AN ANALYSIS OF ALTERNATIVE MOTOR
VEHICLE EMISSION STANDARDS
PREPARED BY: UNITED STATES DEPARTMENT OF TRANSPORTATION
a
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
UNITED STATES FEDERAL ENERGY ADMINISTRATION
MAY 19, 1977
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AN ANALYSIS OF ALTERNATIVE MOTOR
VEHICLE EMISSION STANDARDS
The analysis contained herein assesses the air quality,
health, cost, fuel economy and economic consequences of
specific auto emission control alternatives currently
before Congress. The alternatives are:
A. Administration proposal with 0.4 gpm NOx.
B. Administration proposal with 1.0 gpm NOx.
C. Dingell/Broyhill proposal with 2.0 gpm NOx.
D. Dingell/Broyhill proposal with 1.0 gpm NOx.
E. Senate Committee Proposal.
The specific emission limitations and schedule for each
of these alternatives are provided below.
Y««r Hydrocarbon Carbon Kotioxide Kitrogcn Oxides
Schedule A B C » • A1COEABCDE
l.S 1.5 1.5 1.5 l.S. li 15 15 15 15 2.0 2.0 2.0 2.0 2.0
197» .41 .41 1.5 1.5..41 9 9 15 15 3.* 2.0 2.0 2.0 2.0 2.0
1980 .*! .41 •*! •*! ••'»! « 9 9 3 3.4 2.3 2.0 2.0 2.0 1.0
19M .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 1.0 1.0 ?.0 2.0 1.0
J932 .41.41.41.41.41 3.43.49 9 3.A 1.01.02.01.01.0
.41.41.41.41.41 3.43.45 93.4 .41.02.01.01.0
.41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 .4 1.0 2.0 1.0 1.0
1W5 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 ./. 1.0 2.0 1.0 1.0
This report has been prepared by EPA, FEA and DOT in order
to provide information on these alternatives, including the
Administration's recommendation.
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-I. Summary and Conclusions
Broad segments of the population now live in areas
where ambient concentrations of photochemical oxidants (Ox)
(population 96 million), carbon monoxide (CO) (population
66 million) and nitrogen oxides (NOx) (population 30 million)
exceed the Federal ambient air quality standards.
Automobile emissions produce about 70 percent of the CO in
areas where the National Ambient Air Quality Standards .
(NAAQS) are exceeded. Autos produce about 20 percent of the
hydrocarbons (HC) and NOx nationally, and over twice that
percentage in some urban areas (HC and NOx are precursors of
photochemical oxidants).
Since autos are not the only sources of HC, CO, and NOx,
stringent emission standards for autos will not, by themselves,
eliminate "auto related" air pollution but they will certainly
reduce that pollution and its attendant effects on public
health.
Therefore, the Administration recommends that automotive
emission standards of 0.41 grams per mile (gpm) hydrocarbons,
3.4 gpm carbon monoxide and 1.0 gpm nitrogen oxides be imple-
mented as rapidly as possible to protect the public health.
Public health may require that the NOx standard be set at the
more stringent 0.4 gpm level. Studies currently underway should
enable EPA to resolve this issue by 1980.
Air Quality Benefits of Alternatives
National Ambient Air Quality Standards will probably be ex-
ceeded in some places for each of the auto related pollutants
through the year 2000. Rapid imposition of stringent auto
emission standards will reduce the severity and frequency of
NAAQS violations and the attendant effects on public health.
Table 1 summarizes the projected effects of the auto emissions
standards alternatives on selected air quality indicators.
Such projections must rely on assumptions concerning future
growth and expected levels of stationary source control.
Consequently, the projections should be used as comparative
indicators of the air quality impact of alternatives rather
than as absolute predictions.
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TABLE 1
LONG RANGE AIR QUALITY PROJECTIONS
Pollutant
Emission
Schedule
Final Emis-
sion Level
Percent
Change in
Air Quality
By 2000
Number of
AQCR's with
NAAQS Viola-
tions in the
year 2000
Number of
NAAQS viola-
tions 1980-
2000
CO
C,D A,B,E
*
9.0
-45 to -60*
*
12* to 16
3300* to
14,000i/
3.4
-60 to -70*
5* to 12
•
2000* to
eoooi/
NOX/N02
C B,D,E A
2.0
+13
7
HS2/
1.0
+8
7
iis3/
0.4
-5
4
HC/Ox
A,B,C,D,E
0.41
-45 to -50*
26* to 31
90^/5 62,000!/*
! to
79,000
1. Violations of the 8 hour CO standard projected for .
only 30 AQCR's
2. Violations of the annual NO2 standard for only 14 AQCR's
3. Violations of the 1 hour OX standard for only 48 AQCR's
*with Inspection/Maintenance
Hydrocarbon/Oxidants
There is general agreement that 0.41 gpm for HC should be
imposed as rapidly as possible to mitigate the pervasive
photochemical oxidant (smog) problem. The seriousness of
the problem is shown in Table 1. Even with 0.41 gpm auto
emission control, a strong program of vehicle inspection/
maintenance and stationary HC source control, the NAAQS for
Ox is projected to be exceeded in 26 or more AQCR's in the
year 2000.
There is a one year difference between the several alter-
natives in the timing of 0.41 HC. That one year delay is pro-
jected to cause about 4 percent more violations of the 1 hour
oxidant standard between 1980 and 1990.
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Carbon Monoxide
Both the severity and frequency of violations of the 8 hour
NAAQS for CO are expected to decline through 1990. However,
even the rapid imposition of 3.4 gpm together with an I/M
program will not eliminate the projected violations. A CO
standard of 9 gpm would leave more AQCR's in violation of
NAAQS in the year 2000 than would 3.4 gpm. The less stringent
standard is projected to result in 65-130 (with and without
I/M, respectively) percent more NAAQS violations between 1980
and 2000.
