted in light-duty trucks.
A number of manufacturers commented that alternate dynamometer
power absorption requests should be allowed in order to provide an
incentive for manufacturers to improve vehicle aerodynamics and
tire rolling resistance. This incentive-benefit is important,
however, it is also important that the alternate dynamometer power
absorption requests represent real vehicle improvements.
Several manufacturers commented that an additional 5 to 8
percent adjustment should have been provided by NHTSA because of
the increased stringency of the 1979 light-duty truck exhaust
emission standards. These comments were not related to the ques-
tion of a change in test procedure.
IV. Summary and Conclusions
The 8 percent fuel economy adjustment provided by NHTSA for
changes in the dynamometer power absorption table was probably an
excessive compensation for the actual change in the dynamometer
power absorption used in testing light-duty trucks. This dis-
crepancy occurred because of the extensive use of alternate dyna-
mometer power absorption requests by manufacturers. Elimination
of the option of alternate dynamometer power absorption requests
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for light-duty trucks would make the 8. percent adjustment more
accurate. The option should be retained, .however, since it is
a mechanism by which manufacturers perceive incentive for and
benefits from improvements in vehicle aerodynamics and reductions
in tire energy dissipation.
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References
J_/ EPA-MVEL Technical Report LDTP 17-6, "Shift Schedules for
Emissions and Fuel Economy Testing," November 1977.
21 EPA-MVEL Technical Report TAEB 77-15, "Effects of Shift Points
~~ on Emission and Fuel Economy of a 1977 Chevrolet Chevette,"
December 1977.
_3/ EPA-MVEL Technical Report TAEB 77-12, "Dynamometer and Track
Measurements of Passenger Car Fuel Economy Influences,"
September 1977 (DRAFT).
4V EPA-MVEL Technical Report TAEB 77-18, "Evaluation of Fuel
Economy Performance of 31 Production Vehicles (1977) Relative
to their Certification Vehicle Counterparts," January 1978.
5/ EPA-MVEL Technical Report, "Evaluation of the Representa-
~ tiveness of EPA Fuel Economy Estimates," January 1978 (DRAFT).
6/ EPA-MVEL Technical Memorandum, "Actual Distances in Certifica-
~ tion Testing," (DRAFT)
TJ EPA-MVEL Technical Report SDSB 79-26, "Track to Twin-Roll
Dynamometer Comparison . . .," June 1979.
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Appendix A
SHIFT SCHEDULE COMMENTS
I. Introductory Statement . . .
In 1975, federal regulations provided that test vehicles with
manual, transmissions would normally be shifted at 15, 25 and 40
mph. In order to provide for more appropriate (representative)
shift schedules for unusual vehicles, the regulations also provided
the option of shifting the vehicle at the shift points recom-
mended by the manufacturer.
On July 16 of 1976, the 15, 25 and 40 mph default shift points
were deleted from the regulations. Subsequently the vehicles were
shifted according to the manufacturer's recommendation to the
ultimate purchaser in order to allow more representative shift
schedules. EPA soon began to receive shift point requests which
appeared to be selected primarily to minimize emissions or to
maximize fuel economy, and which did not appear to reflect consumer
use of the vehicle. EPA investigated this problem and conluded
that, many of the shift schedules requested by vehicle manufacturers
were unrepresentative of typical vehicle use.
In order to ensure more reasonable shift schedules in the
future, EPA defined acceptable shift schedules in Advisory Circular
No. 72. This Advisory Circular provides that the allowable shift
schedules are the 15-25-40 mph schedule originally presented in the
regulations, a shift schedule based on a percentage of • maximum
recommended engine rpm, or any other recommended shift schedule
based on typical vehicle use data.
II. Comments
Question 1: "In 1974 and separately in 1975, what percentages
of your product line were represented by test vehicles shifted at
speeds other than the 15-25-40 mph schedule?"
Volkswagen: "VW and Audi have always used 15-25-40 mph
shifting schedules throughout their entire model line."
Toyota: "All 1974 and 1975 MY vehicles utilized the 15-25-40
mph schedule."
Chrysler: "In 1974 and 1975, 100 percent of Chrysler's
certification vehicles were shifted according to the following
schedules:
3-speed: 15-25,
4-speed: 15-25-40."
Ford: "For model years 1974 and 1975, Ford certified and
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measured fuel economy on all its manual transmission vehicles
(passenger cars and light trucks) using the 15-25 mph shift sched-
ule for its 3-speed manual transmissions and 15-25-40 mph for its
4-speed manual transmissions."
General Motors: "In MY 1974, GM used a 15-25-40 miles per
hour manual transmission shift schedule for all light-duty vehi-
cles. Beginning with MY 1975, GM recommended manual transmission
shift schedules in the owners manual for improved driveability and
fuel economy with any selected powertrain."
American Motors: "In the 1974 model year 20 percent of our
carlines were equipped with manual transmissions and all had
recommended shift speeds slightly different than 15-25-40 mph. In
the 1^75 model year 15-2.5 was recommended.
All 1974 and 1975 model year Jeep CJ' s were equipped with
manual transmissions. In the 1974 model year all Jeep CJ' s had
recommended shift speeds slightly different than 15-25-40 mph. In
the 1975 model year 7 percent had recommended shift speeds slightly
different than 15-25-40 mph."
Question 2: "For those vehicles shifted at other than the
15-25-40 mph schedule, what shift speed schedules were used?"
General Motors: "A tabulation from, the MY 1^75 GM owner's
manuals summarizing our then recommended shift schedule is shown in
Figure A-l."
American Motors: The AM 1974 and 1975 MY shift schedules are
shown below.
1974 Model Year
Typical Shift Points Transmission Vehicle Type
18-40 mph M-3 Passenger cars (LDV)
1R-30 mph M-3 Jeep vehicles (LDT)
1R-30-40 mph M-4 Jeep vehicles
1975 Model Year
15/1H-25-30 M-3 Passenger cars
15-25 M-3 Jeep vehicles
10-20-40 M-4 Jeep vehicles
Question 3: "What data are available to indicate that the
alternate shift schedules requested in 1975 were more representa-
tive of consumer use than the 15-25-40 mph schedule?" .
Ford: "For model years 1974 and 1975, Ford certified and
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-3-
measured fuel economy on all of its manual transmission vehicles
(passenger cars and light trucks) using the 15-25 mph shift sched-
ule for its 3-speed manual transmissions and 15-25-40 mph for its
4-speed manual transmissions. Ford, however, recognized the in~use
fuel economy improvement possible using alternate shift schedules
and advised its customers of this opportunity in the owner's
manual, recommending a shift range schedule of 10-15/20-30/above 30
mph." See following excerpts from the Ford Owner's Manual.
Upshifts Shift speeds Downshifts Shift Speeds
1st to 2nd 10 to 15 mph 4th to 3rd 55 to 25 mph
2nd to 3rd 20 to 30 mph 3rd to 2nd 35 to 12 mph
3rd to 4th Above 30 mph 2nd to 1st 20 to 0 mph
Economy Driving Tips
To operate your car as economically as possible, use the following
driving suggestions:
1. Always keep your tires inflated to the recommended
pressure for longer tire life and fuel economy.
2. Accelerate moderately; but do not creep. Get into
high gear quickly so that the engine can operate
economically.
3. Avoid speeding up and slowing down..- Maintain a
level pace and flow with the traffic for good fuel
economy.
4. Try to time the traffic signals so that you stop
as little as possible. Idling and acceleration are
times of greater fuel consumption.
5. Maintain a moderate speed on the highway. Gaso-
line consumption per mile rises sharply with speed
increase.
6. Keep your engine tuned up and keep other mainten-
ance work on schedule for longer life of all parts and
lower operating costs.
7. Keep the required distance from other cars and be
alert to avoid sudden stops. This will greatly reduce
wear on your brake linings.
8. If your car is equipped with the optional fuel
monitor warning light, all of the preceding tips will
help you to adjust your driving habits to keep the
light from glowing.
General Motors: "GM has not intentionally recommended manual
transmission shift speeds that adversely affect customer satis-
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faction or that are difficult to implement. However, we believe
that it is our obligation to recommend customer operation of the
vehicle that is both practical and efficient."
American Motors: "The Jeep Owner's Manual recommended slightly
lower 1-2 and 2-3 shift points because they were appropriate for
off-road 4-speed manual transmission Jeep CJ's."
Question 4: "What typical shift schedule changes have been
used since 1975?"
Toyota: The following shift schedules were used:
Model Year Shift Schedule
1976 All vehicles utilized the
15-25-40 mph schedule.
1977-1978 LDV - Approximately 60% of
manual transmission (M/T)
vehicles used the alternate
schedule.
LOT - Approximately 90% of
M/T vehicles used alternate
schedules.
1979 Due to EPA's policy change
approximately 90% of the
vehicles with M/T used the
15-25-40 mph schedule.
1980 Approximately 92% of all
vehicles with M/T utilize
the 15-25-40 mph shift
schedule."
Chrysler: "Chrysler's shift schedules used for certification
vehicles after 1975 are as follows:
1976 - 3-speed
4-speed
1977 - 3-speed
4-speed
1978 - Federal
California
Omni/Horizon
1979 - 3-speed
4-speed
15-25 •
15-25-40
15-25
15-25-40
15-25-40
20-35-45
15-25-30
15-25
15-25-40."
Ford: "Passenger Car and light truck shift schedules used
through the 1979 model year are tabulated in Exhibits II and III."
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Ford Exhibits II and III. are included as our Figures A-2 and
A-3.
General Motors: "A tabulation from the MY 1975 GM owner's
manuals summarizing our then recommended shift schedules is shown
in Figure A-l. No significant departures from the .15-25-40 sched-
ule are found in this table for MY 1°75 and the same is true
through MY 1978."
American Motors: "The 1976 model year used essentially the
same shift schedule as the 1975 model year (note response to
quest ion 2)."
1977 Model Year
Typical Shift Points (mph) Vehicle Type
1-2 2-3 3-4
15-18* 25-30* Passenger cars
10-15* 20-25* 30-40* Passenger cars
15 25 Jeep vehicles
10 20 40 Jeep vehicles
* Shift whenever a cruise within the specified range has
been reached.
1978 and 1979 Years
Same as 1977 Passenger cars
Same as 1977 Jeep vehicles
**-15-25 Jeep vehicles
** The 4-speed manual transmission is synchronized in
second, third and fourth gears. First is designed
primarily for increased pulling power on grades and
during towing or plowing operations. Normal starting
uses second gear."
Question 5: "What- effect has the use of these post-1975 shift
changes had on specific vehicle fuel economies?"
Toyota: "As a typical example, the table below indicates the
effect on fuel economy due to the shift schedule change. These
data are derived from the 1977 MY Corolla with 2T-C engine.
Shift Schedule City Fuel Economy
15-25-30 mph 23.8 mpg
15-22-30 mph 26.8 mph (13% up)
If an alternate shift schedule is used, generally speaking, we can
realize a city fuel economy increase of approximately 10% of that
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at the 15-25-40 mph schedule. However, this shift schedule change
has no significant effect on the highway fuel economy. Accord-
ingly, a combined fuel economy increase of approximately 6% can be
realized."
Chrysler: "We have not determined the effects on fuel economy
of any difference."
Ford: "Ford's estimate of the individual vehicle and -average
passenger car fuel economy effects of the alternate manual shifts
schedules used in the 1978 model year are shown in Exhibit IV. The
1979 Courier manual transmission calibrations used the 1978 shift
schedule of 10/20/35/45 mph (with 3rd-4th shift at 25 during
cruise. The 1979 shift schedule restrictions caused this shift
schedule to be revised to 15/26/37/57 (with no cruise shift),
resulting in 8% fuel economy degradation for Couriers."
Ford Exhibit IV is included herein as our Figure A-4.
General Motors: "The effect of specific shift schedules upon
specific fuel economy can be very significant and has been reported
to EPA in a letter to Mr. Harrington on January 17, 1978 (Attach-
ment 6). This lett.er cites individual fuel economy losses on
certain models of our product line that resulted from incorporating
the shift schedule guidelines set forth in Advisory Circular
No. 72 in place of our recommended alternate shift schedules."
The complete letter is included as Attachment A-l at the end
of this appendix. The following is an excerpt of this letter
containing the relevant portions of the Attachment.
"A series of tests were performed on available representative
vehicles with 1979 calculations as known at this stage of develop-
ment .
The changes under consideration represent substantial invest-
ments of development time and money; the fuel economy losses on our
manual transmission products, due to this late and unilateral rule
change, are considerable and could affect our corporate average
fuel economy. Evaluation efforts involved the city schedule;
however, we expect some effect on highway fuel economy as well.
Tests were performed on a 151 L-4, 4-speed; a 301 V-8, 4-speed; a
260 V-8, 5-speed; and a 400 V-8, 4-speed using present GM recom-
mended and EPA proposed shift schedules. City fuel economy losses,
as a result of the propsed EPA schedule, ranged from 1.4 to 2.6
miles per gallon and represented percentage losses of from 6.4 to
17.8 percent (Table 1 of the Attachment). These losses are due to
higher EPA proposed shift speeds being imposed on modern engines
specifically designed to run smoothly at lower RPM's."
American Motors: "The only manual transmission shift change
that had a fuel economy impact on our vehicles was Advisory Circu-
-------
lar No. 72 . ... and it resulted in passenger car and Jeep vehicles
manual transmission fuel economy losses of about 1.0 mph (com-
posite)."
Question 6: "What effect has the use of these post-1975 shift
changes had on your corporate average fuel economy?"
Toyota: "The table below indicates the improvement rates on
1977 and 1978 MY CAFE for LDV and LDT separately, which are based
on a rough estimation, when the alternate shift schedule is used."
1977 MY 1978 MY
LDV +2.0% +1.9%
LDT +4.9% +5.0%
Chrysler: "We have not determined the effects on fuel economy
of any differences.-"
Ford: "Ford's estimate of the individual vehicle and average
passenger car fuel economy effects of the alternate manual shift
schedules used in 1978 model year are shown in Exhibit IV (Figure
A-4). This also shows the effect on 1979 corporate. average fuel
economy. The 1979 [LDT] CAFE impact of the reduced Courier fuel
economy was a loss of 0.13 mpg.
The estimated 1979 LDV CAFE effect was about 0.06 mpg reduc-
tion in measured fuel economy."
General Motors: "The estimated effect of this substitution
upon the GM passenger car Corporate Average Fuel Economy (CAFE) was
a loss of 0.08 miles per gallon."
American Motors: "The light truck fleet average fuel economy
penalty was estimated to be 0.6 mpg and the passenger car fleet
average penalty was estimated to be 0.3 mpg.
Additionally, 5-speed transmission programs as well as op-
timization of 3- and 4-speed transmissions have been deferred."
Question 7: "What data can you present that these post-1975
shift schedules are more representative of consumer vehicle use
than the 15-25-40 mph schedule?"
Toyota: "The only relevant data we can present are those
which were contained in attachment to our '1979 MY Part I LDV
Revision Letter #14," dated February 16, 1978, demonstrating
representativeness of an alternate shift schedule, meeting A/C
72.E.3.C., for the 1979 MY Corolla model included in the 3K-C(F)
engine family."
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Ford: "In addition to the marketing research findings sup-
plied to EPA betwen June and October, 1978 (attached), supporting
Ford's revised shift schedule (,'H1) on the 1979 2.3L (non-turbo)
vehicles (approved for use by EPA in its letter to Mr. D. L. Kulp of
October 31, 1978), Ford is presently conducting similar research on
its other engine families offered with a manual transmission."
General Motors: "A tabulation from the MY 1975 GM owner's
manuals summarizing our then recommended shift schedules is shown
in Figure A-l. No significant departures from the 15-25-40 sched-
ule are found in this table for MY 1975 and the same is true
through MY 1978. GM has not intentionally recommended manual
transmission shift speeds that adversely effect customer satisfac-
tion or that are difficult to implement. However, we believe that
it is our obligation to recommend customer operation of the vehicle
that is both practical and efficient."
American Motors: "AM's post-1975 shift schedules are basical-
ly equivalent to the 15-25-40 mph shift schedules, therefore,
questions 7 and 8 do not require our response."
Question 8: "What data can you present to demonstrate that
the fuel economy improvements obtained with the post-1975 shift
schedules were obtained in consumer use of the vehicles?"
Chrysler: "We have not used different shift schedules
in the post-1975 period..."
"Calculated fuel economy effects indicate that if manual
transmission shift schedules were optimized for the EPA cycle, the
fuel economy for these vehicles would be from 2 to 4.5 percent
better than for the 'default' shift schedule. Since any survey of
consumer driving patterns is not likely to show them shifting at
the true optimum, the potential gain over the default schedule
would be some fraction of the 2 to 4.5 percent obtainable."
Ford: "While Ford has no data segregating the in-use fuel
economy improvement of the revised manual transmission shift
schedules from the overall fuel economy improvement realized by its
vehicles from model year to model year (i.e., Ford does not intro-
duce new vehicles with a shift schedule being the only change), we
believe intuitively that our customers are witnessing the same
comparative gain seen during testing on CVS-CH and HWFET cycles."
Question 9: "As more efficient automatic transmissions are
phased in, what will the relationship between manual and auto-
matic equipped vehicles be with respect to EPA measured fuel
economy?
a. Using 1975 shift schedules.
b. Using, post-1975 shift schedules."
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Volkswagen: "No specific data is available in regard to more
efficient automatic in comparison to manual transmissions.
As a comparison, we are providing you with the a table (see
figure A-5) that compares the fuel economy between manual and
automatic transmission certification vehicles."
Toyota: "Our 4-speed automatic transmission,without lock-up
unit, is more efficient than our 3-speed one because of over-drive
usage. According to our 1979 MY certification data and experi-
mental data, the relationships between manual and automatic
equipped vehicles, with respect to fuel economy, can be expressed
as in the following matrix.
The figures in the matrix denote the average percentage of
fuel economy for automatic equipped vehicles to that for manual
equipped vehicles."
Alternate
Shift Schedule used
15-25-40 mph for 1977 and 1978 MY
Fuel Economy with 5 M/T Fuel Economy with 5 M/T
Shift Schedule City HWFET Combined City HWFET Combined
Fuel economy 100 84 94 91 84 R8
with 3 A/T
Fuel economy 9^ 93 97 90 93 91
with L A/T
Chrysler: "As automatic transmissions become more efficient
through utilization of lockup devices and parasitic loss reduction,
it is fully expected the fuel economy differential between auto-
matic and manual transmissions will be reduced."
Ford: "Ford presently expects its future model year manual
transmission calibrations to achieve an average 8-12% higher fuel
economy than comparable vehicle configurations equipped with
automatic transmissions.
In 1975, manual transmissions achieved approximately 10-15%
better fuel economy than automatic transmissions on a similar car
(based on a review of 4,000 mile test data)."
General Motors: "New improvements for added efficiency in our
automatic transmissions can be expected to narrow the fuel economy
difference.between manual and automatic transmission equipped small
vehicles."
American Motors: "AM does not expect to see the 10 percent
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fuel economy advantage (combined city/highway) that manual shift
transmissions currently possess over automatic transmisions to be
overcome in the foreseeable future."
Question 10: "What data can you present to indicate manual
transmissions will be more or less efficient in actual vehicle use
compared with more efficient automatic transmissions?"
Volkswagen: "No specific data is available in regard to more
efficient automatic in comparison to manual transmissions."
Chrysler: "Although relatively little consumer 'in-use' data
exists, that which does supports an average fuel economy advantage
of about 11.5 percent for manual transmission vehicles over similar
vehicles with automatic transmissions. These data were derived
from a 1974 study of Chrysler's executive lease vehicles. The
manual transmission vehicles were concentrated in subcompact
imports and light-duty trucks. This result is in close agreement
with Chrysler Proving Grounds road tests using the SAE-J1082 test
cycles. Proving Grounds results on 1977 through 1979 corporate
vehicles indicated that manual transmission vehicles average about
10.5 percent better fuel economy than automatics.
As automatic transmissions become more efficient through
utilization of lockup devices and parasitic loss reduction, it is
fully expected that the fuel economy differential between automatic
and manual transmissions will be reduced. As an example, the
lockup torque converters are currently expected to improve auto-
matic transmission fuel economy by about 2 percent. This improve-
lent, which occurs principally during highway operation, is ex-
acted to reduce the 'in-use' benefits of manual transmissions to
:he general driving public from about 10 to about 8 percent."
Ford: "We have no in-vehicle, back-to-back data that quanti-
fies difference in efficiency of automatic transmissions versus
lanual transmissions. However,, manuals will always be more ef-
ricient than automatics due to the inherent pump losses, bands and
ilutch drag and torque converter slip (in lower gears) of automatic
General Motors: "New improvements for added efficiency in our
mtomatic transmissions can be expected to narrow the fuel economy
lifference between manual and automatic transmission equipped small
vehicles."
Question 11: "Do you have any programs underway to optimize
mtomatic transmission shift schedules to the EPA test cycles? If
;o please describe."
Toyota: "We have developed a simulation model to obtain
lutomatic transmission optimized curves for better fuel economy for
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various driving modes. Please refer to 'Automatic Transmission
Optimization for Better Fuel Economy1 written by T. Ishihara, A.
Numazawa, K. Suzuki, and T. Yokoi which is contained on pages 1331
to 1342 of the 17th FISITA CONGRESS REPORT (June, 1978)."
Chrysler: "Current automatic transmission shift schedules
were chosen for best overall performance and customer acceptance.
We have no programs underway to change these schedules."
Ford: "No. Automatic transmission shift schedules are not
optimized for the EPA test schedule. Shifts schedules are dictated
by customer acceptance of acceleration performance. Our experience
is that customers complain if shifts are unevenly spaced, too early
or delayed, or too sensitive to torque demand."
American Motors: "We are continuously working with our
suppliers (both manual and automatic transmissions) to improve and
optimize these transmissions and their shift schedules."
Question 12: "The existing shift schedule restrictions allow
you to use any manual transmission shift schedule that you can
demonstrate is or will be in typical use. Do you intend to en-
courage your vehicle purchasers to use alternative shift schedules
so that those schedules can be used during fuel economy testing?
Will this action be accompanied by transmission changes, such as
the use of additional or wide ratio gears? What fuel economy
benefits do you expect?"
Volkswagen: "No."
Toyota: "We think that the alternate shift schedule to obtain
better fuel economy should be allowed even though demonstration
data to represent the typical consumer use is not provided. it
should be, however, acceptable for most consumers from a common
sense standpoint and, further, we should encourage purchasers to
use it with more practicable and effective manner than a recom-
mendation in the owner's manual approved for the past certifica-
tion. Unfortunately, at this time, we have no effective ideas."
Chrysler: "Although we will continue to encourage good
driving habits, we have no plans to determine alternative shift
schedules."
Ford: "If alternative shift schedules offer improved fuel
economy and performance opportunities, Ford will endeavor to
encourage the customer to use these schedules. We do not, however,
presently plan any such revised shift schedule changes. We are,
through market research, trying to determine how people actually
shift so we can share that information EPA."
General Motors: "GM intends to pursue the use of alternate
manual transmission shift schedules that result in efficiency
-------
-12-
improvements for our customers while meeting emissions and drive-
ability requiremnts. The same is true for product design improve-'
ments, such as wide ratio transmission gears. The potential fuel
economy gains from manual transmission improvements cannot be
recognized with the current EPA certification procedures. The
impact of this on light truck CAFE is significant because manual
transmissions have about 20% sales penetration. Therefore, GM is
not projecting any measurable improvement in passenger car or light
truck fuel economy with improved manual transmissions because of
the constraints contained in A/C 72."
American Motors: "At this time we do not plan on pursuing
this type of an in-use approach. We, therefore, cannot answer this
question.
We are studying and planning to use wide ratio gear sets in
our future manual and automatic transmissions."
-------
-13-
General Motors Co.
Figure A-l
GM MY 1975 Owners Manual Shift Schedules I/
3-4
Buick
Apollo-Skylark
L-6 3-speed
V-6 3-speed
Oldsmobile
Omega 3-speed
Starfire 4-speed 20 30 40
Cutlass
L-6 3-speed
V-8 3-speed
•k
ieed
i-speed
>-speed
i-speed
d
d
eed
1-2
20
20
20
20
20
25
20
10
20
20
20
15
20
20
20
20
20
20
20
20
2-3
30
35
20
30
30
25-40 21
30
15
30
30
30
25
25
30
30
30
30
30
30
30
Chevrolet
30
4-speed 10 15
Van 3-speed
Chevelle
Monza
L-4 3-speed
L-4 4-speed 15 25 40
V-8 4-speed 20 25 30
Camaro 3-speed
4-speed 20 30 40
Vega 3-speed
4-speed 20 30 40
Corvette 4-speed 20 30 40
Nova 3-speed
4-speed 20 30 40
NOTES:
I/ Pontiac did not recommend an alternate shift schedule in its
owner's manual.
2j Shift whenever a cruise within the specified range has been
reached.
-------
-14-
Ford Motor Co. Exhibit II
Figure A-2
Passenger Automobile Manual Tranmission Shift Schedules
Shift
1-2
2-3
3-4
4-Speed M/T
F 4/ H 5/ N 2/ P 2/ Q 3/ R
16 13 10 10 20 5
27 24 20 15 30 15
38 31 30 25 40 25
3-Speed M/T
Shift Q 3/ S T
1-2 20 10 10
2-3 30 20 25
U I/ W I/
10 10
20 20
30 30
Z
15
25
X I/ Y I/ Z
10 15 15
25 25 25
35 40 40
I/ Shift directly into fourth gear once vehicle is stabilized at
or above 25 mph.
2/ Omit first gear when driving an unloaded vehicle with first
gear ratio greater than 5:1.
3/ For 3-speed transmission, shift directly into third gear once
vehicle is stabilized at or above 25 mph, for overdrive shift into
fourth gear at recommended speed.
kl Based on A/C #72 "percent rated engine RPM" methodology which
Tncludes "cruise" shifts at 12/20/32.
_5_/ Per EPA approved customer survey.
Vehicle Engine Identification Codes (in-^ or liters)
1976 1977 1978 1979
W2.8 R1.6 R1.6 F1.6
X 2.3 T 200 or 250 T 200 H 2.3
Y 2.3 U 1.6 U 1.6 Z 2.3 or 2.8;
Z 2.8 V 250 V 250 200, 250, or 302
W 1.6 or 2.8 W 2.8; 302
X 2.3; 302 X 2.3; 302
Y 2.3 Y 2.3 or 2.8
Z 2.3 or 2.8; 200
-------
Ford Motor Co. Exhibit III
Model
Courier
F100
E100
1974-5
15/25/40
15/25/40
Figure A-3.
Light Truck Shift Schedules (Q-600# GVW)
1976 1977
10/20/35/45
10/20/35*745
•'cruise = 25
1978
10/20/35*/45
*cruise = 25
15/25/40
except:
CA/4.91/M3:
20/30
49S/5.8L/M3:
10/25
15/25/40
except:
CA/4.9L/M3:
20/30
4.9L/5.0L/M3:
10/20
1979
2.0L: 15/26/37/57
2.3L: 15/26/38/57
15/25/40
15/25/40
Bronco
15/25/40
-------
Ford Motor Co. Exhibit IV
Figure A-4.
Estimated Fuel Economy Effect of Alternate Shift Schedules for Manual Transmissions
Vehicle
Fiesta
Pinto Sedan
Pinto S.W.
Mustang
Fairmont Sedan
Fairmont S.W.
Mu s t ang
Mustang
Fairmont Sedan
Fairmont S.W.
Granada
Mustang
Fairmont Sedan
Fairmont S.W.
Granada 2 dr.
Engine
1.6L
2.3L
2.3L
2.3L
2.3L
2.3L
2 . 3L-T
2.8L
3.3L
3.3L
4.1L
5.0L
5.0L
5.0L
5.0L
Trans
M4-3.58
HM4WR
HM4WR
HM4WR
HM4WR
HM4WR
HM4WR
SROD
SROD
SROD
SROD
SROD
SROD
SROD
SROD
Axle
3.58
2.73
3.08
3.08
3.08
3.08
3.45
3.45
2.73
3.08
3.00
3.08
3.08
3.08
3.00
Shift I/
Schedule Code
R
X
W
Y
Y
Y
Z
Y
X
X
V
X
X
X
X
Estimated 1979 Fuel
Economy Effect Versus
15/25/40 mph Shift Speeds (mpg)
2.14
0.63
1.23
0.58
0.47
0.49
0.00
0.21
0.51
0.51
1.58
0.80
0.55
0.56
0.58
Estimated CAFE Effect -0.0591
(Based on 1979 Projected
Sales Volumes as of Dec., 1977)
_!_/ Proposed for 1979 prior to Advisory Circular #72 — applicable
to 1979 MY and beyond which restricted shift schedule usage.
-------
Volkswagen Co.
-17-
Figure A-5
Volkswagen Fuel Economies
City
Highway
Manual Automatic
Average
Absolute .
difference
Percent
difference
16.7
16.8
26.8
24.3
24.0
16.7
23
22
16
16
17
17
11
19.0
0.4
2
17.3
14.8
24.0
23.4
22.1
18.3
20
22
17
16
17
18
12
18.6
Manual Automatic
24.5
22.7
38.5
37.8
36.5
25.4
37
35
26
26
32
29
18
29.9
4.5
18
20.0
18.5
34.1
32.6
31.1
22.6
29
30
24
22
24
25
17
25.4
Combined
Manual
19
19
31
29
28
20
28
27
19
19
22
21
13
22.7
Automatic
18
16
28
27
25
20
23
25
20
18
19
20
14
21.0
1.7
8
-------
-18-
General Motors Co. Attachment 6
Attachment A-l
GM's letter of January 17, 1978 to R. E. Harrington (EPA)
on "Manual Transmission Shift Speeds."
-------
FE: 1267
Environ.Tun;=l Ac'.miies Stiff
General Motors Cc.'pcuotion
Gcr.eiai ,V.o!ois Tecf.nical Csn;er
V.'anen. MicMigan 43090
January 17, IS78
Mr. R. E. Harrington, Director
Light Duty Vehicle Branch
Certification Division
Mobile Source Air Pollution Control'
U.S. Environmental Protection Agency
2555 Plymouth Road
Ann Arbor, Ml 48105
Dear Mr. Harrington:
Manual Transmission Shift Speeds
The purpose of this letter is to supplement our Mr. M. R. Wilson's
letter to you of December. I, 197.7 on the same subject by providing
information relative to the fuel economy effects on specific General
•Motors light-duty vehicles using EPA's recently 'defined manual shift
schedules presently being considered for' Advisory Circular publication.
