HIGH ALTITUDE VEHICULAR EMISSION CONTROL PROGRAM
VOLUME XI STUDY OF EMISSION DETERIORATION
AND ENGINE DEGRADATION
PREPARED FOR:
STATE OF COLORADO
DEPARTMENT OF HEALTH
DENVER, COLORADO 80220
/AUT0M0TIVE
ATI/ testing
-------
I HIGH ALTjlUDE VEHICULAR EMISSION CONTROL PROGRAM
VOLUME XI STUDY OF EMISSION DETERIORATION
AND ENGINE DEGRADATION
*9
02-45"
PREPARED FOR:
STATE OF COLORADO
DEPARTMENT OF HEALTH
DENVER, COLORADO 80220
/automotive
ATL/ TESTING
-------
REPORT
on
Emission Deterioration
and
Engine Degradation
Six Month Report
for
State of Colorado
Department of Health
June, 197^
prepared by
Automotive Testing Laboratories, Inc.
19900 East Colfax Avenue
Aurora, Colorado 80011
-------
1. INTRODUCTION
In accordance with the requirements of the Colorado Depart-
ment of Health, a High Altitude Vehicular Emission Control Program
has been initiated. The objective of the program is to develop
and implement a plan for the control of motor vehicle emissions.
As part of the overall program, a project involving a sample of
1964-1973 model-year vehicles was begun in July of 1973. The project
was designed to evaluate several strategies for the control of emis-
sions from motor vehicles. Investigations included emission inspection
and engine maintenance, emission control retrofit, modification to
engine tune-up specifications and mandatory engine maintenance.
As the project developed, it became apparent that much of the data
generated by the program could be utilized for purposes outside the
initial scope of the project. A program to evaluate emission
deterioration and engine degradation was subsequently designed and
implemented. The project, involving the re-test of vehicles
available at the conclusion of two consecutive six month intervals,
recently progressed beyond mid-point.
This report has been prepared to present in summary form the
results of testing to date. A more comprehensive report prepared
through the joint efforts of TRW, Inc. and Automotive Testing Lab-
oratories, Inc. is forthcoming.
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2. TECHNICAL DISCUSSION
2.1 PROGRAM OBJECTIVES
The primary objective of the study is to develop emission
deterioration factors which are to be utilized to evaluate the
long term benefits of a mandatory idle inspection and maintenance
program. In this respect, data derived from the study are to be
applied to define a cost-effective idle inspection and maintenance
frequency. A secondary objective is to determine the extent of
owner tampering as may impact on the effectiveness of an inspection/
maintenance program and to determine possible legislative requirements to
maintain overall effectiveness of a mandatory program.
2.2 PROGRAM DESIGN
The program was designed to utilize a preconditioned and pretested
sample of vehicles from which various data, pertinent to program
objectives, could be obtained.
A sample of three-hundred 1964 through 1973 model-year vehicles,
selected to represent that segment of the Colorado light-duty vehicle
(under 6000 lbs GVT-7) population, were used initially to evaluate
idle inspection and maintenance, emission control retrofit and mandatory
engine maintenance. This segment represented about 90%
of the light-duty vehicle population. All vehicles in the sample
were initially subjected to inspection and maintenance. Idle
emission inspections were performed at ten selected state licensed
motor vehicle safety inspection stations. Station personnel were
trained in advance and were required to perform inspection and
maintenance of vehicles in accordance with specific procedures.
All vehicles were laboratory tested in the as-received condition
-------
before delivery to the stations. Vehicles which failed station
inspection and were subsequently repaired were re-tested by
laboratory procedures to determine the effectivenss of station
performance. A segment of the vehicle sample was then utilized
to evaluate emission control retrofit and modified tune-up
specifications.
Following the laboratory evaluation of inspection/maintenance
procedures, selected vehicles were inspected more extensively.
Repairs were performed by laboratory personnel as dictated by
inspection results, and engine control parameters were adjusted
to the specifications recommended by the vehicle manufacturer.
One subsample of vehicles was used to evaluate emission control
retrofit systems; another was used to evaluate modified tuning
specifications. Subsequently, data derived as a result of further
testing on both subsamples were used to evaluate effectiveness of a
concept of mandatory engine maintenance. All vehicles, including
those used exclusively for evaluation of idle inspection and main-
tenance CX/H) and those used for I/M evaluation and evaluation of
mandatory engine maintenance (M/M) were then set-up in preparation
for the emission deterioration and engine degradation phase of the
project.
After initial-phase testing was completed on a given vehicle,
the vehicle was moved to a staging area where post-test engine
adjustment sealing and engine component marking operations were per-
formed. A bead of quick drying enamel paint was applied by means
of a syringe and plunger assembly to screw and nut type engine adjust-
ments. Using the same apparatus, a spot of paint was applied to
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identify certain emission related component parts. Subsequently,
final engine diagnostic procedures were performed and outgoing engine
data were recorded. The completed vehicle was then turned back
to its owner accompanied by a letter of appreciation for partici-
pation and a request for continued cooperation during the deterior-
ation phase of the project. In addition, the letter contained a
description of the follow-on study, a commitment by Automotive Testing
Laboratories, Inc. to perform emission related engine maintenance
for a six month interval and a list of engine parts, components
and adjustments which were covered by the maintenance commitment.
Details of the sealing and identification procedure and a copy of
the letter of commitment are presented in Appendix 1.
Although three-hundred vehicles comprised the initial sample,
the potential size of the sample available for re-test was reduced
to about two-hundred and fifty vehicles. This reduction, numbering
about fifty vehicles, came about as a result of an initial loss of
several vehicles which had been tested and released to owners prior
to start-up of the deterioration study. A number of other vehicles
comprising the initial sample were determined to be unsulted for
deterioration study purposes for various other reasons.
During the time interval following Initial testing, vehicles
comprising the test sample were presumably operated in a typical
manner although several existing factors undoubtedly had some
Impact on mid-point results. Weather conditions during the interval
(August, 1973 through May, 1984), for example, were for the most part
seasonably cold and presumably had an indirect effect on engine
warm-up characteristics, mileage accumulation and maintenance
requirements. Additionally, the fuel crisis and attendant factors,
-------
were predominant thoughout much of the study Interval and are
believed to have potentially biasing effects on study results by
altering mileage accumulation patterns, fuel preference and
overall vehicle useage. The effects of these variables are virtually
impossible to evaluate. In any case, however, the project proceeded
according to design.
In planning for the interval which followed initial testing,
procedures for handling test vehicles exhibiting undesirable operating
characteristics or component failure were devised. A maintenance
commitment was estabished and communicated to the vehicle owner
via the letter agreement described earlier. A vehicle prematurely
returned to the laboratory for repair work was subjected to an on-
the-spot Inspection to establish the validity of a request for
repair. In certain situations, owner disatisfaction with some
aspect of vehicle performance proved to be unfounded. In other
situations, a legitimate requirement for maintenance did in fact
exist. In the latter case, a loan car was issued and the test vehicle
v a retained for further testing and maintenance. In this case, a
series of tests, identical to those performed initially, was conducted,
repairs to the vehicle were completed and the vehicle was returned to its
owner. Data developed as a result of these procedures were retained
for subsequent processing and reporting.
As reported earlier, two hundred and fifty vehicles of the
original sample were judged suitable for retest. It was originally
anticipated that a significant number of vehicles would be
lost to the program for various reasons incuding transfer of
ownership, owner relocation, accidents and negative owner reaction
-------
or loss of interest. In this respect an attrition rate of AO percent
was allowed.
After the nominal interval of six months had elapsed, vehicles
were recalled for deterioration and degradation testing. An attempt
to maintain an Initial tolerance of 180 + 5 days proved to be imprac-
tical. The tolerance was subsequently relaxed to 180 + 10 days to
maintain a high retest rate.
At the appropriate time, one or more attempts to contact
owners whose vehicles qualified for retest were made. As anticipated,
a significant number of owners had moved outside the area, had
sold the test vehicle, had expressed dissatisfaction with some aspect of
the program or had simply became disinterested. On the other hand, a
significant number of vehicles remained available. The remaining
vehicles, numbered at 165, were recalled and retested. Testing pro-
cedures, Identical to those performed initially, were then applied.
At test completion seals applied to engine adjustments and identification
marks applied to emission related components were inspected and the
incoming status of each adjustment and component part was recorded.
Data were then processed and compiled.
Throughout the retest phase of the program laboratory instrumentation
and equipment calibration and operating procedures were maintained
in accordance with standards applied in the initial program. Quality
control tolerances were similarly maintained and procedures relating
to data auditing were applied.
2.3 TEST VEHICLES
Three hundred vehicles were Initially selected and utilized to rep-
resent the 1964 through 1973 Colorado motor vehicle population.
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Approximately two hundred and fifty were prepared for the deterioration
study phase. As anticipated, a significant level of attrition
occured during the six month period and one-hundred and sixty-five
vehicles were actually submitted for retest.
2.3.1 Vehicle Sample Composition
Table 1 shows the distribution of vehicles subjected to retest.
Model-Year
73
72
71
70
69
68
67
66
65
64
Total
Make
Ammo
0
1
1
1
0
1
0
1
0
1
6
Buic
0
0
1
0
0
2
1
0
1
1
6
Cadi
0
0
0
1
0
0
0
0
2
1
4
Chev
6
4
3
3
2
2
5
5
5
5
40
Chry
0
1
1
1
0
0
1
1
0
0
5
Dodg
1
1
0
1
1
1
1
1
0
1
8
Ford
4
4
6
3
2
4
6
5
7
2
43
Merc
0
1
0
0
1
1
1
0
1
0
5
Olds
1
0
0
1
0
1
1
1
1
1
7
Plym
1
3
1
2
2
1
1
1
0
*
13
Pont
1
1
1
1
1
0
3
2
2
0
12
Volk
0
1
1
2
0
2
0
2
1
0
9
Toyo
1
0
1
1
1
0
0
0
0
0
4
Dats
0
0
1
0
0
0
0
0
0
0
1
Opel
1
1
0
0
0
0
0
0
0
0
2
Total
16
13
17
17
10
15
20
18
20
14
165
Table 1. Distribution of Sample after 6 Months
In a comparison of the initial sample (Table 2. Volume II)
versus the sample shown in Table 1., above, it can be
seen that the retested sample approximates the initial sample by
a factor of 0.5 by both make and model-year. From this comparison
it can be concluded that the retested sample approximates the
distribution of light-duty vehicles in Colorado.
2.3.2 Vehicle Preparation and Handling
Upon receipt of the vehicle for retest, an inspection of the
vehicle exterior, interior and exhaust system was performed to
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determine incoming status. A loan car was issued to replace the test
vehicle and the necessary vehicle agreement forms were completed.
The vehicle was then moved to the laboratory for temperature
soaking prior to emission testing and engine inspection.
After a minimum soak period of twelve hours, the vehicle fuel
supply system was disconnected and reconnected to a laboratory fuel
supply system. A batch of summer-grade fuel, utilized for initial
testing had been retained and was used to perform the retests.
Emission tests were then performed, the vehicle was relocated
to another area in the laboratory and an inspection of engine components
and adjustments was completed. The vehicle was then returned to
its owner.
2.4 LABORATORY TESTING AND EVALUATION
Procedures employed for retest were identical to those applied
initially.
2.4.1 Exhaust Emission Testing Procedures
Laboratory standard exhaust emission tests were performed in
accordance with procedures outlined in Federal Register, Volume 33,
Number 124, Part III, dated June 28, 1973. Standard tests were
preceeded by a minimum 12 hour temperature soal: at laboratory
ambient conditions (68° F to 72° F).
Key mode tests were performed in accordance with procedures
outlined by Clayton Ilanufacturing Company of El Monte, California.
Key mode testing and resulting data have no direct bearing on the
objectives of this phase of the study but were included in the
test procedure merely to expand the data base.
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Idle emission testing was performed in conjunction with key
mode testing. Emission samples were taken at no load conditions of
curb idle (Drive gear for automatic transmission equipped vehicles)
and 2500 engine rpm. Instrumentation and operating procedures were
identical to those employed during the initial phase of testing.
Both laboratory and garage-type inspection equipment (listed in
Table 5 of Volume II) were employed.
Instrument and equipment calibrations established in the initial
testing phase were maintained throughout the retest interval.
Analytical system calibrations were established using an inventory
of EPA named gases. Flow calibration of the CVS was verified
using the laminar flow element with calibration traceable to
the National Bureau of Standards. Dynamometer calibrations were
established and verified on a regular basis using the coast-down
technique. In addition, propane recovery tests, N0X converter
efficiency checks and analytical system leak checks were performed
on a daily basis.
2.4.2 Engine Diagnostic Procedures
Diagnoses of engine conditions were performed at two points in
the overall vehicle procedure. During key mode operation on the
Cassis dynamometer the laboratory analytical system recorders were
operational for a period of about one minute. During this interval
and during periods of speed changes, emission traces were observed
for an indication of malfunction evidenced by abnormally high
hydrocarbon (HC) or carbon monoxide (CO) levels. The HC trace
also provided an indication of ignition system mis-fire. Observations
were recorded. Oxides of nitrogen (N0X) emission controls on applicable
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vehicles were also inspected for proper operation during key mode
testing. A fully operational system was indicated by the absence
of vacuum to the distrubutor at low cruise conditions and the
presence of vacuum to the distributor at high cruise conditions.
The second point at which diagnostic procedures were applied was
immediately after dynamometer tests were completed. The vehicle
was removed from the dynamometer area and a more extensive diagnostic
procedure was applied. Concurrently, the inspection to determine the
extent of tampering and alteration or replacement of parts was
performed.
2.5 DATA HANDLING
Data handling, processing and auditing procedures employed for
the retest phase were identical to those employed for the initial
test phase. These procedures are described in detail in Volume II.
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5. analysis of test results
As testing progressed It became apparent that a relatively
complex situation had developed* A discussion of some of the
more obvious problems with respect to the interpretation of
deterioration data is presented below. Interim study report data
are also presented in summary form.
5.1 POSSIBLE FACTORS AFFECTING EMISSION DETERIORATION
As of this date, two studies investigating the feasibility of
emission inspection and maintenance have been completed at altitude.
Both studies Indicate that maximum HC and CO emission reductions
through normal maintenance are in the order of 15% and 10% respectively
as compared to reductions In the Los Angeles area, for example, of
35% for each effluent.3 These figures indicate that in spite of
the altitude factor, Denver area vehicles are closer to an Ideal
state of repair than vehicles in the Los Angeles area.
As indicated in a recent study Involving vehicle tests in three
cities,^ two of which (Chicago and Houston) were situated at
roughly the same elevation but in differing cllmatological areas,
climate appears to have a significant effect on emission levels.
Although the sample composition was essentially the same in both
sites, average HC and CO emissions were lower from vehicles operating
.n the colder climate of the Chicago area than emissions from
vehicles operating in the warmer climate of the Houston area. In
view of this observation and the fact that higher reductions in HC
vnd CO emissions can be achieved from vehicles operating in the mild
Los Angeles climate than can be achieved in the colder climate of
the Denver area, it can be concluded that the Denver area has
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unwittingly derived benefit from its seasonably cold weather and
attendant vehicle maintenance requirements. In this same regard,
however, the current repair status of motor vehicles operating in the
Denver area is such that emission reduction factors attained through
engine maintenance are not nearly as significant as those attained
in other areas of the country. For example, CO emissions from the
Los Angeles car population are in the order of 74.5 grams per vehicle
mile (g/m).D Application of a 35% reduction factor to the Los Angeles
population results in a change in CO emission levels from 74.5 g/m
to 48.4 g/m or about 26.1 g/ra. Denver area CO emission levels, on the
other hand, although significantly higher at about 112.1 g/m (Reference 5)
can be reduced by about 10% to 100.9 g/m. This represents a difference
of 11.2 g/m or about 60% less than absolute CO reduction in the
Los Angeles area.