The more rapid attainment date for 3.4 gpm contained in
Schedule E would reduce the cumulative number of violations
of NAAQS by about 25 percent between 1980 and 1990.
Nitrogen Oxides
Nitrogen dioxide concentrations are projected to increase in
the near future due to general growth of mobile and stationary
NOx sources. That projected increase could be stopped or
reversed toward the end of the century by stringent control
of NOx from both mobile and stationary sources.
Based on limited air quality monitoring data, at least six
of the country's most populous urban areas are projected to
be in violation of the annual average NO2 'ambient levels in
the year 2000 if a 1.0 gpm emission standard is implemented
rapidly. If the standard stays at 2.0 gpm, annual average
air quality levels will be 4% worse in 1990 and 5% worse in 2000,
Reducing the NOx standard to 0.4 gpm would improve air quality
by 9% in 1990 compared to a 1.0 gpm standard (13% compared to
a 2.0 gpm standard). Moreover, it would improve air quality
by 13% in 2000 compared to a 1.0 gpm standard (18% compared
to a 2 gpm standard).
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Health Effects
The adverse effects on public health associated with present
and projected photochemical oxidant concentrations are
serious and well documented. Since there is agreement that
0.41 HC is needed to reduce oxidant formation, no comparison
of the health benefits of different standards is needed.
The reader is referred to Chapter V for a discussion of
oxidant health impacts.
Individuals afflicted with heart disease are most susceptible
to risk of disability due to exposure to high CO levels.
The excess disability due to increased angina attacks is
projected to more than double during the period 1980 to 2000
if the CO standard is set at 9 gpm instead of 3.4 gpm. The
number of excess cardiac deaths would also increase slightly.
The major issue with regard to NOx is the degree to which health
effects are observed at different ambient levels. The current
ambient standard is expressed as an annual average. There is
increasing evidence that short term peak values may have more
impact on observed health effects. Therefore, EPA will be pro-
viding a more definitive position on the need for, and nature
.of, a short term N02 standard as part of the Agency's formal
N02 standard review scheduled for 1979.
A short term air quality standard is.likely to result in a
substantial increase in the number and severity of air quality
violations. Furthermore, because auto NOx emissions would
probably contribute disproportionatly to high, short term
NO2 concentrations, a new short term N02 standard would probably
increase the need for motor vehicle emission control.
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.Costs of Alternativa Emission Schedules
The costs of the several alternative emission schedules are
influenced primarily by the final emission levels. Estimates
of the cost-per-vehicle, the impact on the Consumer Price
Index (CPI), and the aggregate first cost are summarized in
Tables 2 and 3 by the final emission levels of each alternative
Both tables are for 1985 and are in 1977 dollars.
TABLE 2
UNIT COSTS OF ALTERNATIVES i/
(In 1985 Model Year, 1977 Dollars)
Change Relative to
Current Standards
(1.5/15/2)
Initial Cost
(S) If
Lifetime Maintenance (S)
Fuel Economy
(percent)
A
.41/3.
240 -
90 -
-8 to
V.4
330
100
2
B
.41/3. 4/1.0
190
35
-3.
- 250
- 70
5 to +2
Alternatives
C
.41/9/2.0
35 - 100
0-17
-3 to +2
140
35
-3.
D
/9/1.0
- 185
- 70
5 to +2
E
.41/3.4/1.
190
35
-3.
- 250
- 70
5 to +2
0
I/ Ranges reflect assumptions about use of optimal cost or optimal fuel economy
technologies (see Appendix A).
2/ Includes an 80% markup from manufacturer to dealer.
TABLE 3
CPI and Aggregate Cost Impacts
Alternative Standards A B .
Percentage point change in .035 .026 .012 .019 .026
CPI in 19851'
jgregate Stick
Increase ($ B
in 1965 for 1985
cars)?/
Aggregate Sticker Price
increase ($ Billions 3.0 - 4.1 2.3 - 3.1 0.4 - 1.4 1.7 - 2.3 2.3 - 3.1
I/ Based on the higher optimal fuel economy sticker prices which econometric
models indicate will be those selected by the automobile industry to maximize
aalas.
2/ Sticker price cost is not annualized but assumed to be incurred in the year
of sale. Sales in 1985 assumed to be 12.3 million cars. Range reflects
assumptions of optimal cost or optimal fuel economy technologies.
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The data in Tables 2 and 3 indicate that emissions standards
can be met with little or no fuel economy penalty if the industry
employs the optimal fuel economy technology. This will add
to the sticker price of the car. However, even at the most
stringent standards this incremental cost, which is less than
that of the automobile air conditioning ordered with most
new cars, has an insignificant impact on the CPI, less, than
four one-hundreths of one percentage point in all cases.
The impact of the alternatives on gasoline consumption in
1985 is shown in Table 4.
-.-••'•'• . TABU*
•:- IMPACT OF THE ALTERNATIVES OS THE
' GASOLINE OMJUMP1 ION IN CAU.10AR TEAR 1935
;•. Of 197S-19CS K30CL TEAR AUII&
Qiangt In S*$ol1n«
Consuoption (1000
B*rr»li/0*y) . .
Peirtnt ClMnq* in
ToUl Gdsolin*
Coasucpcian
' " • A
Low Hied
-40.1 r +101.8
-.571 »!.«
, .,.__-•
S
low H1a(i
-40.1 . +«7.7
-.Sn ».97X
— "-**^" •
. ••••
c
Lew Hlqh
-O3.a +M.2
-.4n *.775
0
law Htah
-33.3 +«.7
-.47S +.31t
C
Low • Hlah
-40.1 +67.7
-.575 +.971
So.
Table 17 for th. awunptiona used in c.lculatiwi the
*
The data indicate that the alternative schedules do not result
in significant differences in gasoline consumption. in an
cases9the range of estimates overlap, with possible reductions
in total gasoline consumption shown for every schedule i; uh*.
industry utilizes the optimal fuel economy technology. 1^
industry attempts to minimize initial cost (at the cost o.