A series of tests were performed on available representative vehicles
with 1979 calibrations as known at this stage of development. These
evaluations • did, of course, divert test/development resources from their
intended use in evolving 1979 product definition.
Genera! Motors is always willing to contribute test information relative
to the promulgation of new rules under consideration by EPA. However,
as sve have indicated on many occasions in the past, proposed changes
having a substantial impact on the product should be addressed at a less
critical point in the certification program. You must realize that a
manufacturer must carefully plan and, in pursuing these plans, must have
confidence that the agency considers the potential disruption that could
be caused by contemplated program changes. That does not appear to be
the case here; manufacturers first learned of your concern in this area
at the November IS, 1977' EPA-lndustry meeting but were not prior or
subsequently officially contacted for comments and/or information.
The changes under consideration represent substantial investments cf
development time and money; the fuel economy losses on our msnus! trans-
mission products, due to this late and unilateral rule change, are
considerable and could affect our corporate average fuel economy. This
situation could have been moderated if your concerns over representative-'
ness cf shift schedules had been shared with the industry when thsy were
first recognized by EPA.
1-4
-------
R. E. Horrir.citcn
-2-
January 17, I97S
Evaluation efforts involved the city schedule; however, we expect scrr.e
effect en highway fuel economy as well. Tests were performed on a 151
L-4 -1 spaed, 2Ci V-2 4 speed, 250 V-3 5 speed and -?00 V-3 4 speed u:,;r.g
present GM recommended and EPA proposed shift schedules. City fuel
economy losses, as a result of the proposed EPA schedule, ranged from
1.4 to 2.6 miles par osllon and represented percentage losses of from
6.4 to 17.8 percent (Table I). These losses are due to the higher EPA
proposed shift . speeds being imposed on modern engines specifically
designed to run smoothly at lower RPM's.
General M.otors has never recommended manual transmission shift speeds
that would adversely affect customer satisfaction or that are difficult
to implement. They are tailored to average driving conditions as repre-
sented by the Federal Test Procedure and provide acceptable vehicle
driveability under these conditions. We understand your concern - that
recommended shift schedules be representative and' we do not question
EPA's authority to promulgate new rules concerning this subject. From
the data supplied thus far by EPA, however, General Motors has no reason
to believe that EPA's planned shfft schedules are" any more "representative
of. the "real, world" than pur current recommendations. Our key objection
is 'the 'timing of substantive changes of this type at this point in the
1979 certification program,, and we question. EPA's authority, to implement
this type of change without proper notice of- rulemaking and orderly
analysis and consideration of manufacturers' comments.
We are continuing to evaluate the proposed shift schedules on other GM
manual transmission/engine combinations with the expectation that this
information will be -useful in commenting on proposed rulernaking in this
area for use not sooner than the 1880 modal year. General Motors still
awaits your reply to Mr. Wilson's letter of December I, 1977.
y truly yours,
T. M. Fisher, Director
Automotive Emission Control
SJS/aaf/t/040
cc: E. O. Stork
-------
Table 1
City Fuel Economy Effects of
EPA Proposed Monucl Transmission Shift Schedule (66% Ra;ed Engine rprn)
(Current Recommended Shift Schedule Used as Base)
inertia V/r
3000
•3500
3500
4000
4000
4000
Engine
151 L-4
2 bbl
260 V-8
2 bbl
301 V-3
4 bbl
301 V-8
4 bbl
400 V-8
4 bbl
400 V-8
4 bbl
/vlcnua!
Transmission
4-speed
5-speed
4-speed
4-speed
4-speed
4-speed
Fuel Economy (MPG)
Shift Schedule
Current
22.1
20.0
. 16.6
16.1
12.9
12.7
Proposed
20.7
17.7
14.0
14.6
10.6 .
10.7
Loss
1.4
2.3
2-6
1.5
2.3
2.0
Percent
Loss
6.4%
11.5%
15.7%
9.3%
17.8%
15.8%
Note: 301 and 400 V-8 tests v/ere run on rv/o (ecch) representative vehicles
-------
Appendix B
ALTERNATE DYNAMOMETER ADJUSTMENT COMMENTS
I. Introductory Statement
"EPA has always provided the option that a manufacturer may request,
for specific vehicles, dynamometer adjustments which are different from
the values contained in EPA regulations. A request for such alternate
dynamometer power adsorptions must be supported by road test data demon-
strating the appropriateness of the request. In 1975, the regulations
implied the manifold pressure measurements were the required method of
generating acceptable road data. Later the manifold pressure approach
was deleted, and subsequently the coastdown technique has become the
prevalent method of generating supporting data for alternate dynamometer
power adsorption requests. An acceptable coastdown procedure has been
provided to the industry as an EPA Recommended Practice which has been
distributed as an Attachment to Advisory Circular No. 55B."
II. Comments
Question 1: "To what extent were alternate dynamometer adjustments
used in 1974, in 1975? To what extent are they currently used?"
Volkswagen: "1974 models - 2 models out of a total of 9 had alter-
nate Dyno adjustment.
1975 models - 4 models out of a total of 9 had alter-
nate Dyno adjustment.
1980 models - 6 models out of a total of 8 had alter-
nate Dyno adjustment."
Toyota: "We did not adopt the use of alternate DPA (Dynamometer
Power Absorption) for certification and fuel economy testings in 1974 or
1975 MY. However, alternate DPA adjustments were used for approximately
40 percent of our LDV models in the 1979 MY. Further, in the 1980 MY,
alternate DPA adjustments are intended to be used for approximately 75
percent of our LDV models."
Chrysler: "In 1974 and 1975, Chrysler tests were conducted only at
the specified dynamometer loads; that is, no alternate methods were
developed, proposed or used. For the 1980 model year we presently are
involved in certifying all passenger cars with an alternate 'coastdown1
horsepower while trucks are being certified with both the specified
horsepower and alternate horsepower."
Ford: "For model years 1974 and 1975 Ford Motor Company did not
use alternate dynamometer adjustments primarily because the available
procedure (manifold vacuum measurements at a 50 mph steady state speed)
was not sufficiently precise to reflect improvements over the formula
power absorption settings. For model year 1979 the alternate adjust-
ments were approved for 87% of our passenger cars and 100% of our light
trucks sold as complete vehicles."
-------
—2—
General Motors: "GM did not use alternate dynamometer adjustments
during MY 1974 or MY 1975. We anticipate that approximately 64% of our
light duty vehicles manufactured in MY 1979 and 96% in MY 1980 will be
represented by fuel economy tests using alternate horsepower."
American Motors: "Alternate dynamometer adjustments were not used
in 1974 or 1975. They are not currently used but we do plan to use the
coast-down procedure on one light-duty truck and one car engine family
on vehicles that coine equipped with radial tires in 1980."
Question 2: "To what extent has the increased use of alternate
dynamometer power absorptions improved your corporate average fuel econ-
omy compared to your corporate average fuel economy which would have
been obtained if dynamometer power absorptions from the equation con-
tained in the current regulations were used exclusively? If dynamometer
power absorptions from the inertial weight based table of the 1975
regulations were used exclusively? If the use of alternate dynamometer
power absorptions were restricted to the extent they were used in 1974,
in 1975?"
Toyota: "The following data, which are insufficient and therefore,
may not be accurate, indicate whether the increase usage of the alter-
nate DPA has improved CAFE in the 1979 MY as compared to CAFE which
would be obtained if the DPA from the equation contained in the current
regulations were used exclusively, or if the DPA from the inertia weight-
based table of the 1975 regulations were used exclusively.
Comparison to CAFE with Comparison to CAFE with
Exclusive Use of DPA Exclusive Use of DPA from
from Equation Inertial Weight-Based Table
+0.8% +2.6%
Since we opted to use the DPA from the inertia weight-based table for
all 1974 and 1975 MY vehicles, as shown above, 2.6 percent fuel economy
loss in the 1979 MY CAFE is expected."
Chrysler: "In order to demonstrate the effect of changes in
dynamometer adjustment, it would be desirable to test a fleet of vehicles
(cars, 4x2 trucks, and 4x4 trucks) using the 1975 table weights and then
repeat the tests using 1979 alternate adjustments. Chrysler has not
conducted such a test program and because of the considerable amount of
testing required, does not plan to conduct such a program. At this
point, we believe the revision in dynamometer adjustment no longer hurts
our fleet average fuel economy."
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-3-
Ford:
1979 CAFE with alternate power
absorptions
1979 CAFE impact if power
absorptions were restricted to
the 1979 formula CAFE
1979 CAFE impact if power
absorptions were restricted
to the pre-1979 inertial table
PAU
"Fuel Economy
higher/(lower)
than Base
Car
Base
(0.4)
(0.5)
Truck
Base
(0.3) mpg
1.3 mpg
Alternate dynamometer power absorptions were not used in 1974 or 1975."
General Motors: "GM estimates that, for MY 1979, the fuel economy
of GM vehicles is about 1 1/2% better when using alternate horsepower
rather than frontal area horsepower or the inertia weight table. It
should be noted that this improvement was included in the GM 11 car test
program (Attachment 1) which indicated a 0.6 mpg CAFE loss. If alternate
absorber settings were restricted to MY 1974 and 1975 procedure, there
would be no recognized benefit (EPA results) of aerodynamic or rolling
resistance improvements."
General Motors Attachment 1 is not included herein.
American Motors: "Because we have not used coast-down the answer
is none.
The 1979 passenger car fleet average fuel economy would not be
significantly affected if the inertia weight based table values were
used exclusively. The 1979 light truck fleet average fuel economy
decrease is estimated to be 0.1 to 0.4 mpg in addition to the 8 percent
credit that was incorporated into the 1979 nonpassenger automobile
standard by the NHTSA. This large penalty is derived from the large
increase in dynamometer power absorptions, 30 to 36 percent from 1978 to
1979, and the associated recalibration requirements to maintain essentially
constant emission control."
Question 3: "To what extent does current EPA policy (applicable
advisory circulars) on alternate dynamometer adjustment restrict your
ability to make improvements in vehicle fuel economy which would be
observed in consumer use of .the vehicles? Please describe."
Volkswagen: "Undetermined."
Toyota: "We do not think that the current EPA policy on alternate
DPA specifically restricts the ability to make improvements in vehicle
fuel economy which would be observed in consumer use."
-------
-4-
Chrysler: "There are a number of ways in x^hich EPA policy as
expressed in advisory circulars on alternate dynamometer adjustments is
restrictive of our efforts to improve fuel economy.
The first consideration in discussing alternate dynamometer horse-
power is to recognize that 'this is the only means for assuring that all
technological improvements will show up as improvements in fuel economy
during both testing and customer use. When a manufacturer makes a major
effort to improve actual customer use fuel economy by improving aerody-
namics, reducing tire rolling resistance, improving chassis friction
loss, etc., there could be zero measurable benefits on the EPA test
cycle unless the manufacturer 'elects' to use the alternate dynamometer
procedures. However, when this step is taken, procedures must be de-
veloped, reviewed and approved by EPA; extensive road testing is re-
quired and EPA requires extensive confirmation and cross checking.
Nevertheless, we very strongly believe that these actual customer
improvements should be reflected in our test results.
A second area involves tires. For the 4x2 0-8500 GVW trucks using
16.5" tires in the heavier GVW range, we frequently find that there is
no benefit in using 'coastdown' (ref: R. R. Love, Chrysler, December 6,
1978 response to R. L. Strombotne, NHTSA, regarding Question 6). And,
in the case of 4x4 0-8500 GVW trucks, most tires are the 'off road' type
which also show no coastdown benefit. Many of these tires cannot even
be used for the EPA dynamometer test because of the extensive heat
build-up in the artificial laboratory environment (i.e., tire flex on
twin rolls with inadequate air flow). Yet, EPA and NHTSA continue to
project improvements requiring techniques that only show up on coastdown
testing.
Third, the fuel economy standards and testing procedures are in-
tended to reflect a fleet average under a standardized test, yet many
aspects are significantly biased to reduce that average. For example, a
number of options (e.g., station wagon luggage racks, station wagon rear
window vane deflectors, outside mirrors, etc.) interfere with air flow
and reduce vehicle fuel economy. As such, they must be taken into
consideration. However, EPA rules do not consider the option average
level (mean or the fifty percent level). Rather, EPA always requires
'options with projected sales of more than 33 percent
In addition to requiring dynamometer power settings to reflect a
33% option rate, other areas also are involved. Dynamometer power must
be increased 10% for air conditioning if air conditioning installation
rate exceeds 33% (ref: .40 CFR 86.129). Any option over three pounds
must be included in the vehicle weight if its installation rate is over
33% (ref: 40 CFR 86.080-24). If '.representative' (or average) results
are truly desired, all of these items should be calculated on the basis
of actual volume usage.
The EPA test procedure very clearly specifies that the acceptable
laboratory temperature is the range of 68°F to 86°F (ref: 40 CFR 86.130).
For 1979, Chrysler very logically submitted coastdown results for the
midpoint or 77°F. EPA rejected this and requested that data be adjusted
to 68 F. (Note: As testing temperature is reduced, fuel economy declines.)
-------
-5-
Fourth, and even more important than the above very serious con-
siderations, our major objection to EPA's approach to this subject is
their practice of continually making late changes, interpretations, and
confirmations of requirements. Also, so many details are involved in
the Advisory Circulars that EPA must provide an extensive amount of
interpretation. For last year's certification, the process of change
and interpretation lasted roughly from August 1977 to June 1978. It
should also be noted that EPA is not satisfied with the data from Chrysler's
coastdown test, even though they are invited to observe these tests.
Rather, EPA insists on independent tests (for which we must pay, provide
vehicles and supply transportation). Furthermore, a high degree of
confirmation correlation is required with extremely tight tolerances."
Ford: "It is disingenuous for EPA to characterize the coastdown
test procedure as an option to be elected by the manufacturer when
NHTSA1s maximum feasible standards are established using an assumption
of improved aerodynamics.
Current EPA policy on coastdown procedures restricts our ability to
make both mid-model year and specific car/truck model aerodynamic im-
provements by requiring substantially increased test requirements that
cannot always be contained from a workload standpoint nor justified
economically. This was particularly true in the 1979 model year when
EPA was changing requirements or delaying confirmation testing until
after 1979 model production was underway.
In other instances, we are not properly credited for improvements
that we do make on items which are never tested by EPA. For example,.we
are not credited in our CAFE for improvements made to items like optional
outside mirrors unless the particular mirror represents the expected
worst contributor aerodynamic drag. Similarly, we are not credited for
certain improvements made in optional tires or option weight reductions.
The present EPA confirmation procedures for the manufacturer's coastdown
test results further inhibit the early implementation of improved prod-
uct actions."
General Motors; "In many cases, it would be necessary to produce
several horsepoxver settings to cover all options that could affect road
load. The added test and administrative burden does not justify the
small estimated fuel economy gain which causes the manufacturer to
accept a less favorable setting in order to reduce testing requirements."
American Motors; "Current EPA policy (and practice) does not
restrict AM from making improvements. It denies AM the necessary time
to understand and apply these optional procedures to our development
programs and then to our pre-certification program.
For example, the latest alternate dynamometer procedure, Advisory
Circular 55-B, was issued on December 6, 1978 and applied to the 1980
model year vehicles some of which had already started durability testing.
-------
-6-
We are also unable to acquire any useful certification experience
with these procedures because they apply to a single model year. It
would therefore be an exercise in futility for AM to speculate on the
consumer-use impact of these procedures because we are spending all of
our energy in trying to catch up and apply these procedures to our basic
certification program."
Question 4; "Have the administrative procedures implemented since
1975 become burdensome to the point that time and money considerations
preclude their use in some instances as compared to using the standard
Federal Register procedures? Provide details."
Volkswagen: "Yes, to the extent that their net benefit provided
does not exceed that of the standard procedure."
Toyota; "As compared to the use of DPA from the inertia weight-
based table, the use of alternate DPA has required additional testing,
such as coastdown testing and/or intake manifold vacuum measurement.
The intake manifold vacuum measurement method, which was acceptable
until 1978 MY, requires at least 22 man-hours/test vehicle to obtain the
alternate DPA. The coastdown method, which has been acceptable after
1978 MY, requires at least 30 man-hours/test vehicle to obtain the
alternate DPA. Except for the normal test burdens above, it cost us
much time and money to develop our original coastdown test procedure and
test instruments. Additionally, since the coastdown method depends on
weather conditions, it takes more time to complete the coastdoxra testing
than we expect. Therefore, we feel that establishing an alternate DPA
is indeed burdensome. However, manufacturers are continually striving
for reductions in actual road load in their search for better fuel
economy; and it appears to us that the alternative DPA is the proper
method for evaluating the manufacturer's effort's."
Chrysler: "In our efforts to keep up with the increasingly more
stringent fuel economy standards, Chrysler has had to make choices that
x^ere not always the most cost-beneficial design alternative or capital
investment alternatives. Our choice of the 'coastdown' alternate dy-
namometer procedure falls within the same category, i.e., we recognize
the time and expense penalty compared to using the frontal area formula,
but we believe that attaining the higher fuel economy value is a more
important consideration."
Ford: "The effective timing of administrative procedures since
1975 have become burdensome, but have not yet precluded use of the
alternate procedures. As mentioned previously, changes in the 1979
alternate dynamometer setting procedure by EPA were made at such a late
time relative to our development/certification program timing require-
ments that we were unable to use the procedure on all of the eligible
vehicles for Job //I. This produced an unrecoverable CAFE loss because
subsequent vehicle fuel economy run at reduced PAD values had to be
harmonically averaged with the original formula (Job #1) vehicle fuel
economy.
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-7-
Further, new vehicle introductions require engineering prototypes
to be dedicated solely to the coastdown program. This is not only
costly, but due to limited availability of engineering prototypes, can
seriously disrupt other essential programs. An additional risk is the
option in the Advisory Circular for EPA to require additional engineer-
ing prototypes for confirmation procedures.
One of the most burdensome administrative procedures is EPA's
Advisory Circular #72 on alternate manual transmission shift schedules.
The existing procedure in the Federal Register on this subject (42FR16397,
16409) specifies that only the manufacturer's recommended shift speeds
be used during compliance testing. EPA's Advisory Circular, however,
specifies three alternatives available to the manufacturer, one of which
is to shift according to an EPA determined percent of rated engine rpm,
and the others are to use either 15-25-40 mph shift points or to conduct
an elaborate in-field research study to determine exactly how customers
do shift their vehicles.
As we stated in response to the shift schedules, Question #7, Ford
did conduct a research program to determine the appropriate shift schedule
for its 1979 non-turbocharged 2. 3L engine vehicles. This program took
about 3 months to complete, (data attached), it cost approximately
$100,000 to conduct, and was far more sophisticated than required by
Advisory Circular. #72. Nevertheless, EPA repeatedly requested addi-
tional data during the more than 4 months it took to receive approval of
the revised shift schedule."
General Motors; "Manufacturers presently cannot use their own
facilities to confirm horsepower values but must deliver their vehicles
to an independent test site and incur a cost of at least $3000 per test.
This results in a significant amount of time lost from other test programs
while expensive prototypes are being transported and/or are awaiting
regulatory tests. Thus, alternate horsepower values that are close to
frontal area numbers are often not submitted to EPA because of the added
burden resulting from potential confirmatory testing. The small 7%
'quick-check' tolerance is equivalent to the dyno-to-dyno variations
reported for the EPA laboratory. The risk of exceeding this tolerance
is significant since it has the potential of disqualifying emission data
vehicles or fuel economy data vehicles after a significant investment of
time and resource.
The demonstration requirements necessary to justify an approved
alternate shift schedule are so burdensome that the effort cannot be
justified for a relatively low volume manual transmission vehicle,
despite the fact that this configuration may offer better in-use fuel
economy."
American Motors: "This has always been a problem for American
Motors but it has proliferated during the last three years due to numer-
ous changes being made and without regard to the lead-time needs of the
manufacturers. The burden of implementing alternate procedures that may
be valid for only a single model year is often considered prohibitive."
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Appendix C
ACCESSORY COMMENTS
I. Introductory Statement
"EPA now uses a carline/truck designation rather than an engine
family designation for assigning accessory load. Additionally, carline
and truckline have been redefined to some degree. Other than this no
apparent changes have been made in the EPA test procedure which xrould
affect the simulation of vehicle accessories."
II. Comments
Question 1: "Has the carline/truckline approach for assigning
accessory load had an effect on your corporate average fuel economy?
How? To what extent?"
Volkswagen: "No."
Toyota: "Even though some carlines/trucklines exist in the same
engine family, the expected air conditioning installation percentage
base on the engine family approach does not differ so greatly as com-
pared to that based on the carline/truckline approach. Therefore, the
carline/truckline approach for assigning air conditioning load had no
effect on CAFE."
Chrysler: "The switch from engine family to carline for assigning
accessory loading has not had a significant effect on Chrysler's CAFE.
However, the switch from truck engine family accessory loading to truck-
line accessory loading in 1980 has a -0.10 mpg.fleet effect on 4x2 and
essentially a zero (-0.01 mpg) effect on 4x4 light truck fuel economy."
Ford; "The 1980 accessory selection rule which determines the 33%
option criterion by carline rather than by engine family causes the
effective test weight to increase slightly for 1980 passenger cars.
This, and some resultant additional power absorber penalties for air
conditioning, cause an approximate net 0.1 mpg decline in 1980 measured
CAFE. In Ford's January 9, 1979, Position Paper to Ms. Joan Claybrook,
this 0.1 mpg appears as the difference between the 0.3 mpg finer test
weight/options-by-car line penalty and the 0.2 mpg finer test weight
penalty.
The total effect of these selection changes on Ford's 1980 light
truck fuel economy is the same as the carline effect (i.e., 0.3 mpg CAFE
loss) and was reported to NHTSA in Ford's January 17, 1979 response to
NHTSA's NPRM on reconsideration of the 1981 light truck fuel economy
standards."
General Motors: "The carline/truckline approach for assigning
accessory load has not significantly affected our passenger carlines on
the average. However, while the effect on our total truck fleet average
is not currently known, some individual truck models have gained 500 to
750 Ibs. This is due to the effect of the heavier truck accessories,
e.g., optional fuel tank, step bumper and rear air conditioner."
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-2-
American Motors; "Since the EPA has adopted carline/truckline
designations rather than an engine family designation for assigning
options (accessory loads), AM has not found a net fleet average penalty
or benefit. Individual vehicles have increased while others have de-
creased causing the 1980 net impact to be insignificant."
Question 2: "Do you believe that there have been other changes
made in the EPA test procedure which affect the simulation of the load
imposed on the engine by the vehicle accessories? What changes? What
effect?"
Volkswagen; "No."
Chrysler: "We are not aware that other changes in the EPA test
procedure may have changed the simulated effects of vehicle accessories."
Ford: "Ford knows of no other test procedure changes that have
adversely affected accessory load simulation."
General Motors: "GM is not aware of other changes made in the EPA
test procedure that affect the road load simulation."
American Motors: "It is possible that the interaction of Advisory
Circular 55-B (coast-down procedure for 1980) with the carline/truckline
approach would have some effect, but this has not been observed or
determined at this time."
Question 3: "There appears to be increasing use of accessories,
such as air conditioning, in small vehicles. Is the current EPA simula-
tion of air conditioning (10 percent increase in the dynamometer power
absorption) adequate for this simulation since such smaller vehicles
generally would have reduced dynamometer power absorptions?"
Volkswagen: "We find that the 10% increase in dyno horsepower for
air conditioning adequately represents the actual load."
Toyota: "Though we do not have enough data to indicate the re-
lationship between the engine power consumed by air conditioning in
consumer use and the DPA value set on the chassis dynamometer for fuel
economy testing, data are available which demonstrate that a 5 to 10
percent loss on the fuel economy for Celica models with 20R engines
appears when the air conditioning is activated at maximum capacity
during actual vehicle driving as compared to when the air conditioning
is in the OFF condition. Certainly, this effect on the fuel economy is
larger than that due to the 10 percent increase in DPA on the chassis
dynamometer, because the latter loss is 2 to 4 percent according to 1979
MY certification data for Celica models with the 20R engine. This
tendency will be found in large vehicles as well as small vehicles.
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-3-
However, judging from the fact that the air conditioning is not always
activated with the maximum capacity, we believe that the current EPA
simulation of air conditioning load is adequate for this simulation."
Chrysler: "The determination of average fuel economy effects of
accessory operation (i.e., on a nationwide year-round basis) also in-
volves much more complex issues than whether or not the system's opera-
tion is being properly simulated. Air conditioning losses, for example,
vary with ambient temperature, humidity, time of day (i.e., sun load),
driving speeds, acceleration rates, etc., all of which are in turn
affected by geographic variables. To calculate an average effect, one
would have to determine a nationwide vehicle weighted operating condition
and determine the variability of the system's operation over the range
of operating conditions.
EPA's current practice of applying a 10 percent dynamometer horse-
power penalty to carlines with air conditioner installation rates of
greater than 33 percent results in a fuel economy penalty of about 2
percent. This penalty is relatively invariant with horsepower; for
instances, it is about 1.7 percent on larger vehicles and up to about
2.3 percent fuel economy on smaller vehicles. This rule results in
subcompacts being more heavily penalized than larger vehicles.
To illustrate this point, using published air conditioning in-
stallation rates on 1977 models and EPA's vehicle classes from their
fuel economy booklet, the following average installation rates are:
Average Air Conditioning Installation Rate
Subcompact Compact Intermediate Full Size
48.7% 75.3% 80.2% 95.6%
An examination of these numbers gives a clear indication that the
average subcompact fuel economy is being excessively penalized for use
of air conditioning when this option is used on less than one-half of
the volume produced."
Ford: "Depending upon the ambient conditions, the current simula-
tion for air conditioning use (10% increase in PAU setting) may not
adequately account for the effect it has on fuel consumption. EPA has
estimated that the average fuel economy penalty for air conditioning,
when operational at FTP ambient conditions is about 9% in an on-versus-
off comparison. The 10% power absorber increase in the dynamometer
simulation leads to a 2% fuel economy penalty for large cars and a 3%
fuel economy penalty for small cars. This is because the PAU consti-
tutes a larger fraction of the work requirement for small cars. Therefore,
the 10% increase in PAU impacts smaller cars relatively more than it
does larger cars and is consistent with the question1s implication that
air conditioning affects smaller cars' fuel economy more than that of
larger cars. More accurately, it affects lower power-to-weight vehicles
relatively more than high pox^er-to-weight vehicles. The simulation is
consistent and proper for both types of vehicles.
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-4-
It was mentioned at the outset that the 10% PAU increase is an
expedient and leads to a 2%-3% fuel economy decrease rather than the
observed 9% decrease during air conditioner operation. There are two
factors which tend to make this expedient more accurate than it first
appears. First, the EPA selected rules require a vehicle to be tested
with the air conditioning penalty if only 33% or more of that model
contains air conditioners. Second, when the national average duty cycle
of air conditioner operation is considered, the gross effect on con-
sumption is reduced far below the 9% figure cited above. Air condition-
ing is seldom used in northern areas and is seldom used at night in all
areas. It is not difficult to reconcile the 9% figure to a figure of 2%
or below when the actual over-all operation of air conditioning is
considered."
General Motors: "The current EPA air conditioning (A/C) adjustment
factor appears to be an adequate simulation regardless of vehicle size."
American Motors: "We believe the 10 percent factor is an adequate
simulation in small vehicles and may be slightly high for some full-size
vehicles that use fuel-saving cycling compressors."
Question 4: "What would be the effect of a more realistic simu-
lation of air conditioning load on your corporate average fuel economy?"
Volkswagen: "No detailed data available, however, would contribute
to further complication of test procedures."
Toyota: "We do not have a more realistic simulation of air condition-
ing load than the current EPA simulation."
Chrysler: "Modifying EPA test procedures to further refine these
effects would certainly add complication to an already complicated
situation and would require more precision than the EPA test can ever
hope to accomplish.
The determination of average fuel economy effects of accessory
operation (i.e., on a nationwide year-round basis) also involves much
more complex issues than whether or not the system's operation is being
properly simulated. Air conditioning losses, for example, vary with
ambient temperature, humidity, time of day (i.e., sun load), driving
speeds, acceleration rates, etc., all of which are in turn affected by
geographic variables. To calculate an average effect, one would have to
determine a nationwide vehicle weighted operating condition and de-
termine the variability of the system's operation over the range of
operating conditions."
Ford; "As explained in the preceding answer, the present air
conditioner simulation is probably realistic when duty cycle or actual
air conditioning operation in the field is taken into account. The
question implies that this is not the case but certainly the alternative
of testing the air conditioner actually operational is less realistic.
To properly account for air conditioning's fuel economy impact would
require at least two tests (on/off) and a duty cycle weighted average of
the two results.
-------
—5—
Establishing the actual weighting would have to involve extensive .
studies of different areas of the country with different climate con-
ditions with recognition of variations in climate conditions on a year
to year basis. This would lead to the same result presently obtained
but with a huge almost non-containable effort.
In addition, a duty-cycle characterizing actual air conditioner use
would have to be established, velocity proportional air flow around the
vehicle would have to be provided to assure representative convective
cooling, and representative humidity levels would have to be determined
and regulated during testing to assure proper condenser efficiency. The
cost impact of all these additional conditions make the adoption of such
a procedure prohibitive."
General Motors: ". . . GM believes that the current method of
accounting for air conditioning load is a reasonable assessment of the
average penalty the customer experiences."
American Motors: "We believe the current 10 percent increase in
the dynamometer power absorption for carlines/trucklines is reasonably
representative, consequently we have not considered other more-realistic
simulations."
Question 5: "What would be the effect of more realistic simulation
of other engine-driven accessories x^hich are not fully utilized in the
EPA test procedure (i.e., power steering, engine cooling fan, electrical
system load) on your corporate average fuel economy?"
Volkswagen; Refer to answer of question 4.
Toyota: "Other engine-driven accessories such as engine cooling
fan and alternator, except power steering, are operated on the chassis
dynamometer in the same manner as encountered during the consumer use.
With respect to the power steering, since only the engine power loss at
a straight-driving is reflected in the current FTP, it is expected that
the EPA measured fuel economy is slightly better than the fuel economy
encountered during the consumer use including curve-driving. However,
at this time, we are not aware of a practicable and more realistic
simulation of power steering."
Chrysler: "In most instances, accessory operations on the EPA
cycle are yielding results of a reasonable order of magnitude. Modi-
fying EPA test procedures to further refine these effects would certain-
ly add complication to an already complicated situation and would require
more precision than the EPA test can ever hope to accomplish.
