IMS-002/QA-1
Questions and Answers Concerning the
Technical Details of Inspection and Maintenance
April, 1979
Inspection and Maintenance Staff
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
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Questions and Answers Concerning the
Technical Details of Inspection and Maintenance
1. BENEFITS
a) Air Quality - One question often asked is, will I/M programs really help
to solve the CO and oxidant problems? New Jersey has concluded that an
annual reduction in average statewide CO concentrations of 3 percent is
due to I/M. Is other information available on measurable air quality
benefits? Will there be any observable oxidant benefits from I/M in the
near future?
Air quality data now available strongly suggest inspection and
maintenance programs will result in improved air quality.
A recent study of seven years of carbon monoxide (CO) data in New
Jersey has led researchers to conclude that the I/M program, which
began in 1974, and the increasingly stringent new car emission
standards are together responsible for a 28 percent decrease in
ambient carbon monoxide levels. I/M was shown to increase the rate
of improvement of ambient CO levels. The University of Wisconsin
statisticians found that the improvement in air quality occurred
independent of year-to-year weather patterns and at a time when
traffic volume was increasing.
There is strong evidence that the general strategy of controlling
automotive emissions is effective in reducing ozone levels.
Officials from the South Coast Air Quality Management District
attribute most of the credit for a decreasing trend in ozone levels
in the Los Angeles Air Basin to controls on auto emissions. The
area's mean ozone concentration has fallen steadily from a high of
0.228 ppm in 1956 to 0.125 in 1975. In addition, the area has not
experienced a Stage III ozone alert (0.50 ppm) since 1973.
At this time, there are not studies which specifically relate the
effects of tailpipe emission reductions resulting from I/M to
reductions in ozone levels. This is due to the complication of
factors affecting oxidant levels such as meteorology, pollutant
transport, and the impact of stationary hydrocarbon sources.
Several more years of ozone data in I/M areas will be required
before this analysis can be made.
b) Emission Reductions: (FTP) - Arizona, New Jersey and Oregon have reported
substantial reductions in idle emissions. Arizona has also found reduc-
tions in the two cruise modes for which it tests. How do these results
compare to reductions over the entire driving cycle?
It is reasonable to expect HC and CO emission reductions at idle to
carry over to a typical urban driving cycle since urban driving
contains a significant portion of idle mode operation. Data from
the Portland Study substantiate this expected carry over in emis-
sion reductions from the idle test to the Federal Test Procedure.
As the table below indicates, the vehicles which failed the Oregon
state inspection test (an idle test plus a brief physical inspec-
tion) realize significant emission reductions over the entire
Federal Test Procedure (FTP) driving cycle as well as at idle.
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Initial Emission Reductions -
Vehicles Failing Portland Short Test
1975-77 Models
Idle HC
Idle CO
FTP HC
FTP CO
(ppm)
(gpm)
(gpm)
Initial
325
3.09
2.87
40.87
After Maint.
0
1
19
80
.17
.60
.36
% Change
-75.4
-94.5
-44.3
-52.6
1972-74
Initial
3
4
55
328
.20
.04
.30
Models
After Maint.
0
3
34
189
.72
.02
.41
% Change
-42
-77
-25
-37
.4
.5
.2
.8
Data on loaded test FTP reductions occurring as a result of I/M
maintenance are not available from an operating I/M program, since
no I/M program currently uses a loaded test to pass or fail cars.
(Arizona performs the loaded test, but a vehicle is passed or
failed only on the basis of the idle portion of the test.) EPA's
surveillance programs show a relationship between high loaded mode
emission values and high FTP emissions. Thus, one would expect to
see emission reductions over the full FTP as a result of performing
maintenance which reduces emissions over the loaded test.
c) Emission Reductions; (Failure Rate) - Is there a relationship between
the failure rate in existing programs and the emission reductions they
achieve?
The Portland study data for 1975-1977 model year cars have been
analyzed to help determine the effect of failure rate on I/M pro-
gram effectiveness and average cost of maintenance. The results of
the analysis are summarized in the table below. The 31% failure
rate case is based upon an application of the idle HC and idle CO
cutpoints used by the Oregon State inspection test. The other five
cases (27% to 6% failure rate) were derived by moving cutpoints for
idle HC and CO progressively higher in a systematic manner, thus
simulating less stringent programs.
I/M Reductions and Costs
Failed Cars
Failure
Rate
31%
27%
22%
17%
11%
6%
Fleet %
FTP HC
27%
25%
24%
21%
16%
12%
Reductions
FTP CO
35%
33%
29%
27%
18%
12%
FTP
Before
Maint.
Level
2.67
2.85
3.10
3.26
3.73
4.66
HC
% Reduct.
due to
Maint.
42%
46%
49%
53%
63%
66%
FTP CO
Before
Maint.
Level
38.57
40.71
43.36
47.73
50.75
61.39
% Reduct.
due to
Maint.
50%
54%
56%
60%
65%
62%
Average
Maint.
Cost
$22
$22
$23
$25
$27
$34
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-3-
I/M Reductions due to Maintenance for Various Failure Rates*
ftCBUCTIOHfi
12
NC MEOUCTIOH
CO fttOUCTlON
16 24
PfllLURC RflTC
FNILBO CUM NfOlCT)OH9
16 2
a
^«
h-
U.
46
16
flflTC
*Based on EPA's Portland Study data, 1975 to 1977 models.
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-4-
Emission reductions for each failure rate have also been plotted in
the following figures. The top figure gives fleetwide reductions
while the bottom figure gives reductions for the failed fleet. As
would be expected, fleetwide emission reductions increase with
increasing failure rate while emission reductions per failed car
decrease with increasing failure rate. This phenomenon supports
the argument that as fewer cars are failed, those failing are the
highest emitters. The data also show that repair cost is mildly
affected by failure rate.
d) Emission Reductions; (Appendix N) - Are the Appendix N reductions
proven in the field?
EPA's Portland Study is the first complete evaluation of an operating
mandatory inspection and maintenance program. Based on the data
now available (emissions measured over nine months following inspec-
tion and repair, then extrapolated to one year as shown in the
attached graphs), the emission reductions being experienced in
Portland are greater than those predicted bv Appendix N. ("This
comparison is based on a fleet of 1975-77 models undergoing I/M in
which the 1975 models had one inspection and the 1976-77 models no
inspections prior to entering the study.) The results are shown
below.
Preliminary Comparison of Portland I/M Effectiveness
to Appendix N Estimates
Fleet Reductions
HC CO
Portland Study 16% 35%
Appendix N 13% 25%
The above values for Portland may change slightly as the fourth
quarter deterioration data become available, thus the comparison
has been labeled preliminary.
e) Emission Reductions; (Waivers) - Is program effectiveness compromised by
such factors as waivers?
This question will be answered in two parts: 1) waivers based on
the age of vehicle; 2) waivers based on the cost of repair of
failed vehicles.
AGE WAIVERS; Given a typical I/M program with 30% stringency, no
mechanic training, implemented in 1982 and evaluated in 1987, the
reduction in HC and CO due to I/M is estimated to be 28% and 30%
respectively. The effect of exempting any group of vehicles from
the I/M process is shown in the following figure and summarized
below.
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HC EMISSION LEVEL ESTIMflTES FOR PORTLRND flND EUGENE (75-77)
2.00
-1.55
o
1.00
0.55
0.0
flPPENDIX N BENEFIT 13X
PORILflNO BENEFIT j j. '/,
'—• extrapolated
_ PORTLflND
.. EUGENE
20000 24000 28000 32000
MILEflGE
36000
40000
CO EMISSION LEVEL ESTIMflTES FOR PORTLRND flNO EUGENE
30
25
20
10
flPPENDIX N BENEFIT
PORTLflNO BENEFIT
— extrapolated
PORTLflNO
EUGENE
20000 24000 28000 32000 36000
MILEflGE
40000
19 MDMTHS
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Effect of Age
Exempted Model
Years
None
pre '68
pre '75
pre '80
Emission
HC
28
28
24
15
Exemptions
Reduction, %
CO
30
30
25
9
% Fleet VMT Exempted
(1987)
0
.4
4.8
25.0
These data show a negligible effect on I/M effectiveness of exempting
pre-1968 vehicles while program effectiveness is reduced signifi-
cantly for the other exemptions shown. For the pre-1980 exemption
in this scenario, the 25% emission reduction by 1987 (minimal
program requirement) is not achievable.