'fuel economy) total gasoline consumption will increase,_Bat_
in no case by more than 1.45 of .total gasoline consumption i
1985.
REVISED 5/24/77
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The Administration Recommendation
Achievement of 0.41 gpm HC, 3.4 gpm CO and 1.0 gpm NOx is
possible at no fuel penalty given sufficient lead-time and
with a sticker price increase of about $250 (less than the
typical cost of an auto air conditioner). Even 0.4 NOx can
probably be achieved without fuel penalty but at a further
sticker price increase of about $80 although fewer data at
that level are available than at 1.0 NOx. Considering the
public health needs along with the cost, fuel economy impacts
and technological feasibility of the emission reduction tech-
nology, the Administration recommends the following emission
schedule: ' ..-.,..
Model Year HC ' CO NOx
1978 1.5 15 2.0
1979-80 0.41 9 2.0
1981-82 0.41 .3.4 1.0
EPA believes it is likely that the review of NOx health re-
search findings and other relevent data, to be completed
in 1980, will show the need to reduce the NOx emission
standard to 0.4 gpm for the 1983 model year.
Other Considerations
Major improvements in fuel economy are projected during
1978-85 as a result of the requirements of the Energy Policy
and Conservation Act. The advance in fleet fuel economy will
come about through reductions in the weight and size of
automobiles, the introduction of more efficient engines and
other measures. To the extent that emissions standards force
the introduction of the advanced engine technologies which are
also necessary to attain optimal fuel economy, the early
stabilization and implementation of the technology forcing
standards (particularly 1.0 NOx) could facilitate the earlier
achievement of the national fuel economy goals, as well as
improving air quality.
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If the 0.4 gpm NOx standard is required for 1983 models, a
few individual engine families.may have difficulty meeting
it without fuel penalties; diesels may have difficulty
meeting it at all. In order to provide maximum flexibility,
vehicles should be allowed to meet a 1.0 NOx level upon
payment of a nonconformance penalty in an amount slightly
greater than or equal to the difference between the costs of
compliance at 0.4 gpm and 1.0 gpm. Diesel vehicles should
be allowed to meet a 1.0 gpm standard if it can be demon-
strated that they can do so for 100,000 miles.
There is some concern that large diesel vehicles* may not be
able to achieve the 1.0 gpm NOx standard by 1981. To ensure
that there is time for fuel-efficient diesel technology to
evolve and develop, a waiver is proposed up to a 1.5 gpm
level provided that:
1. A good faith effort is made to achieve 1.0 gpm.
2. the 1.5 gpm standard is demonstrated to be met for
100,000 miles.
3. The average fuel economy standard applicable for the
model year is achieved by the vehicle granted such
waiver.
Another concern is that small volume manufacturers who must
rely on outside suppliers to provide many of the advanced
emission control components may need additional lead-time in
order to meet the more stringent emission standards. To
alleviate this concern, low volume manufacturers should be
allowed to meet a 2.0 gpm NOx standard in 1981 before moving
to the 1.0 gpm standard in 1982.
The remainder of this paper is devoted to a review of the
health effects from automotive air pollutants (Section II)
and projected air quality and emission impacts of various
emission schedules (Section III and IV). The relative differences
of certain quantifiable health indicators for various emission
standards schedules will be reviewed (Section V). The tech-
nological feasibility (Section VI) and the cost and fuel
impacts will be summarized (Section VII) as will the economic
impacts (Section VIII).
*3,000 Ibs and above
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II. Health Effects Summary of Carbon Monoxide, Nitrogen Dioxide, and
Photochemical Oxidants
The health effects data base for CD, N02 and oxidants were summarized
in the "Air Quality Criteria" documents published from 1968 through 1970.
Since that time, further research has been conducted to expand health
effects data bases for these pollutants. These criteria documents are
scheduled for revision over the next several years. The oxidant document
will be published in 1978, an N02 document in 1979 and the CO document
in 1980. Each revision will be extensively reviewed by the scientific
community. However, at this time we do not anticipate any significant changes
in the ambient air standards apart from the probable promulgation of a short
term N02 standard. Summarized below are discussions of the health effects of
these pollutants.
Photochemical Oxidants
Nitrogen oxides and hydrocarbons once emitted into the atmosphere undergo
a series of chemical reactions to form other air pollutants, most notably
oxidants. The most abundant photochemical oxidant found in the atmosphere
is ozone.
High oxidant levels are associated with aggravation of asthma and chronic
lung disease, irritation of the respiratory tract in healthy adults, decreased
visual accuity, eye irritation and changes in heart and lung function
in healthy subjects. Human exposure studies also suggest adverse health
response to ozone in combination with other pollutants such as S02.
Toxicological work with experimental animals confirms that exposures to
relatively low levels of ozone produce numerous changes in cell and organ
structure and function including changes indicative of chronic lung disease and
increased suspectibility to infection. Other pulmonary effects have also been
noted including reduced voluntary activity, chromasonal aberrations and
increased neonatal mortality. Available evidence is inadequate to permit
the quantification of toxicological effects observed in animals and of the
synergistic potential of various air pollutants. Nor is there sufficient
data to quantify the effects of ozone on natural ecosystems or on
agriculture although evidence exists of major adverse effects of ozone
pollution in these areas.
Nitrogen Dioxide, N02
In addition to playing a major role in the formation of photochemical
oxidant, nitrogen oxide emissions also produce nitrogen dioxide, (N02).
Epidemiologic studies published to date indicate that levels commonly found
in the ambient air may cause the following effects:
(1) An excess of acute respiratory illness in exposed families,
(2) Decreased lung function in elementary school females,
and . .
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(3) Increased bronchitis morbidity in elementary school
children exposed for two or more years.
Somewhat higher concentrations of N02 have been associated with other
effects including:
r
(1) Changes in the structure of lung tissue in rabbits,
(2) Increased occurance of respiratory infections in mice,
(3) Structural changes in the lung tissue of mice, and
(4) A loss of cellular elements in the lung tissue of rats
(5) Reduced lung function in adults exposed.