At this stage in the Denver emission deterioration study it
would appear that deterioration on the average occurs at a constant
absolute CO emission deterioration rate of about 0.80 g/m per month.
This compares favorably to the Los Angeles CO emission deterioration
rate of about 0.64 g/m per month (extracted from data presented in
Reference 3). Although there are undoubtedly other factors to be
considered, the similarity in CO deterioration rates between the two
areas suggests that under similar maintenance conditions, the absolute
CO deterioration rate is in the same order of magnitude, regardless
of locale. However, since CO reduction on Denver area vehicles
is less significant initially, the significance of the Denver area
deterioration rate is more difficult to define.
Other factors, in addition to those presented above are also
to be considered. For example, the preparatory phase of the study
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was performed during the period from August, 1973 to November, 1973.
The first phase of retest (180 + 10 days after initial testing) was
performed during the period February, 1974 to May, 1974. As a
result a significant segment of mileage accumulation for the first
phase of study was performed during the colder months of winter.
As indicated earlier, cold weather conditions appear to have some
impact on engine maintenance requirements. As yet, the data
available to assess this impact on Denver area vehicles is insufficient.
To add further to the complexity of the program, the Denver
area shared with the rest of the country in an unprecedented modern day
fuel shortage. The impact of the shortage and the attendant alterations
to mileage accumulation patterns, frequency of vehicle useage,
gasoline purchasing habits and general interest in the automobile
by the motoring public are virtually impossible to accurately assess.
It is an established fact, however, that overall vehicle useage was
reduced during the period, which undoubtedly resulted in shorter trips
and fewer miles traveled at normal engine operating temperatures. This
factor of itself may have accelerated failure of spark plugs, for
example, which tend to fail as a result of lower than normal operating
temperature and associated build-up of engine deposits.
Another area which should be discussed in some detail is the
manner in which the study was designed and conducted. As mentioned
earlier, each participant was alerted to the possibility of retest and to
the committment of the laboratory to emission related maintenance.
A surprisingly low number of participants took advantage of this
situation. In addition, each participant was informed of overall
program objectives, a factor which may also have introduced bias.
Another area of study design which may be of some significance is
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the sealing of engine adjustments and identification of engine
components. The mere presence of such marks may have tended to discourage
at least a minimal level of "normal" maintenance on certain of the
vehicles.
In retrospect, it would appear that the problem of. defining
emission deterioration factors from vehicles operating in the Colorado
environment is indeed complex. Moreover, the normal range in vehicular
emission study data, which although tolerable with respect to certain
areas of the country, Los Angeles, for example, may prove to be
too great to allow a reasonable comparison of emissions over an
extended time interval. Finally, it would appear that the data to
be developed in the next six month period are of critical importance
since many of the potentially biasing effects on the program may be
minimized.
Phase III of the study, covering the interval from 6 months to
12 months after initial maintenance, is being approached in a some-
what different manner. Hopefully, gasoline will not be in short
supply and the test participants will return to normal mileage
accumulation patterns, maintenance schedules and fuel purchasing
patterns. Secondly, the next phase will provide data covering a
full year of operation, which should permit an assessment of seasonal
emission and deterioration factors if they truly exist. Thirdly,
the participants remaining at the end of the six month interval
were not alerted to the possibility of another retest which hopefully
will not have a significant influence on any aspect of vehicle operation
and attention. Finally, the novelty of the experiment with respect
to the car owner should diminish to a level where the identification
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marks, applied to permit an assessment of engine alteration, will
hopefully be of little or no significance if indeed they have been
a factor.
5.2 EMISSION DETERIORATION DATA
A summary of mean emission data developed at three points in the
study is presented in Table 2. The data are based on test results
from 165 vehicles and are shown for the 1964 through 1967 model-
year vehicle population and the 1968 through 1973 model-year vehicle
population. A summary for all vehicles is also included.
Population
Condition
Emissions in grams per
mile
HC
(%)
CO
(%)
N0X
(%)
1964-1967
As Rec'd 10.00
136.0
-2774
72 Vehicles
After Mtce. 8.93
-10.7
129.9
-4.5
2.10
-6.3
After 6 Mo. 11.04
10.4
138.4
1.7
2.00
-10.7
1968-1973
As Rec'd 6.27
90.4
2.85
93 Vehicles
After Mtce. 5.22
-16.7
79.5
-12.1
2.76
-3.2
After 6 Mo. 6.22
- 0.9
81.9
-9.5
2.80
-1.8
All Veh.
As Rec'd 7.90
110.3
2.59
165 Vehicles
After Mtce. 6.84
-13.4
101.5
-8.0
2.48
-4.2
After 6 Mo. 8.32
5.3
106.5
-3.4
2.45
-5.4
Table 2. Summary of Emission Data from 165 Vehicles As Received,
After Maintenance and After 6 Months.
As seen in Table 2, emission reductions were obtained as
a result of initial inspection and maintenance for both populations.
However, it would appear that about 60 percent of the initial gain
in CO reduction was lost during the six month interval, primarily,
due to the performance of the older segment of the car population
Similarly, the older cars appear to be chiefly responsible
for the high overall IIC deterioration rates.
In an attempt to resolve a suspected disparity in overall HC
and CO deterioration rates, the total sample of vehicles was
divided into two groups. One group is comprised of vehicles
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utilized solely in the initial program to evaluate inspection and
maintenance. The other group is comprised of vehicles utilized not
only for evaluation of inspection and maintenance but for other
aspects of the program as well (mandatory maintenance). Although not
totally justifiable, the basis for the division is related to the
fact that practicing private sector mechanics were utilized in the
I/M phase of the program and laboratory mechanics were used in
the M/M phase of the program. Initial emissions reduction in the
same order of magnitude were achieved by both groups.
Tables 3 and 4 were constructed to show the differences in
deterioration rates between the I/M and the M/M samples. As indicated
Population Condition
I/M
87 Vehicles
As Rec'd
Emission (grams per mile)
HC
(%)
CO
(%)
N0X
ill
8.18
111.8
T7T4
6.99
-14.5
101.1
-9.6
2.60
-1.5
7.50
-8.3
105.8
-5.3
2.54
-3.8
M/M
78 Vehicles
All Veh.
165 Veh.
As Rec'd
After Mtce.
After 6 Mo.
As Rec'd
After Mtce.
After 6 Mo.
7.59
6.68 -12.0
9.23 21.6
7.90
6.84 -13.4
8.32 5.3
108.7
102.0 -6.1
107.2 -1.3
110.3
101.5 -8.0
106.5 -3.4
2.53
2.34 -7.5
2.35 -7.1
2.59
2.48 -4.2
2.45 -5.4
Table 3. Summary of Emission data from 87 I/M Vehicles, 78 M/M
Vehicles and All Vehicles.
Population Deterioration
Rates (grams
per mile per month)
HC
CO
N0X
87 I/M Vehicles
.0.085
0.783
—TJ7TT82
78 M/M Vehicles
0.425
0.867
-0.033
All Vehicles
0.247
0.833
-0.060
Table 4. Emission Deterioration Rates from 87 I/M Vehicles
78 M/M Vehicles and All Vehicles in grams per mile
per month.
in Table 4, the HC deterioration rate for M/M Vehicles is higher than
the deterioration rate for I/M Vehicles by a factor of 5. On the
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other hand, CO deterioration rates for both groups are about the
same. An examination of engine variables affecting the various
effluents provides a simple explanation for the variations in range.
The emission of CO is primarily a function of fuel/air ratio
(carburetion). Changes in fuel/air ratio, which are normally in a
rich direction, and associated increases in CO emissions are
caused by a number of carburetor and carburetor support system failures.
However, significant changes are normally related to malfunctions in the
idle circuit, the main fuel circuit (changes in float bowl fuel level),
or in the high speed or power circuit. It is unlikely that changes
in carburetion would occur simultaneously. Changes of lesser
significance are normally attributed to the gradual changes
which occur in the air filter element as a result of the accumulation
of dust or oil vapor or in the crankcase ventilation (PCV) valve
resulting from the accumulation of dirt or oil sludge. In any
case, it is highly improbable that CO emissions would change by
more than a factor of 2 under normal circumstances.
HC emissions, on the other hand, can change by a factor of 10
or more through one or more simple malfunctions in the ignition
system. A fouled spark plug, for example, can occur instantaneously
resulting in a complete deactivation of the ignition process in the
affected cylinder. This can result in a tenfold increase in TIC emissions.
Another factor causing high 1IC emission levels is frequently
related to exhaust valve leakage which can develop slowly in time
or quite rapidly under the proper circumstances. Exhaust valve leakage
can also cause a tenfold increase in HC emissions.
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The range in emissions from normal vehicles to malfunctioning
vehicles is decidedly different for HC and CO as evidenced by the
standard deviation for each effluent (from data presented in Appendix 2).
For example, the mean HC level after maintenance of all vehicles is
2.84 grams per mile with a standard deviation of 3.37 g/m. At the
other extreme the mean HC level 6 months later is 3.32 g/m with a
standard deviation of 6.95 g/m. On the other hand the mean CO
level after maintenance of M/M vehicles is 101.5 g/m with a standard
deviation of 46.9 g/m which is in the same order of magnitude as the
mean of 106.5 g/m and the corresponding standard deviation of 54.4 g/m
six months later.
As a final step to determine the reason for high deterioration
rates (HC deterioration in the M/M group in particular), four sets of
computer generated histograms were produced (Appendix 3). These are
comprised of the following histograms showing relative frequency
distribution by percentage of total vehicles in the group versus
emission levels by selected increments:
HC from M/M vehicles as received
" " " " after maintenance.
" " " " after 6 months.
CO from M/M vehicles as received.
" " " " after maintenance.
M " " " after 6 months.
HC from I/M vehicles as received.
" " " " after maintenance.
11 " " " after 6 months.
CO from I/M vehicles as received.
" " " " after maintenance.
" " " " after 6 months.
Observation of the relative frequency distributions indicated
that of the M/M vehicles as received, about two percent were found to
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emit HC at a level greater than 24 g/m. After maintenance, HC
emissions were reduced on those vehicles below a level of 12 g/m.
Jn addition, no vehicles were found to emit HC at a level greater
than 16 g/m. Six months later, however, about six percent of the
M/M vehicles were found to emit IIC above a level of 24 g/m, with one
percent emitting in the 50 to 52 g/m range. A listing of M/M vehicles
which emitted at a level in excess of 24 g/m HC at any of the 3
test points is shown in Table 5. Also shown are the results of a
Vehicle
Veh.
HC
Emissions (grams per mile)
Significant
65 Chev 327
No.
59 .
As Rec'd
26.7
After Mtce.
11.3
After 6 Mo.
18.5
Tamoering?
N/A
66 Olds 425
140
5.8
9.4
37.2
No
70 Plym 313
211
28.9
4.9
5.7
N/A
66 Plym 318
272
8.5
6.7
43.9
No
67 Chev 327
280
13.1
13.1
51.8
No
69 Plym 318
291
6.1
12.7
36.3
No
71 Ford 302
314
8.2
6.9
28.8
No
Table 5. M/M vehicles which emitted HC at Levels in Excess of 24 g/m
at any of the three test points.
subjective analysis of tampering. As indicated by the information shown,
no significant tampering occured on vehicles which showed excessive
increases in HC from After Mtce. to After 6 Mo. tests. The Veh. No.
shown in Table 5 can be referenced to vehicle numbers shown in Volume II
to provide additional identification.
A similar listing of M/M vehicles which emitted CO at levels
in excess of 200 g/ra at any of the three test points is shown in
Table 6. Observation of data shown in Table 6 and graphically
illustrated in the relative frequency distribution plots of
Appendix 3, indicates that about 4 percent of M/M vehicles emitted
in excess of 200 g/m CO initially. As a result of maintenance this
quantity x*as reduced to about 2.5 percent of the vehicles. At the
end of 6 months, however, the quantity had increased to about 8
-------
Vehicle
Veh
CO
Emission (grans per mile)
Significant
No.
As R.ec*d
After Mtce.
After 6 Mo.
Tampering?
64 Olds 330
28
201.9
181.2
173.6
K/A
65 Chev 327
59
302.1
199.9
244.5
Idle Spd-No
67 Chev 283
115
171.2
187.5
225.4
PCV-No
64 Chev 283
123
160.7
197.8
204.7
No
64 Chev 283
172
198.4
211.9
230.3
No
68 Buic 350
220
200.2
137.4
154.5
No
69 Dodg 318
293
115.7
205.2
260.7
No
72 Ford 351
137.7
137.7
154.0
217.9
No
Table 6. M/M Vehicles which Emitted CO at Levels in Excess of 200
g/m at any of the three test points.
Similar data for I/M vehicles are shown in Tables 7 and 8 and
in Appendix 3. As indicated by these data, 3 percent of the I/M vehicles
'Vehicle
Veh
HC
Emissions (grams
per mile)
Significant ^
No.
As Rec
' d After Mtce.
After 6
Mo.
Tamnering?
65 Pont 389
96
33.6
13.3
14.2
N/A
72 Chev 400
177
36.6
5.0
5.2
N/A 1
65 Buic 425
235
24.4
27.6
15.6
N/A
73 Dodg 225
268
3.8
3.8
31.6
No
I
Table 7. I/M
Vehicles TJhich Emitted HC at Levels in Excess of 24 g/m
at
any of the
Three Test
Points.
Vehicle
Veh
CO
Emission (grams
per mile)
Significant ^
No.
As Rec'd
After Mtce.
After 6
Mo.
Tampering?
64 Chev 361
24
221.1
125.5
174.3
No
64 Cadi 429
30
202.0
170.2
158.5
n/a !
67 Buic 340
76
208.6
208.6
198.1
N/A
65 Pont 389
96
188.6
244.7
231.5
N/A
72 Chry 400
177
322.1
74.3
77.1
N/A !
65 Buic 425
235
238.5
248.2
336.8
Idle Spd. No
65 Chev 327
236
208.3
146.7
171.4
No
65 Ford 390
258
156.9
167.5
232.5
Timing-No J
l
Table 8. I/M Vehicles Which Emitted CO at Levels in Excess of
200 g/m at any of the Three Test Points.
were found initially to emit in excess of "24 g/n HC, Maintenance
reduced this quantity to 1 percent which was precisely the quantity
found to emit in excess of 24 g/ra at the end of 6 months. Table
7 indicates the one vehicle accounting for the high HC level at
the 6 month test point to be one which emitted at a relatively
low HC level in the prior two tests. Similarly, 9.5 percent of
-------
the I/M vehicles were found to emit CO in excess of 200 g/m initially.
After maintenance the quantity was reduced to about 3.5 percent where
it remained to the close of the six month Interval. Tampering, again,
does not appear to be a factor causing high HC and CO emissions.
5.3 MAINTENANCE OF VEHICLES DURING THE SIX MONTH INTERVAL AND INDICATIONS
OF TAMPERING
A cursory examination was performed to determine the extent of
vehicle maintenance during the interval (Appendix 4). In this
regard, the following observations were derived.
Of all items sealed, the air cleaner assembly screw was the
item most frequently disturbed (56Z of all vehicles),
presumably for the purpose of Inspecting the air filter
element. The percent of filter assembly disturbance on
vehicles showing increased HC and CO emissions after six
months is roughly equal to the percent of disturbance on
vehicles showing decreases.
The second most frequent item to be disturbed was the air
filter element which Indicated complete replacement.