COST CEILINGS; Portland data have been analyzed to help determine
the effect of cost ceilings on I/M program effectiveness. The
results of the analysis are summarized in the table below. For
maintenance cost ceilings from $25 to $150, failed vehicles with
repair costs above that ceiling were identified. For example, 4%
of the 94 1972-74 model year vehicles in the sample requiring
maintenance had reported maintenance costs greater than $150 and
32% of these 94 vehicles had reported maintenance costs greater
than $25. HC and CO emission reductions were calculated for each
cost ceiling. It was assumed that vehicles above the cost ceiling
received no maintenance and their emission levels thus remained
unchanged. If an I/M program requires that maintenance expen-
ditures up to the cost ceiling be performed, the iiftpact on program
effectiveness, presented below would be less.
1972-74 Model Year Failed Cars 1975-77 Model Year Failed Cars
% Reduction
Reduction
Cost
Ceiling
No Limit
150
100
75
50
25
% within
Cost Limit
100%
96
91
89
83
68
FTP HC
25
24
14
9
9
6
FTP CO
37
36
35
30
28
22
% within
Cost Limit
100%
100
96
94
88
74
FTP HC
40
40
36
36
31
20
FTP CO
48
48
46
46
40
31
The data have been smoothed and plotted in the following figures.
For newer cars, cost ceilings above $75 have only a minimal effect
on fleetwide emission reductions. For older cars, the ceiling must
be in the $100 - $150 range or greater or avoid a reduction in
program effectiveness.
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I/M FLEET EMISSION REDUCTION WITH AGE WAIVERS*
1982-1987 I/H PROGRflM, 30% SF, NO MPCH TRfllNJNG
10,.
35 .
30
a
UJ
or
20
Q
Ul
10
All vehicles**
Excluding
pre-1975
HC REDUCTION
CO REDUCTION
Excluding
pre-1980
*1982-1987 I/M program, 30% stringency factor, no mechanic training.
**Benefit when excluding pre-1968s is the same as benefit for all vehicles.
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I/M Reductions with Cost Ceilings
tie ,
0
CMS Lift TIM FIVf TIMO 04.1
(1975-77 models in Portland)
NC KCOUCTIM
CO HfOlfCTJO*
5@ 168
coir UNIT tfi
150
«* 3
g
r»
24 5
16
200
CUM flVC TIM! OLD MO OLOC»
(1972-74 models in Portland)
NC MCMICTIM
CO MC8IICTIM
25 0
50 100 150
COST LIMIT (t)
MO LIMIT
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f) Emission Reductions - Is program effectiveness compromised by such
factors as private garage reinspection?
Centralized, garage based, and centralized with garage retest
authority programs have the same potential for emission reductions.
Where private repair facilities become involved with testing or
retesting for compliance, the potential for more variable test
results or fraud exist. To overcome this, the state must establish
a strong quality control and enforcement program. Periodic inspec-
tions of repair facility equipment and personnel skills, indepen-
dent testing of vehicles recently repaired, and a good data col-
lection system in which repair facility test results can be com-
pared and matched to other data surveys can assure that program
effectiveness is not reduced.
g) Emission Reductions: (Ambient Effects) - Is program effectiveness
compromised by such factors as high or low ambient temperatures?
The I/M benefits as set forth in MOBILE1 are based on emission
levels and reductions as measured by the Federal Test Procedure.
This test is run at ambient temperature ranging from 20 to 30°C (68
to 86°F). The test is divided into portions which represent cold
start, hot start, and stabilized, warmed-up operation. In areas
with high or low ambient temperatures, the percentages of cold
start, hot start, and stabilized operation will be different than
assumed under FTP conditions (21% VMT cold start, 52% VMT stabilized,
and 27% VMT hot start operation). For areas with higher than FTP
temperatures, more stabilized and hot start operation and less
cold start operation will exist. Since high temperature (up to
about 100°F) does not significantly affect emissions during any
mode of operation, the reductions due to I/M at high temperatures
should be greater than reductions seen at 75°F. The' reductions at 75°F
(absolute and percentagewise) are given below.
Reductions due to I/M During
Stabilized/Hot Start Operation
(1975-77
Cold Start
Stabilized
Hot Start
Overall
Model Year Failed
Absolute
HC
0.80
1.39
0.80
1.27
Cars in Portland)
Reduction (gm/mi) %
CO HC
10.44 23%
26.89 55%
10.35 41%
21.51 44%
75°
Reduction
CO
23%
67%
46%
53%
For areas with cold temperatures, there will be more cold start
operation, less hot start, and perhaps less stabilized. Since cold
temperature has been shown to affect emissions during cold start
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operatlon, I/M's effect at cold temperatures (particularly
with respect to CO, since HC is not a problem below about 50°F)
is not adequately indicated by Portland data alone. Although
data at cold temperatures are limited, all available data have been
collected on 1975-77 model year cars: cars have been classified
as "as-received" and as "tune-up." The as-received cars have been
used to reflect CO emission levels of failed vehicles. Since these
cars were in various states of tune, they likely underestimate the
emissions of those vehicles which would have failed an I/M test.
The results of comparing cold start emissions for the "as-received"
and "tuned-up" fleets are presented below, and indicate, based
on these limited data, that I/M will have a substantial effect
on CO emissions at least to temperatures as low as 20°F.
Estimated CO Reductions Due to I/M
During Cold Start Operation
(1975-77 Model Year Cars)
Absolute Reduction(gm/mi)
20° 23
30° 37
60° 27
75° (Portland) 10
% Reduction
13%
26%
35%
23%
h) Emission Reductions - Is program effectiveness compromised by such
factors as a high volume of transient, non-inspected vehicles in a
region?
I/M's effectiveness is based on the population of inspected vehi-
cles. Therefore, if 10% of the vehicles in a region are transient
and non-inspected, the corresponding fraction of miles traveled by
these vehicles should be included in the 'without I/M' emission
inventory calculation, and should be represented in the 'with I/M'
emission inventory calculation with unchanged emission levels. The
resulting calculation will determine any reduction in air quality
benefit from I/M. As I/M programs become more widespread (over
50 programs are expected to be in operation by 1983) , more of the
transient vehicles will have been inspected in the home state,
thus the impact of transient vehicles will be reduced.
i) Fuel Economy - Can any fuel economy benefits be expected from I/M, and
if so, how much? Earlier studies have shown savings would average 3 to
5 percent for serviced vehicles. Now it appears that the average
mechanic will not adjust a failed car to achieve any fuel benefit. What
happened to the previous assertion?
The fuel economy benefit associated with the typical repairs
performed as a result of an I/M program depends on the skill of the
mechanic and the type of vehicle. Numerous studies have shown that
maintenance performed to manufacturer's specifications can result
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in a 3 to 4 percent fuel economy improvement for current technology
vehicles. EPA's study of the Portland I/M program, however, has
indicated that a fuel economy benefit is not being realized. It is
believed that the lack of training specific to proper emission
control maintenance is a factor. Thus for an area which does not
have widespread mechanic training specific to emission control
maintenance, no fuel economy benefit is expected for current
technology cars. For areas with trained mechanics, a fuel economy
improvement of 3 to 4 percent for repaired cars can be expected.
For future technology cars, the situation is expected to be some-
what different. Beginning with model year 1981 (1980 in California),
passenger cars will commonly utilize mini-computer controlled fuel
and ignition systems. Failures associated with these systems are
likely to cause significant fuel economy penalties. While the
frequency of failures is not currently known, the per-vehicle fuel
economy improvement due to repair, based on tests of several
prototype vehicles, is expected to be 10 to 20 percent.
j) Maintenance Costs - Will overall maintenance costs be reduced with I/M?
We do not have data available upon which to incorporate emission
oriented maintenance performed in the absence of I/M into a net I/M
cost estimate. Some emission maintenance now occurs; an example
is replacement of spark plugs. We can not, however, conclude
overall vehicle maintenance will be reduced as a result of I/M.
Two qualitative arguments shed light on this question. First, I/M
has the objective of increasing the maintenance performed on the
fleet, thus it can be argued I/M will increase maintenance costs.
From the opposite point of view, the idle test acts as an indicator
of the need for maintenance and provides diagnostics. Thus it can
also be argued that with properly trained service personnel,
unnecessary maintenance will be reduced and the quality of maintenance
performed will increase. Since these are only qualitative argu-
ments, we have chosen to consider the cost of inspection and repair
as additional costs of maintenance.
Put into perspective, the average cost to the motorist for I/M is
between $10 to $15 per year. This compares to a Motor and Equipment
Manufacturers Association estimate of $215 of general maintenance and
repairs performed each year per vehicle. Thus the increase in
maintenance cost, in the extreme, is less than 10 percent.
k) Vehicle/Engine Life - Will the useful life of the engine or entire
vehicle be enhanced by I/M?