Recently, there has been considerable interest in the possible effects
of shorter-term exposure to N02. The World Health Organization (WHO) is
currently considering a report on a number of effects from short-term
exposure including:
(1) Increased airway resistance,
(2) Enhanced bronchial constriction in sensitive populations,
and
(3) Increased sensitivity to respiratory infection. .
Although some of these effects appear to be reversible - that is, when N02
levels subside, the effects vanish and no permanent damage or prolonged effect
results - it may be prudent to prevent the effect. As a result of their work,
WHO may state that a short-term threshold level for healthy humans of 0.5 ppm
is warranted because, at this concentration, multiple experimental studies on
animals and humans are in agreement that effects can be demonstrated. The
National Academy of Science has also voiced concern on two occasions for the
need to develop a short term N02 standard. The MAS argues that this "need is
demonstrated in the body of evidence showing acute effects of single or repeated
nitrogen dioxide exposures of six or less hours". EPA will be providing a more
definitive position on the need for, and nature of, a short-term N02 standard
as part of the Agency's formal N02 standard review, scheduled for 1979.
Nitrates and Sulfates
In addition to photochemical oxidants and N02, NOx emissions also can lead
to the formation of nitrates and it is believed that they play a role in the
formation of sulfates. The best available information on health effects
associated with exposure to atmospheric nitrate compounds comes from
toxicological and epidemiological studies, among them the CHESS study.
French, et. al., found suggestions that asthmatic attacks and other acute
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respiratory symptoms were mote frequently associated with nitrates and
sulfates than other measured pollutants including TSP, S02, and respirable
participates. In a more recent analysis of CHESS data obtained in the
southeast United States and in New York City, the statistical correlation
between asthmatic attacks and pollutant concentrations were clearly higher
for suspended nitrates. These results should be viewed in the following
context:
(1) The CHESS studies have been criticized in a recent Congressional
report for their definition of asthmatic effects, for their air
monitoring, and for a number of other methodological problems.
(2) The toxicological evidence supporting a correlation between
particulate nitrate species and effects in animals or in humans
is considerably more limited than the data base for sulfur oxides,
and
(3) The analytical problems associated with measuring particulate
nitrates or atmospheric nitrates are much greater and less well-
defined than that for sulfur oxides.
Carbon Monoxide
Carbon monoxide (CO) is emitted directly by automobile exhaust. CO is
a very stable gas and is usually found in highest concentrations very close
to the emission source. It is believed that highway" vehicles account for
over 90 per cent of the atmospheric CO to which the general public is exposed.
Carbon monoxide interferes with the delivery of oxygen to all tissues of
the body by binding to the hemoglobin inside red blood cells to form carbon-
oxyhemoglobin (COHb). Myocardium and nerve tissues are especially susceptible.
Persons with heart disease are particularly susceptible because they are unable
to increase blood flow to the heart to counteract the reduction of oxygen
delivery. There is much data showing decrement in human performance (visual
function, cognitive function, manual dexterity, auditory vigilance, etc.)
at low levels of COHb (3 to 7 percent) resulting from low level exposure to
CO. Individuals with anemia or emphysema or other lung disease, or who live
at high altitudes are likely to be more susceptible to the effects of CO.
III. Mobile Source Contributions To Current Ambient Air Quality
Motor vehicles are the major source of carbon monoxide and a Substantial '
contributor of nitrogen oxides and hydrocarbons. Accordingly, they play a
major role in the severe oxidant, nitrogen dioxide and carbon monoxide air
-quality problems which exist across the country. Table 1, displays the 1974
national CO, HC and NOx emission estimates.
"T? 7
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Table I
Nationwide Emissions by Source for 1974
Emission in 1,000 of . tons/year
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
6.
Source
Light Gasoline Autos
0-6,500 Ibs GVW
Light Gasoline Trucks
0-8,500 Ibs GVW
Heavy Gasoline Vehicles
8,501 Ibs GVW
Heavy Diesel Vehicles
8,501
Total Highway Vehicles
Non-Highway Mobile Sources
Total Mobile Sources
Oil and Gasoline Production
and Marketing
Organic Solvent Use
Stationary Fuel Comb uut ion
Industrial Processed
Solid Waste
Other Stationary Sources
Total Stationary Sources
Total U.S.
NO*
4,800
900
800
1,600
8,100
2,500
10.600
0
0
13,300
700
200
200
14,400
25,000
(19.
(3.
(3.
(6.
(32.
(10)
(42.
(53.
(2.
(0.
(0.
(57.
2)
6)
2)
4)
4)
4)
24
8)
8)
8)
6)
7,
1,
1.
11,
1,
12,
4.
8.
i;
3,
i,
i,
20,
33,
HC
600
800
400
200
000
600
600
100
900
700
700
000
000
400
000
(23.
(5.
(4.
(0.
(33.
(4.
(38.
(12.
(27.
(5.
(11.
(3.
(3.
(61.
0)
5
2)
6)
3)
8)
2)
4)
0)
2)
2)
0)
0)
8)
CO
52,000
9,500
11,400
800
73,700
9,300
83,000
1,400
11,000
3,500
5,300
21,200
104,200
(49.
(9.
(10.
(0.
(70.
(8.
(79.
0
0
(1.
(10.
(3.
(5.
(20.
9)
1)
9)
8)'
7)
9)
6)
3) ,
6)
4)
1)
4)
•
( ) Percent of Total U.S.
3*0 ,2
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Carbon Monoxide
During 1974, over 104 million tons of CO were emitted in the United States
by man-made sources. Seventy percent of these emissions are attributed to
highway vehicles, with the automobile alone accounting for about fifty percent.