In this respect there appears to be nothing to indicate
an unbalance between vehicles showing Increased emission and
vehicles showing decreased emissions. Air filter elements
were replaced on 12Z of the vehicles.
The next most frequent disturbance occurred with respect to
the spark plugs, which in this case indicated replacement.
This occurred on 8Z of the vehicles with an equal distribution
between vehicles showing Increased HC and CO emissions and
vehicles showing decreased emissions.
Distributor cap locking screws were next in the frequency
of disturbance indicating removal of the cap to service ,
adjust or replace ignition paints and/or condensers.
This occurred on 7% of all vehicles with no apparent
correlation between either Increased or decreased emissions.
The ignition dwell adjustment, indicating either point set
replacement or an adjustment is ranked next and occurred on
5Z of the vehicles. There is no apparent correlation
between replacement or adjustment and either increased
or decreased emissions.
Several items were next In ranking which in each case appeared
to have been either adjusted or replaced on 5% of the
vehicles. Included are: ignition wires, indicating complete
replacement; choke adjustments; and condenser replacement.
-------
Next in order at 42 were idle speed adjustment, timing adjust-
ment, and rotor replacement which were followed by PCV valve
replacement on 3% of the vehicles, idle mixture screw adjust-
ment which occurred on 21 of the vehicles and coil replacement
which occurred on 1% of the vehicles.
Of all items sealed for investigative purposes, some correlation
between vehicles showing Increased CO levels and the performance
of maintenance appears to exist. Items falling into this
category include idle speed adjustments, choke adjustment,
timing adjustment, ignition points adjustment (or replacement),
condenser replacement and distributor cap replacement. Of
these, only the idle speed adjustment and choke adjustment
are considered to relate to CO emissions.
Similarly, an apparent correlation between vehicles showing
Increased HC levels and maintenance appears to exist, but only
with respect to the adjustment of ignition timing and dis-
tibutor cap replacement. In all probability, however, only
the adjustment of ignition timing is significant.
From all indications, it would appear that tampering in the
true sense is minimal. However there appears to be an
indication that, in several cases, engine maintenance which
resulted in increased HC and CO emissions was performed.
5.4 SUMMARY OF OBSERVATIONS.
1. In the overall sample, HC emissions appear to have deteriorated to
the six month point to a level above where they were Initially.
CO emissions appear to have deteriorated to a point where about
60% of the initial reduction has been lost. N0X emission reductions
remain essentially unchanged. HC and CO emission deteriorations
appear to be traceable chiefly to the older vehicles.
2. In the M/M group of vehicles where maintenance was performed by
laboratory personnel not necessarily accustomed to the rigors
of dealing with customer oriented maintenance. HC emissions
appear to have the most significant deterioration rate and have
deteriorated to a point well above the HC levels initially
measured. CO deterioration rates appear to be reasonable
and N0X emissions remain unchanged. Again, the greatest HC
and CO deterioration occurred with respect to the older vehicles.
3. In the I/M group of vehicles where maintenance was performed
by private sector mechanics, the HC emission deterioration
rate appears to be reasonable and about 60% of the initial HC
reduction was retained after 6 months. The CO deterioration
rate also appears to be reasonable and about 55 percent of the
initial reduction was retained. NOx emissions in this group
also remain unchanged.
-------
4. The maintenance performed in the initial phase of the project
whereby the immediate effects of inspections and maintenance
were evaluated, apparently has had little effect in holding down
the number of vehicles which tend to emit at high IIC and CO
levels, particularly with respect to the M/M group. This
factor tends to suggest a requirement for inspection and main-
tenance at 6 month intervals if an effective program is to be
maintained.
5. There does not appear to be strong or even moderate indications
that tampering is a significant with respect to emission deterioration.
However, it would appear that several vehicles which showed
increased HC and CO emissions were maintained without regards
to minimized emission levels. In certain respects, this type
of maintenance may be regarded as tampering.
-------
REFERENCES
1. Environmental Protection Agency, Region VIII; Vehicle Testing to
Determine Feasibility of Emission Inspection at Altitude;
Automotive Testing Laboratories, Inc.; Contract No. 68-01-0439;
Spetember, 1972.
2. State of Colorado, Department of Health; Volume II, Experimental
Characterization of Idle Inspection, Exhaust Control Retrofit and
Mandatory Engine Maintenance; Automotive Testing Laboratories, Inc.,
Contract No. C290526; December, 1973.
3. State of California, Air Resources Board; An Evaluation of the
Effectiveness of Automobile Engine Adjustments to Reduce Exhaust
Emissions; Clean Air Research Company; June, 1973.
4. Environmental Protection Agency; a Study of Emission from Lij»ht-
Duty Vehicles in Denver, Houston and Chicago, Fiscal Year 1972
(APTD-1504); Automotive Testing Laboratories, Inc.; July, 1973.
5. Environmental Protection Agency; A Study of Emissions from Light-
Duty Vehicles in Six Cities (APDT-1497); Automotive Environmental
Systems, Inc.; March, 1973.
-------
APPENDICES
Appendix
No.
1.
2.
3.
4.
Description Page
Letter of Commitment to Emission Related
Maintenance and Engine Component and 26
Adjustment Sealing and Identification
Procedures. 28
Summary of Emission Data and Reduction
for All Vehicles, I/M Vehicles and
M/M Vehicles Before Maintenance, After
Maintenance and After 6 months. 29
Histograms Showing Relative Frequency
Distribution of HC and CO emissions
from I/M and M/M Vehicles Before
Maintenance, After Maintenance and
After 6 Months. 50
Summary of Vehicle Maintenance, 68
-------
AUTOMOTIVE TESTING LABORATORIES, INC.
19900 East Colfax Avenue • Aurora. Colorado 80010
Dear Test Participant;
We wish to express our appreciation to you for the interest you have
shown in the current Colorado Emission Study Program. Your participation
is a key to the success of this program and to future vehicle related
programs which may be developed to improve the quality of Colorado's air.
Unless your car is listed among the few we tested which required
extensive maintenance, you may rest assured that your car will now pass
an engine idle emission test. It is not known, however, how long your
car will remain in this condition. As you may know, one of the objectives
of the study in which you participated is to evaluate the effectiveness of
emission inspection and engine maintenance in existing licensed safety
inspection stations and garages. Information developed from this phase
of the study will help to determine the practicality of such a plan on a
state-wide level. Assuming the test data does indicate that such a plan
is practical, the next question which is posed relates to the frequency
of inspection and maintenance. In order to determine a reasonable inspection
frequency it will be necessary to accumulate more data. In this regard, we
may wish to test your vehicle six months from now. If you tentatively agree
to presenting your car for a re-test, we will:
1. Provide a reasonable amount of emission related maintenance
on your car for the next six months.
2. Provide you with another $10 check after the six month re-test.
3. Provide you with a late model loan car during the time your
car is being re-tested.
We understand that during the next six months the car we tested may
require maintenance. If it does, and you suspect that it may relate directly
to the engine or to the fudl or ignition systems, please contact us before
any corrective maintenance is accomplished. At that time we will advise
you and arrange to make repairs within the scope of our activities. You
may, of course, arrange for emergency repairs, or any repairs for that
matter, without consulting us. In this regard, we wish to emphasize that
we have no legal authority and that your participation is purely voluntary.
The following list is comprised of, but is not limited to, engine
parts which could deteriorate:
-------
1. PCV system
2. Carburetor including air/fuel mixture and speed adjustments
3. Air Filter and/or filter element
4. Spark Plugs
5. Distributor parts including points and condensor, and timing
and dwell adjustments.
6. Spark plug wires
7« Air pump and air injection system if so equipped.
8. NOx emission control system (1973 model-year only)
Many of the usual preventive maintenance procedures have no effect
on emission and may be attended to without consulting with us. These
1. Battery
2. Charging system
3. Oil filter replacement
4. Oil changes
5. Lubrication
If there is any doubt as to the impact maintenance may have on
the program, however, please do not hesitate to call us at 343-8938.
We will respond promptly.
Again, we wish to express our appreciation for your participation,
Hopefully, the data which we are developing as a result of your
cooperation will lead toward cleaner air in Colorado.
Gratefully yours,
Douglas T\. Liljedahl
President
-------
Sealing Procedure
The following Items are spot painted with marking pen paint
(highly resistant to solvents) to allow us to determine if the car
been
tampered with when we run the deterioration study
1.
Air cleaner element
2.
Air cleaner screw
3.
Spark plugs
A.
Spark plug wires
5.
Point adjustment screw
6.
Timing adjustment
7.
Idle mixture screw
8.
Idle RPM screw
9.
Rotor
10.
Condenser
11.
PCV valve
12.
Coil
13.
Choke setting
14.
Distributor Cap
-------
EXHAUST EMISSIONS BEFORE INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
» OF HC CO NOX MPG
VEH. MEAN S.D. MEAN S.D. MEAN S.D. MEAN S.D.
~VEHICLE MAKE
AMER. MOTORS
6
7.70
2.18
101.4
25.9
3.06
1.45
15.39
2.74
auiCK
6
11.20
6.67
171.1
•51.8
2.41
1.56
11.49
1.68
CADILLAC
4
8 0 63
3.75
157.9
50.6
3.01
1.14
10.57
1.62
CHEVROLET
40
8.04
4.53
114.2
55.8
2.14
1.05
14.12
2.61
CHRYSLER
<5
13 0 82
12.91
190.6
83.1
1.96
1.41
10.38
1 .33
OATSUN
1
4.37
0.00
42.2
0.0
3.61
0.00
22.04
0.0 0
DODGE
8
6.25
2.09
95.8
18.2
2.Q7
0.90
14.93
1.67
FORD
43
7.27
3.12
9Q.3
38.1
3.02
1.71
14.9CJ
3.31
MERCURY
5
6.19
2.10
62.6
30 .5
4.31
3.02
14.35
2.46
0LDSM08ILE
7
7,93
3.90
129.7
46.9
2.06
1.11
11 .96
1 . 18
OPEL
2
5.35
0.76
86.2
11.2
1.58
0.26
21 .06
0.81
PLYMOUTH
13
8.47
6.42
121.9
41.2
2.38
0.85
14.23
2.42
PONTIAC
12
9.10
a.21
108.3
50.3
2.47
1.04
12.73
1.21
TOYOTA
4
5.22
1.36
81.2
48.3
2.49
0.67
ia.37
2.44
VOLKSWAGON
0
6.72
3.79
81.6
32.4
2.21
1.13
21.52
1.87
VOLVO
0
~MODEL YEAR
1^64
14
9.47
2.91
143.7
48.6
2.05
1.15
13.86
2.55
1965
20
11.70
7.71
145.3
61.1
2.07
1 .20
14.14
3.97
] 966
18
9.03
2.42
128.2
29.3
2.49
0.87
14.52
3.4n
1967
20
9.56
3.35
128.4
45.0
2.33
1.89
14.47
2.71
196fl
15
7.82
2.63
112.3
42.3
3.01
1.88
14.79
2.75
1969
1 0
5.66
1 .52
94.7
33.5
2.71
1.12
14.58
1.50
1970
17
7.04
5.97
82.8
40.3
3.55
1.63
14.95
3.90
1971
17
5.64
1 .36
79.2
36.2
3.06
1.12
15.65
4.91
1972
18
7.00
7.58
102.8
64. ]
2.57
1 .22
14.54
3.62
1973
16
4.11
1.03
73.0
22.0
2.15
n.97
14.51
3.63
~DISPLACEMENT
LESS THAN 151
19
6.on
2.74
79.6
30.8
2.23
0.97
20 .86
2.21
151 - 250
27
5.79
2. Q1
7Q.1
31 .0
2.81
1.43
17.5Q
2.51
251 - 350
71
9.04
4.41
126.5
47.9
2.25
1. 1Q
13.65
1.42
MORE THAN 350
48
8.16
6.60
116.1
57.4
3.10
1.68
11 .84
1.61
~ INERTIA '/.EIGHT
1800 - 270°
26
5.76
2.62
73.7
29.7
2.61
1.45
20 .66
2.29
2800 - 37°o
72
7.20
3.01
'102.3
30.1
2.41
1.18
14.80
1 .^1
3800 - i+79c<
59
9.76
6.97
132.2
59.0
2.76
1.66
12.19
1 .42
4800 - 57Q9
8
7.43
2.99
139.8
44,9
2.87
1.13
10.89
1.31
~POPULATIONS
1°64 - 1967
7?
10.on
4.80
136.0
47.4
2.24
1 .34
14.27
3.20
1°68 - 1973
93
6.27
4.49
P0.4
43.9
2.85
1.41
14.86
3.60
ALL VEHICLES
165
7.90
4.97
110.3
50 .7
2.59
1.41
14.60
3.43
AUTOMOTIVE TESTING LABORATORIES
» INC.
19^00 E.
COLFAX f
AURORA
» COLO.
8n i> 11
-------
EXHAUST EMISSIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
tt OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
~VEHICLE MAKE
AMER. MOTORS
6
6 .53
1.79
73.7
21.8
3.45
1.18
15.95
2.32
BUICK
6
10.64
8.53
151 .1
62.7
2,49
1.32
11 .60
1.70
CADILLAC
8,47
3.73
149.9
43.3
3.00
1.16
10.74
1.52
CHEVROLET
an
7.11
3.33
109.2
50.3
1 .95
1.06
14.29
2.34
CHRYSLER
5
6.05
0.98
113.3
24.2
2.49
1.21
1 1 .82
1.43
DATSUN
1
4.36
0.00
46.6
0.0
2.91
o.on
21.79
0.00
DODGE
8
7.50
4.13
102.0
56.2
2.48
1. on
15.17
2.20
FORD
43
6.76
2.67
94.3
38.2
2.76
1.51
15. U
3.46
MERCURY
5
6.04
2.08
71.9
35.2
4.44
3.36
13.38
1.98
OLDSMOBILE
7
7.04
2.51
122.6
51.6
2.09
1.18
12.29
1 .14
OPEL
2
4.18
0.84
68.2
11.9
1 .78
0.00
21.61
0.29
PLYMOUTH
13
6.34
2.73
103.3
36.8
2.46
0.96
14.56
2.79
PONTIAC
12
6.85
3.21
104.9
60.3
2.50
1.11
12.99
1.12
TOYOTA
4
3.86
0.45
68.9
54.0
2.30
1.13
19.67
3.83
VOLKSWAGON
9
6.08
2.85
79.8
31.2
1 .°4
0.82
22.02
1 .98
VOLVO
0
~MODEL YEAR
1964
14
8.46
2.39
133.3
46.7
1 .97
1.32
14.15
2.38
1965
20
9.39
4. 90
139.0
52.3
1.95
1.05
14.26
3 • 6 n
1966
1 A
8.22
2.31
116.6
31.6
2.28
0.79
15.25
3.73
1967
20
9.46
2.77
130.5
4? ,
-------
EXHAUST EMISSIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
« OF HC CO NOX MPG
VEH. MEAN S.D. MEAN S.D. MEAN S.D. MEAN S.D.