There are no hard data to quantify whether vehicle/engine life
increases due to I/M related maintenance. It is highly unlikely
that proper maintenance will decrease engine life. In some areas
experience and technical judgment indicate that engine or component
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life may be extended due to proper maintenance. Examples are
carburetor adjustments reducing carbon buildup, valve adjustments
extending valve life, and ignition maintenance preventing misfires
which may damage the catalyst.
1) Loaded/Idle Tests - What actual benefits can be derived from loaded
testing? Are they worth the extra time and cost? Do you recommend
loaded or idle testing?
An evaluation of the idle vs. loaded test involves two aspects: 1)
the ability of each test to identify the worst polluting vehicles,
and 2) the emission reduction achieved when failed cars are repaired
to meet the short test standards. Although EPA is still evaluating
the loaded vs. idle test, it is clear from the Portland study that
the idle test does an excellent job of screening the worst emitters
of HC and CO. Maintenance performed by the mechanics in the
Portland area appears to be effective in reducing FTP as well as
idle emissions. High emitters of NOx are not successfully iden-
tified by the idle test.
The benefit of the loaded test for areas with only HC and/or CO air
quality problems centers around the more complete diagnostics
available from this test. Although the idle test detects most
failures associated with current technology cars, some carburetor
and high speed ignition failures can only be detected with the
loaded mode test. (Loaded mode testing is expected to be more
valuable for the electronic controlled advanced technology vehicles
of the early 1980's. It is also expected, however, that non-loaded
diagnostic methods will be available as an alternative.) Repair of
these defects will result in an increased HC and CO emission reduc-
tion. The CARB Riverside program indicated that mechanics were not
able to translate the diagnostics into larger emission reductions
or more efficient repairs. Thus to realize additional HC and CO
benefits, proper mechanic training appears to be necessary.
Another potential consumer benefit may be a reduction in unnecessary
repairs resulting from the better diagnostics.
For areas which have NOx problems, there are two possible alter-
natives for using I/M as a control strategy. One is to add a
physical inspection of the EGR system to an idle test regime. The
other is to perform a loaded mode test. The idea behind the phy-
sical inspection of the EGR system is to identify only the cars
which have obviously malperforming EGR systems and require main-
tenance just on this group. The other approach is to measure the
NOx exhaust emissions at a high speed/load condition and establish
pass/fail criteria based on these measurements.
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A comparison of these two approaches from the standpoint of effec-
tiveness and cost is currently underway. Some preliminary infor-
mation on the loaded test, based on the Portland study, is avail-
able. These results indicate that at least the high speed mode of
the Federal Three-Mode test is capable of identifying the worst NOx
emitters. The following table presents the FTP NOx levels of
Portland area vehicles passing and failing the high speed test for
NOx. These data show the failed cars had emission levels 60%
higher than those passing the loaded test. (The high speed cut-
points used were 2430 ppm for 1975-76 models and 2165 ppm for 1977
models.)
Effectiveness of the Loaded Test in
Detecting High NOx Emitters
(High Speed Mode of Federal 3-Mode Test)
Loaded Short Test Failure Rate
10% 20% 30%
FTP emissions, passed cars 2.40 gpm 2.28 gpm 2.05 gpm
FTP emissions, failed cars 3.96 3.67 3.47
No I/M program currently requires maintenance to be performed in
response to loaded test standards. Therefore, no appropriate after
maintenance data on failed vehicles exist. However, data from
EPA1 s Restorative Maintenance program indicates that FTP NOx
emissions on 1975-76 model year cars with EGR system or related
failures are reduced to approximately 2.6 gpm as a result of
maintenance. This after maintenance level was applied to the
Portland area 1975-76 models which were failed by the loaded test.
For 1977 models where the federal exhaust emission standard for NOx
is more stringent, it was assumed that failed vehicles could be
maintained to levels which are below their standard by the same
percentage as 1975-76s are below theirs; thus to 1.68 gpm. The
following table provides the estimates of NOx emission reductions
which would be achieved using the assumed post-maintenance levels
for each failure rate, and shows that fleet NOx reductions of 6 to
13% are possible.
The incremental cost of a loaded mode inspection over an idle
inspection includes a higher inspection fee (estimated to be a
maximum of $1.35 extra) and the NOx related repair cost, estimated
at $7.50.* The average additional per vehicle cost of the NOx
inspection and repair is shown in the following table. (All cost
has been attributed to the NOx reduction; the repair cost has been
averaged over the entire fleet.) In addition, the NOx cost-effectivness
is calculated (10,000 miles per year assumed). The cost-effectiveness
is in the range of other NOx control strategies.
*This estimate comes from the Restorative Maintenance Program and
represents primarily the average cost of repairing malperforming EGR
systems.
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Estimated FTP NOX Emission Reductions
(Loaded Test, 1975-77 Models)
FTP NOx Emissions
of Passed Cars
FTP NOx Emissions
of Failed Cars
Before Maintenance
Assumed Post-Maintenance
FTP Emission Levels
for Failed Cars
Fleet FTP Emissions
Before Maintenance
(N = 230)
Fleet FTP Emissions
After Maintenance
% Reduction in NOx
Loaded Short
10%
2.40
3.96
2.38
2.55
2.40
5.9%
due to Maintenance
Test Failure Rate
20%
2.28
3.67
2.36
2.55
2.29
10.2%
30%
2.16
3.44
2.34
2.55
2.22
12.9%
Estimated Cost and Cost-Effectiveness
for NOx Emission Reduction
(Loaded Mode Test, 1975-77 Models)
Loaded Short Test Failure Rate
10% 20% 30%
Cost per inspected vehicle $2.20 $2.85 $3.60
Cost-effectiveness, $/ton $1270 $994 $990
The effectiveness and cost of an EGR inspection for NOx is pre-
sented below for comparison. The results show that the reductions
achieved and cost-effectiveness are similar to the 10% stringency
loaded mode test. Actual EGR inspection effectivness may be some-
what less because of the difficulty of observing the EGR on some
vehicles (e.g., it is sometimes located behind the air cleaner).
Estimated Cost and Cost-Effectiveness
for NOx Emission Reduction
(EGR Inspection, 1975-77 Models)
% vehicles failing inspection 13%
FTP NOx Emissions: Passed cars 2.38 gpm
FTP NOx Emissions: Failed cars 3.46 gpm
Assumed Post-maintenance level 2.32 gpm
% NOx reduction: Failed cars 33%
% NOx reduction: Fleet 6%
Cost of inspection repair: Fleet avg. $2.00
Cost-effectiveness $1210/ton NOx
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To summarize, further analysis is being performed to evaluate the
loaded vs. idle I/M test. Preliminary analysis indicates that an
idle test is an adequate I/M test for areas which require control
only of HC and CO. NOx problems cannot be addressed by an idle I/M
test. Both a loaded test and the physical inspection of the EGR
system are considered to be viable alternatives for controlling NOx
through I/M. We are not yet ready to recommend one procedure for
NOx over the other, but further information will be forthcoming.
m) Appendix N - Are the credits in Appendix N valid? What reasons are
there for the delay in the revised version? Is there sufficient tech-
nical documentation now or will there be in the future to justify the
credits?
Appendix N reflects EPA's best judgment of the benefits associated
with an inspection and maintenance program. Appendix N, as
contained in the computer program MOBILE1, is based on a careful
review of available I/M data and on engineering judgment. EPA
sees no need for revision now.
Later this year, as the Portland study is completed,
and test results from prototype advanced technology vehicles
become available, EPA will revisit Appendix N and make any needed
adjustments. The adequacy of 1979 SIP revisions with respect to
the 25% emission reduction requirements in EPA's I/M policy
(July 17, 1978) will be judged according to MOBILE1 credits.
n) Heavy Duty I/M - What emission reductions can be expected for I/M of
heavy duty vehicles at various stringency levels?
There are no appropriate data to evaluate this question quanti-
tatively at the present time. Based on engineering arguments, one
could expect that emission oriented tune-ups would result in
similar emission reductions on heavy duty trucks as occur on
lighter duty vehicles.
Although no quantitative estimates of heavy duty vehicle I/M's
effectiveness are available, several states either are considering
implementing or already have implemented a heavy duty vehicle I/M
program. New Jersey is now conducting a voluntary I/M program for
heavy duty vehicles and expects to set idle emission, smoke and
noise standards and require compliance in the very near future.
Arizona presently requires inspection of approximately 130,000
heavy duty vehicles. The failure rate for HDVs is slightly higher
than the 16% failure rate for LDVs. Oregon is presently inspecting
approximately 1,000 heavy duty vehicles per month with a failure
rate of about 50%. All three of these programs are based upon the
idle test procedure. None has yet reported any estimate of effec-
tiveness. As data become available, it will be disseminated.