There is one area where added refinements might be made which would
not complicate testing unnecessarily. That would be in providing suffi-
cient air flow to obtain underhood and underbody temperature environ-
ments corresponding with highway operating conditions.
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-6-
The determination of average fuel economy effects of accessory
operation (i.e., on a nationwide year-round basis) also involves much
more complex issues than whether or not the system's operation is being
properly simulated. Air conditioning losses, for example, vary with
ambient temperature, humidity, time of day (i.e., sun load), driving
speeds, acceleration rates, etc., all of which are in turn affected by
geographic variables. To calculate an average effect, one would have to
determine a nationwide vehicle weighted operating condition and de-
termine the variability of the system's operation over the range of
operating conditions. The same analysis would be required for analyzing
the operation of most other accessory systems."
Ford: "Power steering is fully simulated by the present procedure.
This is because the increased pump load during steering maneuvers is
negligible compared to the pump load that is constantly present. A more
realistic simulation of power steering (e.g., movement of the steering
wheel back and forth), therefore, would have negligible effect on fuel
economy.
Operating the electrical systems such as headlights, defrosters,
etc., would reduce measured fuel economy."
General Motors: "GM has not conducted studies to indicate the
penalty of each accessory under all operating conditions."
American Motors: "AM is unable to respond to this question because
we are unaware of the need to simulate the engine-driven accessories
more realistically than the current procedures provide."
Question 6: "Has the lack of accurate representation of accessory
loading precluded or inhibited your development of more efficient acces-
sories or accessory drives?"
Volkswagen; "No."
Toyota: "In spite of x^hether or not the simulation of engine-
driven accessories is reflected in the current FTP realistically, we are
making every effort to reduce engine power loss caused by the various
engine-driven accessories, which is encountered during consumer use.
Therefore, the lack of accurate representation of accessory loading does
not inhibit our development of more efficient accessories."
Chrysler: "Despite the lack of provisions in the regulations for
accurate representation of accessory loading, Chrysler will continue to
develop more efficient accessories and accessory drives in order to
improve consumer fuel economy."
Ford: "Ford is pursuing the development of every practicable
accessory program offering any benefit in the improvement of efficiency."
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-7-
General Motors: "GM has investigated the total vehicle to improve
on-road fuel economy for the customer. Examples of accessory improve-
ments which we investigated were included in our August 7, 1978 response
to NHTSA (Attachment 4, pgs. 13-15). These devices have been under
development regardless of EPA's accessory load procedure during dyna-
mometer testing. As an example, GM has introduced accessory fuel economy
improvements even though they cannot be recognized by the EPA test
procedure."
Attachment 4 is not included herein.
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Appendix D
INERTIA WEIGHT CHANGE COMMENTS
I. Introductory Statement
"Beginning with the 1980 model year, EPA reduced the increments of
simulated inertia by approximately a factor of two (from 500 pounds to
250 pounds for vehicles over 4,000 pounds). This change was made to
provide more accurate simulation of the test vehicle weight."
II. Comments
Question 1: "If the current test weight increments were applied to
first the 1974 test vehicle fleet, then to the 1975 test vehicle fleet,
what percentage of those vehicles would have been tested at higher
simulated inertia? At lower simulated inertia?"
Volkswagen: "At the same 1974 model year curb weights, one model
out of nine total would have been tested at a higher simulated inertia
and one model at a lower.
At the 1975 model year curb weights there would be no changes in
simulated inertia."
Toyota:
Test Test Test
Vehicle Vehicles Shifted to Vehicles Shifted to
MY Higher Simulated Inertia Lower Simulated Inertia
1974 6 of 22 2 of 22
1975 7 of 29 0
Chrysler: "The data for answering these questions is not readily
available."
Ford: "As of 1975, the actual weights of Ford's passenger cars and
light trucks were more or less randomly distributed within each inertia
weight category (IWC). This was not by design, but rather reflects the
absence of a strong external influence which would tend to cause a bias
in one direction or another. Had the finer equivalent test weight (ETW)
categories of the 1980 model year been applied to 1975 model year production
configurations, the following changes in test weight would have occurred.
-------
% Vehicle
Configurations
Tested at
Higher Inertia
Car 28
Truck (0-6000) 19
-2-
ETW vs IWC
% Vehicle
Configurations
Tested at
Same Inertia
41
63
% Vehicle
Configurations
Tested at
Reduced Inertia
31
18
General Motors: "This question has no bearing on the stated pur-
pose of the questionaires."
American Motors; "AM does not believe the question relates to the
issue because the 1981-1984 passenger car fuel economy standards were
based primarily on the 1977 model year cars not the 1974-1975 model year
cars. In addition, our carline mix has changed from a full-line manu-
facturer to a limited-line manufacturer causing us to question the
practicality of even attempting to generate this information.
Our 1974-1975 light-duty truck fleet (0-6000 pounds GVWR) consisted
of Jeep CJ's and AM General Postal Service vehicles:. Applying the
change to the 1974 model year Jeep CJ's would not have changed the
simulated inertia, but in the 1975 model year 50 percent of our Jeep
CJ's would have been tested at a higher simulated inertia weight.
Under the new increments 100 percent of the 1974 and 1975 Postal
Service vehicles would have been tested at a higher simulated inertia
weight."
Question 2: "If the current test vehicle fleet were tested using
the pre-1979 inertia increments what percentage of vehicles would be
tested at higher simulated inertia? At lower simulated inertia?"
Volkswagen: "No vehicle would be tested at a highter simulated
inertia, all of them at lower simulated inertia."
Toyota:
Test
Vehicle's
MY
Percentage of Test
Vehicles Shifted to
Higher Simulated Inertia
Percentage of Test
Vehicles Shifted to
Lower Simulated Inertia
1980
30 of 35
11 of 35
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-3-
Ford: "The passage of the Energy Policy and Conservation Act which
established fuel economy standards and penalties for non-compliance,
there arise a strong incentive to reduce weight to increase fuel economy.
This is reflected, partly, in a biased toward the high end of the inertia
weight categories. It occurred because vehicles with weights in the
lower end of each category were lightened as much as possible'. .. .and
were able to be recategorized into the next lower IWC.
The result of this externally motivated weight reduction, in 1980,
is to cause a difference in average test weight as it would be calcu-
lated by the 1975 and 1980 classification rules. The percentage of
vehicle configurations reclassified is shown below.
The percentage of trucks reclassified into heavier test weight
classes was not as severe as with out passenger vehicles."
IWC vs ETW
Cars
Truck
% Vehicle
Configurations
Tested at
Higher Inertia
75
17
% Vehicle
Configurations
Tested at
Same Inertia
23
62
% Vehicle
Configurations
Tested at
Reduced Inertia
3
21
General Motors; "If the NY 1979 GM fleet were tested per the MY
1980 test procedure utilizing the smaller test weight classes (TWC) and
options by carline, our fleet average test weight would increase by 112
Ibs, as shown in Figure Dl. This analysis considers 70% of GM's high
volume MY 1979 vehicles (California, altitude and low volume configura-
tions were omitted from this analysis) to determine the test weight
penalty independent of vehicle mix and technology changes year-to-year."
American Motors: "The following tables have been simplified and
have not been sales \
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-4-
Truckllne
CJ5/7 4-Cyl 3000 3000 0
6-Cyl 3000 3250 250
8-Cyl 3500 3375 (125)
Wagoneer 8-Cyl 4500 4500 0
Cherokee 6-Cyl 4000 4250 250
8-Cyl 4500 4500 0
Truck J10 6-Cyl 4500 4500 0
8-Cyl 4500 4500 0
Truck J20 8-Cyl 4500 4750 250
Eagle 6-cyl 3750 3812 62
* IW = Inertia Weight Class; TWC = Test Weight Class.
The actual penalty of the change can be noted in all carlines and all
trucklines (except the 8-cylinder CJ)."
Question 3: "What additional improvements in EPA measured fuel
economies would have been obtained if this change in EPA inertia cate-
gories had not been made? What data exist to indicate that these measured
fuel economy improvements would have been realized in consumer use?"
Volkswagen: "Undetermined."
Toyota: "According to our experimental data derived from the 1980
MY Celica with 20R engine, the inertia weight change has an influence on
the fuel economy of 1.5 percent/125 Ibs. inertia increment for city fuel
economy and 1.0 percent/125 Ibs. inertia increment for highway fuel
economy, respectively. Therefore, the assumption in this question will
yield 0.4 percent fuel economy loss on the 1980 MY CAFE because more
test vehicles are shifted to the higher simulated inertia due to the
implementation of test weight increments since 1980 MY, as shown in the
answer to Question 2."
Chrysler: "When EPA first proposed to change the Inertia/Test
Weight Increments (ref: NPRM publication in Federal Register, September
10, 1976 at 41 FR 38674, etc.), Chrysler made detailed projections and
analyses of the 1978 passenger car fleet with the model line-up, vehicle
weights, projected sales and fuel economy current at that point in time.
Our response to the NPRM noted (ref: S. L. Terry, Chrysler, December 6,
1976 response addressed to R. E. Train, Administrator, EPA, pages 5, 6,
and 7) that the proposed finer increments would increase the fleet
average inertia weight by 65 Ibs. and reduce the fleet average fuel
economy by 0.28 mpg."
Ford: "As Ford reported in its Position Paper on the 1981-1984
passenger car fuel economy standards and in its response to the NHTSA
NPRM regarding reconsideration of the 1981 light truck fuel economy
standard, the revised inertia x^eight classifications (ETW vs IWC) for
1980 will reduce our otherwise expected CAFE by 0.2 mpg on passenger
cars and 0.3 mpg on light trucks (including the effect of the revised
procedure for determining option content).
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-5-
These may be viewed as measured gains which were precluded by rule
change. They are not, however, detectable to the consumer.
There is no way to determine whether, or to what extent, the actual
in-use fuel economy of a given vehicle has been, or will be in the
future, changed by the change in EPA's inertia categories."
General Motors: "Contrary to question 3, there would be no addi-
tional improvements by retaining the MY 1975 test weight procedures.
Since the test weight class procedure was changed, GM has been penalized.
The basis for the MY 1981-84 standards was MY 1977 which had the
same weight test procedure as MY 1975 through 1979. Therefore, a proper
comparison is between MY 1979, with the original weight procedures, and
MY 1980, with the revised weight procedures, In this case, the 112 Ib
penalty for the MY 1980 procedures, as indicated in response D2, results
in approximately a 0.1 mpg loss in GM's CAFE. Therefore, if the test
procedure change had not been made, GM would not have been penalized
relative to the MY 1975 test procedure specificied in the Energy Policy
and Conservation Act (EPCA). Since the vehicle did not change, the fuel
economy realized by the consumer is not affected."
American Motors: "AM is not aware of any additional improvements
in EPA measured fuel economy on our vehicles if this change in inertia
categories had not been made. The change represents a low (0.1 to 0.3
mpg) car and truck fleet average fuel economy penalty over the past
inertia categories because our vehicles had tended to group slightly
toward the high end of each previous inertia weight category.
The change had no direct impact on in-use vehicle fuel economy, but
it has caused additional testing and facilities expenditures that could
have been diverted to fuel economy development."
Question 4: "What was the average difference between production
vehicle weights and EPA simulated vehicle weights under the 1979 pro-
cedures? Under the pre-1979 procedures?"
Volkswagen: "No difference."
Toyota:
Number Pre-1980 MY Inertia 1980 MY Test
of Test Weight Increment Weight Increment
"Term Vehicles Procedure Procedure
A 35 79.5 Ibs 43.9 Ibs
B 35 27.9 Ibs -4.2 Ibs
Note: "1980 MY test vehicles are used for this calculation. Term 'A1
means the absolute average of designed production vehicle weight
minus EPA simulated vehicle weight. Term 'B1 means the average
of designed production vehicle weight minus EPA simulated
vehicle weight."
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-6-
Ford: "Ford does not maintain a data.base of average production
and simulated weights."
American Motors: "The simulated inertia weight classes for pre-
1979 and the 1979 models are the same and we are therefore not sure we
understand the question.
AM does not have the information in the form that would show the
average difference between production vehicle weights and EPA simulated
vehicle weights."
Question 5; "Are the above claimed effects permanent or transitory?
If transitory, what percentage of your fleet is affected and for how
long? Please explain you answer."
Volkswagen; "Undetermined."
Toyota: "This is transitory because the sensitivity in the fuel
economy is changeable due to the future vehicle weight reduction at
model change and the future vehicle weight reduction at model change and
the new emission control system to satisfy the future emission standards."
Chrysler: ". . .we have initiated a strong weight reduction
program in order to place all high sales volume vehicles in the lowest
test weight class which is reasonable. While we do not expect to com-
pletely offset the above noted potential loss, we do expect to minimize
the loss in 1980. Eventually, as new vehicles replace old vehicles and
future weight reductions achieved, the loss should approach zero."
Ford: "The effects of reducing the increments of simulated inertia
are permanent."
General Motors: "The effects of the smaller test weight classes
and options determined by carline rather than by engine families are
permanent. In the redesign of our new carlines we must now account for
the average 112 Ib test weight penalty, described in response to Ques-
tion 2, before we obtain any credit under the MY 1980 test procedures
for weight reduction. Therefore, GM would use weight reduction tech-
nology at a considerable expense without realizing any fuel economy
gain."
American Motors: "The effects of the EPA reduced increments of
simulated inertia weight by a factor of two is a permanent test pro-
cedure penalty. We are unaware of any technique we could use that would
permit it to be considered a transitory effect on our fleet average fuel
economy. Our response to Question 2 of this section shows the impact of
this penalty is fleet wide and slightly more significant with respect to
our trucklines than our carlines."
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-7-
General Motors Data
Figure D-l
Effect of MY 1980 Test Weight Class Realignment on GM Fleet
EPA GM Car
Class Line
Midsize
Large
Large
Midsize
Sub-
compact
Sub-
compact
Compact/
Midsize
Sub-
compact
Compact/
A
B
C
E
F
H
K
T
X
Avg. I.WC I/
79 Fleet
79 Regs.
3533
4132
4513
4075
4000
3210
4500
2435
3875
Avg.
Avg. TWC 2J Test Avg. TWC _3/ Average TWC
79 Fleet Weight 80 Fleet From 79 Fleet
80 Regs. Change 80 Regs. 80 Regs.
3725
4269
4638
4256
3940
3230
4750
2440
3875
+192 3723
+137 4160
+125 4481
+181 4178
-60 3907
+20 3209
+250 4302
+5 2434
2910
-2
-109
-157
-78
-33
-21
-448
-6
-965
Midsize
Two- . Y 4000 3875 -125 3700 -175
seater
Fleet Average 3785 3897 +112 3680 -217
Test Weight
Fleet Avg. Loaded 3868 3868 0 3700 -168
Vehicle Weight _4/
JY Inertia Weight Class - MY 1979 definition of broad weight classes
(250/500 Ib increments).
2_l TWC - Test Weight Class - MY 1980 definition of weight, within an
inertia weight class, at which a vehicle is tested based on its loaded
vehicle weight (125/250 Ib increments).
_3/ Avg. MY 1980 TWC represents the effects of GM weight reduction
program for B-C-K-X-Y car lines.
j4/ Loaded vehicle weight - curb weight plus EPA options plus 300 Ib.
-------
Appendix E
EMISSION STANDARDS COMMENTS
I. Introductory Statement
"In the other areas of this questionaire it is important that the
issue of test procedure changes is not confused with comments related to
emission standards. However, since some manufacturers may wish to
comment on issues related to emission standards the following questions
are presented."
II. Comments
Question 1: "Has the imposition of the 0.41/3.4/1.0 emission
standards (1981) inhibited the development of alternate engines and
control strategies relative to conventional spark ignition (SI) en-
gines?"
Volkswagen: "Yes."
Toyota: "To meet the 0.41/3.4/1.0 emission standards in gasoline-
fueled engines, we believe that most of our models will need the final
big measure (i.e., three-way catalyst with feedback control system). If
the NOx standard were not so stringent, conventional engines (or strat-
ified engines) with oxidation catalyst, which have been widely used,
would not be excluded from the market. Considering diesel engines, the
variation in the manufacturing process is expected to lead to the big-
gest difficulty; that of achieving the NOx standard of 1.0 g/mile."
Chrysler: "The imposition of the .41/3.4/1.0 emission standard for
1981 MY has inhibited the development of alternate engines and control
strategies in several ways. With less stringent emission regulations,
development efforts could be more intensely directed tox\rard the im-
provement of fuel economy, optimization of efficiency and specific
output, the minimization of cost, and the more effective use of capital
resources.
For example, a spark ignited gasoline engine operating at extremely
lean air/fuel ratios may be an attractive alternative to the stoichio-
metric, closed loop systems proposed for 1981. Both pre-chamber and
open-chamber arrangements are expected to provide efficiency gains of
several percent and substantial savings in cost and complexity. However,
the allowable hydrocarbon level of 0.41 gm/mi is a severe limitation on
maximum air/fuel ratio and thus on the attainable efficiency gain.
In the case of the diesel engine, there is a direct relation be-
tween efficiency and NOx, and an inverse relation between HC and NOx.
Thus, the imposition of a rigid NOx standard will penalize efficiency to
a substantial degree, while also making more difficult the attainment of
low HC level. The use of EGR alters the magnitude of these relations,
but not the basic trends. EGR may also contribute to increased partic-
ulate emissions.
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-2-
Some of the less common alternative engines are also affected by
restrictive emission standards. Stratified charge gasoline engines.
especially the open chamber variety, are not only influenced, but ulti-
mately efficiency-limited by restrictive HC and NOx standatds. The
rotary Wankel is very sensitive to HC limits, and extensive redesigns
have been developed to meet them.
The gas turbine and Stirling engines may adapt more readily to low
emission requirements, but the attendant cost penalties may be significant."
Ford; "The manpower and capital requirements to meet the stringent
1981 emission standards have substantially impaired our ability to
devote resources to alternate engines and various powertrain strategies.
Our cessation of work on the Stirling engine is an example. Also, we
would probably be further along on Turbo-Charging, PROCO, Diesels and
Turbines if it were not for our all out effort to meet current emission
and fuel economy standards.
In regard to control strategies for conventional spark ignition
engines, Ford has increased its development work on various electronic
control systems and is planning to increase usage of such systems."
General Motors; "The basic objective of GM's continuing alterna-
tive engine research and development programs has been to find and
develop superior alternatives to the spark-ignition gasoline engine.
A prime alternative to spark-ignition engines is the diesel engine.
However, simultaneously meeting the 0.41 HC and 1.0 NOx standards for MY
1981 has proven to be an extremely difficult challenge. At present
levels of technology development, NOx levels of 1.0 g/mi would require
the use of EGR which in turn would increase particulate emission levels
and cause, severe problems with engine durability. With today's tech-
nology the MY 1981 emission standards thus preclude the continued use of
light-duty diesel engines, particularly in the larger vehicles."
American Motors; "Yes, these stringent emission standards require
a total undiluted effort for AM to purchase and adapt the necessary
conventional engine-emission control systems to our cars thereby ex-
cluding us from practically considering alternate engines and control
strategies for the forseeable future."
Question 2: "On September 19, 1978, EPA distributed a draft Ad-
visory Circular with regard to emissions at temperatures and operating
conditions typical of the urban environment, such as vehicle operation
at 50°F, but not specifically evaluated by the FTP. What effect would
this draft Advisory Circular have on your present corporate average fuel
economy? What effect would it have on your future ability to improve
fuel economy as measured on the EPA tests and in consumer use? In
particular, what would be the effect of this draft Advisory Circular on
the use of electronics and on the use of other new types of fuel economy
improvement technology such as turbocharging, and variable displacement
engines? What data are available to support your response?"
Volkswagen: "Undetermined, but we expect a negative effect on
CAFE."
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-3-
Toyota; "At this time, we cannot even imagine what effect it would
have on the fuel economy of each model and how our CAFE might change.
We believe that the difficulty of conformity with the standard, not the
effect on the CAFE, is the primary problem with this draft A/C."
Chrysler; "We have neither the time nor the facilities necessary
to evaluate the effects on fuel economy of 'testing at temperatures other
than those specified by the FTP. In tests conducted by the Canadian
government at reduced ambient temperatures it was found that fuel con-
sumption increases significantly as ambient temperature decreases. SAE
paper 780935 'The Effects of Technology on Automobile Fuel Economy Under
Canadian Conditions,' A.C.S. Hayden, 1978)."
Ford; "The ill-defined and open-ended nature of this draft Advisory
Circular has precluded any definitive analysis as to its impact on fuel
economy."
General Motors; "General Motors has previously reported low ambient
temperature emission tests of oxidation catalyst equipped vehicles (SAE
Paper No. 741052, Attachment 7). In comparison to non-catalyst vehicles
the use of catalysts was shown to improve the warm-up emissions per-
formance of the vehicle. In addition, General Motors also reported same
tests of three-way catalyst equipped vehicles to EPA (FE-1400, July 19,
1978, Attachment 8, and FE-1535, December 20, 1978, Attachment 9).
We believe these tests indicate that present and future catalyst
systems provide a considerable degree of emissions control under non-FTP
test conditions. However, GM does not have data to allow us to assess
the impact of the draft Advisory Circular on our entire product line.
Consequently, it is not possible to estimate the effect of the require-
ments of the draft Advisory. Circular on our present CAFE or on the use
of the fuel economy improvement technology cited in this question."
General Motors Attachments 7, 8, and 9 are not included herein.
American Motors; "Fuel economy effects of this Advisory Circular
could not be measured by AM because there were several major procedural
elements which were not addressed by the EPA. The absence of such
important test elements as tolerances for testing conditions, precon-
ditioning of the vehicle, test fuel specifications and the applicability
of deterioration factors made actual evaluation of these non-FTP stand-
ards impractical.
Should the EPA decide to impose such non-FTP standards in the
future, there could be a negative fuel economy penalty for AM because
the additional tasks will require diverting resources presently involved
in basic fuel economy research into investigation of the impact of non-
FTP emissions."
Question 3: "What effect did the change, by Congress, of the 1978
light-duty vehicle standards of 0.41 gm/mi HC, 3.4 gm/mi CO, and 0.4
gm/mi NOx to 0.41 gm/mi HC for 1980, to 3.4 gm/mi CO to 1981 (with
possible waiver to 7.0), and 1.0 gm/mi NOx in 1981 have on your 1978
-------
-4-
through 1985 corporate average fuel economies? Please answer separately
for conventional SI engines, stratified charge SI engines and diesel
engines."
Volkswagen: "Effects on CAFE not quantified, but an obvious
positive effect is realized when considering the relaxed NOx require-
ments."
Toyota: "A system to meet the California 1983 MY NOx standard of
0.4 g/mile has not been developed. Therefore, it is not evident what
effect the changes had and will have on our CAFE."
Chrysler: "We are presently working toward the research goal of
0.4 gm/mi NOx as established by Section 202(b)(7) of the Clean Air Act
Amendments of 1977. Since we have thus far been unable to attain that
goal, it is not possible for us to measure the effects of a 0.41/3-4/0.4
standard on fuel economy as compared with 0.41/3.4/1.0. At the present
time, it appears that if known technology can be improved and refined to
the point where the 0.4 gm/mi NOx level can be achieved, the necessary
engineering design trade-off will result in a significant fuel economy
penalty."
General Motors; "The emission control systems which shows the most
promise of meeting the 0.41/3.4/0.4 standards employ catalytic treatment
of all three pollutants. Our current test data indicates a 5% loss in
fuel economy due to the MY 1980 emission standards and a 3% minimum loss
for MY 1981 and beyond. In addition, EPA's failure to grant a MY 1981
NOx waiver and/or regulating stringent particulate standards could
preclude the use of the diesel engine as a means of improving our CAFE.
This loss would affect GM's CAFE by 0.4 mpg in MY 1982 and 0.8 mpg in MY
1985."
American Motors: "The 0.4 gram/mile NOx level was not technologically
feasible for the 1978 model year. The change, by Congress, that establish-
ed the 1.0 NOx level for the 1981 model year and reclassified the 0.4
NOx standard to a research goal was appropriate and does not directly
impact our 1978 through 1985 fleet average fuel economy. Remember, the
Energy Policy and Conservation Act car fuel economy standards were based
on the 1975 emission standards.
The 0.41 HC, 3.4 CO and 1.0 NOx standards are estimated to result
in a 1.0 to 1.5 mpg car fleet average fuel economy penalty over the 1.5
HC, 1.5 CO and 2.0 NOx standards (1977-1979)."
Question 4: "Are any synergistic effects present when simultaneous
changes are made in emission standards and test procedures, which do not
occur when one of those factors is changed alone? Explain."
Toyota: "When the lead time is the same, there are synergistic
effects. We request that EPA synchronize revision of the test procedure
with emission standard changes and allow adequate lead time to reduce
the burden on the manufacturer which in turn may be expected to lead to
synergistic effects."
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-5-
Chrysler: "We are unaware of any synergistic technological effects
on fuel economy, attributable to the combined effects of simultaneous
changes in emission standards and test procedures."
Ford: "We are unable to identify any specific synergistic effect
of simultaneous changes, however, we would hypothesize that the negative
effect that would normally accompany changes to both emission standards
and test procedures would be largely eliminated if adequate lead time
were provided - which is usually not the case with regard to test pro-
cedure changes."
General Motors: "GM believes that the effects of simultaneous
changes in emission standards and test procedures on fuel economy are
synergistic. First, GM's 11 car study shovrs that the test procedure
changes caused a significant emission penalty (0.028 gm/mi or 2% of MY
1979 standard for HC and 0.78 gm/mi or 5% of MY 1979 standard for CO).
It is estimated that the recalibration required to account for this test
procedure emission penalty will cause a negative impact on fuel economy.
Second, the calibration change required to meet the stringent MY 1981
emission standards by itself is expected to cause a fuel economy penalty
as indicated in the response to question 3."
American Motors: "AM does not believe there are inherent synergis-
tic effects caused by simultaneously making changes to the standards and
test procedures. However, we have observed many times over the past
three years that changes of test procedures have caused an emissions
increase that requires a recalibration to maintain constant emissions.
Most of the items in Appendix A.under the major significance column are
of this
type."
The American Motors Appendix A has been included as Attachment E-l
at the end of this appendix.
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American Motors
Attachment E-l
Appendix E
Page 1 of 4
EPA TEST PROCEDURE CHANGES SINCE 1975
Items of Direct or Major Significance
Standard HP setting for test
Alternate dynamometer power ab-
sorber (DPA) HP setting procedure
via the EPA Advisory Circulars
1975 Model Year
Procedure
Table value-function
of inertia weight
New Procedure
HP based on aero-
dynamic consider-
ations
Absolute maniford pres- Recommended the
sure or alternate ap- coastdown method
proved by the EPA A/C 55, 3/26/76
A/C 55-A, 2/8/78
Revised A/C 55
A/C 55-B, 12/6/78
Revised A/C 55-A
First Model
Year Affected
1979
1978
1979
1980
Estimated
Negative Impact
on FAFE — MPG
0.1-0.4
Low
Low
0-0.5
Procedures for setting road load
control on dynamometer
Test fuel specs.
octane
lead
phosphorus
sensitivity
Average absolute humidity during
test in EPA lab.
Calibration gas accuracy
Manual
As required by' mfgr.
As required by mfgr.
0.0
not specified
48 grains/lb.(avg)
+ 2% corporate
standards
A/C 55-C. to revise
A/C 55-B
Automatic
93 min.
0.05 max. gm/gal
0.005 gm/gal
7.5 min.
74 grains/lb.(avg)
+ 1% NBS traceable
1981
1977
1978
TBD
Low
Low
1978
1979
Low
Low
-------
American Motors
Attachment E-l (Continued)
Appendix E
Page 2 of 4
1975 Model Year
Items of Direct or Major Significance Procedure
New Procedure
First Model
Year Affected
Manual transmission shift
schedules
"Failure to start" procedure
for hot start portion of test
Manual transmission downshift
procedures
Parameter adjustment-idle mixture
and choke
Parameter adjustment-idle speed
and timing
Inertia weight
33% options by car line
Distance traveled
Evap test method
SPECIFIC CALIFORNIA PROCEDURES
Anti-tampering carburetor
Reduction in allowable maintenance
15, 25 and 40 MPH Technical amendment 1977
shift points unless eliminates 15, 25 and
manufacturer recom- 40 MPH shift points.
Allows recommended
shift points.
mends others
Not specified
None
None
None
A/C 72 changed the
procedure to 15, 25
and 40; rated engine
RPM or in-use survey
data on 1/19/78.
Specified procedure
New requirement
New requirement
New requirement
250/500 Ib increment 125/250 Ib increment
None Requirement
Noninal Actual
Carbon traps SHED enclosure
None
New requirement
CFR 86.078-25(a)(l) All maintenance
intervals extended
1979
Estimated
Negative Impact
on FAFE — MPG
None
Large but dif-
ficult to es-
timate. It
stifles 4 and
5 speed impro-
vements. Use
0.6 MPG est.
1978
1980
1981
1982
1980
1980
1978
1978
1980
1980
Low
Low
0.2-0
0.2-0
Low
. Nil
0.1-0
Low
Low
Low
.3
.4
.4
-------
American Motors
Items of Direct or Major Significance
Numerator of fuel economy formula
(constant)
C02 density
Use test vehicle to set dynamometer
HP for prep
Vehicle pre-conditioning limits at
EPA Lab (5-day prep A/C 50-A)
Diurnal and hot soak ambient temp-
erature requirements
Heat build:
start temp.
completion temp.
time constraints
Test time constraints:
fuel fill—start prep
end prep—start soak
soak times
end diurnal—start C/H CVS
end C/H CVS—start hot soak
Test cell temperature measurement
location
Attachment E-l (Continued)
1975 Model Year
; Procedure New Procedure
2423
51.85 gra/ft.
Allowed
2421
3 51.81 gm/ft.3
Not allowed
Appendix E
Page 3 of 4
First Model
Year Affected
1976
1980
1978
Estimated
Negative
on FAFE -
Nil
(.01)
Nil
Impact
- MPG
Not specified
76-86 deg F
60+2 deg F
5-day limit for
double prep.
68-86 deg F
60+1 deg F
84+2 deg F (evap) Temp rise 24+1 deg F
60 + 10 minutes 60+2 minutes
Not specified.
Not specified
12 hours min.
Not specified
Not specified
Not specified
Sample collection
Constant volume
sampler (CVS)
1 hour maximum
5 mins. max run
12-36 hours
1 hour max.
5 mins. engine run
max., 7 mins. max.
total
Location must be
representative of
temperature ex-
perienced by
vehicle.