Furthermore, autos and other highway vehicles contribute disproportionately
more CO to those areas where high CO is experienced because of dense traffic,
ground level emissions and the canyon street effect. Because of these
emissions, at least 65 air quality control regions (AQCR's) experienced
violations of the 8-hour average carbon monoxide ambient standard
during 1973. However, no monitoring data are available for many areas of
the country where it is suspected that many smaller cities are experiencing
CO problems, particularly during high volume traffic conditions such as
rush hour traffic in downtown areas or around relatively large and busy
shopping centers.
Oxidants
A review of 1973 and available 1974 air quality monitoring data reveals
that there are at least 79 AQCR's in which violations of one-hour ambient
standard for photochemical oxidants (160 micrograms per cubic meter - ug/m3)
were experienced in one or both years. These AQCR's include most of the
large urban areas of the country.
Unlike CO, oxidant concentrations tend to be uniformly spread throughout
the urban area. While most monitoring sites are physically located in or
around urban areas, it is generally believed that dsiie to the formation time
required for an atmospheric movement of oxidants large portions of the rural
areas also are experiencing oxidant concentrations above the national standards
at sometime during the year.
In 1974, nationwide emissions of hydrocarbons (HC), a precursor to
oxidants, were divided approximately 60%/40% between stationary and mobile
sources. The two major sources of HC emissions are automobiles and evaporation
from stationary sources, such as solvent manufacturing, cleaning, and coating
operations. The remaining HC emissions are distributed among a variety of
mobile and stationary sources.
There are large variations among the AQCR's in the contribution of these
categories of sources to overall HC emissions. For example, among the 79
AQCR's discussed above, HC emissions from stationary sources vary from a
low of less than 12% of the total to a high of over 70% of the total.
Nitrogen Dioxide
Air quality monitoring data for the period 1972-74 indicate that 3 or 4
AQCR's are currently experiencing annual concentrations above the national
ambient standard (100 ug/m3) for nitrogen dioxide (N02). In addition, there
are 12 more cities where the annual N02 concentration during 1972-74 was
greater than 80% of the standard. It is estimated that N02 concentrations
in at least 4 of these 12 cities will be above the national standards in the
near future.
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•• '.
VD
M
I
9
o
u
f
V-
u>
MORNItfG
RUSH HOURS
EVENING -.
'RUSH HOURS
ID II IS. |3 ft 15
TIME OF DAY
17 19 It 20
FIG. il ::NOg AIK QUAUPf |M SOOTH COAST -AIR BASlhl
AVERAGED OOER THE AU6yS'T-|
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Nationwide NOx emissions during 1974 are estimated to have exceeded
25 million tons, with stationary sources accounting for 57% of the total.
Automobiles accounted for 19%. Mobile sources contribute greater than
proportionately to short term peak ground level NOx concentrations.
Therefore, the control of NOx emissions from mobile sources will provide
greater reduction in these situations than would be indicated by their
proportion of annual NOx emissions (see Figure 1). This will be particularly
significant should a short term N02 health standard be promulgated.
In summary, a number of AQCR's are currently experiencing air quality
above the ambient standards for the automobile related pollutants. Most
of the problems with 00 are believed to be primarily due to exhaust
emissions from the internal combustion engines. For CO, it is believed
that high concentrations are encountered only in the near vicinity of
large volumes of mobile source traffic, and are, therefore, mainly confined
to the urban areas. Oxidant concentrations above the ambient standard
are being monitored in most areas where monitoring equipment is located.
It is believed that the oxidant problem is pervasive and not confined
solely to the urban areas. While the two largest sources of HC emissions
are automobiles and evaporation (solvent manufacturing, cleaning, coating
operation, etc.) more than 50% of the total emissions come from many relatively
small and diversely located sources, which individually have relatively low
HC emission rates. Most man-make NOx emissions come from fuel combustion
processes, with utility boilers (electric power generators) and the automobile
being the largest individual source categories.
IV. Projecting Air Quality for Future Years
Projecting air quality into the future is a two-step process as shown
below. Changes in emissions from a base year are estimated from growth,
changes in control technology, and changes in emission sources. The change
in air quality is then calculated from the projected change in emissions.
Growth of
Sources
Emissions
Control
Background
Base
Year
Emissions
Q
Emissions
Projection
i
Base Year
Air Quality
Air Quality
Projection
2000
Emissions Projection
As indicated above, emissions in any future year depend upon the growth in
the numbers of each source relative to the base year and the ratio of emissions
from each source, in the projection year to its emissions in the base year, per
unit. This latter factor is dependent upon the degree of control of both new
and existing sources as well as the rate of turnover of older to newer, usually
lower emitting sources.
-------
-17-
Three major source categories are presented in this report. They are
light duty vehicles, other mobile sources, and stationary sources. The
growth rates and degrees of control for each of these source categories
were determined by accounting for specific sources within each category.
Base year emissions are derived from inventories collected by states
and submitted in State Implementation Plans. In some cases, more recent
inventories have been made and placed in the National Emission Data System
(NEDS) and are used for this study. These emission estimates are for
annual averages and therefore may not accurately represent the emissions
at the time of the observed air quality.
Each Air Quality Control Region has a different ratio of mobile
to stationary sources. Therefore projected emissions will be different
for each area because of the different growth rates for different sources.
The largest unknown in the projection model occurs in the estimates of
growth and in future technology and control regulations. Optimistic estimates
for future national growth and stationary source emission reduction tech-
nology were assumed. It is expected that some areas of the country will
experience greater growth than other areas. Some areas may also require
more stringent control than will other areas.
Projection of Air Quality
The air quality projections for each of the three pollutants are somewhat
different. These will be discussed separately.
Carbon Monoxide
Since the "hot spots" for CO are always located in areas of high traffic
density the impact on future air quality of mobile source emissions and their
control appears to dominate the CO situation; stationary sources have very
little impact. Therefore, it is necessary to apply an adjustment factor to the
stationary source categories to realistically estimate future air quality.