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In the 1977 Clean Air Act amendments, Congress established new
vehicle emission standards for trucks which reflect the same emission
reductions from uncontrolled levels as passenger cars. EPA has
been developing an improved test procedure to complement these
standards, which will go into effect in 1983. Included in this
procedure is an idle test and emission standard which will facilitate
establishing warranty provisions and cutpoints for heavy duty
vehicles. Since the technology that will be used on these vehicles
will be similar to that used on current passenger cars, I/M will
be necessary to assure appropriate maintenance is performed and
tampering and misfueling are discouraged.
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2. COSTS
a) Repairs - How do repair costs vary with stringency and test mode?
Will the loaded test reduce repair costs? If so, why are the average
repair costs lower in New Jersey than in Arizona?
As briefly discussed in the response to question "Emission
Reductions: (Failure Rate)," costs appear to vary with stringency
factor. For the Portland sample of failed cars, average repair
costs tend to increase with lower stringency programs. Average
costs of repairs for failed vehicles range from approximately $20
to $35 for stringencies of 30% to 6% respectively. This suggests
that the worst emitters (those identified by low stringency pro-
grams) tend also to have the highest repair costs.
The only available data on loaded test repair costs come from the
California Air Resources Board's Riverside Pilot I/M Program.*
CARB selected two samples of pre-75 model year vehicles; one
sample was subjected to an idle test, the other to a loaded test.
The intent was to determine the costs and effectiveness for the two
tests. The average repair costs were slightly higher for the
loaded test than for the idle test ($23 vs. $21), with emission
reductions on HC, CO, and NOx insignificantly different for the two
tests. The mechanics who were performing maintenance on the loaded
test failures had not been specifically trained in loaded test
diagnostics. Therefore, although the potential for additional
benefit and lower repair costs may exist for the loaded test,
CARB's study suggests that mechanic training is essential for its
realization.
Our latest information indicates that both New Jersey's and Arizona's
average costs of repair are low: $16 and $23, respectively. It
does not seem unreasonable that repair costs should be higher in
areas where a loaded test regime is used simply because more
problems can potentially be diagnosed and fixed. Typically, the
necessary repairs performed in response to failing the idle test
(both N.J. and Arizona pass or fail cars on the basis of an idle
test) involve simple adjustments or replacement of relatively
inexpensive parts such as spark plugs or wires. Thus, the addi-
tional diagnostic information provided by the loaded test would not
be expected to affect repair costs one way or the other for these
typical cars. For cars which have atypical problems, the use of
the loaded test diagnostics may result in more appropriate and
perhaps more costly repairs than would be performed in the absence
of the diagnostic information. This may imply a higher average
cost of repair for the loaded test regime.
^Vehicle Inspection and Maintenance - The California Program, G. Rubenstein,
R. Ingels, R. Weis, and A. Wong, SAE Paper 760557, June 1976.
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b) Costs; (Mechanic Training) - Does mechanic training have a positive
effect on repair costs?
The primary purpose of automotive exhaust emission oriented mecha-
nic training programs is to improve the skills of mechanics in
performing emission related repairs. Successful training programs
provide mechanics with the ability to more rapidly and effectively
diagnose and repair defects which cause high emission levels. This
results in lower costs. However, the knowledge acquired during
emission related training may cause mechanics to do more repairs
than they might otherwise do in an attempt to achieve even greater
emission reductions. Since the costs of these two effects tend to
offset each other, the net result may be little or no change in
average repair costs. Of course, both effects would have a ten-
dency to increase emission reductions and thus program benefits.
c) Costs - What are the average repair - not inspection - costs for private
garage test systems?
The only garage based I/M programs in operation are in Nevada and
Rhode Island. Rhode Island just began mandatory repair, thus no
repair cost data are now available. Nevada's program includes
setting certain parameters to manufacturer specification on all
inspected vehicles, thus data from this program are not applicable
to the typical garage I/M program. However, the repairs required
to pass an exhaust emission test are the same whether the test is
performed in a private garage or in a centralized inspection lane.
Therefore, one would expect the average cost of repairs in a garage
based program to be about the same as that of a lane program,
somewhere between $16 and $32 per failed vehicle.
d) Costs - Will repair costs decrease after programs have been in operation
for several years?
The key to emission reductions and therefore overall I/M program
effectiveness is the ability of the automotive service industry to
provide proper emission related repairs. It is reasonable to
expect that once mechanics have gained some experience with I/M
programs they should be able to repair the failed vehicles more
efficiently and with reduced costs. Very little data exist to
quantify this effect however. Survey data from New Jersey and
Arizona indicate that the I/M programs in those states have expe-
rienced little or no change in repair costs over the past several
years. These surveys are not conclusive, however, and the true
answer to this question will have to wait until more quantitative
data are available.
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e) Cost Analysis; (Cost Effectiveness) - What are the results of the
various cost-benefit analyses performed on I/M? How are the results
affected by varying the assumption of test mode, stringency and other
factors?
Several cost-benefit analyses on 1/M have been performed by EPA to
date. Analyses have been based on 1) Portland data, 2) MOBILE1-
Appendix N estimates, and 3) a combination of Portland data and
MOBILEl-Appendix N estimates. The best currently available esti-
mate of I/M's cost-effectiveness in Portland is based on the 1977
model year vehicle fleet. These vehicles were on the average one
year old when first inspected and maintained. They had received no
inspections prior to entering EPA's Portland Study. Thus, I/M's
effectiveness on these vehicles is relatively easy to track com-
pared with earlier model year cars, some of which had been inspected
prior to entering the EPA study.
A complete year's worth of emission deterioration data is not
available yet, so the observations on nine months of emission
testing have been smoothed and extrapolated to the full year. 1977
model year vehicles in Portland and Eugene were taken as the I/M
and non-I/M fleets respectively. Both fleets were weighted to
better represent the Portland area fleet of 1977 models. (Plots of
deterioration for1975^77vehicles were provided in response to a
previous question.) It should be noted that the initial emission
levels (prior to maintenance) in Portland and Eugene were approx-
imately the same for both HC and CO, suggesting that Eugene vehi-
cles provide a good estimate of Portland area vehicles' emissions
in the absence of I/M. By calculating the areas under the Portland
and Eugene curves respectively, estimates of grams (tons) of HC and
CO eliminated per vehicle over the year following I/M were obtained.
(It was assumed that each fleet traveled 15,000 miles in the year
following the initial test.) The average per vehicle cost of I/M
was estimated by applying Portland's $5 inspection fee to all cars,
and an average $20 repair cost to the 30% failed cars. This cost
($5 x .7 +$25 x .3) averages $H per inspected vehicle. The
effectiveness and cost per vehicle, and the combined cost-effectiveness
estimates are tabulated below.
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I/M's Effectiveness and Costs
1977 Model Year Cars Based on Portland Sudy Data
Effectiveness
HC CO
Tons per vehicle
without I/M .03291 .44973
Tons per vehicle
with I/M .02366 .29612
Tons eliminated
per vehicle .00925 .15361
Costs
Inspection fee = $5/vehicle
Repair Cost = $20 /failed vehicle
Average* Cost of I/M per vehicle (30% failure rate) =
$11 /vehicle
Cost-Effectiveness
(attributing one half of cost to each pollutant)
HC: $11 /2/0.00925 tons = $595/ton
CO: $11 /2/0.15361 tons = $36/ton
The comparable calculations (for catalyst-equipped vehicles following
their first inspection based on MOBILEI-Appendix N estimates are
provided below. Appendix N is understating the benefit seen in
Portland for 1977 models. Since costs are assumed to be the same
as in the Portland scenario, the resulting cost-effectiveness
estimate is numerically higher than that of the Portland fleet.
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I/M's Effectiveness and Costs
1977 Model Year Cars in the Year Following First Inspection
MOBILE1 - Appendix N Estimates
Effectiveness
Tons per vehicle
without I/M
Tons per vehicle
with I/M
Tons eliminated
per vehicle
HC
.02728
.02373
.00355
Costs
CO
.41584
.30208
.11376
Inspection fee = $5/vehicle
Repair Cost = $20/failed vehicle
Average Cost of IM per vehicle (30% failure rate) =
$11 /vehicle
Cost-Effectiveness
(attributing one half of cost to each pollutant)
HC: $11/2/0.00355 tons = $1549/ton
CO: $11/2/0.11376 tons = $48/ton
EPA's best estimate of the range of I/M cost-effectiveness for the
first year is $600 - $1500 per ton HC and $30 - $50 per ton CO for
the split costs case.