Critical flow
venturi (CFV)
1978
1978
1978
1978
1980
i
oo
I
1978
Nil
* Unable to estimate
-------
American Motors
Items of Direct or Major Significance
Calibration gases for NDIR analyzer
curves
Calibration gases for HC and NOx
Analyzer curve fitting technique
Attachment E-l (Continued)
Appendix E
Page 4 of 4
Analyzer response during sampling
Span gas concentration
Analyzers (C02)
One-hour AMA
Evap. system pressure check
40% nominal tank fuel volume
Temperature during soak (Evap.
test)
To.tal (sales weighted) estimate
FOOTNOTE:
1975 Model Year
• Procedure
8 gases
2 gases
Use best judgment
in curve selection
Not specified
Approximately 80% of
full scale
Beckman 315A
Required
Required
Rounded to nearest
1.0 U.S. gallon
1st hr (76-86 deg F)
10+ hr (60-86 deg F)
New Procedure
6 gases
First Model
Year Affected
1978
6 gases 1978
Each data point 1978
within + 2% of
least-squares best-
fit line
20% to 100% of full 1980
scale
At least 70% of 1980
full scale
MSA-202 1978
LA-4 1978
Not allowed 1978
Rounded to nearest 1978
0.1 U.S. gallon
12-36 hr (68-86 1978
deg F)
Estimated
Negative Impact
on FAFE — MPG
Low
Low
Low
Low
Low
Low
Low
Nil
Nil
Low
1.6
i
VO
I
Determining the individual effect of any single procedural change is difficult because of the related'nature of
the items. Where possible an actual or judgmental fuel economy figure has been provided. Whether an item is
direct and major, or indirect and minor, all items are of significance because each has to be considered for its
impact and adds to the engineering task. Time that could have been used in system development now must be
allocated to the analysis of the impact of procedural and regulatory revisions. Emission standard and other
general regulatory revisions which have direct or indirect fuel economy impact and further increase the burden
of compliance are listed on the following pages.
-------
Appendix F
GENERAL COMMENTS
I. Introductory Statement
"The following questions are not within the previous [or sub-
sequent] question groups. However, since these questions address areas
where some changes may have occurred, your comments are requested."
II. Comments
Question 1: "Emissions and fuel economy tests are performed on
vehicles specially prepared by the manufacturer for these tests. Would
there be an effect on your corporate average fuel economy if production
vehicles were randomly selected for fuel economy testing? What effect
do you estimate?"
Volkswagen: "No."
Toyota: "... vehicles from the assembly line might vary slightly
from the [prototype] vehicles for [fuel economy] tests but results could
further be complicated by production slippage, vehicle to vehicle varia-
tion at production, break-in effect between green engine and 4000 miles,
etc. Consequently, we cannot estimate their effect."
Chrysler: "The effect on the corporate average fuel economy if
production vehicles were used instead of prototype vehicles is unpre-
dictable. Testing of production vehicles would not be consistent with
the principle of applying good engineering practice to the design of the
test program because of the variability associated with random pro-
duction sampling of small samples."
Ford: "Because the certification fleet is biased toward the 'worst
case' vehicles, we would expect a random, representative sample of our
production vehicles would produce an average fuel economy slightly
higher than the certification fleet. Additionally, the gross vari-
ability in fuel economy that exists between 'green' engines and stabi-
lized engines would prohibit the drawing of any meaningful relationships
between the two.
The necessity for a large statistically valid sample to obtain
'average' fuel economy values makes this [test procedure] so impractical
as to render the comparison of approaches an unrealistic one."
General Motors: "GM has previously submitted a detailed analysis
to EPA of our production vehicles as compared to their prototype counter-
parts in a December 20, 1978 letter to Mr. C. Gray, FE-1505 (Attachment
10). The suggestion of using production vehicles for fuel economy
testing is not practical since 'production' cars are not available at
the time most emission and fuel economy testing is required."
American Motors: "The idea that production vehicles could be used
for fleet average fuel economy compliance is not considered practical or
-------
-2-
feasible for obvious reasons. If such vehicles were to be randomly
selectd for fuel economy testing we would expect several effects to
counter each other culminating in a random result. For example, we
would expect that random vehicle selection would be to our advantage
because it could not be penalized by the EPA 'worst case1 data-car
selection criteria, but this advantage would be offset by the higher
friction and variability of vehicles that were not properly broken in
prior to testing."
Question 2: "What data can you present to indicate that the fuel
economy improvements measured on the EPA tests have also occurred in
consumer vehicle use?"
Volkswagen: "Our experience, as well as EPA's test data, show
that the Volkswagen-Audi Certification fuel economy data represent
closely actual consumption of in-use vehicles."
Chrysler: ". . . we do not believe that the descrepancy between
EPA fuel economy values and on-road values is so large as to cause undue
concern or so great as a recent DOE report* would indicate. We see no
reason why the difference between the EPA reported fuel economy ratings
and driver-reported ratings now should be any different than in previous
years.
Ford: "While it is generally recognized that average customer
fuel economy has been increasing over the past several years, definitive
customer data are difficult to obtain so that a precise, numerical re-
lationship cannot be cited. One source of information that confirms the
trend of increasing customer gas mileage of cars is that from a large
leasing fleet.
Shown in Exhibit V are the year-by-year average fuel economy figures
for the Ford Motor Company cars in a large leasing fleet managed by
Peterson, Howell and Heather (PH & H). This fleet consists of between
about 5000 and 7500 Ford Motor Company cars each year.
Also shown in Exhibit V is the 1975-1978 trend line for Ford's
annual CAFE figures, which of course are based of EPA test results. The
two solid lines show a virtually parallel relationship, on a year-by-
year percentage basis. The dashed line shown on Exhibit V is the Ford
CAFE trend line for 1975-1979. This line indicates slightly greater
convergence with the PH & H in-use fleet averages than the 1975-1978
CAFE trend line which reflects, in part, the changes made by EPA to the
1975 test procedure.
The mix of Ford Motor Company cars in the PH & H lease fleet does
not cover Ford's entire product line up and production mix (PH & H tends
to be midsize and large models), so the parallel relationship and abso-
lute difference between the EPA CAFE values and PH & H values are not
conclusive, but they do indicate corresponding improvements."
On-Road Fuel Economy Trends and Impacts, DOE Office of Conservation and
Advanced Energy Systems Policy, February 17, 1979."
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-3-
Ford Exhibit V is presented as Figure F-l of this Appendix.
General Motors; "GM has recently submitted analysis in-use fuel
economy experience to EPA, NHTSA, and DOE in the February 8, 1979 letter
to Mr. B. McNutt (Attachment 11). It should be recognized that there is
a non-linear relationship between fuel economy (mpg) and consumption
(gal/mi). Since .the EPA's goal was to same fuel, we believe when quan-
tifying fuel economy improvements they should be measured in terms of
consumption.
The following formula best expains GM's estimate for the relation-
ship between in-use and EPA test procedure:
In-Use Consumption (gal/mi) =0.01 + EPA 55/45 (gal/mi)
This equation is based on the GM postcard consumer surveys, as well
a field fleet data. From MY 1975 to MY 1978 the fuel economy improve-
ments measured on the EPA test procedure were also seen in actual con-
sumer use. When the fuel saved over these years is measured in terms of
consumption (gal/mi) there is not a divergence between EPA and actual
in-use measurement; there is a constant .01 gal/mi offset as indicated
by the formula."
American Motors: "AM does not possess such data and is unsure how
this in-use question relates to the specific concern of this question-
naire."
Question 3: "Prior to the 1975 model year, all EPA fuel economy
measurements were conducted on vehicles selected by EPA." Many of these
vehicles were selected to be the 'worst cast1 offenders from an exhaust
emissions standpoint. Would these vehicles have tended to be 'worst
case' vehicles from a fuel economy standpoint? Since 1975, EPA has
allowed testing of vehicles selected by the manufacturer in the fuel
economy program. To what extent has your corporate average fuel economy
been improved since 1975 by the addition of these potentially favorable
test vehicles?"
Volkswagen: "Due to limited model line of VW and Audi, there has
been no actual change for us in the vehicles selected for emission and
fuel economy testing."
Toyota: "We think that vehicles selected by EPA would also tend to
have been 'worst case' vehicles from a fuel economy standpoint. We know
that the CAFE has been improved by the additional test vehicles but we
could not afford to supply the additional test vehicles because we had
to perform the fuel economy tests under the limits of time, manpower,
facilities and capital."
Chrysler: "'Worst case' vehicle selection for emissions testing
also tend to be worst case fuel economy vehicle selections.
Chrysler's 1979 model year fuel economy data has been analyzed to
illustrate the fleet average effect of voluntary fuel economy data
vehicles in the following manner.
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-4-
A fleet average calculation was performed using only the certifi-
cation data and any additional data necessary to meet the EPA's minimum
requirements. A second fleet average calculation was performed which
included the previously identified data and also all voluntary fuel
economy data submissions. The difference between these calculations
showed an increase of 0.15 mpg on the fleet average attributable to
inclusion of the voluntary fuel economy data submissions. Without the
representation provided by voluntary data, the fleet average would be
biased downward."
Ford: "Of the vehicles selected by EPA for emissions testing, a
certain portion, chosen on the basis of high projected sales, provide
essentially representative fuel economy. Conversely, the 'worst case1
emission veicles, including running change certification vehicles, are
worst case for fuel economy also — their fuel economy understates that
expected from the majority of vehicles of that model type. At the
manufacturers option, are voluntary FEDV's — they provide the manu-
facturer with an opportunity to represent some of the more fuel ef-
ficient configurations and thus partially offset the effect of the worst
case emission vehicles.
Ford's 1978 CAFE was improved by .01 mpg due to testing of voluntary
fuel economy data vehicles. This relatively small effect reflects the
fact that Ford's CAFE was consistently 0.4 mpg above the 18.0 mpg stand-
ard during the 1978 model year and there was, therefore, no incentive to
incur the incremental costs of additional testing on voluntary FEDV's.
For 1979, Ford estimates that voluntary FEDV's will contribute +0.17 mpg
to its final CAFE which is projected to be 19.0 mpg. These voluntary
vehicles are necessary to partially counterbalance the effects of worst
case emissions vehicles.
The above CAFE effects do not include any contribution due to
required FEDV's since Ford has no option with respect to the submission
of such data. Detailed estimates of the CAFE effect of voluntary FEDV's
for model years 1975-1977 are not readily available. These effects are
expected to be small (less than 0.1 mpg) since there are no CAFE stand-
ards for these years."
General Motors: "GM believes that 'worst case* vehicles from an
exhaust emissions standpoint x
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-5-
with the regulation, which means that at least 90 percent of our sales
volume is represented by our fleet average fuel economy, but some low-
volume vehicle options are not represented for practical considerations.1
Question 4: "How does EPA's selection process for fuel economy
testing influence a manufacturer's capability to improve corporate
average fuel economy? How does it influence the potential to make
future improvements in fuel economy?"
Ford: "At the present time Ford has no major objection to the EPA
selection criteria for either required or voluntary fuel economy data
vehicles (FEDV's).
Ford's ability to incorporate running change fuel economy improve-
ments across groups of vehicles (i.e., aerodynamic improvements, im-
proved lubricants) is, however, limited by EPA running change fuel
economy data requirements. For example, it may not be feasible to
implement a fuel economy improvement running change late in the model
year if this change affects a broad range of car line/engine combin-
ations simply because the required fuel economy data would represent an
excessive test burden at that stage of the model year. In such case EPA
should allow manufacturers at their option, to substitute existing test
data that understate the expected results. Further, CAFE improvements
have been mitigated some what by the requirement to harmonically average
a formula DPA value with a subsequently run alternative DPA. It has
always been Ford's position that once a more representative DPA is
available, all applicable vehicles subsequently produced should be
credited with that new DPA, as opposed to being "averaged* with a
previous formula DPA."
American Motors: "AM must concentrate on high-volume vehicles and
defer development of low-volume high-fuel-efficiency models. The in-
fluence of future improvements is also basically a .volume consider-
ation."
Question 5: "It has been a practice of EPA that if laboratory test
results for a particular vehicle were within 10 percent of the manu-
facturer's data for the same vehicle, EPA would use the EPA data.
Recently, however, EPA has used discretionary administrative actions to
select 'official' test results upon which corporate average fuel economy
is calculated. Has this improved or diminished your corporate average
fuel economy? To what extent?"
Toyota: "The present data selection for CAFE has been applied to
Toyota but EPA has tended to select lower test results of either EPA or
our data. Therefore, we think that our CAFE has been diminished and the
difference between the past and the recent has been about 0.4%."
Chrysler: "In exercising its judgment and administrative discre-
tion, the EPA has tended to favor test results that lower Chrysler's
fleet average. The effects of this discretionary action on Chrysler's
fleet average for the 1978 and 1979 model years has been analyzed and
found to be -0.03 mpg and -0.04 mpg respectively."
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-6-
Ford: "In a letter to Mr. Richard E. Harrington, Director, Certifi-
cation Division, MSAPC, EPA, on August 18, 1978, Ford stated that 'For
the 1979 model year to date, EPA's 'engineering judgment' in this
selection (of official test results), by our calculations, has cost us
0.07 mpg in corporate average fuel economy.'"
General Motors; "At the beginning of the MY 1979 programs, EPA
adopted a change in policy to eliminate high test results. This change
in EPA philosophy would not logically be expected to increase our CAFE."
American Motors: "Beginning in the 1979 model year the EPA person-
nel have used their discretionary judgment in selecting official test
results in a manner that tends to be prone to exclusion of high-fuel-
economy data. The EPA discretionary actions have not had a significant
impact on our fleet average fuel economy, but we think some objective
criteria are needed."
Question 6: "The EPA test is conducted with Indolene Clear test
fuel having an octane rating of nearly 98 RON. Typical unleaded fuel
available in the marketplace has an octane rating of 93 RON. To what
extent is your corporate average fuel economy improved by the use of the
higher octane fuel during fuel economy testing, especially with the
utilization of knock sensors? What effect does this difference have on
consumer use fuel economy, wherein retardation of spark timing may be
necessary to avoid objectionable or harmful detonation? How has the
Octane Requirement Increase (ORI) rating of your engines changed with
the switch to unleaded fuel?"
Volkswagen: "Undetermined, however, any effect on CAFE would be
extremely difficult to quantify.
VW and Audi do not employ knock sensors and we have not experienced
Octane Requirement Increase with our engines."
Toyota: "All of our engines have been and are designed to use the
required octane rating of 91 or less RON and utilize no knock sensor.
Therefore, it has little effect on our CAFE to use 98 RON fuel. We
believe that the ORI rating of our engines, with unleaded gasoline, is
almost equal to or a little larger than with leaded gasoline under their
stabilized conditions."
Chrysler: "Chrysler1s corporate average fuel economy is not
affected by the use of 98 RON fuel for emission testing. Consumer fuel
economy should not be significantly affected by basic spark timing
retardation x^ithin the allowable limit of two crank shaft degrees from
the nominal setting. It is thought that the Octane Requirement Increase
(ORI) has substantially increased with the switch to unleaded fuel."
Ford: "We are not aware of any effect of testing at 98 RON versus
93 RON within our present vehicle powertrains. If, however, knock
sensors were used extensively across a manufacturer's product line,
there is little doubt that a higher fuel economy value could be obtained
with the 98 RON fuel versus the commercially available fuels.
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-7-
Since Ford does not presently utilize knock sensors in any of its
vehicles, it is difficult to quantify to what extent our CAFE would be
improved because of their use. The company presently projects a 0.1 mpg
CAFE improvement with the installation of such devices, however, this
projection is based only on engineering judgment.
If retardation of the spark timing was necessary to avoid objec-
tionable or harmful detonation, a reduction in fuel economy would occur.
However, this condition only exists in varying degrees on approximately
5% of Ford's vehicles due to our octane policy, in which we have an EPA
approved field fix to retard the spark advance and thereby improve these
customer's satisfaction. If we were to insist on 100% satisfaction with
91 octane fuel, 95% of our customers would sacrifice fuel economy just
to satisfy the remaining 5%.
ORI is strongly dependent on the specific engine design, its cali-
bration and the severity of service, therefore, any general statement on
the differences in ORI between leaded and unleaded fuel can be correct
only directionally. With this in mind, all that one can state is .that
in general the ORI with unleaded fuel is slightly higher than with the
leaded fuel and it stabilizes at somewhat higher mileage (6 to 12 thou-
sand miles). As far as fuel economy measurement is concerned, ORI
differences between leaded and unleaded gasoline should not be a factor
because most fuel economy is measured at 4000 to 5000 miles."
General Motors; ". . . we do not believe the use of Indolene Clear
test fuel during fuel economy testing on these vehicles had any impact
on our corporate average fuel economy.
The specific question of the effect of Indolene Clear on the fuel
economy of vehicles equipped with knock sensors has been addressed in
responses to EPA in both 1978 and 1979 model years. In both of these
years, GM produced turbocharged engines which were equipped with knock
sensors. Tests were conducted in both model years with Indolene Clear
and with 91 RON unleaded fuel. The results of these tests were pre-
viously provided to EPA (June 28, 1977, Attachment 12 and September 20,
1978, Attachment 13), and are summarized below.
Tests of Knock Sensor Equipped Vehicles
Fuel Economy, mpg
Vehicle No. Fuel City Highway
57116 Indolene Clear 15.73 20.10
91 RON 15.86 21.20
57164 Indolene Clear 16.70 20.30
91 RON 16.79 19.70
94EC196 Indolene Clear 15.2 20.5
91 RON 15.6 21.2
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-8-
These data do not indicate that the use of the higher octane
Indolene Clear test fuel during the EPA tests increased the measured
fuel economy values determined for these knock sensor equipped vehicles.
The impact on consumer in-use fuel economy is thus minimized by
restricting spark retard to only those few vehicles which require this
adjustment. In addition, data provided to EPA on a running change
request indicate little impact of spark retard on fuel economy, as
evaluated in the EPA tests. The data provided in our October 27, 1978
request (Attachment 14), are summarized below:
Effect of Spark Retard on Fuel Economy
Basic Spark Timing Fuel Economy, mpg
Vehicle No. °BTDC City Highway
91WF102-1 18 26.2 33.8
14 26.4 32.3
91FF56 12 18.0 27.1
8 18.6 27.7
91GF96 10 17.8 23.8
6 17.3 23.0
These data indicate that the impact of spark retard on consumer use
fuel economy is minimal, especially in view of the many other factors of
greater influence on fuel economy, such as consumer driving habits,
weather, traffic conditions, etc. The implication that the use of
Indolene Clear test fuel has a negative impact on consumer use fuel
economy is not supported by the data available to GM.
The use of lead compounds in gasolines to improve octane quality
was also recognized to cause vehicle octane requirements to increase
with mileage, as combustion chamber deposits stabilized. In order to
compare the influence of unleaded versus leaded gasolines on Octane
Requirement Increase (OKI), General Motors participated with 14 other
organizations in a Coordinating Research Council (CRC) program in 1970-
71. The results of the program were summarized in an SAE publication
('ORI in 1971 Model Cars - With and Without Lead', H. A. Bigley and J.
D. Benson, SAE paper No. 730013, Attachment 15). In an effort to further
define the influence of selected engine oil, fuel and driving schedule
variables on combustion chamber deposits and ORI, General Motors con-
ducted a vehicle fleet test of 1971-75 GM vehicles ('Some Factors Which
Affect Octane Requirement Increase', J. D. Benson, SAE paper No. 750933,
Attachment 16).
In general, vehicle octane requirements stabilize more rapidly with
leaded fuels. Unleaded fuels may require 15-20,000 miles of operation
before the vehicle requirements stabilize. It is not uncommon for
octane requirements to increase at lower mileages and then decrease as
vehicle mileage accumulation continues. This has been observed for both
leaded and unleaded fuels.
-------
When commercial unleaded, low lead and leaded fuels were compared,
there was no significant fuel effect on ORI. At least 12,000 miles were
required with any fuel before the octane requirements stabilized.
Although the factors influencing vehicle ORI are not as well de-
fined as might be desired, the major difference between unleaded and
leaded ORI appears to be the rate of octane requirement increase, rather
than the value of the final, stabilized octane requirement."
American Motors: "The use of 98 RON for the actual test has no
relationship to AM's fleet average fuel economy because we design,
manufacture and recommend to our customers that our engines should use
fuel with at least an AKI (anti-knock index) of 87. Knock sensors are
not used on any of our cars or light truck engines.
Initial and subsequent octane requirements of engines will vary
slightly from engine to engine or vehicle to vehicle. Each of AM's
carline and truckline power-train combinations is considered to fall
within a narrow distribution band with respect to octane requirements.
Minor adjustments have been possible, within the EPA-accepted specifi-
cation ranges, to accommodate fuels of octane ratings either slightly
higher or slightly lower than the ratings available most commonly. AM
has taken care in the design and production of our engines to avoid
customer complaints that would occur if the octane requirements of our
engines were increased beyond the capability of commercially available
fuel.
The question concerning Octane Requirement Increase (ORI) rating of
our engines before and after the change to unleaded fuels is outside the
scope of this questionnaire. However, we have not found the switch from
leaded to unleaded fuels to significantly affect the numerical ORI level
for our engines."
Question 7: "Certification tests are performed primarily on vehicles
with a nominal accumulated distance of 4,000 miles. What was the actual
average accumulated distance of the vehicles used in the 1975 test
program, in your 1979 test program? Would you favor some other distance
for certification testing?"
Volkswagen: "No difference."
Toyota: "The actual average accumulated distances of our vehicles
used in the 1975 and 1979 test programs were A,000 + 250 miles. It
seems that, for more stabilized fuel economy, the vehicles should run
more distance, but it would be accompanied by problems of manpower, time
schedule, facilities, and cost. Therefore, Toyota would not favor
changing the distance of 4,000 miles."
Chrysler: "It is not possible for us to analyze the considerable
amount of test data necessary to answer this question in the limited
time alloted.
A reduction of the distance traveled to 2,000 miles or even 1,000
miles for certification testing would be preferred from the standpoint
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-10-
of efficiency of resource utilization. However, it should be recognized
that fuel economy improves with mileage (because of reduced chassis
friction) and that it would be appropriate to make some allowance in our
CAFE for this phenomenon."
Ford: "Both as a result of requirements to retest our vehicles and
to provide running changes for improved fuel economy, Ford's 1975 pas-
senger car certification vehicles had an average accumulated test -mileage
of 4,300 miles. For 1979, this average increased to 4,800 miles, re-
flecting the magnitude of changes the company was required to run to
meet the 1979 CAFE standard. We know of no reason to change the distance
for certification testing."
General Motors: "Actual odometer readings for specific tests used
in GM's MY 1975 and MY 1979 test programs are not readily retrieved from
our records. For the MY 1975 test program the large majority of data
was derived from certification and running change vehicles. Conse-
quently, the average accumulated distance would occur in the range of
3750 to 4250 miles (calculated from the tolerance allowed by the reg-
ulations around the nominal 4000 mile test point). For the MY 1979 fuel
economy program, approximate odometer readings are available. As can be
seen from the attached histogram, Figure F7, the average accumulated
distance will occur in or near the 3750-4250 mile range.
At the present time, there is no demonstrated need to change the
distance for certification testing."
GM Figure F7 is presented as Figure F-2 of this Appendix.
American Motors: "The approximate range of AM's 1975 certification
data vehicles (both cars and light-duty trucks) was 4160+150 miles. One
light-duty truck fell outside this range with 4,455 miles.
The approximate range of AM's 1979 certification data vehicles
(both cars and light-duty trucks) was 4020+175 miles. Seven cars fell
outside this range with 4,541 miles being the highest.
AM believes that 3,800-4,800 miles is a practical range and does
not recommend changing the current option which permits up to 10,000
miles for fuel economy testing even though we do not take advantage of
this option."
Question 8: "Front-wheel drive is becoming an increasingly popular
engineering option for producing space-efficient vehicles. Front-wheel
drive vehicles typically have a higher percentage of their curb-weight
on the driving wheels than do their rear-wheel drive counterparts. What
effect does this have on the simulated road load curve and hence fuel
economy? To what extent are alternate dynamometer power absorptions
requested for your front-wheel drive vehicles? To what extent does this
affect their measured fuel economy and benefit your corporate average
fuel economy. How is the air conditioning affected by these alternate
dynamometer adjustments and how does this affect your corporate average
fuel economy?"
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-11-
Volkswagen: "a) None.
b) All of our front wheel drive vehicles have alter
nate dyno power absorption values.
c) Not quantified, but judged to have a positive
effect.
d) Undetermined."
Toyota: "Since front-wheel drive vehicles generally have a higher
percentage of their curb weight on the driving wheels than do their
rear-wheel drive counterparts, the rolling resistances on the chassis
dynamometer are increased and the dynamometer power absorption (DPA) for
the F-F vehicle is smaller than that for the F-R vehicle in order to
simulate the same driving resistance as on the road. The DPA is ad-
justed at 50 mph and regardless of the DPA, but the road load is approx-
imately the same under the low speeds unrelated to DPA value because of
the characteristics of the Clayton Chassis Dynamometer. Therefore, the
front-wheel drive vehicles are at a disadvantage. We use the DPA simu-
lated by coastdown method for front-wheel drive vehicles because they
have, as mentioned above, lower DPA's than rear-wheel drive vehicles.
We estimate that our CAFE may increase up to one percent. We could not
understand your last question in .this paragraph about air conditioner
and we do not know of the effect on fuel economy."
Chrysler: "Chrysler is also concerned with the change in the
dynamometer's 'road load' curve characteristics that may result from the
increased load on the drive axle of front-wheel drive vehicles. However,
in contrast to the suggested fuel economy 'benefit' relative to rear
wheel drive, we feel that if there is a difference (after both are
adjusted to the correct DPA settings) the effect will be detrimental
with respect to the front wheel drive system.
We have found that the 'coast-down' alternate road load procedures
produce DPA settings that are significantly lower than the EPA frontal
area formula values for all Chrysler front-wheel drive vehicles. Con-
sequently, any advisory circular that would inhibit the establishment of
alternate DPA's would have an increasingly larger detrimental effect on
Chrysler's CAFE as our percentage of front-wheel drive vehicle increases.
The basic question of air conditioning load is answered in the 'Acces-
sory' portion of this response."
Ford: "The greater fraction of vehicle weight on the driving
wheels of a front-wheel drive (FWD) car causes it to be penalized on the
EPA dynamometer test. In the example given below, a FWD vehicle of
identical weight to a RWD vehicle experiences 3.5% less measured fuel
economy if the frontal area formula is used to set the dynamometer power
absorber unit (PAU) and 1% less measured fuel economy if the coastdown
technique is used to set each PAU. That is, the reduced PAU of the FWD
vehicle using coastdown does not completely offset the increase in its
dynamometer rolling resistance. Both types of vehicles would have
identical road fuel economy.
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-12-
It is obvious from the above considerations that alternative set-
tings are of crucial importance in partially offsetting the inherent
testing disadvantage of a FWD vehicle. Alternative dynamometer settings
determined by the coastdown technique are being used for Fiesta and will
be used for the 1981 Pinto replacement.
The effect of ... adverse testing characteristics on FWD vehicles
on Ford's corporate average fuel economy cannot be exactly quantified
because there is still a net benefit associated with the package ef-
ficiency. That is, a FWD vehicle can be made to weigh less than a RWD
vehicle of equivalent interior volume and in spite of its testing handi-
caps, the effects on CAFE will be beneficial."
General Motors: "Front-wheel drive (FWD) vehicles when tested on
the present twin roll dynamometer tend to be loaded higher than on the
road throughout the speed range. GM currently uses alternate horsepower
settings for all FWD vehicles since the frontal area equation misrep-
resents the actual road load. The fuel economy benefits of an alternate
horsepower setting for our '80X FWD car were included in our March 20,
1979 letter, to Mr. Finkelstein (Attachment 17).
Please refer to GM's Responses C3 and C4 in Section C, Accessories,
for a discussion of the air conditioning loads."
Section C corresponds to our Appendix C.
American Motors: "Current AM vehicles are either rear-wheel-drive
or four-wheel-drive. We do not have the information necessary to answer
these questions."
Question 9: "The oil industry has recently developed new engine
lubricants incorporating lower viscosity and/or additives with reduced
friction. What would be the effect on your average fuel economy if
these oils were approved.for use? To what extent have they penetrated
the replacement oil market? To what extent x\rould the fuel economy of
in-use vehicles be improved by the use of these oils?"
Toyota: "We estimate that our CAFE could be increased about 1.5
percent by the use of slippery oils and. we think in-use vehicles would
experience a similar result. We do not know to what extent these oils
have penetrated the replacement oil market."
Chrysler; "On the basis of data available to Chrysler, we are led
to conclude at this time that no clear cut advantage will be obtainable
through the use of low friction 'slippery oils' in production vehicles.
Our views on this issue were reported in a March 21, 1979 letter from S.
L. Terry to Joan Claybrook [NHTSA] and a November 8, 1979 letter from S.
L. Terry to R. L. Strombotne [NHTSA]."
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-13-
Ford; "As Ford stated in its response to NHTSA's questionnaires on
1984-86 Passenger Car Fuel Economy Standards (August, 1978) and 1982-84
Light Truck Fuel Economy Standards (September 20, 1978), a test program
comparing Ford's current factory-fill oil and several other oils with
friction reducing additives indicated that an estimated 0.5% improvement
in EPA metro-highway fuel economy is possible with the best of these
improved lubricants that Ford has tested to date. The results of this
program were reported in SAE Paper 780962, 'The Effects of Engine Oil
Additives on Vehicle Fuel Economy, Emissions, Emission Control Components
and Engine Wear.' November, 1978.
Ford has no information as to the extent to which these improved
oils have penetrated the replacement market, nor the fuel economy benefit
of actual in-use of these oils."
General Motors: "Improvements of about 1-3% in EPA fuel economy
have been observed in a limited number of tests using commercial 'fuel-
saving' oils. As indicated by our comments in the February 14, 1979
letter to Mr. Finkelstein (Attachment 2, ref. pg. 8 of attachment 1) GM
still hopes to recommend use of friction modified oils which we project
a fuel economy improvement of about 1%.
To our knowledge, there are 19 engine oils reported to improve fuel
economy that are on the'market in the U.S. and Canada.
It has been our experience that the on-road fuel economy improvements
with 'fuel-saving' engine oils are equal to or greater than those measured
on the EPA test."
American Motors; "AM believes the fleet average fuel economy
(FAFE) benefit (car and light truck) realized -through the use of new,
'improved' oils and rear axle lubricants would be low (0.1 to 0.2 mpg).
This FAFE improvement is over our current factory-fill 10W30 engine oil
and rear axle lube, which we believe is on a par with some of the so-
called new improved products being advertised.