Factors of .20 for area sources, .10 for industry and 0 for power plants
were used. This means that a pound of CO from a new industrial source was
assumed to have only 1/10 the air quality impact on the roadside CO "hot
spot" as a pound of CO emitted on the street in front of the sampler. These
adjustment factors were selected after considering the results from dispersion
models for power plants and industry and a review of the relationship between
traffic density and CO levels in several situations.
-------
18-
Because 00 does not react rapidly in the atmosphere, the assumption of
linearity between the changes in CO concentration and the changes in emissions
near the monitor is reasonable. Measurements of ambient 03 concentration,
however, are not good indicators of regional air quality, because CO concen-
trations are very localized. Moving a monitor a few feet from curb to sidewalk
will cause a large change. High CO concentrations are found at busy intersections,
street-side, and at other locations of high traffic density. The most direct
measurement of the effect on humans of ambient carbon monoxide would be the
percent of blood carboxyhemoglobin in a representative sample of the population.
An eight-hour average background concentration of 1 ppm is assumed for
carbon monoxide.
Hydrocarbons and Oxidants
Photochemical oxidants are not emitted directly into the atmosphere
but result primarily from a series of chemical reactions between oxidant
precursors (nitrogen oxides and organic compounds) in the presence of
sunlight. The principal sources of organic compounds are the hydrocarbon
emissions from automobile and truck exhausts, gasoline vapors, paint
solvent evaporation, open burning, dry cleaning fluids, and industrial
operations. There are also natural sources such as seepage from the
ground and emissions from vegetation. Nitrogen oxides are emitted primar-
ily from combustion sources such as electric power generation units, gas
and oil-fired space heaters, and automobile, dies°l and jet engines. Nitric
oxide (NO) is the major form of nitrogen oxide emitted in combustion processes.J-
Nitrogen dioxide (NO2) is formed from.NO and is the compound which decomposes
in sunlight to initiate the formation of ozone.
The factors which determine the concentrations of oxidants formed in
the atmosphere include: (1) the amount and kinds of organic compounds
initially present and the rate at which additional organics are emitted to the
atmosphere; (2) the amount of nitrogen oxides initially present and their
emission rates; and (3) sunlight ultra-violet intensity, temperature, and
other meteorological factors. The interactions of these factors and the chemical
reactions involved are very con.plex and have been the subject of continuing
scientific investigation during the last 20 years, including atmospheric
studies, laboratory smog chamber studies, and computer simulation of the oxidant
forming process. For the purposes of this analyses it was conservatively assumed
that a proportional model adequately describes the HC-oxidant relationship.
Background levels were assumed to be 0.02 ppm.
-------
-19-
Nitrogen Oxides and Nitrogen Dioxide
Almost all NOx is emitted as NO. The rate at which NO is converted
to N02 is a function of many factors including ozone concentrations,
hydrocarbon concentrations, hydrocarbon reactivities, ultraviolet
radiation intensity and ambient total NO . A portion of the total NO
plus N02 (NOx) from power plants is brought to the ground while a
portion of that Quitted fron motor vehicles is being, dispersed upward.
The NOx is being mixed throughout the urban atmospheric environment and
it becomes reasonably ubiquitous. Over the long-term N02 levels do not
tend to vary strongly across the urban setting. Since, for the projections
only an annual average N02 is projected, it is not critical that the
spatial or temporal variations in concentration be identified and a
linear model is a good first approximation.
The background for NO2 is assumed to be an annual average of 8
ug/m3.
Assumptions Used in the Projection of Air Quality
The projections of air quality are based on the scenarios
summarized in Table 2. These scenarios include a number of emission
standards for light duty vehicles and other mobile sources and single
estimates for growth rates and control for stationary sources.
For light duty vehicles the ne// emission^ standards are assumed to
take effect according to the schedules listed in Table 3. The replace-
ment rate for light duty vehicles.is assumed to provide for a turnover
in vehicles every thirteen -years. The assumed distribution of aqes of
vehicles is presented in Table 4. The emission factor ratios for mobile
sources are summarized in Table 2. The emission reduction assumed for
trucks is less than the emission reduction frcm light duty vehicles.
For carbon monoxide a growth of one percent compounded annually
was selected for all mobile sources. This is a lower growth rate than
has been historically observed for metropolitan areas. It was chosen
to reflect the fact that carbon monoxide is a localized problem where
traffic density is already high and that growth in these areas will
not be as great as for the broader metropolitan areas. No increased
congestion due to this growth was assumed, clearly a conservative
assumption.
For nitrogen oxides and hydrocarbons, growth rates of two percent
compounded annually were selected for all mobile sources. These
are lower than most areas are presently experiencing and are based
based on the assumption that automobile and truck use in metropolitan
areas will not continue to grow at the present rate. They were
-------
Table 2
Assumptions For Air Quality Projections
LIGHT
Emission •
Pollutant Standards
DUTY
VEHICLES
Emission Factor
Ratio to Rase Year
HC & CO 1972 NOX)
Without
Carbon Monoxide A
B
C
D
I
\ Hydrocarbons A
O
CM .
1 B
C
D
E
Nitrogen Oxide* A
B
C
D
E
1980
,59
.59
.61
.61
.56
.48
.48
.50
.50
.48
.73
.73
.73
.73
.70
1990
.17
.17
.32
.31
.17
.17
.17
.19
.17
.17
.29
.53
.66
.53.
.53
I/M
1999
.15
.15
.31
..30
.15
.16
.16
.18
.16
.16
.20
.52
.66
.52
.52
(1970
OTHER MOBILE SOURCES STATIONARY SOURCES
Growth Rate Emission Factor Growth Rate Emission Factor Growth Rate
Percent Ratio to Base Year Percent Ratio to Rase Year Percent
Compounded (1970) Compounded (1970) Compounded
With I/M
1980
.43
.43
.45
.45
.41
.43
.43
.44
.44
.43
.73
.73
.73
.73
.70
1990
.08
.08
.16
.16
.08
.12
.12
.14
.12
.12
.29
.53
.66
.53
.53
1999 1980 1990 1P99 1980 1990 . 1999
.07 LOT .66 .51 .49 .85 .60 .45
.07 HDG .81 .74 .72
.16 HDD .84 .57 .57
IX IX 3.2Z
.16
.07
.11 LDT .66 .39 .34 .85 .50 .25 JO
.11 HDG .81 .46 .38
.13 HDD .97 .89 .88 . .