The calculation of cost-effectiveness estimates relies on two
inputs: cost and effectiveness. Thus, any factor which affects
cost or effectiveness could potentially affect the cost-effectiveness
ratio. Such factors include test mode, stringency of program, cost
or age waivers, emission deterioration with and without I/M,
mechanic training programs, and type of program (centralized or
decentralized). Although, as alluded to in previous responses, the
effects of some of these factors on costs and effectiveness have
been investigated, no comprehensive quantitative summary of the
sensitivity of cost-effectiveness to these various factors is
available now.
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f) Cost Analysis; (Indirect Costs) - Why are indirect consumer costs, such
as time and travel for inspection and repairs, usually neglected in
these analyses?
The indirect consumer costs listed in the question have histori-
cally not been included in cost-effectiveness analyses. One reason
is it is difficult to reach agreement as to their quantification.
Also, no attempt to remove the costs of emission related repairs
which may have been done in the absence of I/M has been made, and
possible indirect benefits such as lower long term maintenance
costs or longer engine life have not been included. These cost
reducing considerations tend to offset the inconvenience factors
described in the question. Thus, to keep the cost and cost-effectiveness
analyses as quantitative and straightforward as possible, only the
direct I/M cost and benefits have been used.
g) Comparing Systems - Too often EPA reports fail to point out the fact
that New Jersey's system is an old, well-established program. The $2.50
test fee does not include a retest nor does it pay for initial capital
costs as other programs must. Negating these factors, how do the
various systems' costs compare? How do capital and manpower costs
differ between the three types of systems?
Table A presents an example which compares typical per vehicle
program costs for an idle emissions inspection with an initial auto
population of 400,000. The following assumptions are made:
program length 5 years
annual interest on
borrowed capital 12%
annual inflation 7.5%
annual population growth 5%
contractor's net return
on investment 8%
depreciation periods:
land no depreciation
construction 20 years
other capital
investments 5 years (length of program)
For the centralized programs, each of the eight required facilities
in this example includes three lanes, each lane performing 26,000
four- to five-minute inspections annually (including retests). For
the decentralized program, each of 640 private garage stations
performs approximately 700 ten-minute inspections annually. One
challenge lane, similar in nature to the lanes used for the cen-
tralized programs, is assumed to be sufficient to provide referee
facilities for 5% of the vehicles in the decentralized program.
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Table A shows that the fee for the various program types is in
the range of 7 to 9 dollars, with the decentralized program the
most expensive. Assumptions other than those shown, such as
adding a program to an existing safety inspection, may affect
these results. Also of interest is the greater percentage of fee
attributed to initial costs of a centralized program. This suggests
that after the initial costs have been paid for, the fee difference
between the centralized and decentralized program will increase.
Table B compares state personnel requirements for the same three
programs. Program design, engineering and evaluation, and public
information functions are not included among these requirements.
Noteworthy is the larger number of state employees required to
monitor a decentralized program compared to the contractor cen-
tralized program.
h) Economic and Social Impact - What effect does I/M have on the under-
privileged? Have waiver systems or free repairs ever been considered?
What effect does I/M have on the repair industry?
Based upon census data, people in the low income groups tend to
drive cars that are on the average five to seven years old.
Depreciation, gasoline, repairs, insurance, etc. on a car in this
age range average from $1200 to $1500 per year. Typical costs for
a vehicle of this age failing an I/M test would be about $20. Some
of that maintenance cost would be incurred without an I/M program.
The net cost of an I/M program would therefore be about $12 to $15
or approximately 1% of the cost of owning and operating a vehicle
of that age.
Several states have considered methods of reducing this financial
burden on the underprivileged. Arizona, for example, has placed a
limit of $75 on the cost of repairs resulting from failing an
inspection test. (See question dealing with the effect of such
waivers on the program's effectivness.) The limit in California is
$50, with a provision to extend it to $75. New Jersey and Oregon,
on the other hand, consider the cost of repairs as a necessary cost
associated with the privilege of driving on the state roads and
place no limits on repair costs.
Those agencies presently conducting I/M programs report no notice-
able change in the service industry as a result of implementing
their programs. As I/M programs have started up, there have been
no reports of shortages of mechanics, or facilities to perform the
necessary maintenance. The number of vehicles on the road per
mechanic has steadily risen over the past two decades to about 235
cars per mechanic currently. While the situation has been called
critical by at least one industry official, it appears that the
current repair force can handle extra I/M related repairs. One
recent survey indicates that over 80% of repair facilities which
perform tune-ups could handle at least an extra 10% workload in
this area, and about one-half of these shops could handle a 30% or
higher increase in tune-up work. New Jersey estimates the extra
work is, on the average, less than 5% of the repair facilities'
workload and that there is no trouble absorbing the work.
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TABLE A
Inspection Fee Breakdown
(Costs to state for contractor and decentralized programs indicated in parentheses)
State Contractor Decentralized
INITIAL COSTS (annualized)
Facility Investment Costs
Land .30 .30
(.02)
Construction .61 .61
Other Investment
(training, equipment, site prep, etc.)
(.04)
.62
Administrative Startup Costs
.25
TOTAL Annualized Initial Costs
1.78
ANNUAL COSTS
Facility Operating Costs
Personnel 3.11
(inspector's time
and overhead)
Other Operating Costs
(equip, maint. , .88
support services, etc.)
Administrative Operating Costs
1.10
TOTAL Annual Operating Costs
5.09
.62
.21
(.10)
1.74
(.10)
(with inflation)
2.42
1.44
.70
(.46)
4.56
(.46)
.89
(.03)
(.22)
.39
(.31)
4.65*
(.19)
.88
(.05)
(1.57)
5.53
(1.81)
ANNUAL INSPECTION FEE
TOTAL Program Cost
to State 6.87
Contractor's net return
6.30
(.56)
.50
6.42
2.12
TOTAL Inspection Fee 6.37 7.36 8.54
"Assumes the mechanic performs inspection.
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TABLB B
5JL?.!:e Personnel' Utilization*
Person-years. For training and hiring categories, these, figures represent total person-years nf ti:;rlnlnp
time for personnel not considered full time staff until program is in actual operation.
State
Contractor
Personnel Area
Start-Up Personnel
Program Administrators (including contract monitor)
Technical Officers (e.g., mechanic training, building,
quality control, etc.)
Data Analysis/Statistical Staff
Secretarial/Clerical Staff
Training and Hiring of Field Facility Staff (including challenge lane)
Training and Hiring of Field Facility Monitors (or station examiners)
Annual Operating Personnel (present dollars)
Program Administration (Including contract monitor)
Technical Officers (mechanical training, qual. cnll., etc)
Data Analysis/Statistical Staff
Secretarial/Clerical Staff
Field Facility Staff (incl. challenge facilities)
Field Facility Monitors (or station examiner)
(3)
(3)
(1)
(3)
(1.6)
"
(11)
(3)
(7)
(2)
(3)
(91)
—
CO
(.1)
(1)
(1)
-
(0.03)
(6)
(3)
(1)
(1)
(1)
-
(1.)
(2)
(2)
(2)
(3)
(0.1)
(0.2)
(9.3)
(2)
(2)
(2)
(3)
(5)
(10)
TOTAL
U06)
(7)
(24)
*These estimates are provided for illustrative purposes only. The ar.tual number of state personnel will vary depending on the intensity
of efforts in each area. Public information and program design, engineering and evaluation efforts are not ahovn.
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i) COWPS Report - What is EPA's response to the Council on Wage and Price
Stability's assessments of the ozone standard and the cost-effectiveness
of I/M? From whence did EPA's cost vs. stringency calculations come?
Was this based on restorative maintenance data or I/M data? What cost-
effectiveness can now be claimed considering the questionable fuel
savings and all indirect and direct consumer costs? Will EPA revise its
cost estimates?
The Council on Wage and Price Stability's assessment of I/M's cost-
effectiveness for ozone was in error due to the fact that repair
costs were attributed to all vehicles, not just those which failed
the I/M test. EPA has pointed this out to COWPS and has provided
them with our cost-effectiveness analysis. EPA's best estimate for
first year cost-effectiveness is $600 to $1500 per ton HC. This
range reflects the higher than expected benefits occurring in the
Portland study. The details of this calculation are presented in
response to the "Cost Analyses: (Cost-Effectiveness)" question. No
fuel economy benefit is assumed. As discussed in a previous
question, neither indirect costs or health and welfare benefits are
included in these calculations.
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3. IMPLEMENTATION
a) Funding - Will funds be available for any of the following: mechanics'
training, public information programs, construction of I/M facilities,
preliminary or continuing studies, pilot programs or introductory full-
scale mandatory inspection/maintenance programs, or the administrative
costs associated with I/M?