We do not track the replacement-oil market. We cannot predict the
in-use improvement likely to be gained. '
Question 10: "What effect has the EPA changes in dynamometer
calibration (electronic feedback dynamometer control system and changes
made to support automatic control features) had on your corporate
average fuel economy?"
Chrysler: "All tests which have been run comparing automatic and
manual horsepower control have shown no significant difference in emis-
sion levels or fuel economy as a result of changes in dynamometer cali-
bration."
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-14-
Ford: In summary, "... test analyses show that the estimated
impact of the PAU exponent and the EPA Vehicle Factor Potentiometer
changes on Ford's 1980 CAFE is a loss 0.1 mpg."
General Motors: "Directionally, the automatic feedback requirement
on the dynamometer is expected to provide a loss in fuel economy as
compared to the manual operation. This conclusion is based on a simu-
lation (SAE paper No. 780287 Computer Simulation of Emissions and Fuel
Economy, Attachment 18)."
American Motors: "We believe the effect of the automatic feedback
dynamometer method over the previous manual operation method is a low
0.0 to 0.3 mpg fuel economy penalty (see Appendix A). We have not made
a comparison study of the two methods to quantify our judgement."
American Motors Appendix A is included as Attachment E-l.
Question 11; "What effect has the change in average humidity level
from 55 grains to 75 grains at the EPA test facility had on your cor-
porate average fuel economy?"
Volkswagen: "Undetermined, but we expect a decrease in measured
fuel economy."
Chrysler; "Our calculations show that the change in average humid-
ity level from 55 grains to 75 grains has decreased our CAFE by 0.7
percent. (This was calculated on the basis of information in SAE paper
780287.)"
Ford: "In an EPA test report entitled 'An Evaluation of the Fuel
Economy Performance of Thirty-One 1977 Production Vehicles Relative to
their Certification Vehicle Counterparts,' dated January, 1978, prepared
by F. Peter Hutchins and James Kranig, the conclusion was reached that
the 20 grain increase in humidity at EPA caused a .'downward shift in
fuel economy results of about one (1) to two (2) percent.'
In a subsequent Ford experiment conducted in July, 1978, using an
environmentally controlled emission test cell, Ford found that the
average metro-highway fuel economy effect was approximately a 1.1%
decrease in fuel economy for a 20 grain increase in humidity (using
Ford's 1978 model year sales mix). Considerable scatter in this data
was observed, but all cars experienced a fuel economy loss of from 0.9
to 1.5%.
However, since only about 50% of Ford fuel economy results for 1979
are tests conducted at the EPA laboratory and the balance are conducted
at Ford's laboratory where the humidity is maintained at approximately
55 grains HO per Ib of dry air the actual effect on Ford's CAFE is a
decrease in the range of 0.5 to 1.0%. The impact of this humidity
change on 1979 (19 mpg) CAFE is 0.75% or 0.14 mpg CAFE decrease."
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General Motors; "GM does not have data to specifically quantify
the effect on our corporate average fuel economy of the change in average
humidity level from 48 grains per pound to 74 grains per pound at the
EPA test facility."
American Motors: See Attachment E-l.
Question 12: "What effect has the change from the use of the
nominal vehicle distance traveled per test to the use of the actual
measured vehicle distance traveled had on your corporate average fuel
economy? What effect would this have on your future ability to improve
your corporate average fuel economy as you shift to vehicles of lower
power-to-weight ratios which cannot actually travel the nominal distance?"
Toyota: "When the fuel economies of our 1980 MY vehicles were
determined by the use of actual measured vehicle distance traveled, it
was evident that their values, as tabulated below, shox^ed about 0.2 to
0.6% decrease.
Combined Fuel
Engine Displacement Economy Loss
1.5 liters About 0.6%
1.8 liters About 0.3%
2.2 liters About 0.2%
2.6 liters About 0.2%
Therefore, our CAFE resulted in about 0.25% decrease. In the case where
a vehicle has too low a power-to-weight ratio to trace the FTP mode, the
CAFE may decrease more."
Chrysler: "Our Proving Ground test data show that fuel economy was
0.91% lower on the urban cycle than would have been the case if nominal
distances were used. This is based on a February 1978 survey of the
measured distance results on 102 official certification tests run at the
Chrysler Proving Grounds.
The same data showed successively lower measured distances as
engine size decreased. When distances for twenty-five front-wheel drive
vehicles were compared to the nominal of 7.5 miles, a fuel economy
penalty of 1.26% was indicated."
Ford: "Ford's response to EPA's interim final rulemaking on 'Fuel
Economy Testing; Calculation and Exhaust Emissions Test Procedures for
1977-1979 Model Year Automobiles' dated December 9, 1976, included a
discussion of this distance travel change. Data were presented in this
response which showed that this change would cause a negative 0.3%
effect on metro-highway fuel economy. A subsequent study performed
using data from Ford's 1978 and 1979 4000-mile certification vehicles
showed that the fuel economy results in the Ford laboratory averaged
0.6% lower due to the use of actual versus theoretical driving distance.
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-16-
Ford continues to believe that there is a systematic difference
between fuel economy measured using actual dynamometer distance versus
nominal distance, and the CAFE penalty will increase in future model
years as a result of an increased mix of low power-to-weight vehicles
that are most affected by this procedure change since they are more
likely to be unable to accelerate at rates high enough to follow the
time-speed driving trace. These vehicles, therefore, may travel less
than the theoretical cycle distance, resulting in a lower calculated
fuel economy when calculated on the basis of actual distance.
A 0.6% impact on a 19 mpg CAFE figure amounts to a fuel economy
detriment of almost 0.12 mpg. This CAFE-lowering effect will become
greater in future model years as a result of our plans to continue
decreasing average power-to-weight ratio of Ford's vehicles."
General Motors: "Data from the eleven car GM MY 1975-1980 test
procedure study, Attachment 1, were analyzed to note the actual distance
traveled versus the nominal-MY 1975 distance. The results of this
eleven car study indicated that the actual distance contributes a 0.08
mpg loss on the city fuel economy test, no effect on highway fuel econ-
omy and a 0.05 mpg loss in the combined (55/45) fuel economy. This same
analysis indicated that the difference due to actual versus nominal
distance is not a function of the vehicle power-to-weight ratio."
American Motors; "An analysis of seven 1980 model year data sets
using the nominal versus the actual distance traveled showed a .083 mpg
(combined) penalty. We believe the fleet average fuel economy penalty
to be about 0.1 mpg and that it may progressively increase as lower-
power-to-weight vehicles struggle to keep up with the acceleration rates
on the Federal Test Procedure."
Question 13: "What will be the effect of a requirement to couple
the front and rear rolls of two-roll dynamometers on measured fuel
economy and on your corporate average fuel economy?"
Toyota: "We cannot reply to this question because we have not
investigated this effect."
Chrysler: "Coupling the front and rear rolls would increase the
frictional horsepower absorbed by the dynamometer. An anticipated
reduction in slippage between tires and rolls Would logically be ex-
pected to increase the horsepower load on the vehicle and this would
penalize the measured fuel economy."
Ford: ". . .we did conduct a test program to simulate the coup-
ling of two rolls. This program consisted of running a 4000 Ib I.W. and
vehicle alternating the speed input to the driver's aid from the front
to the rear roll. The speed trace off the rear roll duplicated normal
test conditions and the speed trace off the front roll simulated the
rolls being coupled together. Listed below are the test results from
that program:
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-17-
1978 CVS C/H Tests
Fuel
Grams/Mile Econ.
HC CO NOx MPG
Mean Values—Front Roll 1.82 8.95 2.88 12.99
Mean Values—Rear Roll 1.70 5.55 2.12 14.09
% Increase (Decrease) 7.06% 61.26% 35.85% (7.81)%
Analysis of Variance NSD SD SD SD
(95% Confidence Limit).
1978 HWFET Tests
Fuel
Grams/Mile Econ.
HC CO NOx MPG
Mean Values—Front Roll .72 1.28 2.94 17.44
Mean Values—Rear Roll .64 .61 2.32 18.54
% Increase (Decrease) .12.50% 109.84% 26.72% (5.93)%
Analysis of Variance SD SD SD SD
(95% Confidence Limit)
„ , Front Roll - Rear Roll ....
% Increase = — _ --.. xlOO
Rear Roll
NSD - No significant difference; SD - Significant difference
Based on the limited data available to Ford, this change in dynamometer
test configuration from that used in 1975 would significantly . . . re-
duce fuel economy ..."
General Motors; "GM believes that a requirement to couple the
front and rear rolls of two-roll dynamometers is likely to introduce a
loss in measured economy."
American Motors; "We judge that a slight loss in measured fuel
economy and fleet average fuel economy will occur due to the slippage
and other operational factors. This change will probably have the
"double fuel economy penalty' in that it not only directly penalizes
economy but will probably increase emissions causing and additional fuel
economy loss to be incurred to offset the emissions increase."
-------
-18-
Question 14: "Do you know of any procedural changes other than
those listed in previous questions which have already affected your
corporate average fuel economy, or have increased or diminished your
potential to make future improvements?"
Volkswagen; "No."
Toyota: "We do not think there are other procedural changes which
have already affected our CAFE or have increased or diminished our
potential to make future improvements."
Chrysler: "We are not aware of any additional changes that may
have affected our corporate average fuel economy. It should be noted
the process of instituting changes in procedures could have adverse-
effects on fuel economy if adequate lead time is not provided so that
the revisions can be accomodated in our product development plans
without unnecessary disruptions."
Ford; "In addition to the previously mentioned procedural changes
which have reduced our tested fuel economy, Advisory Circular 24-2 has
had a definite adverse effect on Ford's 1979 CAFE. This CAFE loss was
the result of having to recalibrate those vehicles equipped with Ford's
electronic engine control systems which have been designed to provide a
lean cruise control (LCC) option. The metro-highway fuel economy bene-
fit of this system was approximately 4%. In order to comply with ....
new emission standards, Ford was compelled to recalibrate its original
system. This recalibration reduced the fuel economy benefit of the LCC
system from 4% to 1%. The following table presents the estimated CAFE
effect due to this procedure change.
CAFE Impact of LCC System Recalibration
M-H F.E. Projected Volume 1979 CAFE
-0.6 mpg 69974 -0.02 mpg
Therefore, the overall impact of this ruling goes far beyond the
1979 model year and, in fact, impacts Ford's ability to comply with the
1985 CAFE standards.
General Motors; "EPA often does not give sufficient lead time to
the manufacturers when making changes in the policy and guidelines which
affect the testing process.
The highway NOx requirements, in EPA' Advisory Circular No. 24-2,
may inhibit fuel economy optimization at highway speeds."
American Motors; "Yes, please refer to Appendix A (Attachment E-l)
for a complete listing of these other changes."
-------
-19-
Ford Motor Corporation
FIGURE F-l. Ford Final CAFE vs Average
Ford Fuel Economy in PH & H Fleet
Fleet :
(F'ord Only}'
-FT-FfWF!
10 _
1975
1976
1977
1978
1979
Model Year
-------
General Motors
Figure F-7
rue
120
no
100
90
80
12
IS ?0
v-
60
a;
1-4
50
40
20
20
10 h
1979 MODEL YEAR
GM TESV
G 17 22 27 32 37
FIGURE F-2 ; GM Histogram Showing
Vehicle Tests vs Odometer Miles
i
IS3
o
-------
Appendix G
LIGHT-DUTY TRUCK ROAD LOAD COMMENTS
I. Introductory Statement
"In establishing the light-duty truck fuel economy standards for
model years 1979 through 1981, the NHTSA allowed an 8 percent fuel
economy penalty for procedural change in establishing road load horse-
power for light-duty trucks which was effective in model year 1979."
II. Comments
Question 1: "Was the adjustment appropriate? If not, what should
it be? What data are available to support your position?"
Toyota: "When it was used for the 1979 MY vehicles, it caused
about a 7 percent reduction in our CAFE. Therefore, we believe that
this adjustment of 8 percent fuel economy penalty was appropriate."
Chrysler; "While we generally believe the 8% allowance may be
somewhat on the low side, it appears to be a reasonable allowance."
Ford: "No, an 8% adjustment was not adequate; based on Ford data
the adjustment should have been 10% for test procedure changes alone...
A detailed response to this question was provided in Ford's January 10,
1977 response to NHTSA on the NPRM on Average Fuel Economy Standards for
the 1979 model year non-passenger automobiles."
General Motors; "As stated in GM's October 13, 1978 response to
NHTSA's Light Truck Questionnaire (Attachment" 5), GM agrees with NHTSA's
adjustment to the MY 1979 standards for dynamometer HP test procedure
changes. However, GM had submitted data that demonstrated the more
stringent exhaust emission standards in MY 1979 and beyond result in a
5.1% fuel economy penalty. This penalty was not factored into the final
MY 1979 and beyond light truck fuel economy standards."
American Motors: "AM considers the 8 percent adjustment to be a
conservative adjustment, but we are disappointed that the NHTSA failed
to consider the fuel economy penalty due to the increased stringency of
the 1979 emission standards including the effect of increased NOx emissions
from higher engine loading due to the revised test procedure. We believe
an additional 5 to 8 percent penalty was overlooked by the NHTSA and
should be reconsidered at this time."
Question 2; "When computing the above adjustment, alternate dyna-
mometer power absorption requests were not considered. Should such
alternate dynamometer power absorptions be allowed?"
Volkswagen: "Yes."
-------
-2-
Toyota: ". . .we have no need to consider it at this time."
Chrysler: "It is important that alternate dynamometer power absorp-
tion setting determinations be allowed in order to encourage light-duty
truck manufacturers to incorporate fuel economy improvement features for
which they might otherwise receive no credit when restricted to formulas
for determining DPA."
Ford: "Alternate dynamometer power absorptions provide a positive
motivation for manufacturers to aerodynamically improve their vehicles."
General Motors: "The vehicles GM used to establish the MY 1979
light truck test procedure penalty in our previous submissions were MY
1976 and 1977 0-6000 Ib GVWR two-wheel drive vehicles. EPA used a
regression analysis of the actual coast data from these vehicles to
establish the frontal area formula; therefore, it did not make any
difference on these vehicles if the alternate (coastdown) procedure was
used. GM does not currently have a complete analysis of the effects of
test procedure . . . for the 0-8500 Ib fleet."
American Motors; "Yes, because the alternate dynamometer power
absorption method provides incentive for manufacturers to make aero-
dynamic improvements."
Question 3: "To what extent do you anticipate using alternate
dynamometer power absorptions?"
Volkswagen: "On all models where a clear benefit is realized over
the standard procedure."
Toyota; "We do not anticipate using alternate DPA."
Chrysler: "As Chrysler continues to improve vehicle aerodynamics
and to investigate changes in tire construction and tread compounds, we
would anticipate using alternate DPA settings for all vehicles."
Ford: "Ford will continue to use alternate DPA's wherever neces-
sary to reflect improved aerodynamic characteristics. We expect most
light trucks will use alternate DPA's in the future."
General Motors: "In MY 1980 GM intends to use the alternate
(coastdown) dynamometer almost exclusively for our light-duty vehicles."
American Motors: "In the 1980 and 1981 model years we anticipate
that one truckline out of six will use an alternate dynamometer power
absorption value to reflect trucks equipped with radial tires."
Question 4: "Should the 8 percent correction factor be reduced to
account for any reduction in the actual anticipated test dynamometer
power absorptions?"
Volkswagen: "No data available."
-------
-3-
Toyota: "He consider 8% to be a reasonable number."
Chrysler: "We do not believe that the 8 percent correction factor
should be reduced. As stated above, any reduction in future EPA settings
will be the results of product improvements for which manufacturers
should receive full credit."
Ford: "No. Ford indicated in its response to the NPRM on 1979
Light Truck Fuel Economy Standards, that the proper correction factor
should be 10% for procedural changes implemented in 1979."
General Motors; "GM believes that the 8% adjustment to the orig-
inally proposed standards should not be changed because the light truck
fuel economy standards were based on projected fuel economy improvements
which can only be measured using the alternate dynamometer horsepower
setting procedure."
American Motors: "No, see the response to question 1 in this
section."
-------
APPENDICES
-------
Test Vehicle ID 25001
Manufacturer Oldsmobile
Table A-l
Vehicle Descriptions
Tires
Manufacturer Firestone
Make/Model Cutlass 1980
Body/Style 4 dr. Sedan
V.I.N.. 3MG69RAM12836
Mileage (mi) 9937
Engine 260 CID V8
Carburetor 2 bbl
Ignition Electronic
Transmission Auto
Air Conditioning Yes
Curb Weight (Ib) 3959
Drive Axle Weight (Ib) 1677
Model/Type 721 SBR
Size/Ratio P195/75 R14
Belt Fabric 2 Poly/2 Steel
Wall Fabric 2 Poly
Veh. Mfg. Recommend, F/R 26/26 psi
Tire Pressure Adjusted to, F/R 26/26 psi
-------
Test Vehicle ID 25002
Manufacturer Ford
Table A-2
Vehicle Descriptions
Tires
Make/Model Pinto 1980
Body/Style 2 dr. Hatchback
V.I.N. OT11A106438
Mileage (mi) 12510
Engine 2.3L 4
Carburetor 2 bbl
Ignition Electronic
Transmission Auto 3 Speed
Air Conditioning Yes
Curb Weight (Ib) 3039
Drive Axle Weight (Ib) 1339
Manufacturer Firestone
Model/Type 721 SBR
Size/Ratio BR 78-13
Belt Fabric 1 Poly/2 Steel
Wall Fabric 2 Poly
Veh. Mfg. Recommend, F/R 24/24 psi
Tire Pressure Adjusted to, F/R 24/24 psi
-------
Test Vehicle ID 25003
Manufacturer Ford
Table A-3
Vehicle Descriptions
Tires
Manufacturer Firestone
Make/Model Custom F-100 1981 Model/Type 721 SBR
Body/Style Pickup
V.I.N. 1FTCF10E513 UA/12153
Mileage (mi) 12535
Engine 4.9L 16
Carburetor 1 bbl
Ignition
Electronic
Transmission Auto 3 Speed
Air Conditioning Yes
Curb Weight (Ib) 3652
Drive Axle Weight (Ib) 147.8
Size/Ratio P215/75R15
Belt Fabric 2 Poly/2 Steel
Wall Fabric 2 Poly
Veh. Mfg. Recommend, F/R 35/35 psi
Tire Pressure Adjusted to, F/R 35/35 psi
-------
Test Vehicle ID 25004
Manufacturer Chevrolet
Table A-4
Vehicle Descriptions
Tires
Manufacturer
Make/Model Citation 1980
Body/Style 3 dr.
V.I.N. 1X087AW124660
Mileage (mi) 20100
Engine 173 CID V6
Carburetor 2 bbl
Ignition Electronic
Transmission -Auto
Air Conditioning Yes
Curb Weight (Ib) 3108
Drive Axle Weight (Ib) 1993
Goodyear
Model/Type Arriva SBR
Size/Ratio P185/80 R13
Belt Fabric 1 Poly/2 Steel
Wall Fabric 1 Poly
Veh. Mfg. Recommend, F/R 26/26 psi
Tire Pressure Adjusted to, F/R 26/26 psi
-------
Test Vehicle ID 25005
Manufacturer Ford
Table A-5
Vehicle Descriptions
Tires
Manufacturer
Make/Model Escort L 1981
Body/Style 3 dr. Hatchback
V.I.N. 1FABP0527BW112377
Mileage (mi) 21445
Engine 98 CID 14
Carburetor 2 bbl
Ignition Electronic
Transmission Man 4 Speed
Air Conditioning Yes
Curb Weight (Ib) 2424
Drive Axle Weight (Ib) 1453
Goodyear
Model/Type Arriva SBR
Size/Ratio P165/80 R13
Belt Fabric 1 Poly/2 Steel
Wall Fabric 2 Poly
Veh. Mfg. Recommend, F/R 35/35 psi
Tire Pressure Adjusted to, F/R 35/35 psi
-------
Test Vehicle ID 25006
Manufacturer Plymouth
Make/Model Horizon 1981
Table A-6
Vehicle Descriptions
Tires
Manufacturer Firestone
Body/Style 4 dr. Sedan
V.I.N. 1P3BL28A1BD117347
Mileage (mi) 18,739
Engine 1.7L 14
Carburetor 2 bbl
Ignition Electronic
Transmission Auto 3 Speed
Air Conditioning Yes
Curb Weight (Ib) 2690
Drive Axle Weight (Ib) 1703
Model/Type 721 SBR
Size/Ratio P165/75 R13
Belt Fabric Poly/Fiberglass
Wall Fabric Poly
Veh. Mfg. Recommend, F/R 35/35 psi
Tire Pressure Adjusted to, F/R 35/35 psi
-------
Test Vehicle ID 25007
Manufacturer AMC
Table A-7
Vehicle Descriptions
Tires
Make/Model Concord 1981
Body/Style 4 dr. Sedan
V.I.N. 1AMCA0557CR106107
Mileage (mi) 11,610
Engine 4.2L 16
Carburetor 2 bbl
Ignition Electronic
Transmission Auto 3-Speed
Air Conditioning Yes
Curb Weight (Ib) 3503
Drive Axle Weight (Ib) 1480
Manufacturer Goodyear
Model/Type Arriva SBR
Size/Ratio P195/75R14
Belt Fabric Poly/Steel
Wall Fabric Poly
Veh. Mfg. Recommend, F/R 28/28 psi
Tire Pressure Adjusted to, F/R 28/28 psi
-------
Test Vehicle ID 25008
Manufacturer Honda
Table A-8
Vehicle Descriptions
Tires
Manufacturer Dunlop
Make/Model Civic 1982
. Body/Style 3 dr. Hatchback
V.I.N. JHMSL5325CS002019
Mileage (mi) 14,709
Engine 1.3L 4
Carburetor 1 bbl
Ignition Electronic
Transmission Man 5 Speed
Air Conditioning Yes
Curb Weight (Ib) 2241
Drive Axle Weight (Ib) 1334
Model/Type SP4N
Size/Ratio 155 SR13
Belt Fabric
Wall Fabric
Steel
Poly
Veh. Mfg. Recommend, F/R 32/32 psi
Tire Pressure Adjusted to, F/R 32/32 psi
-------
Table B-l
Coastdown and Track Fuel Economy Instrumentation
Fifth Wheel - Labeco "Trac Test" 1877
Distance Readout - Labeco 5231
Data Logger - TI Silent 700, Model 765
Magnetic Tape Interface - Techtran 817-A
Chart Recorder - HP Recorder
Power Inverter - Nova Electric 2560-12
Flow Transducer and Display - Fluidyne Model 1240T
Temperature Recorder - Omega 5137-5M
Thermocouple Amplifier - Omega Omni - Amp 1
Thermocouple Reference Junction - Omega MCJ-J
Single Scanner - Omega Dataplex 10
-------
L£GEND
RED : FTP- HFET TRACK.
BLUE.- CURVED COA3TPOH/M
&LU£. J\KKOW: ORIENTATION O/=
n>
I
KJ
TEXAS AftU UNIVERSITY SYMCU
RESEARCH ANNEX
-------
Table B-3
Fuel Specifications
Federal
Specifications
API Gravity None
Octane, min RON
Sensitivity, min.
Lead, g/gal
Phosphorous, g/gal max.
Sulfur, wt % max.
Reid Vapor Pressure, Ib/in^
Distillation, °F
IBP
10% pt
50% pt
90% pt
EP
Hydrocarbon Composition
Olefins, % max.
Aromatics , % max.
Saturates
93
7.5
0.00-0.05
0.005
0.10
8.7-9.2
75-95
120-135
200-230
300-325
415
10
35
Indolene[l]
57.5
97.1
8.6
0.004
0.0003
0.011
8.8
86
124
219
310
401
3.3
33
63.7
Howell[l]
58.0
94.1
7.8
0.003
Nil
—
9.2
86
126
221
316
369
Nil
30.2
69.8
[1] Measured fuel specifications.
-------
Table B-4
Dynamometer Fuel Economy Instrumentation
Dynamometer - Clayton CTE-50 (Arrangement B)
Roll Coupler - Clayton Mfg.
Chart Recorder - Horiba Video Monitor
Cooling Fan - Hartzel 22-24N24
Volumetric Sampler - Horiba CVS-20A CFV 350 CFM
Analytical System - Horiba FIA-21 HC
Horiba CLA-22 NOx
Horiba AIA-23 C02
Horiba AIA-23 (A-S) CO
Analytical Gases - Scott Environmental, 2% Accuracy
Timing System - HP, 0.1 msec. Accuracy
Test Fuel - EEE Clear Howell Hydrcarbons
- Amoco Indolene
-------
Table C-l
Track Results
Cutlass Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)[l]
Uncoupled Roll
Dynamometer Results (mpg)[l]
(mpg)[2]
FTP
13.85
13.73
13.45
x 13.68
s 0.21
s/x"(%) 1.5
HFET
19.47
19.32
18.78
x 19.19
s 0.36
Volumetric[2]
FTP
14.03
14.03
13.89
13.98
0.08
0.6
HFET
20.30
20.29
20.09
20.23
0.12
Carbon Balance
FTP
14.56
14.62
14.50
14.56
0.06
0.4
HFET
20.74
20.66
20.76
20.72
0.05
Volumetric[2]
FTP
14.25
14.05
13.97
14.09
0.14
1.0
HFET
20.00
20.53
20.39
20.31
0.27
Carbon Balance
FTP
14.05
14.96
14.45
14.49
0.46
3.2
HFET
20.12
21.90
20.64
20.89
0.92
s/x(%) 1.9
0.6
0.3
1.4
4.4
[1] Dynamometer adjustments based on straight track coastdown
times.
[2] Fuel Economy results corrected for density variations due to
temperature.
-------
Table C-2
Track Results
s/x(%) 1.2
Pinto Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)
Uncoupled Roll
Dynamometer Results (mpg)
X
s
(mpg)
FTP
16.86
17.00
17.25
17.04
0.20
Volumetric
FTP
18.23
18.14
18.17
18.18
0.05
Carbon Balance
FTP
19.76
18.82
19.50
19.36
0.49
Volumetric
FTP
18.53
18.53
18.30
18.45
0.13
Carbon Balance
FTP
19.40
19.36
19.64
19.46
0.15
0.3
2.5
0.7
0.8
HFET
HFET
HFET
HFET
HFET
x
s
23.53
0.24
25.75
0.24
26.84
0.68
26.68
0.10
27.60
0.11
1.1
0.9
2.5
0.4
0.4
-------
Track Results
1.1
Table C-3
Ford F-100 Data
Coupled Roll
Dynamometer Results (mpg)
Uncoupled Roll
Dynamometer Results (mpg)
X
s
(mpg)
FTP
14.44
14.76
14.65
14.62
0.16
Volumetric
FTP
15.16
15.15
15.17
15.16
0.01
Carbon Balance
FTP
15.62
15.24
14.90
15.25
0.36
Volumetric
FTP
15.57
15.84
15.62
15.68
0.14
Carbon Balance
FTP
15.92
15.96
15.68
15.85
0.15
0.1
2.4
0.9
1.0
x
s
HFET
18.23
18.61
18.58
18.47
0.21
HFET
20.51
0.01
HFET
20.24
20.76
20.26
20.42
0.29
HFET
HFET
21.60
0.10
21.29
0.30
1.1
0.05
1.4
0.5
1.4
-------
Table C-4
Track Results
(mpg)
FTP
18.24
18.72
18.58
18.50
18.37
19.22
19.27
19.23
19.30
x" 18.83
s 0.43
x
s
26.43
26.09
26.87
26.29
25.77
27.32
26.55
27.25
27.76
26.70
0.65
Citation Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)
Volumetric
FTP
18.68
18.82
18.96
18.86
18.30
19.21
19.49
19.39
19.43
19.02
0.40
2.1
HFET
28.28
28.48
28.18
28.72
29.03
28.65
29.28
29.19
29.30
28.79
0.43
Carbon Balance
FTP
18.82
19.00
19.02
18.90
18.32
19.18
19.48
19.40
19.42
19.06
0.37
1.9
HFET
27.70
28.02
27.74
27.94
28.44
27.60
29.34
28.26
28.82
28.21
0.58
Uncoupled Roll
Dynamometer Results (mpg)
Volumetric
FTP
18.99
18.78
18.65
18.77
19.21
18.51
18.80
18.99
18.75
18.83
0.21
1.1
HFET
29.32
28.93
29.60
30.10
29.78
29.40
29.08
29.17
29.48
29.43
0.36
Carbon Balance
FTP
19.52
19.24
18.82
18.82
19.56
18.88
18.70
19.10
18.94
19.06
0.31
1.7
HFET
27.90
29.24
29.24
29.34
29.14
28.82
28.62
28.44
28.96
28.75
0.48
s/x(%) 2.4
1.5
2.1
1.2
1.7
-------
Table C-5
Escort Fuel Economy Data
Track Results
(mpg)
FTP
23.43
23.45
23.12
x 23.33
s 0.19
s/x(%) 0.8
HFET
35.50
33.08
34.85
x" 34.48
s 1.25
Coupled
Dynamometer
Volumetric
FTP
23.78
23.93
24.63
24.11
0.45
1.9
HFET
39.01
40.13
40.65
39.93
0.84
Roll
Results (mpg)
Carbon Balance
FTP
23.74
24.04
24.86
24.21
0.58
2.4
HFET
38.24
39.54
39.84
39.21
0.85
Uncoupled Roll
Dynamometer Results (mpg)
Volumetric
FTP
24.56
24.64
24.74
24.65
0.09
0.4
HFET
40.50
39.91
41.30
40.57
0.70
Carbon Balance
FTP
24.46
24.96
25.02
24.81
0.31
1.2
HFET
39.76
39.44
40.70
39.97
0.65
s/x(%) 3.6
2.1
2.2
1.7
1.6
-------
Track Results
(mpg)[2]
FTP
Table C-6
Horizon Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)[l]
Volumetric
FTP
Carbon Balance
FTP
Uncoupled Roll
Dynamometer Results (mpg)[l]
Volumetric Carbon Balance
FTP
FTP
X
s
20.77
2.28
10.9
HFET
21.37
21.82
21.60
0.32
1.5
HFET
22.58
23.20
22.89
0.44
1.9
HFET
22.22
0.57
2.6
HFET
23.42
0.34
1.5
HFET
X
s
30.18
1.89
6.3
33.04
0.67
2.0
Coupled Roll
Dynamometer Results (mpg)[2]
X
s
Volumetric
FTP
21.31
21.66
20.98
21.32
0.34
Carbon Balance
FTP
22.38
22.96
22.42
22^59 ~
0.32
1.6
HFET
1.4
HFET
33.04
0.21
0.6
33.46
34.10
34.06
33.87
0.36
1.1
Uncoupled Roll
Dynamometer Results (mpg)[2]
Volumetric Carbon Balance
FTP
21.71
0.19
0.9
HFET
FTP
23.26
23.44
22.96
23.22
0.24
1.0
HFET
33.82
0.26
0.8
X
s
32.89
0.32
1.0
32.72
0.24
0.7
33.11
0.54
1.6
[1] Dynamometer adjusted using straight track coastdown times.