~VEHICLE MAKE
AMER. MOTORS
6
6.08
2.12
75.7
22.7
3.67
1.62
16.15
1.90
BUICK
6
8.71
3.92
166.5
94.3
2 o 38
1.20
11.°0
2.39
CADILLAC
4
6.33
1.30
126.0
31.7
2.75
0.90
11.48
1.65
CHEVROLET
40
8.92
8.05
115.1
56.8
1 j> 98
1.25
14. 10
2.40
CHRYSLER
5
6.23
1.04
116.5
38.9
2.71
1.73
11.37
1.26
DATSUN
1
3.75
0.00
45.2
0.0
3,43
OcOO
21. 12
0.00
DODGE
8
10.86
9.08
114.7
66 o 0
2c 53
1.30
14.34
2.03
FORD
43
8.30
4.99
9°. 8
49.9
2.73
1.63
15.13
3.29
MERCURY
5
6.41
3.45
76.1
49.6
3 o 50
2.30
13.. 45
1.77
OLDSMOBILE
7
10.60
11.80
119.0
49.5
2.00
1.20
12.49
1.08
OPEL
2
5.94
2.76
80.2
23.7
1.55
0.05
20.20
2.70
PLYMOUTH
13
11 .26
13.00
116.0
47.1
2.51
1.29
13.83
2.94
PONTIAC
12
7.97
3.72
114.1
57.5
2.44
1.33
12.59
0.93
TOYOTA
4
4.35
1.08
87.3
51.7
1.69
0.72
20.05
3.87
VOLKSWAGON
9
5.15
3.52
64.7
30 .1
2.23
0.71
22.04
1.89
VOLVO
0
~MODEL YEAR
1964
14
9.72
3.72
141,3
52.9
2.03
1.36
14.05
2.33
1965
20
9.51
3.72
151 o 4
68.9
1.77
0.95
13.83
3.64
1966
18
13.10
10.38
132.1
40.0
2.15
0.95
14.31
3.60
1967
20
11.64
10.10
128.8
45.9
2.07
1.59
14.25
2.74
1968
15
5.81
1.51
89.0
40.6
2.83
1.23
15.31
3.57
I960
10
9.01
10.10
100.4
65.5
2.58
1.50
14.67
2.42
1970
17
5.41
2.45
82.8
39.0
3.12
1.46
15.27
4.02
1971
17
7.07
6.23
72.5
34.8
3.17
1.55
16.03
4.75
1972
18
5.27
2.46
79.8
45.9
2.86
1.73
15.16
3.48
1973
16
5.89
6.90
75.0
22.8
2.12
1.15
14.31
3.19
~DISPLACEMENT
LESS THAN 151
19
5.03
2.54
73,1
32.3
1.98
0.74
21.05
2.43
151 - 250
27
6.62
5.74
77.6
40.7
3.10
1.74
17.74
2.25
251 - 350
71
10.25
8.46
123.9
51.2
1.95
1.07
13.52
1.60
MORE THAN 350
48
7 o 74
5.41
110.4
60.8
3.01
1.54
12.22
1.75
~INERTIA WEIGHT
1800 - 2799
26
5.10
2.57
69.1
32.1
2.48
1.43
20.85
2.30
2800 - 3799
72.
7 .76
5.10
101.3
48.9
2.24
1 .30
14.85
1.98
3800 - 4799
59
10.69
9.50
126.0
59.7
2.66
1.55
12.33
1.41
4800 - 5799
8
6.41
1.68
131.8
49.6
2.69
1.28
10.95
1.50
~POPULATIONS
1964 - 1967
72
11 .04
7.84
138.4
53.1
2.00
1.22
14.11
3.11
1°68 - 1973
Q3
6.22
5.33
81.9
41.1
2.80
1.46
15.16
3.67
ALL VEHICLES
165
8.32
6.95
106.5
54.4
2.45
1.42
14.70
3.47
AUTOMOTIVE TESTING LARORATORIES.INC.
19°00 E. COLFAX» AURORA r COLO, 80011
-------
EXHAUST EMISSION REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
# OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S
.D.
~VEHICLE MAKE
AMER. MOTORS
6
1.17B
1.60
27.65
32.7
-0.393
0.82
-0
. 554
0
.82
RUICK
6
0 . 566
2.20
20.04
26.9
-0.086
0.49
-0
.114
0
.76
CADILLAC
4
0.157
0.31
7.96
15.9
0.017
0.03
-0
• 161
0
.32
CHEVROLET
40
0.936
2.62
4.95
25.6
0.186
0.59
-0
. 164
1
.14
chryslfr
5
7.772
13.49
77.21
1 03.1
-0.527
0.81
-1
.U4 3
1
.80
DATSUN
1
0.011
0 .no
-4.40
0.0
0.705
0.00
0
.257
0
.on
OODGE
a
-1.253
3.41
-6.13
45.0
0.483
1.31
-n
.232
1
.17
FORD
43
0.515
1 .95
5.03
22. a
0.265
1.05
-0
.115
1
.05
MERCURY
5
0.150
1 .36
-9.39
16*8
-0.137
1.22
0
.965
1
.44
OLDSMOBILE
7
0.888
3.47
7.08
24.4
-0.027
0.35
-0
.325
0
.38
OPEL
2
1. 162
0.08
18.07
0.7
-0.196
0.27
-0
.547
0
.52
PLYMOUTH
13
2.123
6.93
18.55
16.4
-0.087
0.47
-0
.326
0
. °2
PONTIAC
12
2.257
5.79
3.43
25. 1
-0.030
0.49
-0
.255
0
.8ft
TOYOTA
4
1.362
0.96
12.24
12.5
0.187
0.52
-1
.306
1
.60
VOLKSWAGON
o
0.635
1.32
1.72
19.3
0.271
0.93
-0
.498
1
.31
VOLVO
0
~MODEL YEAR
1964
14
1.012
2.47
10.40
31 .2
0.083
0.37
-0
• 2°1
0
.87
1 965
20
2.318
5.73
6.35
34.4
0.119
0.61
-0
.119
1
.18
1 Qpf.
18
0.812
1 .70
11 .59
1 °. 9
0.213
0.64
-0
.734
1
.07
1967
20
0.0O6
1.87
-2.09
19.4
0.139
0.29
0
.073
0
.71
1968
15
1.125
2.96
17.40
34.3
0.393
1 .17
0
.017
1
. 46
1 Q69
10
-0.5O9
2.34
-4.97
35. 1
-0.026
1.26
-0
.205
1
.18
1970
17
2.255
5.79
8.24
20.6
0.365
1 .36
-0
.40 0
1
.no
1971
17
0.763
1.14
10.32
16.1
0.058
0 .55
-0
.296
1
.17
1Q72
IB
2.047
7.45
27. 13
61. 1
-0.273
0.Q1
-0
.507
1
.46
1973
16
-0.091
0.74
-0.26
10.1
0.023
0.33
0
.025
0
.65
~DISPLACEMENT
LESS-THAN 151
19
0 .821
1.31
5.93
15.9
0.189
0.69
-0
.646
1
.28
151 - 250
27
0.143
1.16
3.93
22.8
0.011
0 .49
-0
.264
1
.29
251 - 350
71
1.294
3.99
7.44
28. 1
0.287
0.79
-0
.111
1
.01
MORE THAN 350
48
1.319
5.52
14.65
43.7
-0.123
0.95
-0
.276
1
.04
~INERTIA WEIGHT
1800 - 279"
26
0.713
1 .18
5.39
19.0
0.150
0.69
-0
.440
1
.42
2800 - 379Q
7?
0.393
2.01
4.24
25.7
0.162
0.93
-0
.113
1
.11
3800 - 479Q
59
2. 174
6.16
16.61
42. 1
0.045
0.76
-0
.362
0
• °8
4800 - 570Q
8
-0.050
0.58
3.13
12.3
0.028
0.04
0
.050
0
.37
~POPULATIONS
1°64 - 1967
72
1 .070
3.50
6. 1 0
26.8
0.141
0.50
-0
.253
1
.01
106fl - 1Q73
o3
1.049
4.39
10.87
35. 1
0.089
0.98
-0
.240
1
.17
ALL VEHICLES
165
1 .058
4.01
8.7Q
31.8
0.112
0.81
-0
.246
1
.10
AUTOMOTIVE TFSTING LABORATORIES
;» inc.
IQUfin E.
COLFAX,
AURORA
• COLO.
ROM 1
-------
EXHAUST EMISSION REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
ALL
VEHICLES
« OF
HC
CO
NOX
MPG
VEH.
MEAN
S. D g
MEAN
S.D.
MEAN
S.D.
MEAN
• 1
O 1
• 1
in 1
~VEHICLE MAKE
AMER. MOTORS
6
1.621
2.58
25.67
22.1
-0.611
0.22
-0.757
1.08
BUICK
6
2 0 494
3.40
4.58
56. 8
0.033
1.01
-0.411
1.55
CADILLAC
4
2.294
3.90
31.81
23.2
0.264
0.73
-0.904
1.59
CHEVROLET
40
-0.879
6.61
-0.86
27.4
0.162
0.80
0.028
1.56
CHRYSLER
5
7.585
13.49
74.10
99.9
-0.747
0.94
-0,994
1.77
DATSUN
1
0.621
O.on
-2.98
0.0
0.186
0.00
0.926
0.00
DODGE
8
-4.615
9.57
-18.89
57.1
0.431
1.48
0.594
1.52
FORD
43
-1.028
4.20
-0.54
36 0 0
0.287
1.34
-0.137
1.46
MERCURY
5
-0.222
3 0 01
-13.52
21.2
0.808
1.08
0.895
1.87
OLDSMOBILE
7
-2.671
13.05
10.70
29.5
0.058
0.42
-0.533
0.95
OPEL
2
-0.592
2.00
6.08
12.5
0.034
0.22
0.862
1.89
PLYMOUTH
13
-2.790
14.77
5.88
27.2
-0..138
1.05
0.398
1 .36
PONT I AC
12
1.128
5.88
-5.78
22.9
0.029
0 .62
0.141
1.00
TOYOTA
4
0.874
0.84
-6.09
19.1
0.802
0.42
-1.686
1.87
VOLKSWAGON
9
1.564
4. 58
16. 86
33.3
-0.014
1.06
-0.523
2.32
VOLVO
0
~MODEL YEAR
1964
14
-0.257
3.80
2.40
31.4
0.025
0.70
-0.190
1.15
1965
20.
2.189
5.58
-6.09
41.4
0.291
0.74
0.310
1.63
1966
18
-4.068
11.03
-3,91
30.8
0.345
0.89
0.211
1.40
1967
20
-2.079
8.90
-0.40
35.2
0.263
0.72
0.220
1.68
1968
15
2.008
3.23
23.36
29.4
0. 188
1.12
-0.519
1.91
1969
10
-3.156
9.66
-5.71
51.3
0.130
1.21
-0.087
1.67
1970
17
1.6 25
5.95
0.00
34.7
0.434
1.53
-0.325
1.27
1971
17
-1.432
5.51
6.67
22.6
-0.106
1.03
-0.378
1.60
1972
18
1.736
7.81
23.01
64.3
-0.295
1.45
-0.620
1.53
1973
16
-17780
6.98
-2.06
15.8
-6-.026
0 .5®
0.202
1.46
~DISPLACEMENT
LESS THAN 151
19
0.970
3.21
6.51
26.2
0.245
0.85
-0 .189
2.20
151 - 250
27
-0.837
5.59
1.54
28.4
-0.291
1.40
-0.151
1.89
251 - 350
71
-1.211
8. 47
2.61
33.7
0.301
0.84
0.130
1.33
MORE THAN 350
48
0.420
7.74
5.63
51.0
0 .088
1.07
-0.383
1.28
~INERTIA WEIGHT
1B00 - 279a
26
0.659
2.82
.4.61
28.6
0.133
1.34
-0.184
2.20
2800 - 379°
72
-0.559
4.57
0..9Q
33. 0
0.165
1.02
-0.04O
1.43
3800 - 479°
59
-0.935
11. 10
6.20
47.3
0.096
0.95
-0.136
1.36
480 0 - 5799
8
1.028
3.01
8.04
40.1
0.180
0.60
-0.063
1.45
~POPULATIONS
1964 - 1Q67
72
-1.036
8.18
-2.31
34.8
0.245
0.76
0.163
1.49
1Q68 - 1°73
Q3
0. n 4 0
6.72
8.47
40.3
0.051
1.20
-0.307
1 .55
ALL VEHICLES
165
-0.424
7.39
3.77
38.2
0.136
1.03
-0.102
3
IT)
r-H
AUTOMOTIVE TESTING LABORA TORIES.INC.
lQn0tl E. COLFAX# AURORA. COLO. BO01 1
-------
PERCENT REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
# OF
VEH.
HC
¦PERCENT REDUCTIONS
CO NOX
MPG
~VEHICLE MAKE
AMER. MOTORS
RUICK
CADILLAC
CHEVROLET
CHRYSLER
DATSUN
OOOGE
FOPD
MERCURY
OLDSMOBILE
OPEL
PLYMOUTH
PONT I AC
TOYOTA
VOLKSWAGON
VOLVO
6
6
4
un
5
1
8
43
5
7
2
13
12
4
9
0
15. po
5.06
1.R2
11.63
56 .24
n.24
•20,06
7.08
2.42
11 .20
21.73
25.07
24.79
26.08
9.45
27.28
11.71
5,04
4.34
40.52
-1 0.42
-6.39
5.07
¦15.01
5.46
20.96
15.22
3.17
15.07
2.11
-12.84
-3.57
0.57
8.70
-26.86
19.51
16.29
8.78
-3. 18
-1 .30
-12.39
-3.65
-1.23
7.50
12.24
-3.60
-0 .9o
-1.53
-1.16
-13.91
1 .16
-1.55
-0.77
6.73
-2.72
-2.60
-2.29
-2.on
-7.11
-2.31
*MODEL YEAR
1 Q64
1965
1066
1 967
1968
1 °69
1970
1971
1972
1973
14
20
IB
20
15
10
17
17
18
16
10.69
19.81
8.99
1.01
14.39
-10.23
32.05
13.53
29.22
-2.22
7.24
4.37
9.04
-1.63
15.49
-5.25
9.95
13.03
26.38
-0.36
4.03
5.74
8.54
5.95
13.03
-0.96
10.28
1.89
-10.63
1.07
-2.10
-0 .84
-5.06
0.50
0.11
-1.41
-2.67
-1.89
-3.49
0. 17
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
19
27
71
48
13.67
2.48
14.32
16.17
7.46
4.97
5.88
12.62
8.47
0.40
12.75
-3.96
-3.10
-1 .50
-0.82
-2.33
* INERTIA WEIGHT
1800 - 2799 26
2800 - 379Q 72
3800 - 479Q 59
4800 - 579Q 8
12.. 39
5.45
22.28
-0.68
7.31
4.14
12.57
2.24
5.73
6.71
1.63
0.97
•2.13
¦0.77
•2.97
0.46
~POPULATIONS
1964 - 1967
!o6fl _ 1Q73
ALL VEHICLES
72
93
165
10.70
16.73
13.40
4.4Q
12.03
7.97
6.27
3.12
4.31
¦1 .77
¦1 .62
•1.68
AUTOMOTIVE TESTING LABORATORIES' INC.
lQc.nn E. COLFAX» AURORA. COLO. 80011
-------
PERCENT REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
ALL VEHICLES
8 OF
VEH.