Funds are available through the EPA regional offices to help
support the implementation tasks listed above. Once mandatory
inspection begins, the program should be self-supporting from the
inspection fees collected.
Funds were made available in FY78 to support I/M studies in many
states. In FY79 over $5 million has been allocated to support
state I/M activities. In the FY80 budget EPA has proposed
additional funds be made available for the states implementing I/M.
Other grant funds may also be available from the Regional offices.
Priority in distributing funds will be given to those states with
or making progress towards obtaining enabling legislation.
b) Delays - How many states plan to request extension beyond June 1979 to
obtain legislation? On what basis will EPA make decisions on the requests?
At this time two states have requested an extension in obtaining
legislation to beyond July 1, 1979. These requests have been
denied. The Clean Air Act, as amended in 1977, requires proof of
legal authority to implement the elements of the non-attainment
plans (Section 172(b)(10)), including inspection maintenance. In
the absence of such proof, a SIP cannot be fully approved. To
facilitate submittal and review of the SIPs, and in recognition of
the fact that most legislatures will not meet until after the
January 1, 1979 SIP submittal deadline, EPA will accept, in lieu of
certification of legislative authority, a commitment by the governor
to a schedule for implementing I/M. A required date in that schedule
is certification of adequate legal authority by July 1, 1979; at
that time evidence of legal authority must be submitted to EPA.
The Costle and Hawkins policy memos of February 24, 1978, July 17,
1978, and February 21, 1979 detail limited exceptional cases in
which an extension from EPA in certifying legal authority is possible.
These are:
a) There was insufficient opportunity to conduct necessary
technical analyses and/or
b) The legislature has had no opportunity to consider any
necessary enabling legislation for inspection/maintenance
between enactment of the 1977 Amendments to the Act and
June 30, 1979.
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Regarding the first point, the large amount of information avail-
able from contractor studies, EPA, and operating I/M programs
coupled with the 18 months which have passed since the Clean Air
Act Amendments indicate that extensions on this basis will not be
needed. On the second point, the state must show there has been
insufficient opportunity to consider legislation since passage of
the 1977 amendments to the Clean Air Act. EPA will grant no
extension if the legislature has had an opportunity to consider
enabling legislation but has not given such legislation serious
consideration. In any case, an extension will not be considered by
EPA until after June 1, 1979.
c) Delays - What will be EPA's response to delays in implementation?
Can the definition of "as expeditiously as practicable" be widened to
accept an implementation schedule that would initiate a mandatory inspection/
voluntary maintenance program two and one-half years after legislation?
This would run for one year to fine-tune the entire I/M program - including
standards, mechanics training, and administrative processes. After that
year, mandatory maintenance would be required.
The Act requires I/M to be implemented as expeditiously as practicable.
EPA policy has recently extended the date for mandatory inspection
and repair to beginning no later than 1981 for decentralized programs
and no later than 1982 for centralized programs. In general, SIP
schedules should reflect realistic intermediate milestones which
can accomodate unanticipated delays while achieving the deadline
for mandatory repair.
d) Public Information - What assistance is available for public information
programs? Arizona's experience is known, but how have other states
handled the public education problem?
An understanding by the public and other affected groups of the
need for and operation of I/M is essential to the success of the
program. For this reason a public information program is a
required element of the SIP I/M implementation schedule. Assis-
tance for States pursuing I/M public information programs is
available in the form of grants from U.S. EPA Regional Offices and
a multi-media package on I/M developed by EPA and the American Lung
Association. I/M information materials which are available include:
Film - "On the Road to Clean Air" - this 17-minute color film
covers the purpose and need for I/M programs, the benefits and
costs and how a program operates. Available from your local
ALA chapter or from EPA Regional Offices on a free-loan basis.
Publications - "Information Document on Automobile Emissions
Inspection and Maintenance Programs" - EPA-400/2-78-001 (February
1978), a report produced pursuant to Section 108 of the Clean
Air Act which presents substantial information on all aspects
of inspection/maintenance programs. Available from EPA, (I/M
Staff, 2565 Plymouth Road, Ann Arbor, MI 48105).
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"Motor Vehicle Emissions; Inspection/Maintenance Kit," - EPA-
460/3-78-013 (September, 1978). A loose-leaf binder containing
information on benefits, legislation, public awareness, and an
extensive section on cost estimation.
"Tuning Down Auto Air Pollution" - a 16-page booklet which
discusses the need for I/M programs, the benefits and costs
and how a program works. Available from EPA.
"Get a Check-up for your Car?" - a leaflet on the need for
keeping cars well maintained to cut pollution along with
pointers on what can go wrong with your engine and what to do
about it. Available in English and Spanish from your local
ALA chapter or EPA regional office.
"Do Your Own Car" - a leaflet which explains pollution
control systems and gives the reasons why motorists should not
tamper with those devices. Available from EPA.
"The Health Effects of Air Pollution" - a 16-page pamphlet
which discusses the various air pollutants and the effects
they have on health. Available from EPA.
"I/M Update" - a bi-monthly information service for the exchange
of news and ideas on I/M implementation. Available from EPA.
Materials for the Mass Media - American Lung Association (ALA)
TV spot - a 60-second television presentation which emphasizes
the need for regular car maintenance to minimize auto-related
air pollution. Produced in cooperation with the ALA and Car
Care Council. Available from ALA and EPA.
ALA radio spots - four 30-second presentations, including one
in Spanish, which stress the connection between air pollution
and the automobile. Available from ALA and EPA.
In California, Hamilton Test Systems is obligated by contract to
design and operate a public information and education campaign,
under the direction and review of the California Air Resources
Board. Funds have been budgeted throughout the five-year lifespan
of the contract. Initially these funds will be used to produce
material for many communications media, including brochures, fact
sheets, newsletters, slide and film presentations, pamphlets,
billboards and announcements for radio and television.
Portland, Oregon has utilized mobile vans with emission analyzers
for demonstrations at major shopping centers and other key activity
centers. Oregon found that bumper stickers were one of the most
successful public information tactics.
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In New Jersey, posters were circulated in large volume around the
state. Each new car dealer and garage that purchased an emission
analyzer was contacted and the state compiled lists of approved
analyzers and garages which owned them. The dealers and garages
displayed signs indicating they had the analyzers.
Two program elements stand out as being widely used as I/M public
information techniques. One is the use of radio and television
spot announcements and newspaper advertisements. A second technique
that is key to reaching the individual motorist is preparing an
informational pamphlet and mailing it to all vehicle owners, usually
along with motor vehicle registration forms. Both California and
Arizona have indicated costs for these elements to be approximately
$0.12 per vehicle.
States with existing I/M programs have indicated that as the public
becomes used to the program there may be somewhat less need for an
intensive public information effort. There would still be a need
to inform motorists of any significant changes in program operations
or other modifications of program elements such as waivers, exemp-
tions, repair cost ceiling, inspection fees, or registration pro-
cedures. This could entail periodic mailing or possibly some media
announcements. The public should also be made aware of the status
of the program in terms of emissions reductions achieved.
e) Emission Control Devices (Catalysts) - Cars with fouled catalysts can
pass current I/M standards. They pollute more than they should, but is
there any reasonable test that can spot this?
There are a number of possible causes for catalyst failures among
in-use vehicles. Poisoning by lead deposits as a result of improper
use of leaded fuel is thought to be the most common, but plugging
or fouling with other substances, deliberate removal or tampering,
and thermal damage as a result of other neglected engine malper-
formances are also possible. Whatever the cause of the failure, a
vehicle with a failed catalyst will pollute more than it should and
will fail to meet the Federal HC and CO emission standards, as
measured by the lengthy Federal Test Procedure. The vehicle will
also emit more than a similar vehicle in good condition when tested
using any of the I/M-type short tests. This includes the idle
test, the short test currently used to pass and fail vehicles in
all of the I/M programs now in operation. Despite that fact that
emissions increase at idle, it is possible for a vehicle with an
inoperative or failed catalyst to pass current I/M idle standards.
There are a number of contributing factors that make this possible.
Current I/M idle standards have been set fairly loosely relative to
what vehicles in good condition are capable of achieving. This
keeps the number of failing vehicles manageable in terms of the
capacity of the repair industry to fix them and the capacity of
the I/M program to reinspect them, while achieving significant air
quality benefit. It tends to result in vehicles being failed only
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if their problems are easily and inexpensively repaired, as observed
in the Portland study. It also helps ensure that very few vehicles
which would actually be found to have low emissions on the Federal
Test Procedure are mistakenly failed and maintained unnecessarily.