2X 2Z 3.2Z
.11 •
.11
•20 tDT .77 .51 .48 .90 .70 .50
•S2 HDG 1.04 .93 .91
.66 HDD .95 .93 .93
2X 2X 3. OX
.52
.52
-------
-21-
TABLE 3
LIGHT DUTY VEHICLE EXHAUST EMISSION STANDARDS SCHEDULES
Model Year Hydrocarbons Carbon Monoxide Nitrogen Oxides
Emission Schedule ABCDE ABCDE ABCDE
1978 1.5.1.5 1.5 1.5 1.5 15 15 15 15 15 2.0 2.0 2.0 2.0 2.0
1979 .41 .41 1.5 1.5 .41 99 15 15 3.4 2.0 2.0 2.0 2.0 2.0
1980 .41 .41 .41 .41 .41 9 999 3.4 2.0 2.0 2.0 2.0 1.0
1981 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 1.0 1.0 2.0 2.0 1.0
1982 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 1.0 1.0 2.0 1.0 1.0
'1983 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 .4 1.0 2.0 1.0 1.0
1984 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 .4 1.0 2.0 1.0 1.0
o
1985 .41 .41 .41 .41 .41 3.4 3.4 9 9 3.4 .4 1.0 2.0 1.0 1.0
-------
-22-
TABLE 4
DISTRIBUTION OF VEHICLE MILES TRAVELED BY AGE OF
0 to 1 yr.
1 to 2 yr.
2 to 3 yr.
3 to 4 yr.
4 to 5 yr.
5 to 6 yr.
6 to 7 yr.
7 to 8 yr.
8 to 9 yr.
9 to 10 yr.
10 to 11 yr.
11 to 12 yr.
12 to 13 yr.
13 yr and over
AUTOMOBILE
11
14
13
12
10
9
7
6
4
3
1
1
1
2
.2%
.3%
.0%
.1%
.8%
.4%
.9%
,3%
.7%
.2%
.9%
.3%
.3%
.6%
-------
-23-
selected because the hydrocarbons and nitrogen oxides are the precursors
for oxidant and nitrogen dioxide formation, pollutants which are a
problem over wide areas and are not restricted to localized areas of high
traffic density.
Stationary source growth rates were estimated from economic indicators
for four groupings of sources: electric generation, industrial activites,
area sources and other point sources. The sources of carbon monoxide and
hydrocarbons are expected to grow at 3.2 percent compounded. A growth of
3.0 percent was assumed for nitrogen oxide sources.
A single scenario was modeled for stationary sources based on new
control technology with successively more stringent controls being
applied from 1980 to 1990 and 2000. The assumption about possible control
technology was based on a review of existing technologies and technologies
which are still under development. In some cases it is unclear how the
degree of control estimated will actually be achieved but the estimates
were based on technological optimism. For the degree of control assumed,
regulations in addition to the present regulations would be necessary to
achieve the emission reductions.
While national growth rates were assumed for this study, the con-
tribution of each source category in the base year was estimated for each
specific area of the country.
The contributions for each source category were taken from State
Implementation Plans OP, if these were not considered adequate, estimated
from data within the National Emissions Data System (NEDS). The source
contributions by region are presented in Tables 5, 6, and 7.
Carbon Monoxide Air Quality Projections
Table 8 summarizes the impact on carbon monoxide air quality of the
different emission standards schedules based on the conservative assumptions
summarized above. By 1990 average air quality levels are projected
to improve by 60% (68% with I/M) under either schedules A, B or E but only
by 47% and 48% under schedules C.and D (61% with I/M). A total of 12
AQCR's are projected to exceed the standard in 1990 under schedules A, B
and E (only 5 with I/M) whereas 15 will exceed under schedules C and D
(11 with I/M). Over the decade 1980 to 1990 Schedule E will result in the
minimum number of violations, 4,521, of all scenarios run (1,535 with I/M).
Schedules A and B will result in 5,533 violations, a 22% increase over
Schedule E. (1910 or a 24% increase with I/M). Under schedules C and D the
number of violations would virtually double to over 9100 (a 64% increase to
-------
-24-
TABLE 5
SOURCE CONTRIBUTION OF CARBON MONOXIDE EMISSIONS IN PERCENT FOR BASE YEAR
No.
004
009
013
015
024
028
029
030
031
Urban Area
Birmingham
North Alaska
Clark-Mohave
Phoenix-Tucson
Los Angeles
Sacramento Valley
San Diego
San Francisco
San Joaquin Valley
Light Duty
Vehicles
71
69
73
73
74
72
74
73
72
Other Mobile
Sources
23
21
27
26
25
25
26
26
27
Stationary*
Sources
6
10
0
1
1
3
0
1
1
036 Denver 73 26 1
042 Hartford-N.Haven 74 26 0
043 NY-NJ-Conn. 74 25 1
045 Philadelphia 72 26 2
047 National Capitol 73 26 1
062 E. Wash.-N. Idaho 73 26 1
067 Chicago 70 26 4
080 Indianapolis 72 26 2
094 Kansas City 72 27 1
115 Baltimore 72 26 2
119 Boston 74 26 0
131 Minn.-St. Paul 73 26 1
158 Central New York 74 25 1
193 Portland 71 25 4
197 S.W. Penna. 72 26 2
220 Wasatch Front 72 26 2
229 Puget Sound 73 26 1
Other Urban Areas 60 36 3
*
Stationary sources have been adjusted to account for receptor location
**
Emissions inventory for other urban areas based on U.S. average emissions
-------
-25-
TABLE 6
SOURCE CONTRIBUTION OF HYDROCARBON EMISSIONS IN PERCENT FOR BASE YEAR
No.