HC
-PERCENT REDUCTIONS—
CO NOX
MPG
~VEHICLE MAKE
AMER. MOTORS
BUICK
CAOILLAC
CHEVROLET
CHRYSLER
DATSUN
DODGE
FORD
MERCURY
OLDSMOBILE
OPEL
PLYMOUTH
PONT IAC
TOYOTA
VOLKSUAGON
VOLVO
6
6
4
40
5
1
8
43
5
7
2
13
12
4
9
0
21.04
22.26
26.58
-10.93
54.89
14.19
-73.88
-14.14
-3 o 59
-33.69
-11.06
-32.96
12.40
16.74
23.28
25.33
2.68
20.15
-0.76
38.89
-7.05
-19.71
-0.54
-21.61
8.25
7.05
4.82
-5.33
-7.50
20.68
-19.98
1 o 35
8.77
7.58
-38.06
5.15
14.54
9.49
18.77
2.81
2.13
-5.83
1.19
32.18
-0.66
-4.92
-3.58
-8.55
0.20
-9.58
4.20
3.98
¦0.91
6.24
-4 o 45
4,09
2.80
1.11
-9.18
-2.43
~MODEL YEAR
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
14
20
18
20
15
10
17
17
18
16
-2.71
18.71
-45.04
-21.75
25.68
-53.88
23.09
-25.39
24.78
-43.31
1.67
-4.19
-3.05
-0.31
20.80
-6.03
0.00
8.42
22.38
-2.83
1.24
14.07
13.84
11.29
6.23
4.78
12.22
-3.47
-11.49
1.20
-1.37
2.19
1.46
1.52
-3.51
-0.60
-2.18
-2.42
-4 .26
1.39
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
19
27
71
48
16.16
-14.46
¦13.40
5,15
8.18
1.95
2.07
4,85
10.99
¦10 .38
13.37
2.85
¦0.91
¦0.86
0.95
¦3.23
~INERTIA WEIGHT
1800 - 279°
2800 - 37?o
3800 - 4799
4800 - 5799
26
72
59
8
11 .45
-7.76
-9.58
13.83
6.26
0 o 97
4,69
5.75
5,09
6.87
3.46
6,27
¦0.89
¦0.33
¦1.11
-0.58
~POPULATIONS
1964 - 1 °67
1968 - 1973
ALL VEHICLES
72
°3
165
-10.36
0.79
-5.37
-1.70
a.37
3.41
10.92
1.80
5.25
1.14
•2.07
¦0.70
AUTOMOTIVE TESTING LABORA TORIES.INC.
19°00 E. COLFAX. AURORA t COLO. PO1U1
-------
EXHAUST EMISSIONS BEFORE INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
« OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
~VEHICLE MAKE
AMER. MOTORS
4
7.25
2.45
04.3
27.1
3.21
1.41
16.90
1 .69
BUICK
4
13.03
7.68
172.7
61.4
2.67 .
1.88
12.14
1.52
CADILLAC
4
8.63
3.75
157.9
50.6
3.01
1. 14
10.57
1 .62
CHEVROLET
17
8.3i+
3.40
114.9
44.7
2.C7
0.87
15.59
3.13
CHRYSLER
5
13,82
12.91
190.6
83.1
1.96
1.41
10.38
1.33
DATSIJN
1
4.37
o.nn
42.2
0.0
3.61
0.00
22 .04
0 . 0 0
DODGE
5
5.97
1.78
88.7
18.3
3.08
1.06
14.98
1 .62
FORD
18
7.24
3. on
103.0
39.4
3.07
1.63
15.63
3.79
MERCURY
2
8.15
1.24
83.7
39.0
5.36
5.25
12.09
1.4-t
OLDSMOBILE
a
7.58
2.30
125.5
41.6
2.55
1.28
12.29
1 .28
OPEL
2
5.35
0.76
86.2
11.2
1.58
0.26
21.06
0.81
PLYMOUTH
5
6.57
2.81
101 .2
48.7
2.54
0.78
16.46
1.03
PONTIAC
5
11.71
12.53
101 .6
52.9
2.47
0.89
13.00
1.75
TOYOTA
4
5.22
1 .36
81.2
48.3
2.49
0.67
18.37
2.44
VOLKSWAGON
7
7.26
4.16
85.8
36. 1
2.24
1.30
21.51
2.09
VOLVO
0
~MODEL YEAR
196U
9
8.04
1.78
12Q.9
52.4
2.42
1.30
14.38
3.05
1965
15
11.12
7.86
134.1
52.5
2.11
0.99
14.70
4 .36
1966
11
9.50
2.85
128.3
31.2
2.39
0.92
15.47
3."
1967
14
8.80
2.62
122.9
40.4
2.57
2.03
14.16
2.27
1968
5
9.24
4.04
125.4
14.8
2.34
1.43
16.1 1
3.Q2
I960
2
6.39
0.28
127.0
37.0
1.81
0.39
15.01
0.43
1 Q70
11
5.43
2.19
80.5
42.9
3.71
1 .69
15.31
4.20
1971
7
5.28
1.34
71 .4
34.6
2.94
1.02
17.02
5.36
1972
7
9.20
12.14
105.8
98. 1
2.91
1.41
16.48
4.P0
1973
6
4.09
0.67
67.6
12.6
2.78
1.21
18.10
3 • 68
~DISPLACEMENT
LESS THAN 151
17
6.14
2.85
81 .1
32.3
2.24
1.03
20.78
2.30
151 - 250
18
6.38
3.25
80.9
32.8
2.86
1.60
17.98
1.7o
251 - 350
28
8.61
2.65
127.8
38.5
2.28
0. °1
13.92
1 .33
MORE THAN 350
21
10.46
8.68
137.9
64.9
3.17
1.82
11.41
1.53
~INERTIA WEIGHT
180n - 279a
21
6.08
2.77
76.3
31.2
2.56
1.54
20.62
2.18
2B00 - 379°
31
7.50
3.17
103.1
34.7
2.41
0.99
15.82
1 .87
3800 - U7°a
27
10.81
8.02
141.0
62.3
2.90
1.79
12.22
1 .62
4flOO - 579«
fl
7.43
2.9?
13°.fi
4U". 9
2.87
1.13
10.89
1.31
~POPULATIONS
1°64 - 1967
HQ
9.53
4.84
128.9
43.9
2.36
1.38
14.66
3. 47
1 - 1973
38
6.43
5.5°
8Q.8
52.9
2 • 9°
1.41
16.37
4.20
ALL VEHICLES
87
8.18
5.38
111.8
51.6
2.64
1.42
15.41
3.88
AUTOMOTIVE TESTING LABORATORIES~INC.
-------
EXHAUST EMISSIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
# OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
•
o
•
1
MEAN
S.D.
MEAN
S.D.
~VEHICLE MAKE
AMER. MOTORS
u
6.30
1 .48
84.8
17.1
3.24
1.39
17.34
1.06
BUICK
u
13.1?
0.82
164.2
75.9
2.64
1.64
12.15
1.7°
CADILLAC
4
a.a 7
3.73
14Q.9
43.3
3.00
1.16
1 0.74
1.52
CHEVROLET
17
7.79
3.35
110.3
38.5
1.88
0.92
15.71
2.65
CHRYSLER
5
6.05
0 .98
113.3
24.2
2.49
1 - PI
11.82
1.43
DATSUN
1
4.36
0.00
46.6
OoO
2. °1
0.00
21 =79
0.00
DODGE
5
6.12
2.65
76.8
40.7
2.76
0,79
15.51
1 .84
FORD
18
6.tO
2.27
93.°
41,2
3.10
1 .5°
1 5.92
4.11
MERCURY
2
8.15
1.24
83.7
39.0
5.36
5.25
12. 09
1.44
OLDSMORILE
4
7.30
2.37
114.4
47.7
2.61
1 .28
12.44
1.48
OPEL
2
4.18
0.84
68.2
11.9
1.78
0.00
21.61
0.29
PLYMOUTH
5
6.21
3.21
89.9
54.0
2.78
1.2?
16.76
2.41
PONTIAC
5
7.88
4.38
116.2
76.5
2.30
1 .06
12.90
1.60
TOYOTA
u
3.86
n ,U5
68.9
54 .0
2.30
1 .13
19.67
3.83
VOLKSWAGON
7
6.29
3.21
81.6
35.7
1.90
0.93
22.10
2.28
VOLVO
0
~MODEL YEAR
1964
9
7.47
1.92
110.8
37.2
2.56
1.31
14.82
2.68
1965
15
9.18
5.64
132.7
56.0
2.05
1 .09
1U.66
4.3 3
1966
11
8.29
2.89
11.5.3
32.3
2.01
0.62
16.34
4.34
1Q67
It
9.28
2.42
128.9
M .0
2.45
2.11
13.86
1.91
1 °68
5
7.21
3.43
Q6.0
33.7
2.53
0.78
16.95
3.86
1969
2
5.13
1.08
117.8
42.4
1.58
0.90
1 5 0 U-2
0.56
1970
11
u.54
1 .on
70.5
41.2
3.56
1.52
15.70
4. 3 4
1971
7
4.38
0.85
63. 1
34.9
2.89
1.37
17.87
6.36
1 Q72
7
4.38
l.OQ
59.3
26.3
3.40
1.17
17.66
4.0 0
1973
6
4.05
1.12
64.6
12.7
2.78
1.16
17.94
3.78
~DISPLACEMENT
LESS THAN 151
17
5.16
2.29
73.6
34.0
2.07
0.88
21 .48
2.68
151 - 250
18
6.42
3.3"
80.9
40.9
2.78
1.59
17.99
1 .62
251 - 350
28
7.68
2.51
114.7
40.2
2.18
0.88
14.37
1.47
MORE THAN 350
24
7.91
4.92
119.9
54.6
3.31
1.77
11 .69
1.46
~INERTIA WEIGHT
1800 - 279°
21
5.18
2.29
70.7
33.5
2.36
1.35
21 .11
2 0 56
2800 - 379Q
31'
7.1?
2.a?
°6.1
37.9
2.33
1.04
16.12
1.82
380 0 - 479°
27
8.10
u.67
1 20.0
53.8
3.00
1.80
12.67
1 .60
4800 - 579°
a
7.48
3.05
136.7
41.5
2.84
1.12
10.84
1. 1Q
~POPULATIONS
1°64 - 1Q67
no
8.70
3.70
123.7
43.6
2.25
1.40
14.84
3.45
IQ68 - 1073
38
4.79
1 .74
72.0
34.8
3.04
1 .30
16.Q7
4.3-
ALL VEHICLES
87
6.99
3.57
101.1
47.4
2.60
1.41
15.77
3.
AUTOMOTIVE TFSTING LABORATORIES'INC.
-------
EXHAUST EMISSIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
INSPECTION AND
maintenance vehicles
tt OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
* VEHICLE MAKE
AMER. MOTORS
4
6.60
2.48
78.8
27.1
3.85
1.65
17.21
0.80
BUICK
4
10.40
3.72
193.7
103.3
2.30
1.36
11.94
2.95
CADILLAC
4
6.33
1.30
126.0
31.7
2.75
0.90
11.48
1.65
CHEVROLET
17
8. 3fl
2. 69
112.7
41.7
2.13
1.44
15.18
2.27
CHRYSLER
5
6.23
1.04
116.5
38.9
2.71
1.73
11.37
1.26
DATSUN
1
3.75
0.00
45.2
0.0
3.43
0.00
21.12
0.00
DODGE
5
12.04
11.16
90.7
38.6
2.52
1.12
14.59
0.72
FORD
18
7.79
3.33
108 .5
51.2
2.81
1.58
15.55
3.68
MERCURY
2
9.34
4.35
115.4
64.6
3.82
3.99
11.94
1.31
OLDSMOBILE
4
6.53
1.79
110.0
45.1
2,59
1.27
12.95
1.07
OPEL
2
5.94
2.76
80.2
23.7
1.55
0.05
20.20
2.70
PLYMOUTH
5
5.35
1.91
85.7
39.2
3.17
1.35
16.34
2.89
PONT I AC
5
8.86
4.80
121.4
66.3
1.93
0.74
12.43
1.17
TOYOTA
4
4.35
1.08
87.3
51.7
1.69
0.72
20. 05
3.87
VOLKSWAGON
7
5.19
4.03
63.4
34.5
2.23
0.79
.22.42
1.9°
VOLVO
0
~MODEL YEAR
196 4
9
7.83
1.81
117.0
46.5
2.70
1.22
14.95
2.48
1965
15
8.70
3.39
145.8
73.7
1.92
0.97
14.19
4.09
1 966
11
9.84
3.04
122.8
39.9
2.04
0.81
15.64
3.84
1967
14
8.57
2.14
125.9
36.5
2.27
1.64
13.80
1.38
1968
5
5.31
1.82
84.4-
34.7
2.60
0.40
17.03
5.49
1969
2
5.91
0.46
130.3
37.9
1.13
0.44
15.54
1.76
1970
11
4.67
1.15
74.0
31.2
3.53
1.57
15.57
4.34
1971
7
5.90
4.03
67.5
30.8
3.25
2.11
17.32
5.87
1972
7
5.65
3.31
65.9
29.8
3.05
1.34
17.15
4.07
1973
6
8.79
11.19
70.1
12.6
2.56
1.38
17.10
3.51
~DISPLACEMENT
LESS THAN 151
17
5.04
2.68
73.5
34.2
1.96
0.77
21.08
2.57
151 - 250
18
7.95
6.63
85.8
42.0
3.04
1.73
17.56
1.94
251 - 35(1
2B
7.98
2.34
116.4
38.9
2.13
0.98
14. 12
1 .24
MORE TH£N 350
24
8.35
3.50
131.2
65.6
3.05
1.64
11.61
1.57
~INERTIA WEIGHT
1800 - 279a
21
5.30
2.79
72.7
32. 4
2.19
1.02
20.79
2.47
2 800 - 379°
31
8.01
5.26
100.6
41.0
2.40
1.47
15.67
1.80
3800 - 479Q
27
8.96
3.04
129.8
61.6
2.92
1.58
12.54
1.60
4800 - 579°
a
6.41
1.68
131 .8
49.6
2.69
1.28
10.95
1.50
~POPULATIONS
1964- - 1967
49
8.76
2.74
12Q. 6
52.6
2.19
1.21
14.54
3.16
1Q6R - 1°73
38
5.88
4.89
75.0
31.0
2.9a
•1.52
16.73
4.38
ALL VEHICLES
87
7.50
4.07
105.8
51.9
2.54
1.40
15.50
3.88
AUTOMOTIVE TESTING LABORATORIES!INC.
-------
EXHAUST EMISSION REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
n OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
* VEHICLE MAKE
AMER. f-'.OTORS
4
fl .948
1.90
9.59
19.2
-0.026
0.05
-0.445
0.8Q
BUICK
4
-0.092
2.27
8.50
20.4
0.029
0.59
-0.017
0.95
CADILLAC
4
0.157
0.31
7.96
15. a
0.017
0.03
-0.161
0.32
CHEVROLET
17
0.557
1. 16
4.60
19.7
0 .1 83
0.36
-0.118
1.15
CHRYSLER
5
1 cllP
13.4Q
77.21
103.1
-0.527
0.81
-1.443
1.8°
DATSUN
1
o.ou
0 oOO
-4.40
0.0
0o705
0.00
0.257
0.0<"i
DODGE
5
-0.152
2.46
11 .86
35.4
0.313
1.18
-0.523
1.28
FORD
1 8
0.838
2.15
9.08
19.7
-0.0 36
0.40
-0.295
1.01
MERCURY
2
OoOno
0 .00
0.00
0.0
0.000
0.00
0.000
0.0H
OLDSMORILE
4
0.281
0.56
11.04
22.1
-0.053
0.1]
-0 .146
0.29
OPEL
2
1.162
0.08
18.07
0.7
-0.196
0.27
-0.547
0.52
PLYMOUTH
5
0.355
0.76
11.31
17.2
-0 .237
0.53
-0.302
0.84
PONT I AC
5
3.831
9.21
-14.61
23 i 9
0. 163
0.26
0 .091
0 .25
TOYOTA
4
1 .362
0.96
12.24
12.5
0.187
0.52
-1.306
1.60
VOLKSWAGON
7
0.975
1.31
4.23
21.5
0.246
1.06
-0.590
1.44
VOLVO
n
~MODEL YEAR
1964
9
0.567
0.76
19.17
32.1
-0.138
0.24
-0.439
0.82
1965
15
1.933
5.54
1.42
27.4
0 . 060
0.31)
0.036
1.16
1 °66
11
1.211
1.4o
12.99
18.5
0 .376
0.73
-0.879
1.17
1967
14
-0.478
1.51
-5. Q8
17.5
0 .128
0 .27
0.295
0 .63
1968
5
2.030
1 .27
29.35
23.9
-0.192
0 .70
-0.843
1.14
1969
2
1 .260
1 .36
a.36
5.4
0.231
0.51
-0.410
0.13
1970
11
0.8A7
1 .57
9.9°
18.1
0.150
0 .83
-0.386
0. 6o
1971
7
0.901
1 .31
8.28
12.2
0.H58
0.58
-0.843
1.51
1972
7
4.812
11 .82
46.44
90.0
-0.497
0.76
-1.185
1.57
1973
6
0.037
0.81
3.01
8.0
0 . 005
0.05
0.159
0 .33
~DISPLACEMENT
LESS THAN 151
17
0.983
1 .29
7.46
16.1
0 .169
0.72
-0.702
1.32
151 - 250
18
-0.030
0.92
0.06
17.3
0.073
0.43
-0.008
1.2?