[2] Dynamometer adjusted using curved track coastdown times.
33.11
0.43
1.3
-------
Table C-7
Track Results
Concord Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)
Uncoupled Roll
Dynamometer Results (mpg)
X
s
mpg)
FTP
18.25
18.27
18.20
18.24
O.OA
Volumetric
FTP
19.17
18.37
18.27
18.60
0.49
Carbon Balance
FTP
18.84
18.82
18.84
18.83
0.01
Volumetric
FTP
18.39
18.83
18.72
18.65
0.23
Carbon Balance
FTP
19.24
19.54
19.30
19.36
0.16
s/x(%) 0.2
2.7
0.1
1.2
0.8
HFET
HFET
X
s
27.93
27.94
28.37
28.08
0.25
28.65
28.70
28.55
28.63
0.08
HFET
28.83
0.29
HFET
29.33
0.27
HFET
29.78
29.38
29.00
29.38
0.39
s/x(%) 0.9
0.3
1.0
0.9.
1.3
-------
Track Results
(mpg)[2]
FTP
32.30
34.51
33.17
X
s
33.33
1.11
3.3
Table C-8
Civic Fuel Economy Data
Coupled Roll
Dynamometer Results (mpg)[1]
Volumetric
FTP
34.03
1.35
4.0
Carbon Balance
FTP
36.02
35.82
33.98
35.27
1.12
3.2
Uncoupled Roll
Dynamometer Results (mpg)[l]
Volumetric Carbon Balance
FTP
36.62
0.21
0.6
FTP
38.02
37.72
37.90
37.88
0.15
0.4
HFET
HFET
X
s
43.52
0.18
0.4
42.88
1.67
3.9
HFET
44.86
43.82
41.56
43.41
1.69
3.9
HFET
48.34
48.36
48.43
48.38
0.05
0.1
HFET
48.66
48.88
49.04
48.86
0.19
0.4
Coupled Roll
Dynamometer Results (mpg)[2]
Volumetric Carbon Balance
FTP
FTP
Uncoupled Roll
Dynamometer Results (mpg)[2]
Volumetric Carbon Balance
FTP
FTP
X
s
X
s
34.83
34.18
34.51
0.46
1.3
HFET
44.43
0.48
1.1
36.26
36.00
35.40
35.89
0.44
1.2
HFET
44.34
43.92
45.60
44.62
0.87
2.0
36.30
33.58
33.77
34.55
1.52
4.4
HFET
46.40
1.13
2.4
37.48
34.78
35.18
35.81
1.46
4.1
HFET
47.16
1.39
2.9
[I] Dynamometer adjusted using straight track coastdown times.
[2] Dynamometer adjusted using curved track coastdown times.
-------
Table D-l
Oldsmobile Cutlass Data
Track Results - Volumetric Measurements
Bae 1
AD(mi) FE(mpg) FC(gpm)
3.560 12.25 0.0816
3.539 12.21 0.0819
3.563 12.08 0.0828
FTP-Composite
AD(mi)
10.996
10.848
11.010
x 10.951
s 0.080
s/x(%) 0.8
FE(mpg)
13.85
13.73
13.45
13.68
0.21
1.5
FC(gpm)
0.0722
0.0728
0.0743
0.0731
0.0011
1.5
Bag 2
AD(mi) FE(mpg) FC(gpm) AD(mi)
3.896 13.81 0.0724 3.540
3.789 13.56 0.0738 3.520
3.887 13.34 0.0749 3.560
Warm-Up HFET
AD(mi) FE(mpg) FC(gpm) AD(mi)
10.139 19.04 0.0525 10.217
10.214 19.08 0.0524 10.205
10.202 18.42 0.0543 10.196
x 10.206
s 0.011
S/JE(%) 0.1
Bag 3
FE(mpg) FC(gpm)
15.32 0.0653
15.41 0.0649
14.84 0.0674
HFET
FE(mpg) FC(gpm)
19.47 0.0514
19.32 0.0518
18.78 0.0521
19.19 0.0521
0.36 0.0009
1.9 1.8
[1] Actual distance.
[2] Fuel economy.
[3] Fuel consumption.
-------
Table D-2
Oldsmobile Cutlass Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
AD(mi)
Bag 1
FE(mpg)
FC(gpm)
3.544 13.26 0.0754
3.566 13.56 0.0737
3.584 13.10 0.0763
FTP-Composite ^
AD (mi)
10.886
10.958
11.008
x" 10.950'
s 0.061
FE(mpg)
14.05
14.96
14.45
14.49
0.46
FC(gpm)
0.0712
0.0669
0.0692
0.0691
0.0022
AD(mi)
Bag 2
FE(mpg)
3.806 13.72
3.834 14.72
3.862 14.14
Warm-Up HFET
AD (mi)
10.142
10.202
10.216
FE(mpg)
20.00
21.40
20.46
FC(gpm)
0.0729
0.0679
0.0707
FC(gpm)
0.0500
0.0467
0.0489
X
s
AD (mi)
3.536
3.558
3.562
AD (mi)
10.122
10.188
10.220
10.177
0.050
Bag 3
FE(mpg)
15.46
16.78
16.40
HFET
FE(mpg)
20.12
21.90
20.64
20.89
0.92
FC(gpm)
0.0647
0.0596
0.0610
FC(gpm)
0.0497
0.0457
0.0484
0.0479
0.0020
s/x(%) 0.6
3.2
3.1
s/x(%) 0.5
4.4
4.3
-------
Table D-3
Oldsmobile Cutlass Data
rnamometer Results - Rolls Uncoupled, Volume
Bag 1
FE(mpg) FC(gpm)
12.65 0.0790
12.18 0.0821
12.22 0.0819
FTP-Composite
FE(mpg) FC(gpm)
14.25 0.0702
14.05 0.0712
13.97 0.0716
x" 14.09 0.0710
s 0.14 0.0007
Bag 2
FE(mpg) FC(gpm)
14.09 0.0710
13.95 0.0717
13.86 0.0721
Warm-Up HFET
FE(mpg) FC(gpm)
20.04 0.0499
20.07 0.0498
20.02 0.0500
X
s
Bag 3
FE(mpg) FC(gpm)
15.73
15.85
15.71
0.0636
0.0631
0.0637
HFET
FE(mpg) FC(gpm)
20.00
20.53
20.39
20.31
0.27
0.0500
0.0487
0.0490
0.0492
0.0007
s/x(%) 1.0
1.0
1.4
1.4
-------
Table D-4
Oldsmobile Cutlass Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
AD(mi)
3.534
3.540
3.548
Bag 1
FE(mpg)
13.28
13.52
13.42
FC(gpm)
0.0753
0.0740
0.0745
FTP-Composite
AD (mi)
10.896
10.900
10.914
10.903
0.010
FE(mpg)
14.50
14.56
14.62
14.56
0.06
FC(gpm)
0.0690
0.0687
0.0684
0.0687
0.0003
AD(mi)
3.806
3.812
3.808
Bag 2
FE(mpg)
14.04
14.08
14.20
FC(gpm)
0.0712
0.0710
0.0704
AD(mi)
3.554
3.548
3.558
Warm-Up HFET
AD (mi)
10.176
10.182
10.184
FE(mpg)
20.90
20.64
20.06
FC(gpm)
0.0478
0.0484
0.0416
X
s
AD (mi)
10.170
10.164
10.162
10.165
0.004
Bag 3
FE(mpg)
16.62
16.58
16.70
HFET
FE(mpg)
20.76
20.74
20.66
20.72
0.05
FC(gpm)
0.0602
0.0603
0.0599
FC(gpm)
0.0482
0.0482
0.0484
0.0483
0.0001
s/x(%) 0.1
0.4
0.4
s/x(%) 0.04
0.3
0.2
-------
Table D-5
Oldsmobile Cutlass Data
lynamometer Results - Rolls Coupled
Bag
FE(mpg)
12.63
12.63
12.47
1
FC(gpm)
0.0791
0.0792
0.0802
FTP-Composite
FE(mpg)
14.03
14.03
13.89
x 13.98
s 0.08
FC(gpm)
0.0713
0.0713
0.0720
0.0715
0.0004
Bag
FE(mpg)
13.84
13.82
13.68
Warm-Up
FE(mpg)
19.85
19.87
, Volumetric Measurements
2
FC(gpm)
0.0722
0.0724
0.0731
HFET
FC(gpm)
0.0504
0.0503
X
s
Bag
FE(mpg)
15.50
15.62
15.53
HFET
FE(mpg)
20.30
20.29
20.09
20.23
0.12
3
FC(gpm)
0.0645
0.0640
0.0644
FC(gp'm)
0.0493
0.0493
0.0498
0.0495
0.0003
s/x(%) 0.6
0.6
s/x(%) 0.6
0.6
-------
Table D-6
Ford Pinto Data
Track Results - Volumetric Measurements
AD (mi)
Bag 1
FE(mpg)
FC(gpm)
3.593 13.27 0.0701
3.546 13.86 0.0721
3.508 '.4.60 0.0685
FTP-Composite
AD (mi)
11.009
10.876
10.811
x" 10.899
s 0.101
FE(mpg)
16.86
17.00
17.25
17.04
0.20
FC(gpm)
0.0593
0.0588
0.0580
0.0587
0.0007
Bag 2
AD (mi) FE(mpg)
3.834 17.45
3.810 17.20
3.794 17.37
Warm-Up HFET
AD(mi)
10.203
10.099
10.143
FE(mpg)
22.81
22.81
23.73
FC(gpm)
0.0573
0.0581
0.0576
FC(gpm)
0.0438
0.0438
0.0421
X
s
AD (mi)
3.582
3.520
3.509
AD (mi)
10.147
10.063
10.089
10.100
0.043
Bag 3
FE(mpg)
17.95
18.23
19.02
HFET
FE(mpg)
23.73
23.26
23.60
23.53
0.24
FC(gpm)
0.0557
0.0548
0.0526
FC(gpm)
0.0421
0.0430
0.0424
0.0425
0.0005
s/x(%) 0.9
1.2
1.1
s/x(%) 0.4
1.1
1.1
-------
Table D-7
Ford Pinto Data
Dynamometer Results - Rolls Uncoupled Carbon Balance Measurements
Bag 1
AD(mi) FE(mpg) FC(gpm)
3.556 17.34 0.0577
3.568 17.04 0.0587
3.572 17.40 0.0575
FTP-Composite
AD (mi)
10.976
11.002
11.024
x 11.000
s 0.024
FE(mpg)
19.64
19.36
19.40
19.46
0.15
FC(gpm)
0.0509
0,0517
0.0515
0.0514
0.0004
AD(mi)
Bag 2
FE(mpg)
3.848 20.10
3.864 19.24
3.868 19.82
Warm-Up HFET
AD (mi)
10.214
10.212
10.232
FE(mpg)
26.64
26.90
FC(gpm)
0.0498
0.0520
0.0505
FC(gpm)
0.0375
0.0372
X
s
AD(mi)
3.572
3.570
3.584
AD (mi)
10.204
10.212
10.234
10.217
0.016
Bag 3
FE(mpg)
22.02
21.88
21.38
HFET
FE(mpg)
27.70
27.62
27.48
27.60
0.11
FC(gpm)
0.0454
0.0457
0.0468
FC(gpm)
0.0361
0.0362
0.0364
0.0362
0.0002
s/x(%) 0.2
0.8
0.8
s/x(%) 0.2
0.4
0.4
-------
Table D-8
Ford Pinto Data
x
s
imeter Results - Rolls Uncoupled, Volumt
Bag 1
FE(mpg) FC(gpm)
15.77 0.0634
15.67 0.0638
15.70 0.0637
FTP Composite
FE(mpg) FC(gpm)
18.53 0.0540
18.53 0.0540
18.30 0.0547
18.45 0.0542
0.13 0.0004
Bag 2
FE(mpg) FC(gpm)
18.77 0.0533
18.45 0.0542
18.86 0.0530
Warm-Up HFET
FE(mpg) FC(gpm)
26.05 0.0384
25.60 0.0391
25.77 0.0388
Bag 3
FE(mpg) FC(gpm)
19.32
20.23
20.29
0.0518
0.0494
0.0493
HFET
FE(mpg) FC(gpm)
26.75
26.72
26.56
0.0374
0.0374
0.0376
x 26.68 0.0375
s 0.10 0.0001
s/x(%) 0.7
0.7
s/x(%) 0.4
0.3
-------
Table D-9
Ford Pinto Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
Bag 1
Bag 2
Bag 3
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm)
3..550 17.34 0.0577
3.554 16.42 0.0609
3.538 16.84 0.1188
3.812 19.66 0.0509
3.826 18.92 0.0529
3.814 19.88 0.0503
3.536 22.34 0.0448
3.536 20.92 0.0478
3.538 21.30 0.0469
FTP-Composite
Warm-Up HFET
HFET
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm)
10.898 19.76 0.0506
10.916 18.82 0.0531
10.890 19.50 0.0513
x" 10.901 19.36 0.0517
s 0.013 0.49 0.0013
10.154 26.44 0.0378
10.176 25.50 0.0392
10.156 26.80 0.0373
10.136 27.26 0.0367
10.158 26.06 0.0384
10.156 27.20 0.0368
x 10.150
s 0.012
26.84
0.68
0.0373
0.0010
s/x(%) 0.1
2.5
2.5
s/x(%) 0.1
2.5
2.6
-------
Table D-10
Ford Pinto Data
Jynamometer Results - Rolls Coupled, Volumetric Measurements
Bag
1
FE(mpg) FC(gpm)
15.04 0.0665
15.08 0.0663
14.96 0.0668
FTP-Composite
FE(mpg)
18.23
18.14
18.17
x" 18.18
s 0.05
FC(gpm)
0.0548
0.0551
0.0550
0.0550
0.0002
Bag
FE(mpg)
18.76
18.06
18.58
Warm-Up
FE(mpg)
25.27
24.52
25.35
2
FC(gpm)
0.0533
0.0554
0.0538
HFET
FC(gpm)
0.0396
0.0408
0.0394
X
s
Bag
FE(mpg)
19.99
19.52
20.05
HFET
FE(mpg)
25.76
25.50
25.98
25.75
0.24
3
FC(gpm)
0.0500
0.0512
0.0499
FC(gpm)
0.0388
0.0392
0.0385
0.0388
0.0004
s/x(%) 0.3
0.3
0.9
0.9
-------
Table D-ll
Ford Pickup Data
Track Results - Volumetric Measurements
AD(mi)
3.678
3.682
3.657
Bag 1
FE(mpg)
12.47
13.45
13.10
FC(gpm)
0.0802
0.0743
0.0763
. FTP-Composite
AD (mi)
11.373
11.415
11.353
x 11.374
s 0.036
FE(mpg)
14.44
14.76
14.65
14.62
0.16
FC(gpm)
0.0692
0.0678
0.0683
0.0684
0.0007
AD(mi)
4.017
4.022
3.999
Bag 2
FE(mpg)
14.93
14.91
14.83
FC(gpm)
0.0670
0.0671
0.0674
AD(mi)
•3.678
3.711
3.697
Warm-Up HFET
AD (mi)
10.526
10.645
10.613
FE(mpg)
17.73
19.30
18.44
FC(gpm)
0.0564
0.0518
0.0542
X
s
AD (mi)
10.530
10.616
10.578
10.575
0.043
Bag 3
FE(mpg)
15.19
15.54
15.58
HFET
FE(mpg)
18.23
18.61
18.58
18.47
0.21
FC(gpm)
0.0658
0.0643
0.0642
FC(gpm)
0.0548
0.0537
0.0538
0.0541
0.0006
s/x(%) 0.3
1.1
1.1
s/x(%) 0.4
1.1
1.1
-------
Table D-12
Ford Pickup Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
AD(mi)
Bag 1
FE(mpg)
FC( gpm)
3.546 14.26 '0.0701
3.552 14.62 0.0684
3.534 14.02 0.0713
FTP-Composite
AD(mi)
10.874
10.912
10.864
x" 10.883
s 0.025
FE(mpg)
15.92
15.96
15.68
15.85
0.15
FC(gpm)
0.0628
0.0627
0.0638
0.0631
0.0006
AD(mi)
Bag 2
FE(mpg)
3.794 16.08
3.820 16.14
3.790 16.06
Warm-Up HFET
AD( ml )
10.124
10.130
10.138
FE(mpg)
20.93
20.88
20.74
FC(gpm)
0.0622
0.0620
0.0623
FC(gpm)
0.0478
0.0479
0.0484
X
s
AD(mi)
3.534
3.540
3.540
AD( mi )
10.104
10.124
10.116
10.115
0.010
Bag 3
FE(mpg)
17.08
17.34
17.30
HFET
FE(mpg)
21.63
21.16
21.08
21.29
0.30
FC( gpm)
0.0585
0.0577
0.0578
FC(gpm)
0.0462
0.0473
0.0474
0.0470
0.0007
s/x(%) 0.2
1.0
1.0
s/x(%) 0.1
1.4
1.4
-------
Table D-13
Ford Pickup Data
Dynamometer
FE(mpg)
13.88
14.04
13.58
Results - Rolls Uncoupled, Volumetric Measurements
Bag 1
FC(gpm)
0.0720
0.0712
0.0737
FTP-Composite
FE(mpg)
15.57
15.84
15.62
x" 15.68
s 0.14
FC(gpm)
0.0642
0.0631
0.0640
0.0638
0.0006
Bag
FE(mpg)
15.78
16.05
15.90
Warm- Up
FE(mpg)
20.79
20.98
20.87
2
FC(gpm)
0.0634
0.0623
0.0629
HFET
FC(gpm)
0.0481
0.0477
0.0479
X
s
Bag
FE(mpg)
16.60
16.99
16.84
HFET
FE(mpg)
21.48
21.68
21.63
21.60
0.10
3
FC(gpm)
0.0602
0.0589
0.0594
FC(gpm)
0.0466
0.0461
0.0462
0.0463
0.0003
s/x(%) 0.9
0.9
s/x(%) 0.5
0.6
-------
Table D-14
Ford Pickup Data
x
s
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
Bag 1
AD( mi ) FE(mpg) FC(gpm)
3.536 13.62 0.0734
3.558. 13.26 0.0754
3.540 13.08 0.0765
FTP-Composite
AD(mi)
10.888
10.912
10.854
10.885
0.029
FE(mpg)
15.62
15.24
14.90
15.25
0.36
FC(gpm)
0.0640
0.0656
0.0671
0.0656
0.002
AD(mi)
Bag 2
FE(mpg)
3.806 16.04
3.812 15.80
3.784 15.80
Warm-Up HFET
AD(mi)
10.142
10.128
10.124
FE(mpg)
19.68
19.80
19.96
FC(gpm)
0.0623
0.0633
0.0633
FC(gpm)
0.0508
0.0505
0.0501
X
s
AD(mi)
3.546
3.542
3.530
AD(mi)
10.130
10.128
10.108
10.122
0.012
Bag 3
FE(mpg)
16.62
16 . 00
16.18
HFET
FE(mpg)
20.24
20.76
20.26
20.42
0.29
FC( gpm)
0.0602
0.0625
0.0618
FC(gpm)
0.0494
0.0482
0.0494
0.0490
0.0001
s/x(%) 0.3
2.4
2.4
s/x(%) 0.1
1.4
1.4
-------
Table D-15
Ford Pickup Data
Dynamometer Results - Rolls Coupled
Bag
1
FE(mpg) FC( gpm)
13.16 0.0760
12.98 0.0771
12.74 0.0785
FTP-Composite
FE(mpg)
15.16
15.15
15.17
x 15.16
s 0.01
FC(gpm)
0.0660
0.0660
0.0659
0.0660
0.0001
Bag
FE(mpg)
15.51
15.62
15.52
Warm-Up
FE(mpg)
19.83
19.82
19.42
, Volumetric Measurements
2
FC(gpm)
0.0645
0.0640
0.0644
HFET
FC(gpm)
0.0504
0.0505
0.0515
X
s
Bag
FE(mpg)
16.19
16.09
16.25
HFET
FE(mpg)
20.52
20.50
20.51
20.51
0.01
3
FC(gpm)
0.0618
0.0622
0.0615
FC(gpm)
0.0487
0.0488
0.0488
0.0488
0.0001
s/x(%) 0.1
0.1
s/x(%) 0.05 0.1
-------
Table D-16
Chevrolet Citation Data
Track Results - Volumetric
Bag 1
AD(mi)
3.
3.
3.
3.
3.
3.
3.
3.
3.
541
585
589
551
643
642
636
542
557
FE(mpg)
16.00
16.39
16.03
15.78
16.15
16.14
17.61
17.66
17.55
FC(gpm)
0
0
0
0
0
0
0
0
0
.0625
.0610
.0624
.0634
.0619
.0620
.0568
.0566
.0570
FTP-Composite
AD (mi)
10.
11.
11.
10.
11.
11.
11.
10.
10.
x" 11.
s 0.
938
065
131
990
252
237
236
949
947
083
134
FE(mpg)
18.24
18/72
18.58
18.50
18.37
19.22
19.27
19.23
19.30
18.83
0.43
FC(gpm)
0
0
0
0
0
0
0
0
0
0
0
.0548
.0534
.0538
.0540
.0544
.0520
.0519
.0520
.0518
.0531
.0012
AD(mi)
3.843
3.904
3.934
3.866
3.977
4.016
3.983
3.859
3.859
Bag 2
FE(mpg)
18.08
18.64
18.51
18.51
18.29
19.50
19.06
18.80
18.83
Measurements
Bag 3
FC(gpm) AD(mi) FE(mpg) FC(gpm)
0.0553
0.0536
0.0540
0.0540
0.0547
0.0513
0.0525
0.0532
0.0531
3.554
3.576
3.608
3.573
3.632
3.579
3.617
3.548
3.558
Warm-Up HFET
AD (mi)
10.217
10.289
10.314
10.236
10.396
10.300
10.372
10.241
FE(mpg)
25/80
25.65
26.43
25.95
25.39
27.00
26.31
26.74
FC(gpm)
0.0388
0.0390
0.0378
0.0385
0.0394
0.0370
0.0380
0.0374
X
s
AD(mi)
10.198
10.220
10.282
10.191
10.340
10.325
10.501
10.211
10.218
10.276
0.101
20.51
20.88
20.91
20.87
20.43
21.34
21.09
21.43
21.77
0
0
0
0
0
0
0
0
0
.0488
.0479
.0478
.0479
.0489
.0469
.0474
.0467
.0459
HFET
FE(mpg)
26.
26.
26.
26.
•25.
27.
26.
27.
27.
26.
0.