Such mistakes are inevitable when using the idle test or any other
short test to pass and fail vehicles, since these tests repeat only
a portion of the Federal Test Procedure; the number of such
mistakes becomes very small when the idle standards are set rela-
tively loosely.
On the other hand, relatively loose idle standards allow some
vehicles which actually have problems which make them pollute more
than they ideally should to pass the idle test. Vehicles with
catalyst failures may be among these, in part because the catalyst
failure does not cause idle emissions to exceed the relatively
loose idle standards and in part because it is sometimes possible
to counteract the idle emissions increase due to catalyst failure
by adjusting certain engine parameters to nonrecommended settings.
Such maladjustments do not reduce emissions on the Federal Test
Procedure enough to compensate for the catalyst failure, and there-
fore only camouflage the catalyst failure.
Catalyst failures are only one of several types of problems which
cause cars to pollute more than they should but without causing
them to fail current idle test I/M standards. Mild forms of car-
buretor maladjustment, choke maladjustment, and EGR problems are
the most common of the other problems with similar effects. Taken
together and compared to the problems which currently account for
most idle test failures, catalyst failures and problems with similar
effects are important but not the major item of concern. The problems
which currently account for most idle test failures are more common
and more severe, taken together. As a result the vehicles which do
fail idle standards are responsible for most of the "excess" HC
and CO emissions of the in-use fleet of catalyst-equipped cars.
Even though an I/M program using an idle test and standards like
those used in current programs will not spot all vehicles with
failed catalysts, it can over time reduce the number of such
vehicles on the road, relative to what this number would be without
I/M. Drivers can be expected to be more reticent about deliberately
destroying or removing their vehicles' catalysts, for fear of
decreasing their chances of passing the I/M test. (EPA is inves-
tigating tampering rates in New Jersey which does not actually
inspect for tampering in its I/M program, to compare them with
tampering rates in non-I/M areas to see if this expectation is
borne out.) Drivers may also be more reluctant about improperly
using leaded fuel. And any I/M program raises the public's con-
sciousness of motor vehicle emissions and their relationship to air
pollution; this alone may reduce the frequency of tampering and
misfueling.
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As stated above and as implied by the question, the problem of
identifying failed catalysts is an important one, even though not
a critical one from the standpoint of I/M's effectiveness, and one
which EPA is currently pursuing. It is possible that loaded-mode
I/M tests would be more successful in spotting failed catalysts.
It is also possible that a simple idle test conducted at a higher
engine speed (as in the Two-Speed Idle Test) would be better. A
visual inspection certainly would be able to detect vehicles whose
owners have removed the catalyst (about one-half of one percent of
all 1975 and later model year cars), and this can give some improve-
ment to air quality. Finally, EPA is investigating other simple
tests to detect failed catalysts which could be adapted to an I/M program.
f) Emission Control Devices (Fuel Switching) - Is there any way for EPA,
perhaps in concert with the Department of Energy, to initiate a change
in the gasoline pricing policy to make leaded gas equal, if not greater,
in cost than unleaded gasoline?
EPA shares the questioner's concern about the incentive for mis-
fueling catalyst vehicles created by gasoline price differentials,
particularly in light of the potential impact of price deregulation
on those differentials. EPA itself does not have any statutory
authority which would allow it to change gasoline pricing policy.
EPA has been discussing this issue with the Department of Energy
(DOE), which does have this authority, and with other executive
branch offices. An agreement has been reached. Under the agreement,
DOE will propose a rulemaking which would limit the retail price
differential between leaded and unleaded gasoline. The Notice of
Proposed Rulemaking is expected at about the end of March, 1979.
DOE will propose limiting the price differential to approximately
its current level, a move which would prevent misfueling from
becoming more prevalent after gasoline prices are deregulated. DOE
will invite public comments on whether some other maximum limit on
the differential should be adopted instead, and on the regulatory
mechanism for enforcing the limit (i.e., on whether a "trigger
level" should be established which would have to be exceeded before
regulations took effect or whether they should be in effect con-
tinuously) . EPA hopes that State air agencies will participate in
this rulemaking by submitting comments to the public docket.
Vehicle drivers and service station operators are the ones who
choose to misfuel. Their choices are capable of being influenced
by factors other than price differential. EPA is conducting a
public awareness campaign to inform these persons of the harm
resulting from misfueling, in an effort to dissuade them. State
agencies can contribute by running similar campaigns. It should
also be noted that the existence of an I/M program can be a deter-
rent to misfueling because it raises people's awareness of motor
vehicle pollution and also causes them to think ahead about their
vehicles' ability to pass the next inspection. In addition, a
State can check for tampering to the fuel filler neck restrictor as
part of the I/M inspection. This would provide a strong incentive
not to tamper with the restrictor and thus would reduce the inci-
dence of misfueling.
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g) Emission Control Devices (Physical Inspection) - Is a test for tam-
pering by checking the functioning of emission control devices worth-
while from both a cost and an emission benefit standpoint?
A recent survey performed in conjunction with six state safety
inspection programs has shown approximately 20% of all 49-state
cars now on the road have been grossly tampered. The EGR system,
which primarily affects NOx emissions, is the most common target
for tampering, with a tampering rate of about 18%. Other forms of
tampering have rates of at most a few percent. (These rates include
cases where a malfunction may have occurred naturally but is equi-
valent to one caused deliberately.) The survey data show that
tampered vehicles tend to have higher than average idle emissions
and thus tend to fail an idle test more frequently. For example,
45% of the tampered vehicles in the survey failed a set of idle
standards (the New Jersey Phase III standards), while only 35% of
all the vehicles in the survey failed. (A smaller sample of
California cars also showed about 20% gross tampering, but for
presently unexplained reasons the portion of the tampered cars
which would fail I/M standards is lower, about 10%.) The higher
idle emissions of tampered vehicles are due in part to the effect
of the tampering itself and in part to the fact that tampered
vehicles tend to be misadjusted as well. The net effect is that a
sizable fraction of tampered vehicles will be sent to get repairs
even in an I/M program that does not inspect for tampering. Some
of these will have the tampering corrected; a state can increase
the number through mechanics' training and/or regulations governing
repair practices.
EPA has not yet analyzed the available survey data to see whether
a loaded mode test would identify a larger fraction of the tampered
vehicles than does the idle test. Engineering considerations alone
suggest that it would, at least for emission control system elements
which affect exhaust emissions. (Positive crankcase ventillation
(PCV) and evaporative emission controls do not always have an
effect on exhaust emissions.)
For a state to be certain of identifying cases of tampering and
getting them repaired, there is no substitute for a tampering
inspection. The Portland, Oregon I/M program has found the
inclusion of a tampering inspection to be workable.
Any I/M program can be expected to be a deterrent to tampering. An
I/M program that includes a tampering inspection presents a par-
ticularly strong deterrent. The survey mentioned above showed that
tampering sharply increases with vehicle age. If an I/M program
prevents this increase it will achieve additional emission reduc-
tions at low cost.
The table shown below represents a very preliminary estimate of how
much the fleet-average emissions of 1975 and later cars would be
reduced if vehicles with the listed types of tampering were repaired.
A more definitive analysis and quantification is now underway.
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Preliminary Estimate of Fleet Emission Reductions
(1975 and Newer Cars) Resulting from Tampering Inspections
(Base Emissions: 1.7 gpm HC, 25 gpm CO)
Component Approximate Approximate Fleet Emission Reductions
or System Tampering Rate* HC_ CO NOx
PCV 2.5% 1.4% 0 0
Air Pump 1.3% 0.8% 1.5% 0
Catalyst Removed 0.8% 0.7% 0.5% 0
Evaporative
Emissions Canister 1.3% 0.6% 0 0
Fuel Tank Cap
and Seal 0.7% 0.2% 0 0
EGR 13% 0 uncertain 5-18%
*The "tampering" rates listed here include some malfunctions, such as
those due to inadequate maintenance, which are not due to tampering but
which may be detectable in a tampering inspection. Tampering rates
are based on all in-use passenger cars of 1975 and newer model years (as
measured in the Mobile Source Enforcement Division 1978 Tampering Study),
not just those actually equipped with the particular emission control
component or system.
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EPA1s preliminary appraisal is that inspecting the listed components
would have a cost-effectivness for HC and CO that is competitive
with the idle inspection itself. The same is true for a NOx/EGR
inspection, as is described in question 1L: "Load/Idle Test."
h) Mechanics Training - What success has been achieved with mechanics
training programs? Why were the Colorado State workbooks aimed prin-
cipally at emission control devices while most repairs do not consider
these? Will EPA structure programs to consider this problem and the
changes envisioned in future emission controls and engines?