251 - 350
28
0.929
1 .96
13.13
22.9
0.100
0.55
-0 „4U7
0.81
MORE THAN 350
24
2.550
7.54
18.07
55.8
-0.137
0.51
-0.287
1.07
* INERT IA WEIGHT
lflOO - 279°
21
0.897
1.20
5.67
16.9
0. 195
0.67
-0 .4RR
1.51
2800 - 379°
31
0.383
1.83
6.99
21.5
0.073
0.55
-0.305
0.90
3800 - 479°
27
2.706
7.07
21.04
53.2
-0. 108
0.54
-0.452
1 .06
4800 - 579°
8
-0.050
0.58
3.13
12.3
0. 028
0.04
0.P50
0.37
~POPULATIONS
106u - 1Q67
4°
0.831
3.3?
5.16
25.2
0.114
0.45
-0.183
1 .05
1°68 - 1°73
38
1.648
5.15
17.7a
41 .ft
-0.050
0.67
-0.593
1.11
ALL VEHICLES
87
1.188
4.21
10.68
33.9
0.042
0.56
-0.362
1 .09
AUTOMOTIVE TESTING LABORATORIES*INC.
loonn E. COLFAX» AURORA» COLO, R0011
-------
EXHAUST EMISSION REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
n OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
~VEHICLE MAKE
AMER. MOTORS
4
D.645
2.22
15.58
19.6
-0.633
0.27
-0.306
1.03
BUICK
4
2.629
4.31
-21.08
51.7
0.367
1.09
0.196
1.59
CADILLAC
4
2.294
3.<50
31.81
23.2
0.264
0.73
-0.904
1.59
CHEVROLET
17
-0.039
2.22
2.20
27.2
-0.065
0.96
0.407
1.62
CHRYSLER
5
7.585
13.49
74.10
9°.9
-0.747
0.94
-0.PQ4
1.77
DATSUN
1
0.621
0.00
-2.98
0.0
0.186
0.00
0.926
0. 00
DODGE
5
-6.074
12.23
-2.02
33.7
0.557
1.18
0.392
1.39
FORD
ia
-0.547
3.78
-5.53
33.4
0.256
1.03
0.081
1.53
MERCURY
2
-1.183
5.59
-31.75
25.6
1.542
1.26
0.154
2.75
OLDSMOBILE
4
1.044
1.13
15.45
30.2
-0.032
0.19
-0 .661
1.01
OPEL
2
-0.592
2.00
6.08
12.5
0.034
0.22
0.862
1.89
PLYMOUTH
5
1.214
1.08
15.58
24.4
-0.633
0.94
0.126
1.64
PONTIAC
5
2.851
9.37
-19.78
19.8
0.537
0.26
0.562
l.m
TOYOTA
4
0.874
0.84
-6.09
19.1
0.802
0.42
-1.686
1.87
VOLKSWAGON
7
2.071
5.16
22.43
36.2
0.007
1.20
-0.908
2.51
VOLVO
0
~MODEL YEAR
1964
9
0.213
2.25
12.94
27.4
-0.285
0.68
-0.570
1.01
1965
15
2.420
6.13
-11.62
43.7
0.187
0.52
0.511
1.79
196o
11
-0.333
3.04
5.52
34.4
0.345
0.95
-0.174
1.39
1967
14
0.230
2.20
-2.94
31.2
0.307
0.81
0.358
1.64
1968
5
3.921
5.10
40.97
32.7
-0.268
1.36
-1.817
2.28
1969
2
0.480
0.74
-3.34
0.9
0.666
0.04
-0.533
1.33
1970
11
0.758
1.87
6.48
31 .1
0.182
1.28
-0.252
0.96
1971
7
-0.62 5
3-.70'
3.91
. 7.1
-0.312
1.44'
-0 .202
1.91
1972
7
3.544
12.62
39.83
91.8
-0.140
1.36
-0.674
1.94
1973
6
-4.703
11 .32
-2.47
15.1
0.221
0.63
1.004
1.58
~DISPLACEMENT
LESS THAN 151
17
1.109
3.37
7.58
27.6
0.284
0.88
-0.309
2.30
151 - 250
18
-1.567
6.77
-4.90
27.1
-0.134
1.29
0.420
1 .74
251 - 350
28
0.626
2.43
11.48
28.5
0 .146
0.70
-0.197
1.23
MORE THAN 350
24.
2.113
8.43
6.69
64.1
0.122
1.03
-0.202
1.47
* INERTIA '.'/EIGHT
1800 - 2799
21
0.786
3.12
3.64
26.9
0.368
1.. 0 3
-0.168
2.28
2800 - 3799
31
-0.507
5.53
2.57
27.0
0.003
0.96
0.149
1.40
3800 - 4799
27
1.848
7.94
11.20
60.6
-0.026
1.01
-0.320
1.40
4800 - 57°9
8
1.028
3.01
8.04
40.1
0.180
0.60
-0.063
1.45
~POPULATIONS
1964 - 1°67
40
0.771
4.04
-0.78
35.7
0.170
0.76
0.115
1 .55
1968 - 1973
38
0.556
7.56
14.76
45.9
0.005
1.18
-0.35°
1.73
ALL VEHICLES
87
0.677
5.80
6.01
41.0
0.098
0 . Q6
-0.092
1.64
AUTOMOTIVE TESTING LABORATORIES
.. INC.
19°00 E.
COLFAXr
AURORA
, COLO.
aoon
-------
PERCENT REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
U OF PERCENT REDUCTIONS
VEH. HC CO NOX MPG
~VEHICLE MAKE
AMER. MOTORS
RUICK
CADILLAC
CHEVROLET
CHRYSLER
DATSUN
DODGE
FORD
MERCURY
OLDSMOBILE
OPEL
PLYMOUTH
PONTIAC
TOYOTA
VOLKSWAGON
VOLVO
4
4
4
17
5
1
5
la
2
4
2
5
5
4
7
0
13.09
-0,71
1 o 82
6 . 68
56.24
0.24
-2.54
11.58
0.00
3.71
21.73
5.40
32.72
26.08
13.43
10o 17
4 o 92
5o 04
4 o 0 1
4 0.52
¦10.42
13.37
8.81
0.00
8.80
20.96
11.18
-14.37
15.07
4.93
-0.82
1.10
0.57
8.86
-26.86
19.51
10.18
-1.16
0.00
-2.06
-12.39
-9.33
6.61
7.50
10.98
-2.63
-0.14
-1 .53
-0 .76
-13.°1
l.lo
-3.49
-1.89
0.00
-1.19
-2.60
-1 .84
0.70
-7.11
-2.74
~MODEL YEAR
1964 9 7.06
1965 15 17.39
196b 11 12.75
1967 14 -5.43
1968 5 21.98
1969 2 19.70
1970 11 16.34
1971 7 17.08
1972 7 52.33
1973 6 0.91
14.75 -5.73 -3.05
1.06 2.83 0.25
10.12 15.73 -5.69
-4.86 4.96 2.08
23.41 -8.20 -5.23
7 c 21 12.73 -2.73
12.41 4.04 -2.52
11.60 1.96 -4.95
43.91 -17.09 -7.19
4 o 45 0.19 0.88
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
17
18
28
24
15.99
-0.48
10.79
24.38
9.20
0.07
10.27
13.-10
7.53
2.55
4.38
-4.32
-3.38
-0.05
-3.21
-2.51
* INERTIA WEIGHT
1800 - 279°
2800 - 3799
3800 - 479°
4800 - 5799
21
31
27
8
14.75
5.11
25.04
-0.68
7.43
6.78
14.92
2.24
7.63
3.05
=3 o 72
0.97
-2.37
-1.93
—o 7 0
0.46
~POPULATIONS
1964 - 1°67
1968 - 1973
ALL VEHICLES
49
38
87
8.72
25.62
14.53
4.01
19.81
9.55
4.82
— 1.66
1.61
-1.25
-3 . 62
-2.35
AUTOMOTIVE TESTING LAPORATORIES»INC.
19°00 E. COLFAX t AURORA» COLO. 8001 1
-------
PERCENT REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
INSPECTION AND MAINTENANCE VEHICLES
U OF
VEH.
HC
•PERCENT REDUCTIONS
CO NOX
MPG
~VEHICLE MAKE
AMER. MOTORS
BUICK
CADILLAC
CHEVROLET
CHRYSLER
DATSUN
DODGE
FORD
MERCURY
OLDSMOBILE
OPEL
PLYMOUTH
PONT IAC
TOYOTA
VOLKSWAGON
VOLVO
4
4
4
17
5
1
5
lfl
2
4
2
5
5
4
7
0
8.90
20.18
26.58
-0.47
54.89
14.19
-101.78
-7.55
-14.50
13.78
-11.06
18". 50
24.36
16.74
28.52
16.51
-12.21
20.15
1.92
38.89
-7.05
-2.28
-5.37
-37.95
12.31
7.05
15.38
-19.46
-7.50
26.13
-19.70
13.75
8.77
-3.15
-38.06
5.15
18.09
8.36
28.77
-1.24
2.13
-24;59
21.76
32.18
0.33
-1.81
1.61
-8.55
2.61
-c .58
4.20
2.62
0.52
1.27
-5.37
4.09
0.76
4.32
-9.18
-4.22
~MODEL YEAR
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
9
15
11
14
5
2
11
7
7
6
2.65
21.77
-3.51
2.62
42. 46
7.50
13.96
-11.85
38.55
-114.95
9.96
-8.66
4.31
-2.39
32.68
-2.63
8.04
5.48
37.67
-3.65
-11.81
8.87
14.46
11.93
-11.46
37.79
4.91
-10.59
-4.81
7.93
-3.97
3.48
-1.13
2.53
-11.28
-3.55
-1.64
-1.71
-4.09
5.55
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
17
18
28
?4
18.05
-24.54
7.27
20.20
9.35
¦6.06
8.98
4.85
12.69
-6.46
6.40
3.85
-1.49
2.34
-1.41
-1.77
~INERTIA WEIGHT
1800 - ?7QQ
2800 - 37QO
3800 - 47P9
4800 - 57QQ
21
31
27
8
12. Q2
-6.76
17.10
13.83
4.77
2.49
7.94
5.75
14.36
0.11
-0.91
6.27
-0.61
0.94
-2.62
-0.58
~POPULATIONS
1Q64 - 1Q67
1968 - 1973
ALL VEHICLES
4Q
38
87
8.09
8.64
8.28
-0.60
16.44
5.37
7.20
0.17
3.72
0.78
¦2.20
-0.60
AUTOMOTIVE TESTING LABORATORIES.INC.
19«00 E. COLFAX, AURORA. COLO. 80011
-------
EXHAUST EMISSIONS BEFORE INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE
VEHICLES
a OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
~VEHICLE MAKE
AMER. MOTORS
2
fl.62
1.81
115.4
24.0
2.74
2.07
12.38
1.25
BUICK
2
7.55
2.34
168.0
45.5
1 .89
0.86
10.19
1.4t
CADILLAC
0
CHEVROLET
23
7.82
5.29
113.7
63.8
2.19
1.18
13.04
1.44
CHRYSLER
0
DATSUN
0
DODGE
3
6.71
2.91
107.8
11.8
2.78
0.74
14.85
2o 12
FORD
25
7.29
3 o 27
96.6
37.8
2.99
1.80
14.54
2.90
MERCURY
3
4.88
1.28
48.5
19.0
3.60
1.59
15.85
1.60
OLDSMOBILE
3
8.39
6. 08
135.3
62.6
1.40
0.29
11.52
1.10
OPEL
0
PLYMOUTH
a
9.66
7.88
134.8
32 06
2.27
0.92
12.84
1.47
PONTIAC
7
7.24
3. 06
113.0
52.0
2.47
1.21
12.55
0.75
TOYOTA
0
VOLKSVjAGON
2
4.81
1.36
66 e 6
1 .6
2.11
0.04
21.56
1.38
VOLVO
0
~MODEL YEAR
1964
5
12.04
2.90
168.6
31.1
1.40
0.30
12.94
0.88
1965
5
13.46
7.80
179.0
78.6
1.93
1.83
12.47
1. °6
1966
7
8.29
1.41
128.1
28.6
2.66
0.84
13.04
1 .44
1967
6
11.31
4.42
141 .2
56.4
1 .77
1.53
15.19
3.69
1968
'lO
7.11
1.37
105.8
50.5
3.35
2.05
14.13
1.86
1 969
8
5.72
1 .69
86.7
29.5
2.93
1.14
14.47
1.67
1970
6
9.9°
9.40
87. 1
38.5
3.25
1.62
14.27
3.53
1971
10
5.90
1.39
84.7
38.2
3.15
1.23
14.68
4,60
1972
11
5.61
1.05
101.0
34 „ 5
2.35
1.10
13.31
2.03
1973
10
4.12
1.23
76.2
26.2
1.77
0.57
12.35
0.84
~DISPLACEMENT
LESS THAN 151
2
4.81
1.36
660 6
1.6
2.11
0.04
21.56
1.38
151 - 250
9
4 o 59
1.66
75.4
28.5
2.71
1.08
16.82
3.59
251 - 350
43
9.32
5.27
125.6
53.5
2.24
1.34
13.48
1.46
MORE THAN 350
24
5.85
1.64
94.2
38.9
3.03
1.56
12.28
1.60
~INERTIA WEIGHT
1800 - 2799
5
4.3°
1.27
62.7
22. 0
2.83
1.11
20.84
2.96
2B00 - 379°
41
6. Q8
2.Q0
101.7
42.6
2.41
1.32
14.03
1 .56
3800 - 479Q
32
8 o 87
5.92
124,8
56.0
2.64
1.56
12.17
1.26
<+800 - 5799
0
~POPULATIONS
1964 - 1967
23
11.02
4.64
15] .4
51.8
1.99
1.26
13*45
2.38
1968 - 1973
55
6.16
3.58
on. 8
37.0
2.76
1.41
13.81
2.68
ALL VEHICLES
78
7.59
4.49
108.7
50.0
2.53
1.40
13.70
2.59
AUTOMOTIVE TESTING LARORATORIES.INC.
jponn E. COLFAX. AURORA. COLO, snnil
-------
EXHAUST EMISSIONS AFTER INSPECTION AMD MAINTENANCE
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE VEHICLES
» OF HC CO NOX MPG
VEH. MEAN S.D. MEAN S.D. MEAN S.D. MEAN S.D.