43
09
87
29
77
32
55
25
76
70
65
FC(gpm)
0.0378
0.0383
0.0372
0.0380
0.0388
0.0366
0.0377
0.0367
0.0360
0.0375
0.0009
s/x(%) 1.2
2.3
2.3
s/x(%) 1.0
2.4
2.4
-------
Table D-17
Chevrolet Citation Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
AD(mi)
3.542
3.542
3.542
3.558
3.550
3.518
3.530
3.530
3.538
Bag 1
FE(mpg)
17.76
17.44
16.96
15.70
17.38
17.52
17.46
17.56
17.58
FC(gpm)
0.0563
0.0573
0.0590
0.0637
0.0575
0.0571
0.0573
0..0569
0.0569
FTP-Composite
AD (mi)
10.906
10.914
10.900
10.908
10.892
10.832
10.848
10.844
10.852
x 10.877
s 0.033
FE(mpg)
19.52
19.24
18.82
18.82
19.56
18.88
18.70
19.10
18.94
19.06
0.31
FC(gpm)
0.0512
0.0520
0.0531
0.0531
0.0511
0.0530
0.0535
0.0524
0.0528
0.0525
0.0009
AD(mi)
3.818
3.826
3.808
3.808
3.800
3.762
3.786
3.792
3.776
Bag 2
FE(mpg)
18.98
18.80
18.22
18.66
19.16
18.08
17.74
18.48
18.00
FC(gpm)
0.0527
0.0532
0.0549
0.0536
0.0522
0.0553
0.0564
0.0541
0.0556
AD(mi)
3.546
3.546
3.544
5.542
3.542
3.552
3.532
3.522
3.538
Warm-Up HFET
AD (mi)
10.162
10.190
10.156
10.154
10.146
10.088
10.132
10.092
10.118
FE(mpg)
28.20
28.12
28.36
28.80
28.90
28.36
27.90
28.34
28.26
FC(gpm)
0.0355
0.0356
0.0353
0.0347
0.0346
0.0353
0.0358
0.0353
0.0354
X
s
AD (mi)
10.166
10.210
10.156
10.144
10.142
10.098
10.090
10.094
10.104
10.134
0.041
Bag 3
FE(mpg)
22.40
21.92
22.00
22.52
22.60
22.00
22.06
21.92
22.44
HFET
FE(mpg)
28.30
27.90
29.24
29.34
29.14
28.82
28.62
28.44
28.96
28.75
0.48
FC(gpm)
0.0446
0.0456
0.0455
0.0444
0.0442
0.0455
0.0453
0.0456
0.0446
FC(gpm)
0.0353
0.0358
0.0342
0.0341
0.0343
0.0347
0.0349
0.0352
0.0345
0.0348
0.0006
s/x(%) 0.3
1.7
1.7
s/x(%) 0.4
1.7
1.7
-------
Table D-18
Chevrolet Citation Data
lometer Results - Rolls Uncoupled, Volume
Bag
FE(mpg)
16.17
16.17
15.98
14.84
16.28
16.26
16.42
16.47
16.44
1
FC(gpm)
0.0618
0.0618
0.0626
0.0674
0.0614
0.0615
0.0609
0.0607
0.0608
FTP-Composite
FE(mpg)
18.99
18.78
18.65
18.77
19.21
18.51
18.80
18.99
18.75
18.83
0.21
FC(gpm)
0.0527
0.0532
0.0536
0.0533
0.0520
0.0540
0.0532
0.0527
0.0533
0.0531
0.0006
Bag
FE(mpg)
18.86
18.51
18.41
19.00
18.93
18.45
18.38
18.65
18.12
Warm-Up
FE(mpg)
28.14
28.03
28.20
28.76
28.70
28.25
28.25
28.39
28.50
2
FC(gpm)
0.0530
0.0540
0.0543
0.0526
0.0528
0.0542
0.0544
0.0536
0.0552
HFET
FC(gpm)
0.0355
0.0357
0.0355
0.0348
0.0348
0.0354
0.0354
0.0352
0.0351
X
s
Bag
FE(mpg)
21.74
21.63
21.47
21.92
22.42
20.57
21.86
21.89
22.13
HFET
FE(mpg)
29.32
28.93
29.60
30.10
29.78
29.40
29.08
29.17
29.48
29.43
0.36
3
FC(gpm)
0.0460
0.0462
0.0466
0.0456
0.0446
0.0486
0.0457
0.0457
0.0452
FC(gpm)
0.0341
0.0346
0.0338
0.0332
0.0336
0.0340
0.0344
0.0343
0.0339
0.0340
0.0004
s/x(%) 1.1
1.1
1.2
1.2
-------
Table D-19
Chevrolet Citation Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
AD(mi)
3.526
3.536
3.546
3.538
3.530
3.536
3.540
3.528
3.532
Bag 1
FE(mpg)
17.18
17.74
17.92
17.56
14.86
18.04
18.12
18.40
18.34
FC(gpm)
0.0582
0.0564
0.0558
0.0569
0.0673
0.0554
0.0552
0.0543
0.0545
FTP-Composite
AD (mi)
10.848
10.860
10.868
10.886
10.854
10.854
10.838
10.852
10.856
x 10.857
s 0.014
FE(mpg)
18.82
19.00
19.02
18.90
18.32
19.18
19.48
19.40
19.42
19.06
0.37
FC(gpm)
0.0531
0.0526
0.0526
0.0529
0.0546
0.0521
0.0513
0.0515
0.0515
0.0525
0.0010
AD(mi)
3.788
3.796
3.792
3.810
3.792
3.800
3.780
3.792
3.792
Bag 2
FE(mpg)
18.32
17.96
18.30
18.20
18.38
18.52
18.76
18.46
18.46
FC(gpm)
0.0546
0.0557
0.0546
0.0549
0.0544
0.0540
0.0533
0.0542
0.0542
AD(mi)
3.534
3.528
3.530
3.538
3.532
3.540
3.518
3.532
3.532
Warm-Up HFET
AD (mi)
10.130
10.122
10.128
10.114
10.124
10.122
10.090
10.112
10.100
FE(mpg)
27.50
27.72
27.46
28.02
28.12
27.88
28.44
28.34
28.62
FC(gpm)
0.0364
0.0361
0.0364
0.0357
0.0356
0.0359
0.0352
0.0353
0.0349
X
s
AD (mi)
10.132
10.098
10.102
10.108
10.090
10.104
10.094
10.118
10.100
10.105
0.105
Bag 3
FE(mpg)
21.42
22.62
21.70
21.70
21.98
21.60
22.42
22.52
22.74
HFET
FE(mpg)
27.70
28.02
27.74
17.94
28.44
27.60
29.34
28.26
28.82
28.21
0.58
FC(gpm)
0.0467
0.0442
0.0461
0.0461
0.0455
0.0463
0.0446
0.0444
0.0440
FC(gpm)
0.0361
0.0357
0.0360
0.0358
0.0352
0.0262
0.0341
0.0354
0.0247
0.0355
0.0007
s/x(%) 0.1
1.9
1.9
s/x(%) 0.1
2.1
2.0
-------
Table D-20
Chevrolet Citation Data
lynamometer Results - Rolls Coupled, Volume t
Baj
FE(mpg)
16.46
16.93
17.01
16.58
14.01
17.16
17.29
17.28
17.45
5 1
FC(gpm)
0.0608
0.0591
0.0588
0.0603
0.0714
0.0583
0.0578
0.0579
0.0573
FTP-Composite
FE(mpg)
18.68
18.82
18.96
18.86
18.30
19.21
19.49
10.39
19.43
x 19.02
s 0.40
FC(gpm)
0.0535
0.0531
0.0527
0.0530
0.0547
0.0520
0.0513
0.0516
0.0515
0.0526
0.0011
Bag
FE(mpg)
18.26
18.22
18.52
18.43
18.58
18.87
19.06
18.91
18.84
Warm-Up
FE(mpg)
27.69
27.80
27.43
28.15
28.22
27.94
-2-8.50
28.60
28.72
—
2
FC(g-pm)
0.0548
0.0549
0.0540
0.0543
0.0538
0.0530
0.0525
0.0529
0.0531
HFET
FC(gpm)
0.0361
0.0360
0.0365
0.0355
0.0354
0.0358
0.0351
0.0350
0.0348
X
s
Bag
FE(mpg)
21.51
21.72
21.57
21.74
21.75
21.68
22.31
22.24
22.37
HFET
FE(mpg)
28.28
28.48
28.18
28.72
29.03
28.65
29.28
29.19
29.30
28.79
0.43
3
FC(gpm)
0.0465
0.0460
0.0464
0.0460
0.0460
0.0461
0.0448
0.0450
0.0447
FC(gpm)
0.0354
0.0351
0.0355
0.0348
0.0345
0.0349
0.0341
0.0343
0.0341
0.0347
0.0005
s/x(%) 2.1
2.1
1.5
1.5
-------
Table D-21
Ford Escort Data
Track Results - Volumetric Measurements
AD(mi)
3.593
3.555
3.563
Bag 1
FE(mpg)
21.17
21.13
20.25
FC(gpm)
0.0472
0.0473
0.0494
FTP-Composite
AD(mi)
11.140
11.040
11.069
x" 11.083
s " 0.051-
FE(mpg)
23.43
23.45
23.12
23.33
0.19
FC(gpm)
0.0427
0.0426
0.0433
0.0429
0.0004
AD(mi)
3.947
3.898
3.926
Bag 2
FE(mpg)
22.95
22.81
22.71
FC(gpm)
0.0436
0.0438
0.0440
AD(mi)
3.600
3.587
3.580
Warm-Up HFET
AD (mi)
10.246
10.262
10.289
FE(mpg)
34.91
34.22
34.05
FC(gpm)
0.0286
0.0292
0.0294
X
s
AD (mi)
10.232
10.233
10.191
10.219
0.024
Bag 3
FE(mpg)
26.39
26.80
26.49
HFET
FE(mpg)
35.50
33.08
34.85
34.48
1.25
FC(gpm)
0.0379
0.0373
0.0378
FC(gpm)
0.0282
0.0302
0.0287
0.0290
0.0010
s/x(%) 0.5
0.8
0.8
s/x(%) 0.2
3.6
3.6
-------
Table D-22
Ford Escort Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
Bag 1
Bag 2
Bag 3
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm)
3.512 22.68 0.0441
3.606 22.92 0.0436
3.618 23.02 0.0434
3.800 23.24 0.0430
3.886 24.18 0.0414
3.866 23.92 0.0418
3.524 29.08 0.0344
3.598 28.60 0.0350
3.602 29.40 0.0340
FTP-Composite
X
s
AD(mi)
10.836
11.090
11.086
11.004
0.146
FE(mpg)
24.46
24.96
25.02
24.81
0.31
FC(gpm)
0.0409
0.0401
0.0400
0.0403
0 ..0005
Warm-Up HFET
HFET
AD( mi )
10.082
10.328
10.324
FE(mpg)
38.92
38.76
40.44
FC(gpm)
0.0257
0.0258
0.0247
X
s
AD( mi )
10.080
10.310
10.306
10.232
0.132
FE(mpg)
39.76
39.44
40.70
39.97
0.65
FC(gpm)
0.0252
0.0254
0.0246
0.0251
0.0004
s/x(%) 1.3
1.2
1.2
1.3
1.6
1.6
-------
Table B-23
Ford Escort Data
•namometer Results - Rolls Uncoupled, Volumetric Measurements
Bag
FE(mpg)
21.01-
21.66
21.65
1
FC(gpm)
0.0476
0.0462
0.0462
FTP-Composite
FE(mpg)
24.56
24.64
24.74
x 24.65
s 0.09
FC(gpm)
0.0407
0.0406
0.0404
0.0406
0.0002
Bag
FE(mpg)
23.90
24.07
23.96
Warm-Up^
FE(mpg)
39.23
38.92
40.77
2
FC(gpm)
0.0418
0.0415
0.0417
HFET
FC(gpm)
0.0255
0.0257
0.0245
X
s
Bag
FE(mpg)
29.17
28.44
29.14
HFET
FE(mpg)
40.50
39.91
41.30
40.57
0.70
3
FC(gpm)
0.0343
0.0352
0.0343
FC(gpm)
0.0247
0.0251
0.0242
0.0247
0.0005
s/x(%) 0.4
0.4
s/x(%) 1.7
1.7
-------
Table D-24
Ford Escort Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
AD (mi)
Bag 1
FE(mpg)
FC(gpm)
3.512 22.62 0.0442
3.520 23.38 0.0447
3.532 23.44 0.0427
FTP-Composite
AD (mi)
10.832
10.852
10.858
x" 10.847
s 0.014
FE(mpg)
23.74
24.04
24.86
24.21
0.58
FC(gpm)
0.0421
0.0416
0.0402
0.0413
0.0010
AD(mi)
Bag 2
FE(mpg)
3.802 22.60
3.796 22.76
2.798 23.62
Warm-Up HFET
AD (mi)
10.098
10.132
10.100
FE(mpg)
37.74
38.62
40.08
FC(gpm)
0.0442
0.0439
0.0423
FC(gpm)
0.0265
0.0259
0.0250
X
s
AD(mi)
3.518
3.534
3.528
AD (mi)
10.128
10.122
10.112
10.121
0.008
Bag 3
FE(mpg)
27.30
28.68
29.10
HFET
FE(mpg)
38.24
39.54
39.84
39.21
0.85
FC(gpm)
0.0366
0.0349
0.0344
FC(gpm)
0.0262
0.0253
0.0251
0.0255
0.0006
s/x(%) 0.1
2.4
2.4
s/x(%) 0.08
2.2
2.2
-------
Table D-25
Ford Escort Data
lynamometer Results - Rolls Coupled, Volumetric Measurements
Bag 1
FE(mpg) FC(gpm)
21.40 0.0467
21.03 0.0475
22.03 0.0454
FTP-Composite
FE(mpg) FC(gpm)
23.78 0.0421
23.93 0.0418
24.63 0.0406
x" 24.11 0.0415
s 0.45 0.0008
Ba^
FE(mpg)
23.06
23.07
23.79
Warm-Up
FE(mpg)
37.65
38.88
40.04
2
FC(gpm)
0.0434
0.0434
0.0420
HFET
FC(gpm)
0.0266
0.0257
0.0250
x
s
Bag 3
FE(mpg) FC(gpm)
27.35 0.0366
28.38 0.0352
28.71 0.0348
HFET
FE(mpg) FC(gpm)
39.01 0.0256
40.13 0.0249
40.65 0.0246
39.93 0.0250
0.84 0.0005
1.9
1.9
s/x(%) 2.1
2.1
-------
Table D-26
Plymouth Horizon Data
Track. Results - Volumetric Measurements
AD (mi)
Bag 1
FE(mpg)
FC(gpm)
3.527 16.59 0.0603
3.641 14.73 0.0679
3.575 19.16 0.0522
FTP -Composite
AD(mi)
10.849
11.274
11.058
x" 11.060
s 0.213
FE(mpg)
21.75
18.17
22.40
20.77
2.28
FC(gpm)
0.0460
0.0550
0.0446
0.0485
0.0056
Bag 2
AD(mi) FE(mpg)
3.709 22.97
4.059 18.77
3.908 23.22
Warm-Up HFET
AD(mi)
10.316
10.136
10.259
FE(mpg)
30.32
26.94
30.29
FC(gpm)
0.0435
0.0533
0.0431
FC(gpm)
0.0330
0.0371
0.0330
X
s
AD(mi)
3.613
3.574
3.575
AD(mi)
10.281
10.121
10.252
10.218
0.085
Bag 3
FE(mpg)
24.20
20.03
23.60
HFET
FE(mpg)
31.03
28.01
31.50
30.18
1.89
FC(gpm)
0.0413
0.0499
0.0424
FC(gpm)
0.0322
0.0357
0.0317.
0.0332
0.0022
s/x(%) 1.9
10.9 11.6
s/x(%) 0.8
6.3
6.4
-------
Table D-27
Plymouth Horizon Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
AD(mi)
Bag 1
FE(mpg)
FC(gpm)
3.526 19.90 0.0503
3.562 20.14 0.0497
3.544 21.20 0.0472
FTP-Composite
AD (mi)
10.874
10.972
10.882
x 10.909
s 0.054
FE(mpg)
23.08
23.42
23.76
23.42
0.34
FC(gpm)
0.0433
0.0427
0.0421
0.0427
0.0006
AD(mi)
Bag 2
FE(mpg)
3.792 23.12
3.854 23.56
3.802 23.56
Warm-Up HFET
AD (mi)
10.174
10.186
10.200
FE(mpg)
32.42
33.34
33.22
FC(gpm)
0..0433
0.0424
0.0424
FC(gpm)
0.0308
0.0300
0.0301
X
s
AD(mi)
3.556
3.556
3.536
AD (mi)
10.156
10.170
10.174
10.167
0.010
Bag 3
FE(mpg)
26.16
26.36
26.56
HFET
FE(mpg)
33.54
33.86
34.06
33.82
0.26
FC(gpm)
0.0382
0.0379
0.0377
FC(gpm)
0.0298
0.0295
0.0294
0.0296
0.0002
s/x(%> 0.5
1.5
1.4
s/x(%) 0.1
0.8
0.7
-------
Table D-28
Plymouth Horizon Data [1]
Dynamometer Results - Rolls
AD(mi)
3
3
3
.564
.582
.550
Bag 1
FE(mpg)
19.98
20.00
19.52
FC(gpm)
0
0
0
.0501
.0500
.0512
Uncoupled, Carbon Balance Measurements
AD(mi)
3.
3.
3.
FTP-Composite
AD (mi)
10
10
10
x 10
s 0
s/x~(%) 0
.991
.976
.942
.970
.025
.2
FE(mpg)
23.26
23.44
22.96
23.22
0.24
1.0
FC(gpm)
0
0
0
0
0
1
.0430
.0427
.0436
.0431
.0005
.1
824
840
828
Bag 2
FE(mpg)
23.36
23.70
23.12
FC(gpm)
0.0428
0.0422
0.0433
AD(mi)
3.580
3.554
3.564
Warm-Up HFET
AD (mi)
10.
10.
10.
188
168
200
FE(mpg)
32.72
33.02
32.18
FC(gpm)
0.0306
0.0303
0.0311
X
s
s/x(%)
AD (mi)
10.150
10.174
10.164
10.162
0.012
0.1
Bag 3
FE(mpg)
26.24
26.32
25.99
HFET
FE (mpg )
33.28
33.42
32.62
33.11
0.43
1.3
FC(gpm)
0.0381
0.0380
0.0385
FC(gpm)
0.0300
0.0299
0.0307
0.0302
0.0004
1.4
[1]
Dynamometer adjusted using curved track coastdown times.
-------
Table D-29
Plymouth Horizon Data
Dynamometer Results - Rolls Uncoupled
Bag 1
FE(mpg) FC(gpm)
16.38 0.0610
15.88 0.0630
17.25 0.0580
FTP-Composite
FE(mpg) FC(gpm)
21.57 0.0464
22.64 0.0442
22.49 0.0445
"x" 22.22 0.0450
s 0.57 0.0012
s/x(%) 2.6 2.7
Bag
FEQpg)
23.03
24.49
23.27
Warm-Up
FE(mpg)
31.26
31.63
31.86
, Volumetric Measurements
2
FC( gpm)
0.0434
0.0408
0.0430
HFET
FC(.gpm)
0.0320
0.0316
0.0314
s
Bag
FE(mpg)
23.62
25.69
25.82
HFET
FE(mpg)
33.46
34.10
34.06
33.87
0.36
1.1
3
FC( gpm)
0.0423
0.0389
0.0387
FC(gpm)
0.0299
0.0293
0.0294
0.0295
0.0003
1.1
-------
Table D-30
Plymouth Horizon Data [1]
Dynamometer
FE(mpg)
16.69
16.34
15.93
Results - Rolls Uncoupled
Bag 1
FC(gpm)
0.0599
0.0612
0.0628
FTP-Composite
FE(mpg)
21.64
21.57
21.92
x 21.71
s 0.19
s/x"(%) 0.9
FC(gpm)
0.0462
0.0464
0.0456
0.0461
0.0004
0.9
Bag
FE(mpg)
22.45
22.34
23.10
Warm-Up
FE(mpg)
31.56
31.26
30.70
, Volumetric Measurements
2
FC(gpm)
0.0445
0.0448
0.0433
HFET
FC(gpm)
0.0317
0.0320
0.0326
X
s
sWZ)
Bag
FE(mpg)
24.56
25.54
25.37
HFET
FE(mpg)
33.46
33.39
32.49
33.11
0.54
1.6
3
FC(gpm)
0.0407
0.0392
0.0394
FC(gpm)
0.0299
0.0299
0.0308
0.0302
0.0005
1.7
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-31
Plymouth Horizon Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements [1]
Bag 1
AD(mi) FE(mpg) FC( gpm)
3.524 19.24 0.0520
3.548 20.68 0.0484
FTP-Composite
AD(mi) FE(mpg) FC(gpm)
10.922 22.58 0.0443
10.900 23.20 0.0431
10.852
x" 10.891 22.89 0.0437
s 0.036 0.44 0.0008
s/x(%) 0.3 1.9 1.9
Bag 2
AD(mi) FE(mpg) FC(gpm) AD(mi)
3.844 22.66 0.0441 3.554
3.808 22.98 0.0435 3.544
Warm-Up HFET
AD(mi) FE(mpg) FC(gpm) AD(mi)
10.172 32.66 0.0306 10.142
10.166 32.72 0.0306 10.148
10.172 31.82 0.0314 10.154
x 10.148
s 0.006
s/x(%) 0.1
Bag 3
FE(mpg)
25.82
25.96
HFET
FE(mpg)
33.16
33.16
32.80
33.04
0.21
0.6
FC( gpm)
0.0387
0.0385
FC(gpm)
0.0302
0.0302
0.0305
0.0303
0.0002
0.6
[1] Third FTP test voided.
-------
Table D-32
Plymouth Horizon Data [1]
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
Bag 1
Bag 2
Bag 3
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC( gpm)
3.530 19.24 0.0520
3.540 20.16 0.0496
3.552 19.24 0.0520
3.770 22.32 0.0448
3.806 22.90 0.0437
3.822 22.32 0.0448
3.546 25.50 0.0391
3.556 25.72 0.0389
3.550 25.80 0.0388
FTP-Composite
Warm-Up HFET
HFET
X
s
AD(mi)
10.846
10.902
10.924
10.891
0.040
FE(mpg)
22.38
22.96
22.42
22.59
0.32
FC(gpm)
0.0447
0.0436
0.0446
0.0443
0.0006
AD(mi)
10.166
10.200
10.186
FE(mpg)
32.12
32.64
32.64
FC(gpm)
0.0311
0.0306
0.0306
X
s
AD(mi)
10.148
10.144
10.160
10.151
0.008-
FE(mpg)
32.50
32.98
32.68
32.72
0.24
FC(gpm)
0.0308
0.0303
0.0306
0.0306
0.0003
s/x(%) 0.4
1.4
1.4
s/x(%) 0.1
0.7
0.8
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-33
Plymouth Horizon Data
Dynamometer Results - Rolls Coupled, Volumetric Measurements
Bag 1
FE(mpg) FC( gpm)
16.05 0.0623
16.75 0.0597
FTP-Composite
FE(mpg) FC(gpm)
21.37 0.0468
21.82 0.0458
x 21.60 0.0463
s 0.32 0.0007
s/x(%) 1.5 1.5
Bag
FE(mpg)
22.80
23.00
Warm-U p
FE(mpg)
31.29
31.19
30.53
2
FC( gpm)
0.0439
0.0435
HFET
FC(gpm)
0.0320
0.0321
0.0328
X
s
./ai)
Bag
FE(mpg)
23.60
24.23
24.84
HFET
FE(mpg)
33.34
33.50
32.27
33.04
0.67
2.0
[1]
3
FC( gpm)
0.0424
0.0413
0.0403
FC( gpm)
0.0300
0.0299
0.0310
0.0303
0.0006
2.1
[1] Third FTP test voided.
-------
Table D-34
Plymouth Horizon Data [1]
Dynamometer
Results - Rolls Coupled,
Bag 1
FE(mpg) FC( gpm)
15.95 0.0627
16.93 0.0590
15.79 0.0633
FTP-Composite
FE(mpg)
21.31
21.66
20.98
x" 21.32
s 0.34
s/x(%) 1.6
FC(gpm)
0.0469
• 0.0462
0.0477
0.0469
0.0008
1.6
Bag
FE(mpg)
22.07
22.75
22.05
Warm-Up
FE(mpg)
30.76
30.98
30.98
Volumetric
2
FC(gpm)
0.0453
0.0439
0.0454
HFET
FC(gpm)
0.0325
0.0323
0.0323
x
s
Measurements
FE(mpg)
Bag 3
FC( gpm)
24.84 0.0403
23.86 0.0419
23.77 0.0421
HFET
FE(mpg)
32.68
33.26
32.72
32.89
0.32
1.0
FC(gpm)
0.0306
0.0301
0.0306
0.0304
0.0003
1.0
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-35
AMC Concord Data
Track Results - Volumetric Measurements
AD(mi)
Bag 1
FE(mpg)
FC(gpm)
3.576 15.88 0.0630
3.574 15.77 0.0634
3.562 16.05 0.0623
FTP-Composite
AD (mi)
11.131
11.104
11.082
x" 11.106
s 0.025
FE(mpg)
18.25
18.27
18.20
18.24
0.04
FC(gpm)
0.0548
0.0547
0.0550
0.0548
0.0002
AD(mi)
Bag 2
FE(mpg)
3.974 18.43
3.929 18.37
3.942 18.64
Warm-Up HFET
AD (mi)
10.265
10.296
10.219
FE(mpg)
26.20
27.11
27.27
FC(gpm)
0.0543
0.0544
0.0537
FC(gpm)
0.0382
0.0369
0.0367
X
s
AD(mi)
3.581
3.601
3.578
AD (mi)
10.274
10.272
10.128
10.225
0.084
Bag 3
FE(mpg)
19.89
20.21
19.12
HFET
FE(mpg)
27.93
27.94
28.37
28.08
0.25
FC(gpm)
0.0503
0.0495
0.0523
FC(gpm)
0.0358
0.0358
0.0352
0.0356
0.0003
s/x(%), 0.2
0.2
0.3
s/x(%) 0.8
0.9
1.0
-------
Table D-36
AMC Concord Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
AD(mi)
Bag 1
FE(mpg)
FC(gpm)
3.568 17.62 0.0568
3.574 18.40 0.0543
3.588 18.02 0.0555
FTP-Composite
AD (mi)
10.972.
11.006
10.998
x" 11.001
s 0.005
FE(mpg)
19.24
19.54
19.30
19.36
0.16
FC(gpm)
0.0520
0.0512
0.0518
0.0517
0.0004
Bag 2
AD(mi) FE(mpg)
3.828 18.86
3.860 19.08
3.834 18.80
Warm-Up HFET
AD (mi)
10.190
10.228
10.216
FE(mpg)
29.14
29.12
29.12
FC(gpm)
0.0530
0.0524
0.0532
FC(gpm)
0.0343
0.0343
0.0343
x
s
AD(mi)
3.576
3.574
3.576
AD (mi)
10.182
10.202
10.190
10.191
0.010
Bag 3
FE(mpg)
21.54
21.54
21.52
HFET
FE(mpg)
29.78
29.38
29.00
29.38
0.39
FC(gpm)
0.0464
0.0464
0.0465
FC(gpm)
0.0336
0.0340
0.0345
0.0340
0.0005
s/x(%) 0.04
0.8
0.8
s/x(%) 0.1
1.3
1.3
-------
Table D-37
AMC Concord Data
lynamometer Results - Rolls Uncoupled
Bag 1
FE(mpg) FC(gpm)
16.31 0.0613
17.19 0.0582
16.55 0.0604
FTP-Composite
FE(mpg) FC(gpm)
18.39 0.0544
18.83 0.0531
18.72 0.0534
x 18.65 0.0536
s 0.23 0.0007
Bag
FE(mpg)
18.49
18.56
18.56
Warm-Up
FE (mpg )
27.76
28.64
28.44
, Volumetric Measurements
2
FC(gpm)
0.0541
0.0539
0.0539
HFET
FC(gpm)
0.0360
0.0349
0.0352
X
s
Bag 3
FE(mpg) FC(gpm)
19.-92 0.0502
20.73 0.0482
20.88 0.0479
HFET
FE(mpg) FC(gpm)
29.64 0.0337
29.15 0.0343
29.19 0.0343
29.33 0.0341
0.27 0.0003
1.2
1.3
0.9
1.0
-------
Table D-38
AMC Concord Data
Dynamometer Results - Rolls Coupled, Carbon Balance Measurements
AD(mi)
Bag 1
FE(mpg)
FC( gpm)
3.570 17.74 0.0564
3.598 17.70 0.0565
3.586 17.48 0.0572
FTP-Composite
AD(mi)
10.938
10.982
10.956
I 10.959
s 0.022
FE(mpg)
18.84
18.82
18.84
18.83
0.01
FC(gpm)
0.0531
0.0531
0.0531
0.0531
0.0000
AD(mi)
Bag 2
FE(mpg)
3.830 18.38
3.816 18.44
3.818 18.32
Warm-Up HFET
AD(mi)
10.180
10.184
10.192
FE(mpg)
28.48
28.56
28.64
FC( gpm)
0.0544
0.0542
0.0546
FC(gpm)
0.0351
0.0350
0.0349
X
s
AD(mi)
3.538
3.568
3.552
AD(mi)
10.182
10.174
10.198
10.185
0.012
Bag 3
FE(mpg)
20.82
20.66
21.24
HFET
FE(mpg)
28.52
28.86
29.10
28.83
0.29
FC( gpm)
0.0480
0.0484
0.0471
FC(gpm)
0.0351
0.0347
0.0344
0.0347
0.0004
s/x(%) 0.2
0.1
0.0
s/x(%) 0.1
1.0
1.0
-------
Table D-39
AMC Concord Data
Dynamometer Results - Rolls Coupled,
Bag 1
FE(mpg) FC(gpm)
20.14 O.OA96
16.42 0.0609
16.28 0.0614
FTP-Composite
FE(mpg) FC(gpm)
19.17 0.0522
18.37 0.0544
18.27 0.0547
x" 18.60 0.0538
s 0.49 0.0014
Bag
FE(mpg)
18.24
18.32
17.98
Warm-Up
FE(mpg)
27.64
27.04
26.98
Volumetric Measurements
2
FC( gpm)
0.0548
0.0546
0.0556
HFET
FC(gpm)
0.0362
0.0370
0.0371
X
s
Bag 3
FE(mpg) FC(gpm)
20.38 0.0491
20.11 0.0497
20.57 0.0486
HFET
FE(mpg) FC(gpm)
28.65 0.0349
28.70 0.0348
28.55 0.0350
28.63 0.0349
0.08 0.0001
s/x(%) 2.7
2.5
0.3
0.3
-------
Table D-40
Honda Civic Data
Track Results - Volumetric Measurements
Bag 1
AD(mi) FE(mpg) FC( gpm)
3.512 29.65 0.0337
3.521 30.51 0.0328
3.469 29.85 0.0335
FTP-Composite
AD(mi)
10.947
10.831
10.688
x 10.822
s 0.130
FE(mpg)
32.30
34.51
33.17
33.33
1.11
FC(gpm)
0.0310
0.0290
0.0301
0.0300
0.0010
Bag 2
AD(mi) FE(mpg)
3.929 32.64
3.791 36.20
3.732 34.31
Warm-Up HFET
AD(mi)
9.608
10.154
10.142
FE(mpg)
39.08
41.01
40.89
FC(gpm)
0.0306
0.0276
0.0291
FC(gpm)
0.0256
0.0244
0.0245
X
s
AD(mi)
3.506
3.519
3.487
AD(mi)
9.884
10.145
10.089
10.039
0.137
Bag 3
FE(mpg)
33.78
34.74
33.78
HFET
FE( mpg )
43.72
43.45
43.39
43.52
0.18
FC(gpm)
0.0296
0.0288
0.0296
FC(gpm)
0.0229
0.0230
0.0230
0.0230
0.0001
s/x(%) 1.2
3.3
3.3
s/x(%) 1.4
0.4
0.3
-------
Table D-41
Honda Civic Data
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measuremeni-s
Bag 1
AD(mi) FE(mpg) FC( gpm)
3.578 35.38 0.0283
3.574 35.32 0.0283
3.584 35.52 0.0282
FTP-Composite
AD(mi)
10.924
10.938
10.994
x 10.952
s 0.037
FE(mpg)
38.02
37.72
37.90
37.88
0.15
FC(gpm)
0.0263
0.0265
0.0264
0.0264
0.0001
Bag 2
AD(mi) FE(mpg) FC(gpm) AD(mi)
3.816 38.38 0.0261 3.530
3.834 37.94 0.0264 3.530
3.858 38.02 0.0263 3.552
Warm-Up HFET
AD(mi) FE(mpg) FC(gpm) AD(mi)
10.120 46.16 0.0217 10.122
10.168 46.54 0.0215 10.166
10.182 46.66 0.0214 10.208
x 10.165
s 0.043
Bag 3
FE(mpg)
39.76
37.44
39.70
HFET
FE(mpg)
48.66
48.88
49.04
48.86
0.19
FC( gpm)
0.0252
0.0267
0.0252
FC(gpm)
0.0206
0.0205
0.0204
0.0205
0.0001
s/x(%) 0.3
0.4
0.4
s/x(%) 0.4
0.4
0.5
-------
Table D-42
Honda Civic Data[l]
Dynamometer Results - Rolls Uncoupled, Carbon Balance Measurements
Bag 1
Bag 2
Bag 3
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm)
3.576 35.60 0.0281
3.556 31.94. 0.0313
3.546 32.86 0.0304
3.816 37.44 0.0267
3.806 34.46 0.0290
3.816 34.78 0.0288
3.538 39.10 0.0256
3.550 37.82 0.0264
3.522 38.10 0.0262
FTP-Composite
X
s
AD( mi.)
10.930
10.912
10.884
10.909
0.023
FE(mpg)
37.48
34.78
35.18
35.81
1.46
FC(gpm)
0.0267
0.0288
0.0284
0.0280
0.0011
s/x(%) 0.2
4.1
4.0
Warm-Up HFET
HFET
AD(mi) FE(mpg) FC(gpm) AD(mi) FE(mpg) FC(gpm)
10.160 46.76 0.0214
10.176 44.40 0.0225
10.138 45.34 0.0221
10.198 48.76 0.0205
10.144 46.40 0.0216
10.146 46.32 0.0216
X
s
10.163
0.031
47.16
1.39
0.0212
0.0006
s/x(%) 0.3
2.9
3.0
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-43
Honda Civic Data
Dynamometer Results - Rolls Uncoupled
Bag 1
FE(mpg) FC(gpm)
33.68 0.0297
33.23 0.0301
33.50 0.0299
FTP-Composite
FE(mpg) FC(gpm)
36.86 0.0271
36.48 0.0274
36.51 0.0274
"x 36.62 0.0273
s 0.21 0.0002
Bag
FE(mpg)
37.58
37.50
37.22
Warm-Up
FE(mpg)
44.77
45.10
45.10
, Volumetric Measurements
2
FC(gpm)
0.0266
0.0267
0.0269
HFET
FC(gpm)
0.0223
0.0222
0.0222
X
s
Bag 3
FE(mpg) FC(gpm)
38.07 0.0263
37.22 0.0269
37.59 0.0266
HFET
FE(mpg) FC(gpm)
48.34 0.0207
48.36 0.0207
48.43 0.0206
48.38 0.0207
0.05 0.0001
s/x(Z) 0.6
0.6
0.1
0.3
-------
Table D-44
Honda Civic Data[l]
Dynamometer
FE(mpg)
33.48
30.42
30.74
Results - Rolls Uncoupled
Bag 1
FC(gpm)
0.0299
0.0329
0.0325
FTP-Composite
FE(mpg)
36.30
33.58
33.77
x 34.55
s 1.52
s/x"(%) 4.4
FC(gpm)
0.0276
0.0298
0.0296
0.0290
0.0012
4.2
Bag
FE(mpg)
36.65
33.62
33.86
Wann-Up
FE(mpg)
45.27
43.07
43.93
, Volumetric Measurements
2
FC(gpm)
0.0273
0.0297
0.0295
HFET
FC(gpm)
0.0221
0.0232
0.0228
X
s
s/x(%)
Bag
FE(mpg)
37.90
36.12
36.09
HFET
FE(mpg)
47.69
45.57
45.94
46.40
1.13
2.4
3
FC(gpm)
0.0264
0.0277
0.0277
FC(gpm)
0.0210
0.0219
0.0218
0.0216
0.0005
2.3
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-45
Honda Civic Data
Dynamometer
AD(mi)
Bag 1
FE(mpg)
Results -
FC( gpm)
3.556 33.60 0.0298
3.460 33.48 0.0299
3.564 32.06 0.0312
FTP-Composite
AD(mi)
10.938
10.850
10.884
x 10.891
s 0.044
FE(mpg)
36.02
35.82
33.98
35.27
1.12
FC(gpm)
0.0278
0.0279
0.0294
0.0284
0.0009
Rolls Coupled, Carbon Balance Measurements
AD(mi)
Bag 2
FE(mpg)
3.840 36.26
3.836 36.18
3.782 33.70
Warm-Up HFET
AD(mi)
10.124
10.124
10.152
FE(mpg)
42.92
42.20
40.74
FC( gpm)
0.0276
0.0276
0.0297
FC(gpm)
0.0233
0.0237
0.0245
X
s
AD(mi)
3.542
3.554
3.538
AD(mi)
10.120
10.126
10.114
10.120
0.006
Bag 3
FE(mpg)
37.78
37.06
36.26
HFET
FE(mpg)
44.86
43.82
41.56
43.41
1.69
FC( gpm)
0.0265
0.0270
0.0276
FC(gpm)
0.0223
0.0228
0.0241
0.0231
0.0009
s/x(%) 0.4
3.2
3.2
s/x(%) 0.1
3.9
4.0
-------
Table D-46
Honda Civic Data[l]
Dynamometer
Bag 1
Results -
AD(mi) FE(mpg) FC(gpm)
3.556 33.74 0.0296
3.556 33.44 0.0299
3.560 31.62 0.0316
FTP-Composite
AD(mi)
10.912
10.916
10.948
x 10.925
s 0.020
s/x(Z) 0.2
FE(mpg)
36.26
36.00
35.40
35.89
0.44
1.2
FC(gpm)
0.0276
0.0278
0.0282
0.0279
0.0003
1.1
Rolls Coupled, Carbon Balance Measurements
Bag 2
AD(ml) FE(mpg) FC(gpm) AD(mi)
3.820 36.34 0.0275 3.536
3.816 36.34 0.0275 3.554
3.824 36.00 0.0278 3.564
Warm-Up HFET
AD(mi) FE(mpg) FC(gpm) AD(mi)
10.150 42.28 0.0237 10.138
10.130 42.48 0.0235 10.146
10.152 42.26 0.0237 10.050
3C 10.111
s 0.053
s/x(%) 0.5
Bag 3
FE(mpg)
38.32
37.50
37.70
HFET
FE(mpg)
44.34
43.92
45.60
44.62
0.87
2.0
FC( gpm)
0.0261
0.0267
0.0265
FC(gpm)
0.0226
0.0228
0.0219
0.0224
0.0005
2.1
[1] Dynamometer adjusted using curved track coastdown times.