Reports from I/M programs in which mechanic training has been
implemented indicate considerable success. In Phoenix a 2-hour
training program conducted at automobile dealerships and independent
garages was aimed at improving mechanics' ability to perform common
emission related repairs such as setting the idle air/fuel ratio.
The Arizona motor vehicle inspection program staff has reported
noticeable improvement in idle emission reductions resulting from
this training. They found fewer cases of vehicles continuing to
fail the emission standards after maintenance and a generally
better acceptance of the program by the service industry.
The Colorado State University (C.S.U.) training materials were
aimed principally at emission control devices in order to fill a.
void in the existing training programs. These materials were
prepared to supplement the training in basic automotive repair
being conducted in vocational training schools. At the time they
were developed by C.S.U., basic training materials were available
to cover most common engine repairs, but none were available to
cover the newly introduced emission controls. Incorporation of the
new materials into existing training programs for new mechanics was
part of a long range program to upgrade emission related maintenance.
In order to improve the emission repair skills of practicing mechanics
and produce a more immediate benefit, C.S.U. is now working on a
new short course which will cover the detection, causes and cor-
rections of HC and CO failures, infrared gas analyzer operation,
diagnostic procedures, and EGR operational checks. This course
will be pilot tested in Denver starting March, 1979. EPA will have
these materials updated and/or modified as necessary for future
emission control systems and repair procedures.
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j) New Car Testing and Cars of the Future - Some states are considering
testing new cars after their sale. Would EPA consider testing all
vehicles at the assembly plant with a short test as in I/M? States
could then decide on the necessity of post-sale tests. What will be the
effect on I/M - both its operation and effectiveness - of EPA's proposal
that new cars meet emission standards over the entire range of timing
and carburetion adjustments? Will an engine parameter check be necessary
with these vehicles?
Data needed to respond to the first part of this question have not
been received in time to be included in this letter. A response
will follow later.
On January 12, 1979, EPA promulgated regulations which will require
that automobiles are capable of meeting federal emission standards
anywhere within the range of adjustments available on certain
components. The devices which limit the adjustability of a compo-
nent must be tamperproof. Components affected by these regulations,
and the model year to which the regulation applies, are: idle
mixture adjustment (1981); choke (1981); idle speed (1982); initial
spark timing (1982). The inclusion of these components in the
regulations was in direct response to the results of the restorative
maintenance testing performed by EPA, in which these parameters
were most frequently fqund to be maladjusted.
For cars using current technology emission controls in 1981 and
later model years, failures of an I/M test are expected to decrease
due to these regulations. In 1981, however, emission control
technology for most cars is expected to change significantly. This
new technology is expected to have different maintenance require-
ments which will minimize the need to periodically adjust common
tune-up parameters. Maintenance for this new technology is expected
to involve periodic replacement of oxygen sensors and repair of
input sensors to the electronic control system, items not commonly
found on current technology systems. I/M will help assure these
new maintenance and repair requirements are met, for it is expected
in many cases that the driver will not perceive a need to take
corrective actions (e.g., driveability may remain good). In addi-
tion, the emissions in the failed modes are expected to be at least
as high as those seen on today's maladjusted vehicles. Thus while
it is hoped the failure rate will decrease, it is expected that the
amount of excess emissions per failed vehicle will increase relative
to the lower federal emission standards.
These factors, combined with the widespread occurrence of tampering
and misfueling, establish a need for I/M programs for new technology
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vehicles into the 1980's. And of course, the current fleet of
cars, for which maladjustments are widespread, will remain in the
fleet for .10 years or more, and I/M is the only strategy to control
their excess emissions.
An engine parameter check may also be a valuable tool in assessing
the operation of the new electronic control systems. On some
vehicles this may be as simple as checking a diagnostic light on
the instrument panel. An emission check, however, is expected to
continue as the primary indicator of the total vehicle's emission
performance.
j) Warranty - When will final warranty rules be promulgated? Will the New
Jersey type of idle test be sufficient to invoke the warranty provision
of the Clean Air Act? Would a private garage inspection system be.
acceptable under warranty rules? How will enforcement be carried out?
Final emission performance warranty regulations and idle test
standards will be promulgated this year, effective beginning with
1980 or 1981 model year vehicles. This warranty will be available
to owners whose vehicles fail the Federal warranty idle test standard.
Further, by law the warranty will be available only if some penalty
or sanction is imposed; a non-mandatory program will not be suf-
ficient. Either a centralized (inspection lane) or decentralized
(private garage) program will be acceptable. EPA will not normally
be involved in the day-to-day operation of these regulations.
However, failure of a manufacturer to comply will be a "prohibited
act" as specified in Section 203 of the Clean Air Act; civil pen-
alties up to $10,000 are possible. If problems arise, EPA will
take appropriate enforcement.
k) EPA Reports and Rules - What is the cause of the delay in the publication
of the Oregon study, Appendix N, and the warranty rules?
The Oregon I/M study will not be complete until early 1980. To
deal with the need for information on the preliminary results of
the study, a series of interim reports have been planned. The
first preliminary report, dealing with the initial effects of
maintenance was published in May 1978. The second preliminary
report, which analyzes the deterioration over the first six months
after maintenance, is now available. Additional reports are planned
as the study progresses; all reports are available through the EPA
regional offices.
Modifications based on comments to the proposed Appendix N (FR2422177)
have been incorporated into the computer program MOBILE1, which is
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being widely used to calculate emission inventories and I/M credits
for the January, 1979 SIP submittals. This computer program con-
tains EPA's best estimate of the benefits of I/M. Appendix N has
not been finalized in order to allow for modeling changes which
will best reflect the incoming data from the Portland study and
testing of advanced prototype vehicles. A final Appendix N will be
promulgated late this year.
Warranty coverage under section 207(b) will be promulgated prior to
the widespread initiation of I/M programs, a prerequisite for its
application. The enforcement provisions are being reproposed in
response to the change in warranty provisions in the 1977 Clean Air
Act Amendments. The enforcement and short test regulations will be
promulgated for the 1981 model year with a good chance of them
being applicable to model year 1980 as well.
1) EPA Reports and Rules - Why is inconsistent information regarding fuel
economy benefits of I/M being given out?
Every attempt is made to inform the EPA Regions and the States of
the latest information on I/M benefits. In the case of fuel economy
benefits, the Portland study presented preliminary data which
conflicted with the other fuel economy studies. In the interim
while this apparent discrepancy was under investigation, some
inconsistency in interpreting the various studies was sure to
occur. As set forth in a previous question, the fuel economy
benefit of I/M is now better understood and quantified, and a
report detailing the fuel economy analysis will be distributed to
the Regions and States in April.* •
m) EPA Reports and Rules - Can't reports such as the EPA information docu-
ment be updated periodically to reflect new information and correct
erroneous data?
As new information on I/M becomes available, it will be distributed
to EPA Regions and to the states. The form this information may
take will vary from updates of existing reports (such as the Portland
Study) to new technical support reports. The recently distributed
information kit, in looseleaf format, will be used to update
information whenever possible. To obtain the latest information
available on any I/M-related topic, a request may also be addressed
to the Ann Arbor I/M Staff.
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It is impossible to update each document each time a piece of data
changes. The approach EPA is taking is to publish changing data
whenever it may impact on conclusions concerning I/M. In the
example given in the question, the New Jersey cost estimate did
decrease based on a newer study, however the range of repair costs
quoted by EPA ($16 to $32 per failed vehicle) was still valid.
n) Information Center - Would EPA consider funding or lending assistance to
establishment of a better I/M information network among the states. All
affected states should be kept up-to-date on recent reports, legislation,
and other information. Some states have expressed interest in obtaining
copies of current enabling legislation and study efforts by other states.
If your office could compile this information and provide it for distri-
bution through the regions, it would be of much help. EPA should be
sure to make its reports and summaries sufficiently detailed to withstand
the numerous challenges faced on the state level.
It is our view that a satisfactory system for distributing reports
to the states exists. As information and reports such as the
Portland Study become available, they will be distributed to the
EPA regions, who will send the information to the states. Likewise,
questions concerning I/M should be addressed by the state to the
Regions, who will assure the appropriate answer or information is
obtained.
A newsletter, entitled I/M Update will be issued bi-monthly and
will be used to disseminate information on recent developments in
I/M. A list of older studies on I/M is included in the I/M infor-
mation document. Specific to the question, copies of enabling
legislation and a list of study reports on I/M options will be available
from the regional offices.
* US. GOVERNMENT PRINTING OFFICE: 1979- 650-029/0041
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