~VEHICLE MAKE
AMER. MOTORS
2
6.98
2.97
51.6
6.2
3.87
0.75
13.15
0 . 33
BUICK
2
5.66
0.45
124.9
17.6
2.21
0.70
10.50
1 .66
CADILLAC
0
CHEVROLET
23
6.60
3.29
108.5
58.4
2.01
1.18
13.24
1 .38
CHRYSLER
0
DATSUN
0
DODGE
3
9.80
5.73
143.9
59.4
2.01
1.31
14.60
3.08
FORD
25
7.01
2.Q5
94.5
36.7
2.51
1 .43
14.52
2.86
MERCURY
3
4.63
0.66
64.1
38.6
3.83
2.72
14.25
2.00
OLDSMOBILE
3
6.70
3.19
133.5
65.4
1.40
0.67
12.08
0.72
OPEL
0
PLYMOUTH
R
6.43
2.62
111.7
21.1
2.26
0.77
13.18
2.10
PONTIAC
7
6.11
2.14
96.7
50.7
2.64
1.20
13.05
0.77
TOYOTA
0
VOLKSWAGON
2
5.36
1.34
73.7
6.7
1.75
0.28
21.73
0.31
VOLVO
0
~MODEL YEAR
1964
5
10.23
2.24
174.0
33.6
0.92
0.24
12.96
1.12
1965
5
q.qo
2.56
157.8
37.7
1 .63
0.96
13.05
1.24
1966
7
8.1 1
1.10
118.7
33.0
2.70
0 .88
13.5^
1.^1
1967
6
9.88
3.71
134.2
49.6
1.60
1.35
15.63
3.59
1968
10
6.44
3.33
94.4
39.8
2.67
1 .59
13.68
1 .36
1969
8
6.79
3.19
95.2
55.7
3.02
1.93
14.63
1.78
1970
6
5.22
1 .41
82.1
33.5
2.49
0.96
14.69
3.76
1971
.10
5.23
0.96
72. Q
28.3
3. 09
1.20
1 4.60
u.27
1972
11
5.32
2.15
86.1
35.4
2.49
1.01
13.38
2.27
1973
10
4.29
1 .05
78.4
30.0
1 .74
0.84
12.40
1.10
~DISPLACEMENT
LESS THAN 151
2
5.36
1 .3U
73.7
6.7
1 .75
0.28
21 .73
0.31
151 - 250
9
4.1 n
0.92
63.7
28.4
2.82
1 .08
17.60
2.80
251 - 350
"3
7.79
3.25
121 .a
45. 1
1 .83
0 . Q8
13.37
1.37
MORE THAN 350
24
5.77
1.91
83.0
39.5
3.13
1.51
12.54
1 .43
~INERTIA WEIGHT
lann - 27°°
5
4.45
1.18
58.5
16.9
2.87
1 .29
21.08
1
2800 - 37QQ
41
6.58
2.87
9Q. 5
42.9
2.18
1.28
13.9o
1 .67
3BflO - 479Q
32'
7.15
3.14
111.9
51.0
2.47
1.35
12.46
1. 13
4800 - 5799
0
~POPULATIONS
1964 - 1°67
23
9.44
2.53
143.3
42.4
1 .80
1 .12
13.85
2.30
1Qft8 - 1a73
55
5.52
2.30
84.7
36.8
2.57
1 .32
13.80
2.63
ALL VEHICLES
78
6 • 68
2. °6
102.0
46.8
2.34
1.31
13.82
2.52
AUTOMOTIVE TESTING LABORATORIES'INC.
loono E. COLFAX t AURORA. COLO. 80-111
-------
EXHAUST EMISSIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
MANOATORY MAINTENANCE VEHICLES
» OF HC CO NOX MPG
VEH. MEAN S.D. MEAN S.D. MEAN S.D. MEAN S.O.
~VEHICLE MAKE
AMER. MOTORS
2
5.05
0.83
69.5
16.1
3.31
2.15
14.03
1 .67
RUICK
2
5.3?
1 .06
112.1
59.9
2.53
1.28
11.81
1.55
CADILLAC
0
CHEVROLET
23
9.32
10.45
116.8
66.7
1 .86
1.10
13.?°
2.20
CHRYSLER
0
DATSUN
0
DOOGE
3
8.90
5.49
154.8
91.8
?»56
1.84
13.92
3.60
FORD
25
8.67
5.94
°3.6
49.0
2 .68
1.70
14.83
3.02
MERCURY
3
4.46
0.34
49.9
15. Q
3.28
1.56
14.47
1 .25
OLDSMOBILE
3
16.02
18.33
130.9
62.7
1 0 23
0.57
11.88
O.r.fl
OPEL
0
PLYMOUTH
a
' 14.95
15.72
135.0
43.0
?.10
1.15
12.27
1 .67
PONT IAC
7
7.35
3.00
108.8
55.2
2.80
1 .59
12.71
0 .79
TOYOTA
0
VOLKSWAGON
2
5.02
1 .28
69.2
6.7
2.20
0.53
20,73
0.56
VOLVO
0
~MODEL YEAR
l°6u
5
13.14
3.96
185.1
32.4
0.81
0.37
12.44
0 .57
1&65
5
1 1 .96
3.93
168.5
5^. 3
1 .33
0.81
12.76
1 .58
1 Qnn
7
18.23
15.48
146.9
.38.2
?.31
1.18
12.??
1.-7
1967
6
18.78
16.98
135.6
66.9
1.61
1.52
15.29
4 . 66
1 Oftfl
1 0
6.06
1 .37
91.3
44.8
2.94
1 . 4Q
1 4 „ 0 'I
0 . = ft
10oQ
P.
9 .7°
1 1 .31
93.0
70.6
2.94
1 .45
14.45
2.fl
1Q70
ft
6.77
3.62
90.0
49.5
2.36
0.86
14.73
3.67
1 °71
10
7.B9
7.51
76. 1
38 .6
3.11
1.13
15.12
3. ~6
1972
11
5.02
1.89
88.7
53.2
2.75
1 «9Q
13.8°
2.-6
1973
1 0
4.15
0.9?
78.0
27.4
1 .86
0.97
12.63
1 .34
~DISPLACEMENT
LESS TH4N 151
?
5.02
1 .28
69.2
6.7
2.20
0.53
?0.73
0.56
151 - 250
9
3.Q7
1 .30
61 .0
34.4
3.21
1.87
18.1?
2.-7
251 - 350
43
11 .73
10.49
128.8
57.7
1 .83
1.11
13.14
1 .70
MORE THAN 350
24
7.13
6.84
89.6
48.5
2.97
1 .47
12.84
1 .74
~INERTIA WEIGHT
J BOO - 27QQ
5
4.26
1.14
54.0
?°.o
3.68
?. 30
21.09
1 .57
2600 - 3799
41
7.58
5.0 3
101.9
54.6
2.1?
1.16
14.2?
1 • G0
3800 - 17Qo
32
12.16
12.50
122.8
58.9
2.45
1 .52
12.15
1 .22
4800 - 579°
n
~POPULATIONS
1°64 - 1Q67
23
15.an
12.07
1 57.0
50.3
1 .5Q
1.17
13.10
? . c 6
1°68 - 1Q73
55
6.46
5.64
86.7
46.6
2.67
1.42
14.08
2.*1
ALL VEHICLES
78
9.24
9. 1 0
1 07.4
57.3
2.35
1.43
13.81
2.70
AUTOMOTIVE TESTING LfiRORA TORIESrINC.
l°CiOO E. COLFAX t AURORA. COLO. 80011
-------
EXHAUST EMISSION REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE VEHICLES
8 OF HC CO NOX MPG
VEH. MEAN S.D. MEAN S.D. MEAN S.D. MEAN S.D.
~VEHICLE MAKE
AMER. MOTORS
2
1 .639
1.16
63.76
17.B
-1.125
1.31
-0.773
0.92
BUICK
2
l. Rat
1.89
43. 12
27.8
-0.316
0.16
-0.308
0.22
CADILLAC
0
CHEVROLET
23
1.215
3.31
5.22
29.6
0.1BR
0.72
-0.199
1.16
CHRYSLER
0
DATSUN
0
DODGE
3
-3 « 089
4.53
-36.10
49.3
0.766
1.73
0.254
0.97
FORD
25
0.282
1.80
2.11
24.9
0.482
1 .30
0.014
1 .07
MERCURY
3
0.250
1.92
-15.65
20.5
-0.229
1.71
1 .609
1.60
OLDSMOBILE
3
1 .697
5.83
1 .80
31.3
0.008
0.60
-0.564
0.41
OPEL
0
PLYMOUTH
-B
3.22R
8.86
23.07
15.2
0.007
0.44
-0.341
1.02
PONTIAC
7
1.13?
1.18
16.32
17.5
-0.168
0.5B
-0.501
1.10
TOYOTA
n
VOLKSWAGON
2
-0.557
0.02
-7.07
5.1
0.357
0.31
-0.175
1 .07
VOLVO
0
~MODEL YEAR
1964
5
1. B12
4.18
-5.38
24.9
0.481
0. 17
-0.023
0.9Q
1965
5
3.472
6.78
21.14
51 .2
0 . 2Q5
1 .15
-0.58?
1 .24
1 966
7
0.185
1 .Q6
9.30
23.2
-0.043
0 .38
-0.506
0.94
1 °67
6
1.437
2.07
6.98
22.2
0. 165
0.36
-0.4u'5
0. ft 5
196R
10
0.673
3.50
1 1 .42
38.2
0.685
1.2B
0.4H7
1 .45
lQfiQ
B
-1.06a
2.35
-8.51
38. Q
-o.non
1.41
-0.154
1 .33
1970
6
4 .763
a. 53
5.04
26.0
0.75a
2.06
-0.425
1.51
1«71
10
0.667
1 .07
11 .74
18.8
0.058
0.56
0.087
0.71
197?
11
0.287
1 .?a
1U.B4
32.5
-0.131
1 .00
-0.076
1.27
1973
10
-0.168
0.72
-2.2?
11.1
0.033
0.43
-0.055
0 . 80
~DISPLACEMENT
LESS THAN 151
2
-0.557
0.02
-7.07
5.1
0.357
0.31
-0.175
1.07
151 - PRO
Q
(1.491
1.55
1 1 .68
30.7
-0.112
0.60
-0.775
1 .32
251 - 350
43
1 .531
4.PQ
.3.74
30.6
0.410
0 .90
0.107
1.06
MORE THAN 350
24
0.088
1 .50
1 1.24
27.Q
-0. JOB
1.26
-0.264
1 .04
*INFRTIA WEIGHT
1800 - ?7QO
5
-0.060
0.78
4.22
28.fi
-0.041
0.81
-0.240
1.07
2R00 - 37QQ
U1
0.400
2.16
2.15
28.6
0.22R
1.13
0.031
1 .23
3800 - 47o<=
32
1.724
5.35
12.88
30.1
0.174
0.89
-0.286
0.°2
4R00 - 57QO
0
~POPULATIONS
!Of,u - 1°67
23
1 .58(1
3.87
B. 1 1
30.5
0 . 1 °B
0.60
-0.402
O.oi
IQftB - 1973
55
0 .635
3.77
6.09
2°.l
0. 1 R5
1.15
0.003
1.16
ALL VEHICLES
7fl
0.Q14
3.80
6.68
20.4
0.1R9
1.01
-0.116
1.10
AUTOMOTIVE TFSTINJG L&BOH
iATORIES
» INC.
IQ^On E.
COLFAX.
At iRORA r
COLO.
Ron 11
-------
EXHAUST EMISSION REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE
VEHICLES
tt OF
HC
CO
NOX
MPG
VEH.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
MEAN
S.D.
* VEHICLE MAKE
aver, motors
2
3.575
2 .64
45.R7
8.0
-0.567
0.08
-1.657
0 .42
PUICK
2
2.2?4
1 .27
R5.01
14'. 4
•0.636
0.41
-1.625
0.11
CADILLAC
0
CHEVROLET
23
-1.son
8.54
-3.13
27.9
0.330
0.63
-0.253
1.50
CHRYSLER
n
DATS' IN
0
DODGE
3
-2.184
2.67
-47.00
85. 0
0.22?
2.19
0.931
1 .Ofi
FORD
25
-1.375
4.R3
3.05
38. 1
0 .7)08
1 .55
-0.2Q4
1 .42
MERCURY
3
0.41 P
1.02
-1 .37
4.2
0.319
0.80
1 .389
1 .52
OLDSMOBILE
3
-7.624
21 .09
4.38
33.7
0.178
0 .66
-0.361
1 .04
OPEL
0
PLYMOUTH
n
-5.293
18.83
-0.18
28.5
0.171
1 .06
0.568
1 .24
PONTIAC
7
-0.10?
0.78
4.23
20.4
-0.333
0 .55
-0.16"
0.Q5
TOYOTA
0
VOLKSWAGON
2
-0.211
0 .OR
-2.61
5.0
-0.091
0.57
0.825
0 .83
VOLVO
0
*MODEL YEAS
1964
5
-1 . 102
5.95
-16.56
31.8
0.585
0.2?
0 .404
1 .17
1 °65
5 '
1 . 497
3. Q6
1 0.47
31.5
0.601
1 .2?
- 0 o 2 ° 5
0 .°0
1 966
7
-9.937
16.23
-18.73
17.3
0 .345
0 .87
0.817
1 .28
1 967
6
-7.467
15.44
5.54
45. Q
0.161
0.50
-0.100
1 .89
1 068
1 0
1 .05?
1 .26
1 4.5A
24.7
0.416
O.OR
0.131".
1 .39
1 969
R
-u.064
1 0.73
-6.30
58.2
-0 . Of,a
1 .33
0 . 024
1 .80
1970
6
3.214
10.0ft
-11 .87
40.6
0.896
1 . Q6
-0.459
1 .81
1971
10
-1.9Q8
6.64
8.59
?Q.4
0 .038
0.66
-0.439
1.46
1972
11
0.585
2.0Q
12.31
40.5
-0.394
1 .57
-0.586
1.30
1 °73
10
-0.026
0.91
-1.82
17.0
-0.091
0.57
-0.27°
1 .21
~DISPLACEMENT
LE5S THAN 151
2
-0.211
0.08
-2.61
5.0
-0.091
0.57
0.825
0 .83
151 - 250
9
0.623
0.81
14.43
27. Q
-0.505
1.66
-1„2°4
1 .73
251 - 350
43
-2.408
1 0 . 50
-3.16
35.8
0.403
0.91
0 .343
1 .36
MORE THAN 350
24
-1.273
6.73
4.58
37.3
0.055
1 .14
-0.564
1 .05
~INERTIA WEIGHT
180 0 - 27 9u
5
0.127
0.70
8.71
38.3
-0.P54
2.10
-0.251
2'. 09
2800 - 379°
41
-0.598
3.76
-0.20
37.2
0.288
1 .07
-0.198
1 .44
3800 - U7QO
3?
-3.28?
12.85
1 .Q8
32.7
0.198
0.90
0.020
1 .32
4800 - 5799
0
~POPULATIONS
1 9A4 - 1 Or>7
23
-4.«R6
1 2 .56
-5.58
3^.1
0.405
0.76
0 . 2 6 r •
1 .37
1968 - 1 973
55
-0.30 0
6.11
4.13
35.8
0 .083
1.21
-0.271
1 .43
ALL VEHICLES
78
-1.653
8.70
1 .27
35. 1
0.178
1.10
-0.11?
1 .4?
AUTOMOTIVE TESTING LABORATORIES,INC.
-------
PERCENT REDUCTIONS AFTER INSPECTION AND MAINTENANCE
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE VEHICLES
n of
VEH.