-------
Table D-47
Honda Civic Data
Dynamometer Results -.Rolls Coupled,
Bag 1
FE(mpg) FC( gpm)
31.66 0.0316
30.65 0.0326
29.85 0.0335
FTP-Composite
FE(mpg) FC(gpm)
35.06 0.0285
34.54 0.0290
32.50 0.0308
x 34.03 0.0294
s 1.35 0.0012
Bag
FE(mpg)
35.55
35.48
32.53
Warm-Up
FE(mpg)
41.48
41.28
39.75
Volumetric Measurements
2
FC( gpm)
0.0281
0.0282
0.0307
HFET
FC(gpm)
0.0241
0.0242
0.0252
X
s
Bag 3
FE(mpg) FC(gpm)
36.72 0.0272
35.92 0.0278
34.60 0.0289
HFET
FE(mpg) FC(gpm)
44.07 0.0227
43.61 0.0229
40.97 0.0244
42.88 0.0233
1.67 0.0009
s/x(%) 4.0
4.1
3.9
4.0
-------
Table D-48
Honda Civic Data[l]
Dynamometer
FE(mpg)
31.88
31.52
29.77
Results - Rolls Coupled,
Bag I
FC(gpm)
0.0314
0.0317
0.0336
FTP -Composite
FE(mpg)
34.83
34.18
x 34.51
s 0.46
s/x(%) 1.3
FC(gpm)
0.0287
0.0293
0.0290
0.0004
1.5
Bag
FE(mpg)
35.50
35.39
Warm-Up
FE(mpg)
41.05
41.72
41.05
Volumetric Measurements
2
FC(gpm)
0.0282
0.0283
HFET
FC(gpm)
0.0224
0.0240
0.0244
X
s
/ S W \
S j X^ /Q j
FE(mpg)
36.54
36.27
35.61
Bag 3
FC(gpm)
0.0274
0.0276
0.0281
HFET
FE(mpg)
44.11
44.19
44.98
44.43
0.48
1.1
FC(gpm)
0.0227
0.0226
0.0222
0.0225
0.0003
1.2
[1] Dynamometer adjusted using curved track coastdown times
-------
Table E-l
Coastdown Data
Vehicle Oldsmobile Cutlass
Coastdown Type Track-straight
Test Date 10-22-80
Tire Pressure (psi) 26/26
Ambient Temp (°F) 60
Barometer (in Hg) 29.79
Test Weight (Ibm) 3974
Drive Axle Wt. (Ibm) 1702
Driving Rotating Equivalent (Ibm) 7_2_
Non-Driving Rotating Equivalent (Ibm) 68
Total Weight (test wt. + rotating equivalent, Ibm) 4113
Uncorrected Data
Coastdown Time (sec) 15.31
F0 (Ibf) 45.1
F2 (Ibf-sec2/ft2) 0.0145
Corrected Data
Coastdown Time (sec) 15.97
F0 (Ibf) 43.3
F2 (Ibf-sec2/ft2) 0.0139
Dynamometer Corrected Results
Mass Correction (Ibm) 4072 (4000 + 72)
Dynamometer Coastdown Time (sec) 15.81
-------
Table E-2
Coastdown Data
Vehicle Oldsmobile Cutlass
Coastdown Type Track-curved
Test Date 10-22-80
Tire Pressure (psi) 26/26
Ambient Temp (°F) 59
Barometer (in Hg) 29.80
Test Weight (Ibm) 3953
Drive Axle Wt. (Ibm) 1686
Driving Rotating Equivalent (Ibm) 71
Non-Driving Rotating Equivalent' (Ibm) 67
Total Weight (test wt. + rotating equivalent, Ibm) 4091
Uncorrected Data
Coastdown Time (sec) 14.74
F0 (Ibf) 44.4
F2 (Ibf-sec2/ft2) 0.0152
Corrected Data
Coastdown Time (sec) 15.41
F0 (Ibf) 44.0
F2 (Ibf-sec2/ft2) 0.0144
Dynamometer Corrected Results
Mass Correction (Ibm) 4071 (4000 + 71)
Dynamometer Coastdown Time (sec) 15.34
-------
Table E-3
Coastdown Data
Vehicle Oldsmobile Cutlass
Coastdown Type Dyno-straight, coupled
Test Date 3-9-81
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 4000 (3959)
Drive Axle Wt. (Ibm) 1669
Driving Rotating Equivalent (Ibm) 71_
Non-Driving Rotating Equivalent (Ibm) ~-
Total Weight (test wt. + rotating equivalent, Ibm) 4071
Uncorrected Data
Coastdown Time (sec) 16.23
F0 (Ibf) 44.5'
F2 (Ibf-sec2/ft2) 0.0131
Corrected Data
Coastdown Time (sec) 16.23
F0 (Ibf) 44.5
F2 (Ibf-sec2/ft2) 0.0131
Dynamometer Corrected Results
Mass Correction (Ibm) 4071
Dynamometer Coastdown Time (sec) 16.23
-------
Table E-4
Coastdown Data
Vehicle Oldsmobile Cutlass
Coastdown Type Dyno-straight, uncoupled
Test Date 3-9-81
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 4000 (3959)
Drive Axle Wt. (Ibm) 1669
Driving Rotating Equivalent (Ibm) 71_
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 4071
Uncorrected Data
Coastdown Time (sec) 16.34
F0 (Ibf) 40.0'
F2 (Ibf-sec2/ft2) 0.0138
Corrected Data
Coastdown Time (sec) 16.34
F0 (Ibf) 40.0
F2 (Ibf-sec2/ft2) 0.0138
Dynamometer Corrected Results
Mass Correction (Ibm) 4071
Dynamometer Coastdown Time (sec) 16.34
-------
Table E-5
Coastdown Data
Vehicle
Ford Pinto
Coastdown Type
Test Date
Track-s traight
10-19-80
Tire Pressure (psi)
Ambient Temp (°F)
Barometer (in Hg)
Test Weight (Ibm)
24/24
30.05
3091
Drive Axle Wt. (Ibm)
1341
Driving Rotating Equivalent (Ibm)
56
Non-Driving Rotating Equivalent (Ibm)
53
Total Weight (test wt. + rotating equivalent, Ibm)
3200
Uncorrected Data
Coastdown Time (sec)
F0 (Ibf) '
11.65
59.3'
'(Ibf-sec2/ft2)
0.0123
Corrected Data
Coastdown Time (sec)
F0 (Ibf)
12.33
56.0
F2 (Ibf-sec2/ft2)
0.0116
Dynamometer Corrected Results
Mass Correction (Ibm)
3056 (3000 + 56)
Dynamometer Coastdown Time (sec)
11.78
-------
Table E-6
Coastdown Data
Vehicle
Ford Pinto
Coastdown Type
Test Date
Track-curved
11-19-80
Tire Pressure (psi)
Ambient Temp (°F) _
Barometer (in Hg) _
Test Weight (Ibm)
24/24
50
30.04
3084
Drive Axle Wt. (Ibm)
1338
Driving Rotating Equivalent (Ibm)
56
Non-Driving Rotating Equivalent (Ibm)
52
Total Weight (test wt. + rotating equivalent, Ibm)
3192
Uncorrected Data
Coastdown Time (sec)
F0 (Ibf)
11.22
59.7'
F2 (Ibf-sec2/ft2)
Corrected Data
Coastdown Time (sec)
0.0131
12.12
F0 (Ibf)
53.9
F2 (Ibf-sec2/ft2)
0.0124
Dynamometer Corrected Results
Mass Correction (Ibm)
3056 (3000+56)
Dynamometer Coastdown Time (sec)
11.60
-------
Table E-7
Coastdown Data
Vehicle Ford Pinto
Coastdown Type Dyno-straight, coupled
Test Date 3-10-81
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 3000 (3091)
Drive Axle Wt. (Ibm) 1294
Driving Rotating Equivalent (Ibm) 56
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 3056
Uncorrected Data
Coastdown Time (sec) 11.32
F0 (Ibf) 44.7
F2 (Ibf-sec2/ft2) 0.0136
Corrected Data
Coastdown Time (sec) 11.32
F0 (Ibf) 44.7
F2 (Ibf-sec2/ft2) 0.0136
Dynamometer Corrected Results
Mass Correction (Ibm) 3056
Dynamometer Coastdown Time (sec) 11.32
-------
Table E-8
Coastdowtx Data
Vehicle Ford Pinto
Coastdown Type Dyno-straight, uncoupled
Test Date 3-10-81
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 3000 (3091)
Drive Axle Wt. (Ibm) 1294
Driving Rotating Equivalent (Ibm) 56
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 3056
Uncorrected Data
Coastdown Time (sec) 12.06
F0 (Ibf) 38.4'
F2 (Ibf-sec2/ft2) 0.0134
Corrected Data
Coastdown Time (sec) 12.06
F0 (Ibf) 38.4
F2 (Ibf-sec2/ft2) 0.0134
Dynamometer Corrected Results
Mass Correction (Ibm) 3056
Dynamometer Coastdown Time (sec) 12.06
-------
Table E-9
Coastdown Data
Vehicle Ford F-100
Coastdown Type Track-straight
Test Date 5-25-81
Tire Pressure (psi) 35/35
Ambient Temp (°F) 78
Barometer (in Hg) 29.62
Test Weight (Ibm) 4153
Drive Axle Wt. (Ibm) 1707
Driving Rotating Equivalent (Ibm) 75
Non-Driving Rotating Equivalent (Ibm) 71
Total Weight (test wt. + rotating equivalent, Ibm) 4299
Uncorrected Data
Coastdown Time (sec) 12.56
F0 (Ibf) 48.7"
F2 (Ibf-sec2/ft2) 0.0201
Corrected Data
Coastdown Time (sec) 12.53
F0 (Ibf) 49.7
F2 (Ibf-sec2/ft2) 0.0200
Dynamometer Corrected Results
Mass Correction (Ibm) 4325 (4250 + 75)
Dynamometer Coastdown Time (sec) 12.61
-------
Table E-10
Coastdown Data
Vehicle Ford F-100
Coastdown Type Track-curved
Test Date 6-18-81
Tire Pressure (psi) 35/35
Ambient Temp (°F) 79
Barometer (in Hg) 29.70
Test Weight (Ibm) 4171
Drive Axle Wt. (Ibm) 1726
Driving Rotating Equivalent (Ibm) 75
Non-Driving Rotating Equivalent (Ibm) 71
Total Weight (test wt. + rotating equivalent, Ibm) 4317
Uncorrected Data
Coastdown Time (sec) 12.41
F0 (Ibf) 55.0"
F2 (Ibf-sec2/ft2) 0.0194
Corrected Data
Coastdown Time (sec) 12.22
F0 (Ibf) , 57.8
F2 (Ibf-sec2/ft2) 0.0193
Dynamometer Corrected Results
Mass Correction (Ibm) 4325 (4250 + 75)
Dynamometer Coastdown Time (sec) 12.24
-------
Table E-ll
Coastdown Data
Vehicle Ford F-100
Coastdown Type Dyne-straight, coupled
Test Date 8-13-81
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 4250 (4214)
Drive Axle Wt. (Ibm) 1735
Driving Rotating Equivalent (Ibm) 76
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 4326
Uncorrected Data
Coastdown Time (sec) 13.10
F0 (Ibf) 47.7"
F2 (Ibf-sec2/ft2) 0.0190
Corrected Data
Coastdown Time (sec) 13.10
F0 (Ibf) 47.7
F2 (Ibf-sec2/ft2) 0.0190
Dynamometer Corrected Results
Mass Correction (Ibm) 4326
Dynamometer Coastdown Time (sec) 13.10
-------
Table E-16
Coastdown Data
Vehicle Chevrolet Citation
Coastdown Type Dyno-straight, uncoupled
Test Date 6-11-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 3000 (3105)
Drive Axle Wt. (Ibm) 2009
Driving Rotating Equivalent (Ibm) 56
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 3056
Uncorrected Data
Coastdown Time (sec) 13.28
F0 (Ibf) 35.8
F2 (Ibf-sec2/ft2) 0.0129
Corrected Data
Coastdown Time (sec) 3056
F0 (Ibf) 35.8
F2 (Ibf-sec2/ft2) .. 0.0129
Dynamometer Corrected Results
Mass Correction (Ibm) 3056
Dynamometer Coastdown Time (sec) 13.28
-------
Table E-12
Coastdown Data
Vehicle Ford F-100
Coastdown Type Dyno-straight, uncoupled
Test Date 7-27-81
Tire Pressure (psi) 45
Ambient Temp (°F) ' 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 4250 (4175)
Drive Axle Wt. (Ibm) 1732
Driving Rotating Equivalent (Ibm) 75
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 4325
Uncorrected Data
Coastdown Time (sec) 13.05
F0 (Ibf) 47.6'
F2 (Ibf-sec2/ft2) 0.0194
Corrected Data
Coastdown Time (sec) 13.05
F0 (Ibf) ; 47.6
F2 (Ibf-sec2/ft2) 0.0194
Dynamometer Corrected Results
Mass Correction (Ibm) 4325
Dynamometer Coastdown Time (sec) 13 .05
-------
Table E-13
Coastdown Data
Vehicle
Chevrolet Citation
Coastdown Type
Test Date
Track-s traight
10-16-81
Tire Pressure (psi)
Ambient Temp (°F)
Barometer (in Hg)
Test Weight (Ibm)
26/26
87
29.69
3108
Drive Axle Wt. (Ibm)
1989
Driving Rotating Equivalent (Ibm)
56
Non-Driving Rotating Equivalent (Ibm)
53
Total Weight (test wt. + rotating equivalent, Ibm)
3217
Uncorrected Data
Coastdown Time (sec)
F0 (Ibf)
15.16
32.2'
F2 (Ibf-sec2/ft2)
0.0121
Corrected Data
Coastdown Time (sec)
F0 (Ibf)
14.63
34.9
F2 (Ibf-sec2/ft2)
0.0122
Dynamometer Corrected Results
Mass Correction (Ibm)
3056 (3000 + 56)
Dynamometer Coastdown Time (sec)
13.90
-------
Table E-14
Coastdown Data
Vehicle Chevrolet Citation
Coastdown Type Track-curved
Test Date __ 2-11-82
Tire Pressure (psi) 26/26
Ambient Temp (°F) 59
Barometer (in Hg) 29.86
Test Weight (Ibm) 3113
Drive Axle Wt. (Ibm) 1978
Driving Rotating Equivalent (Ibm) 56_
Non-Driving Rotating Equivalent (Ibm) 53
Total Weight (test wt. + rotating equivalent, Ibm) 3222
Uncorrected Data
Coastdown Time (sec) 13.81
F0 (Ibf) 36.6
F2 (Ibf-sec2/ft2) 0.0130
[ <•>
Corrected Data
Coastdown Time (sec) 14.54
F0 (Ibf) 36.3
F2 (Ibf-sec2/ft2) 0.0121
Dynamometer Corrected Results
Mass Correction (Ibm) 3056 (3000 + 56)
Dynamometer Coastdown Time (sec) 13.79
-------
Table E-15
Coastdown Data
Vehicle Chevrolet Citation
Coastdown Type Dyno-straight, coupled
Test Date 5-31-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 3000 (3101)
Drive Axle Wt. (Ibm) 2005
Driving Rotating Equivalent (Ibm) 56.
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 3056
Uncorrected Data
Coastdown Time (sec) 13.29
F0 (Ibf) 41.5'
F2 (Ibf-sec2/ft2) 0.0118 -
Corrected Data
Coastdown Time (sec) 13.29
F0 (Ibf) 41.5
F2 (Ibf-sec2/ft2) 0.0118
Dynamometer Corrected Results
Mass Correction (Ibm) 3056
Dynamometer Coastdown Time (sec) 13.29
-------
Table E-17
Coastdown Data
Vehicle Ford Escort
Coastdown Type Track-straight
Test Date 4-26-82
Tire Pressure (psl) 35/35
Ambient Temp (°F) 80
Barometer (in Hg) 29.73
Test Weight (Ibm) 2434
Drive Axle Wt. (Ibm) 1444
Driving Rotating Equivalent (Ibm) 44
Non-Driving Rotating Equivalent (Ibm) 41
Total Weight (test wt. + rotating equivalent, Ibm) 2519
Uncorrected Data
Coastdown Time (sec) 13.50
F0 (Ibf) 25.Q-
F2 (Ibf-sec2/ft2) 0.0112
Corrected Data
Coastdown Time (sec) 13.74
F0 (Ibf) 25.7
F2 (Ibf-sec2/ft2) O.Q1Q8
Dynamometer Corrected Results
Mass Correction (Ibm) 2544 (2500 + 44)
Dynamometer Coastdown Time (sec) 13.87
-------
Table E-18
Coastdown Data
Vehicle Ford Escort
Coastdown Type Track-curved
Test Date 4-1-82
Tire Pressure (psi) 35/35
Ambient Temp (°F) 76
Barometer (in Hg) 29.81
Test Weight (Ibm) 2428
Drive Axle Wt. (Ibm) 1433
Driving Rotating Equivalent (Ibm) 44
Non-Driving Rotating Equivalent (Ibm) 41
Total Weight (test wt. + rotating equivalent, Ibm) 2513
Uncorrected Data
Coastdown Time (sec) . 13.19
F0 (Ibf) 27.8
F2 (Ibf-sec2/ft2) 0.0110
Corrected Data
Coastdown Time (sec) 13.16
FQ (Ibf) 28.8
F£ (Ibf-sec2/ft2) Q.0109
Dynamometer Corrected Results
Mass Correction (Ibm) 2544 (2500 + 44)
Dynamometer Coastdown Time (sec) 13.32
-------
Table E-19
Coastdown Data
Vehicle Ford Escort
Coastdown Type Dyno-straight, coupled
Test Date 6-1-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2500 (2422)
Drive Axle Wt. (Ibm) 1462
Driving Rotating Equivalent (Ibm) 44
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2544
Uncorrected Data
Coastdown Time (sec) 12.98
F0 (Ibf) 38.9
F2 (Ibf-sec2/ft2) 0.0094
Corrected Data
Coastdown Time (sec) 12.98
F0 (Ibf) 38.9
F2 (Ibf-sec2/ft2) 0.0094
Dynamometer Corrected Results
Mass Correction (Ibm) 2544
Dynamometer Coastdown Time (sec) 12.98
-------
Table E-20
Coastdown Data
Vehicle Ford Escort
Coastdown Type Dyno-straight, uncoupled
Test Date 6-11-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2500 (2422)
Drive Axle Wt. (Ibm) 1453
Driving Rotating Equivalent (Ibm). 44
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2544
Uncorrected Data
Coastdown Time (sec) 14.15
F0 (Ibf) 33.1
F2 (Ibf-sec2/ft2) 0.0091
Corrected Data
Coastdown Time (sec) 14.15
F0 (Ibf) 33.1
F2 (Ibf-sec2/ft2) 0.0091
Dynamometer Corrected Results
Mass Correction (Ibm) 2544
Dynamometer Coastdown Time (sec) 14.15
-------
Table E-21
Coastdown Data
Vehicle Plymouth Horizon
Coastdown Type Track-straight
Test Date 7-23-82
Tire Pressure (psi) 35/35
Ambient Temp (°F) 86
Barometer (in Hg) 29.80
Test Weight (Ibm) 2695
Drive Axle Wt. (Ibm) 1690
Driving Rotating Equivalent (Ibm) 49
Non-Driving Rotating Equivalent (Ibm) 46
Total Weight (test wt. + rotating equivalent, Ibm) 2789
Uncorrected Data
Coastdown Time (sec) 13.99
F0 (Ibf) 35.1
F2 (Ibf-sec2/ft2) 0.0104
Corrected Data
Coastdown Time (sec) 13.48
F0 (Ibf) 37.8
F2 (Ibf-sec2/ft2) 0.0106
Dynamometer Corrected Results
Mass Correction (Ibm) 2789 (2750 + 49)
Dynamometer Coastdown Time (sec) 13. 52
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Table E-22
Coastdown Data
Vehicle Plymouth Horizon
Coastdown Type Track-curved
Test Date 7-27-82
Tire Pressure (psi) 35/35
Ambient Temp (°F) 86
Barometer (in Hg) 29.84
Test Weight (Ibm) 2708
Drive Axle Wt. (Ibm) 1686
Driving Rotating Equivalent (Ibm) 49
Non-Driving Rotating Equivalent (Ibm) 46
Total Weight (test wt. + rotating equivalent, Ibm) 2803
Uncorrected Data
Coastdown Time (sec) 13.46
F0 (Ibf) 29.3
F2 (Ibf-sec2/ft2) 0.0123
Corrected Data
Coastdown Time (sec) 13.43
F0 (Ibf) 29.2
F2 (Ibf-sec2/ft2) 0.0123
Dynamometer Corrected Results
Mass Correction (Ibm) 2799
Dynamometer Coastdown Time (sec) 13.41
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Table E-23.
Coastdown Data
Vehicle Plymouth Horizon
Coastdown Type Dyno-straight, coupled
Test Date 8-20-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2750 (2689)
Drive Axle Wt. (Ibm) 1701
Driving Rotating Equivalent (Ibm) 48
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2798
Uncorrected Data
Coastdown Time (sec) 13.11
Fn (Ibf) 37.4
o
F2 (Ibf-sec2/ft2) 0.0113
Corrected Data
Coastdown Time (sec) 13.11
F0 (Ibf) 37.4
F2 (Ibf-sec2/ft2) 0.0113
Dynamometer Corrected Results
Mass Correction (Ibm) 2798 (2750 + 48)
Dynamometer Coastdown Time (sec) 13.11
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Table E-24
Coastdown Data
Vehicle Plymouth Horizon
Coastdown Type Dyne-straight, uncoupled
Test Date 8-26-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2750 (2689)
Drive Axle Wt. (Ibm) 1734
Driving Rotating Equivalent (Ibm) 48
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2798
Uncorrected Data
Coastdown Time (sec) 13.21
F0 (Ibf) 39.7
F2 (Ibf-sec2/ft2) 0.0107
Corrected Data
Coastdown Time (sec) 13.21
F0 (Ibf) ' 39.7
F2 (Ibf-sec2/ft2) 0.0107
Dynamometer Corrected Results
Mass Correction (Ibm) 13.21
Dynamometer Coastdown Time (sec) 2798 (2750 + 48)
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Table E-25
Coastdown Data
Vehicle AMC Concord
Coastdown Type Track-straight
Test Date 7-28-82
Tire Pressure (psi) 28/28
Ambient Temp (°F) 89
Barometer (in Hg) 29.81
Test Weight (Ibm) 3508
Drive Axle Wt. (Ibm) 1493
Driving Rotating Equivalent (Ibm) 63
Non-Driving Rotating Equivalent (Ibm) 60
Total Weight (test wt. + rotating equivalent, Ibm) 3631
Uncorrected Data
Coastdown. Time (sec) 15.20
Fn (Ibf) 35.9
o
F2 (Ibf-sec2/ft2) 0.0137
Corrected Data
Coastdown Time (sec) 14.67
F0 (Ibf) 39.0
o
F2 (Ibf-sec2/ft2) 0.0138
Dynamometer Corrected Results
Mass Correction (Ibm) 3563 (3500 + 63)
Dynamometer Coastdown Time (sec) 14.39
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Table E-26
Coastdown Data
Vehicle AMC Concord
Coastdown Type Track-curved
Test Date 7-27-82
Tire Pressure (psi) 28/28
Ambient Temp (°F) 79
Barometer (in Hg) 29.74
Test Weight (Ibm) 3493
Drive Axle Wt. (Ibm) 1488
Driving Rotating Equivalent (Ibm) i 63
Non-Driving Rotating Equivalent (Ibm) 59
Total Weight (test wt. + rotating equivalent, Ibm) 3615
Uncorrected Data
Coastdown Time (sec) 14.49
Fn (Ibf) 37.4
F2 (Ibf-sec2/ft2) 0.0143
Corrected Data
Coastdown Time (sec) 14. 31
F0 (Ibf) 39.2
F2 (Ibf-sec2/ft2) 0.0142
Dynamometer Corrected Results
Mass Correction (Ibm) 3563 (3500 + 63)
Dynamometer Coastdown Time (sec) 14.11
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Table E-27
Coastdown Data
Vehicle AMC Concord
Coastdown Type Dyno-straight, coupled
Test Date 8-20-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 3508
Drive Axle Wt. (Ibm) 1463
Driving Rotating Equivalent (Ibm) 63
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 3563
Uncorrected Data
Coastdown Time (sec) 13.50
F0 (Ibf) 32.1
F2 (Ibf-sec2/ft2) 0.0165
Corrected Data
Coastdown Time (sec) 13.50
F0 (Ibf) 32.1
F2 (Ibf-sec2/ft2) 0.0165
Dynamometer Corrected Results
Mass Correction (Ibm) 3563
Dynamometer Coastdown Time (sec) 13.50
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Table E-28
Coastdown Data
Vehicle
AMC Concord
Coastdown Type Dyno-straight, uncoupled
Test Date 8-25-82
Tire Pressure (psi)
Ambient Temp (°F) _
Barometer (in Hg) _
Test Weight (Ibm)
45
68
29.00
3508
Drive Axle Wt. (Ibm)
1442
Driving Rotating Equivalent (Ibm)
63
Non-Driving Rotating Equivalent (Ibm)
60
Total Weight (test wt. + rotating equivalent, Ibm)
3563
Uncorrected Data
.Coastdown Time (sec)
Fn (Ibf) 32.4
13.55
F2 (Ibf-sec2/ft2) 0.0164
Corrected Data
Coastdown Time (sec)
13.55
F0 (Ibf) 32.4
F2 (Ibf-sec2/ft2)
0.0164
Dynamometer Corrected Results
Mass Correction (Ibm)
3563
Dynamometer Coastdown Time (sec)
13.55
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Table E-29
Coastdown Data
Vehicle Honda Civic
Coastdown Type Track-straight
Test Date 10-01-82
Tire Pressure (psi) 32/32
Ambient Temp (°F) 81
Barometer (in Hg) 29.78
Test Weight (Ibm) 2277
Drive Axle Wt. (Ibm) 1334
Driving Rotating Equivalent (Ibm) 41
Non-Driving Rotating Equivalent (Ibm) 39
Total Weight (test wt. + rotating equivalent, Ibm) 2357
Uncorrected Data
Coastdown Time (sec) 12.65
F0 (Ibf) 27.7
F2 (Ibf-sec2/ft2) 0.0107
Corrected Data
Coastdown Time (sec) 12.49
F0 (Ibf) 29.8
F2 (Ibf-sec2/ft2) 0.0105
Dynamometer Corrected Results
Mass Correction (Ibm) 2291 (2250 + 41)
Dynamometer Coastdown Time (sec) 12.14
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Table E-30
Coastdown Data
Vehicle Honda Civic
Coastdown Type Track-curved
Test Date 10-04-82
Tire Pressure ( psi) 32/32
Ambient Temp (°F) 80
Barometer (in Hg) 29.72
Test Weight (Ibm) 2276
Drive Axle Wt. (Ibm) 1332
Driving Rotating Equivalent (Ibm) 41
Non-Driving Rotating Equivalent (Ibm) 39
Total Weight (test wt. + rotating equivalent, Ibm) 2356
Uncorrected Data
Coastdown Time (sec) 12.50
F0 (Ibf) 24.6
F2 (Ibf-sec2/ft2) 0.0115
Corrected Data
Coastdown Time (sec) . .12.32
F0 (Ibf) 25.9
F2 (Ibf-sec2/ft2) 0.0115
Dynamometer Corrected Results
Mass Correction (Ibm) 2291 (2250 + 41)
Dynamometer Coastdown Time (sec) 11.98
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Table E-31
i
Coastdown Data
Vehicle Honda Civic
Coastdown Type Dyno-straight, coupled
Test Date 10-25-82
Tire Pressure (psi) 45
Ambient Temp (°F) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2250
Drive Axle Wt. (Ibm) 1335
Driving Rotating Equivalent (Ibm) 40
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2290
Uncorrected Data
Coastdown Time (sec) 12.065
F0 (Ibf) 25.8
F2 (Ibf-sec2/ft2) 0.0112
Corrected Data
Coastdown Time (sec) • 12.065
F0 (Ibf) 25.8
F2 (Ibf-sec2/ft2) 0.0112
Dynamometer Corrected Results
Mass Correction (Ibm) 2290
Dynamometer Coastdown Time (sec) 12.065
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Table E-32
Coastdown Data
Vehicle Honda Civic
Coastdown Type Dyno-straight, uncoupled
Test Date 10-12-82
Tire Pressure (psi) 45
Ambient Temp ( °F ) 68
Barometer (in Hg) 29.00
Test Weight (Ibm) 2250
Drive Axle Wt. (Ibm) 1334
Driving Rotating Equivalent ( Ibm) 40
Non-Driving Rotating Equivalent (Ibm) —
Total Weight (test wt. + rotating equivalent, Ibm) 2290
Uncorrected Data
Coastdown Time (sec) 12.07
F0 (Ibf) 26.3
F2 (Ibf-sec2/ft2) 0.0110
Corrected Data
Coastdown Time (sec) 12.07
F0 (Ibf) 26.3
F2 (Ibf-sec2/ft2) 0.0110
Dynamometer Corrected Results
Mass Correction ( Ibm) 2290 ^^^
Dynamometer Coastdown Time ( sec) 12 .07
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