HC
-PERCENT REDUCTIONS
CO NOX
MPG
~VEHICLE MAKE
AMER. MOTORS
BUICK
CADILLAC
CHEVROLET
CHPYSLER
DATSUN
DODGE
FORD
MERCURY
0LDSM03ILE
OPEL
PLYMOUTH
PONTIAC
TOYOTA
VOLKSViAGON
VOLVO
2
2
0
23
0
0
3
25
3
3
0
3
7
0
2
0
19.ni
24. 96
15.54
-46.02
3o«7
5.11
20 .22
33.43
15.63
-11.5ft
55.25
P5. 66
4.59
-33.49
2.19
-32.27
1.33
17. 11
14.43
-10.61
-40.99
¦16.72
8. 5fl
27.58
16.13
-6.34
0.55
0.33
-6.82
16.90
-6.24
-3.02
-1.52
1 .71
0.10
10.15
.89
-2.65
-4.00
-0.81
~MODEL
1 964
1965
1966
1967
1968
1969
1 Q70
1971
1972
1973
YEAR
5
5
7
6
10
8
6
10
11
10
15.05
25.80
2.23
12.70
a.46
¦18.59
47.7n
11.31
5.12
-4.09
-3.1Q
11.81
7.33
4.95
10.79
-9.81
5.79
13.87
14.70
-2.91
34.40
15.28
-1.62
9.31
20.42
-3.07
23.33
1.85
-5.55
1.89
-0.18
¦4.67
¦3. Rfi
•2.93
3.16
-1.06
-2.98
0.59
-0.57
-0.45
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
2
O
43
24
¦11.58
10.70
16.44
1.50
•10.61
15.49
2.97
11.93
16.90
-4.12
IB.31
-3.58
¦0.81
-4.60
0.79
-2.15
* INERTIA V;EIGHT
1800 - 27°M
2800 - 3799
3800 - 4799
4800 - 579Q
5
41
32
0
-1.36
5.73
1°. 43
6.73
2.11
10'. 32
-1.45
9.48
6.58
-1.15
0.2?
-2.35
~POPULATIONS
1964 - 1967
1968 - 1°73
ALL VEHICLES
23
55
78
14.34
10.31
12.04
5.35
6.71
6.15
9. Q5
6.70
7.46
-2.QO
0.02
-0.85
AUTOMOTIVE TESTING LABORATORIES* INC.
19a0 0 E. COLFAX. AURORA t COLO. 80011*
-------
PERCENT REDUCTIONS AFTER SIX MONTHS
1975 FEDERAL TEST PROCEDURE
MANDATORY MAINTENANCE VEHICLES
ti OF
VEH.
HC
¦PERCENT REDUCTIONS
CO NOX
MPG
~VEHICLE MAKE
AMFR. MOTORS
81 lICK
CADILLAC
CHEVROLET
CHRYSLF3
OAT SI IN
DODGE
FORD
MERCURY
OLDSMOBILE
OPEL
PLYMOUTH
PONTIAC
TOYOTA
VOLKSWAGON
VOLVO
2
2
0
23
0
n
3
25
3
3
n
fl
7
0
2
0
ui .47
29.47
-19.18
•32.51
¦1 8.84
R o 5ft
-90.83
-54.a?
-1.41
-4.39
39 o 75
33 o 27
-2.76
-43.60
3=16
-2.82
3.23
-0.14
3.74
-3.91
-2 0.66
-33.60
15.05
7 o 98
10.32
8.85
12.64
7.51
-13.49
-4.30
•13.39
¦15.94
-1 .94
6.27
-2.02
8.76
-3.14
4.43
-1.27
3.83
~MODEL YEAR
1°64
1965
1966
1967
1968
1 °6°
1 °70
1 971
1972
1973
5
5
7
6
10
8
6
10
11
10
-9.15
11.12
-119.87
—66.00
14 0 79
-71 .03
32. 18
-33.8°
10.42
—0 • 64
-9.82
5.85
-in.62
3.92
13.76
-7.27
-13.63
10. 15
12.1 9
-2.39
4 1.86
31 . 16
12.97
9.13
12.40
-0.32
27.54
1.20
-16.73
-5.15
3.82
-2.37
6.27
-0 . 66
0 . °2
0.17
-3.2?
•2.99
-4.40
•2.26
~DISPLACEMENT
LESS THAN 151
151 - 250
251 - 350
MORE THAN 350
2
Q
43
24
-4.39
13.56
-25.84
-21.75
-3.91
19.14
-2.51
4 o 86
-4.30
•18.64
ia. oo
1.80
3.83
•7.69
2.55
-4.59
~INERTIA WEIGHT
1800 - 279°
2 80 0 - 37°°
3800 - 479°
4800 - 5799
5
41
32
0
2.88
-8 o 57
-36.9Q
13.88
-0.20
1.59
¦30.2C
11 .98
7.50
¦1.20
-1.41
0.16
~POPULATIONS
1964 - 1Q67
1Q68 - 1Q73
ALL VEHICLES
23
55
78
-44.35
-4. fir,
-21.77
-3.69
4.5.r)
1. 16
20.31
3.03
7.04
1.08
-1.9o
-0.82
AUTOMOTIVE TESTING LABORATORIES*INC.
IQ'MVi E. COLFAX» AUKO^Af COLO. Hflull
-------
ALL VEHICLES
BEFORE INSPECTION AND MAINTENANCE
PERCENTAGE OF VEHICLES
5.0
10.0
15.0
20.0
25.0
0.0000 -*
*
20»0000 -*******
* *
40.0000 -***********:)«*************
* *
60.0000 -**********************************
* *
80.0000 -******************~***************
* *
100.0000 -**********************************
* *
120.0000 -*****************************
* *
140.0000 -****************************
* *
160.0000 -**********************
* *
* *
* *
-*******
* *
-***
*
260.0000 -*
*
280.0000 -*
*
300.0000 -**
**
320.0000 -**
**
340.0000 -**
*
360.0000 -*
*
380.0000 -*
*
400.0000 -*
C
0
R 180.0000
A
M 200.0000
S
/ 220.0000
M
I 240.0000
L
E
-------
ALL VEHICLES
ATTER INSPECTION AND MAINTENANCE
C
0
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
140.0000
160.0000
R 180.0000
A
>r 200.0000
s
/ 220.0000
M
I 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
5.0
PERCENTAGE OF VEHICLES
10.0 15.0
20.0
25.0
¦*
*
* *
~ *
* *
* *
* *
-************************************
* *
* *
* *
4c *
* *
¦***~*
*
¦***
* *
-***
*
-*
*
¦*
*
-*
*
-*
*
-*
*
•*
*
-*
-------
ALL VEHICLES
AFTER SIX MONTHS
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
140.0000
160.0000
180.0000
C
0
G
R
A
M 200.0000
S
/ 220.0000
M
1 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
5.0
PERCENTAGE 07 VEHICLES
10.0 15.0
20.0
25.0
¦**
**
* *
**************************
* 4c
*************************************
* *
*************************************
* *
************************************
* *
**************************
* *
************************
* *
******************
* *
-*****************
* *
*********
* *
.******
* *
.******
**
¦**
+ *
-* +
*
-*
*
-**
**
-**
*
-*
*
-*
*
-*
-------
INSPECTION AND MAINTENANCE VEHICLES
BEFORE INSPECTION AND MAINTENANCE
5.0
PERCENTAGE OF VEHICLES
10.0 15.0
20.0
25.0
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
C 140.0000
0
160.0000
G
r 180.0000
A
M 200.0000
S
/ 220.0000
M
X 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
•*
*
•***
* *
• He*************************
* *
**********************************
* *
************************************
* *
************************************
* *
**********************************
* *
* *
- * * + * + 3|C * + 3|C + + + + + * * + * + * *
* *
*************
* *
*********
* *
*********
* *
*******
*
-*
*
¦*
*
-*
*
"***
* *
-***
*
-*
*
-*
*
"*
-------
INSPECTION AND MAINTENANCE VEHICLES
AFTER INSPECTION AND MAINTENANCE
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
C 140.0000
0
160.0000
G
R 180.0000
A
M 200.0000
s
/ 220.0000
M
1 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
5.0
PERCENTAGE OF VEHICLES
10.0 15.0
20.0
25.0
-*
*
* *
* *
* *
* *
* *
-jfc****
* *
-**************************
* *
— **************************
* *
-***************
*
-***
* *
-***
*
-******
* *
—******
*
-*
*
-*
*
-*
*
-*
*
-*
*
-*
*
-*
-------
INSPECTION MD MAINTENANCE VEHICLES
AFTER SIX MONTHS
C
0
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
140.0000
160.0000
r 180.0000
A
M 200.0000
S
/ 220.0000
M
I 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
5.0
PERCENTAGE OF VEHICLES
10.0 15.0
20.0
25.0
¦*
*
***********
* *
* *
**********************************
* *
>******************3|c*********************
* *
* *
.*********************************
* *
»**************:;;***********^: :.::(:****
* *
******************
* *
*************
* *
*********
*
-******
* *
*******
*
•*
*
-*
*
-*
*
-***
* *
-***
*
-*
*
-*
*
-*
-------
MANDATORY MAINTENANCE VEHICLES
BEFORE MAINTENANCE
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
C 140.0000
0
160.0000
G
R 180.0000
A
M 200.0000
S
/ 220.0000
M
1 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
5.0
PERCENTAGE OF VEHICLES
10.0 15.0 20.0
25.0
-*
*
* *
-************************
* *
-sis*********************************
* *
-************************~*********
* *
-********************************
* *
****************** *******
* *
-********************************
* *
—**********************
* *
* *
-******
* *
-******
*
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MANDOTORY MAINTENANCE VEHICLES
AFTER MAINTENANCE
PERCENTAGE OF VEHICLES
5.0 10.0 15.0
20.0
25.0
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
C 140.0000
0
160.0000
G
R 180.0000
A
M 200.0000
S
f 220.0000
M
! 240.0000
L
E 260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
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-------
MANDATORY MAINTENANCE VEHICLES
AFTER SIX MONTHS
PERCENTAGE OF VEHICLES
5.0
10.0
15.0
20.0
25.0
C
0
G
R
A
M
S
/
M
1
L
E
0.0000
20.0000
40.0000
60.0000
80.0000
100.0000
120.0000
140.0000
160.0000
180.0000
200.0000
220.0000
240.0000
260.0000
280.0000
300.0000
320.0000
340.0000
360.0000
380.0000
400.0000
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-------
ALL VEHICLES
BEFORE INSPECTION AND MAINTENANCE
PERCENTAGE OF VEHICLES
10.0
20.0
30.0
40.0
50.0
H
C
G
R
A
M
S
/
M
I
L
E
0.0000 -*
*
2.5000 -***************************
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7.5000 -********************************
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10.0000 -************************
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12.5000 -*********
* *
15.0000 -********
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17.5000 -***
*
20.0000 -*
*
22.5000 -**
**
25.0000 -**
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27.5000 -**
**
30.0000 -**
*
32.5000 -**
**
35*0000 -**
**
37.5000 -**
*
40.0000 -*
*
42.5000 -*
*
45.0000 -*
*
47.5000 -*
*
50.0000 -*
*
52.5000 -*
-------
ALL VEHICLES
AFTER INSPECTION AND MAINTENANCE
PERCENTAGE OF VEHICLES
10.0
30.0
40.0
50.0
H
C
G
R
A
M
S
/
M
I
L
E
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
17.5000
20.0000
22.5000
25.0000
27.5000
30.0000
32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52.5000
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*
-*
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-*
*
-*
*
-*
*
-*
*
-*
-------
ALL VEHICLES
AFTER SIX MONTHS
10.0
PERCENTAGE OF VEHICLES
20.0 30.0 40.0
50.0
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
H 17.5000
C
20.0000
G
R 22.5000
A
M 25.0000
S
/ 27.5000
M
I 30.0000
L
E 32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52.5000
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*
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**
-**
-------
INSPECTION AND MAINTENANCE VEHICLES
BEFORE INSPECTION AND MAINTENANCE
PERCENTAGE OF VEHICLES
10.0
20.0
30.0
40.0
50.0
0.0000 -#
*
2.5000 -************************
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5.0000 -********************************
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7.5000 -********************************
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10.0000 -************************
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H 17.5000 -**
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42.5000 -*
*
45.0000 -~
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47.5000 -*
*
50.0000 -*
*
52.5000 -*
-------
INSPECTION AND MAINTENANCE VEHICLES
AFTER INSPECTION AND MAINTENANCE
PERCENTAGE OF VEHICLES
10.0
20.0
30.0
40.0
50.0
H
C
G
R
A
M
S
/
M
I
L
E
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
17.5000
20.0000
22.5000
25.0000
27.5000
30.0000
32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52•5000
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-------
INSPECTION AND MAINTENANCE VEHICLES
AFTER SIX MONTHS
PERCENTAGE OF VEHICLES
10.0
20.0
30.0
40.0
50.0
0.0000 -**
**
2.5000 -**************************
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5*0000 -*********************************
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7.5000 -*********************************
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10.0000 -*************************
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* *
15.0000 -********
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H 17.5000 -**
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20.0000 -*
G *
R 22.5000 -*
A *
H 25.0000 -*
S *
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M *
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L **
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35.0000 -*
*
37.5000 -*
*
40.0000 -*
*
42.5000 -*
*
45.0000 -*
*
47.5000 -*
*
50.0000 -*
*
52.5000 -*
-------
MANDATORY MAINTENANCE VEHICLES
BEFORE 'MAINTENANCE
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
17.5000
20.0000
22.5000
H
C
G
R
A
M 25.0000
S
/ 27.5000
H
I 30.0000
L
E 32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52.5000
10.0
PERCENTAGE OF VEHICLES
20.0 30.0
40.0
50.0
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* *
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-*
*
-*
*
-*
*
-*
*
-*
-------
MANDATORY MAINTENANCE VEHICLES
AFTER MAINTENANCE
PERCENTAGE OF VEHICLES
10.0
20.0
30.0
40.0
50.0
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
H 17.5000
C
20.0000
G
R 22.5000
A
M
S
/
M
I
L
E
25.0000
27.5000
30.0000
32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52.5000
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*
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*
-*
*
-*
*
-*
*
-*
*
-*
*
-*
*
-*
*
-*
-------
MANDATORY MAINTENANCE VEHICLES
AFTER SIX MONTHS
H
C
G
R
A
M
S
/
M
I
L
E
0.0000
2.5000
5.0000
7.5000
10.0000
12.5000
15.0000
17.5000
20.0000
22.5000
25.0000
27.5000
30.0000
32.5000
35.0000
37.5000
40.0000
42.5000
45.0000
47.5000
50.0000
52.5000
10.0
PERCENTAGE OF VEHICLES
20.0 30.0
40.0
50.0
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**
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-------
SUMMARY OF VEHICLE MAINTANNCE
NUMBER OF VEHICLES SHOWING MAINTENANCE
ALL EMISSIONS EMISSIONS
ITEM INDICATING VEH -DECREASED- -INCREASED-
MAINTENANCE HC CO HC CO
TOTAL VEHICLES 165 75 73 90 92
IGNITION WIRES 8 4 3 4 5
COIL 2 1111
SPARK PLUGS 13 7 5 6 8
AIR FILTER 19 10 9 9 10
AIR CLEANER SCREW 93 43 38 50 55
IDLE MIXTURE SCREW 3 2 112
IDLE SPEED SCREW 7 4 13 6
CHOKE 8 4 2 4 . 6
DISTRIBUTOR SCREW 7 2 2 5 5
POINTS SCREW 9 4 2 5 7
CONDENSER 8 3 2 5 6
ROTOR 7 3 3 4 4
DISTRIBUTOR CAP 11 5 3 6 8
PCV VALVE 5 2 2 3 3
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