004
005
013
015
024
028
029
030
031
033
036
043
045
047
079
067
070
106
115
119
131
153
160
173
193
197
214
215
216
229
Urban Area L1ght Duty Other Mobl'le
urban Area Vehicles Sources
Birmingham
Mobile-Pensacola
Clark-Mohave
Phoenix-Tucson
Los Angeles
Sacramento Valley
San Diego
San Francisco
San Joaquin
S. E. Desert
Denver
NY-NJ-Conn.
Philadelphia
National Capitol
Cincinnati
Chicago
St. Louis
S. Lou.-SJE. Texas
Baltimore
Boston
Mi nneapol i s -St . Paul
El Paso-Las Cruces
Genesse-Finger Lakes
Dayton
Portland
S.W. Pennsylvania
Corpus -Christi
Dallas-Ft. Worth
Hous ton-Gal veston
Puget Sound
46
47
54
51
47
39
. 54
39
37
40
55
50
54
55
48
27
30
43
25
49
44
59
57
47
42
48
18
47
28
59
21
. 19
15
20
22
18
25
18
17
18
26
23
25
25
22
13
22
20
13
23
26
28
26
22
19
23
9
20
13
27
Stationary
Sources
33
34
31
29
31
43
21
64
46
42
19
•27
21
20
30
60
48
37
62
28
30
13
17
31
39
29
73
33
59
14
Geographic Areas
Northeast
East Central
Mid Central
Southeast
West Central
Southwest
West
42
38
16
32
37
18
34
22
25
11
23
37
18
25
36
37
73
44
25
64
42
-------
-26-
TABLE 7
SOURCE CONTRIBUTION OF NITROGEN OXIDE EMISSIONS IN PERCENT FOR BASE YEAR
No.
015
024
030
036
043
045
047
067
070
115
131
215
216
220
Urban Area
Phoenix-Tucson
tos Angeles
San Francisco
Denver
NY-NO-Conn.
Philadelphia
National Capitol
Chicago
St. Louis
Baltimore
M1nneapolis-St. Paul
Dallas-Fort Worth
Houston
Wasatch Front
Geographic Divisions
Northeast
East Central
M1d Central
Southeast
West Central
Southwest
West
Light Duty
Vehicles
40
46
45'
32
26
21
31
21
12
20
24
30
15
37
28
18
20
. 19
26
19
29
Other Mobile
Sources
22
18
20
15
10
11
12
12
13
11
19
24
15
18
17
18
17
19
30
23
28
Stationary
Sources
38
36
35
53
64
68
57
67
75
69
57
46
70
45
55
64
63
62
44
58
43
-------
i
r-
r*
I
TABLE 8
COMPARISON OP CO AIR QUALITY IMPACTS FOR VARIOUS AUTOMOBILE
C
o
EMISSION STANDARDS
Emission Standard
For Automobiles
Schedule C
Schedule D
Schedule A end B
Schedule B
I & M
Status
Without
With
Without
With
Without
With
Without
With
Mobile
Source
Growth
Rate
1Z
1Z
1Z
1Z
1Z
1Z
1Z
1Z .
Average Percent Change
in CO Air Quality
as Compared to 1970
Level
1980
27
39
27
39
28
40
30
42
1985
43
58
43
58
51
62
54
64
1990
47
61
48
61
60
68
60
68
2000
45
58
46
58
59
67
59
67
o
Number of AQCR's Projected
to be above CO Standard Out
of 30 AQCR's
1980
25
23
25
23
24
23
24
22
1985
21
12
21
12
14
8
14
8
Examined
1990
15
11
15
11
12
5
12
5
2000
16
12
16
12
12
5
12
5
Total Number of Times 8-hour CO Standard*
is Projected to be Violated in 30 AQCR's
Examined.
1980
2,241
1,003
2,241
1,003
2,074
941
1,823
764
1985
709
112
709
112
290
47
201
35
1990
443
t
63
405
63
86
17
86
19
2000
581
95
534
95
86
17
86
17
1980-1990
9,200
2,523
9,137
2,523
5,533.
1,910
4,521
1,535
1930-200(
14,320
3,313
13,831
3,313
6,393
2,080
5,381
1,705
-------
-28-
2523 with I/M). It should be noted that the numbers of violations
are only for the 26AQCR's modelled; additional violations would occur
in.other areas which were not modelled.
Hydrocarbons/Oxidants
Table 9 summarixes the oxidant air quality impact of the various
hydrocarbon standards. For schedules A, B and E it is estimated that
37AQCR's out of 48 modelled will still exceed standards in 1990 (36
with I/M) compared to 40AQCR's with schedules C and D (36 withl/M).
The average percent change in air quality falls from a 37% improvement
with schedules A, B and E (40% withl/M) to a 36% improvement with
schedules C and D (39% with I/M). In terms of violations of the
oxidant standard, schedules A, B- and E result in 51,992 over the period
1980 to 1990 (44,327 with I/M or 15% less) whereas schedules C and D
result in 54,582 and 53,381 violations,respectively (46,522 and 45,511
with I/M), an increase of 5% and 3%, respectively.
Nitrogen Dioxide
9
Table 10 summarizes the annual average N02 air quality impact of the
alternative emission standards considered. Only under schedule A will the
air quality improve between now and 1990 and even then by only 3%;
schedules B, D and E are projected to result in a 6% worsening of air
quality while schedule C is projected to degrade the air quality by 10%.
While 4ACQR's .will exceed the standard under schedule A, 6AQGR's are
projected over the standard under schedules B, D and E and 7 over .
with schedule C.
Table 10A summarizes the short term N02 air quality impact of the
alternative emission standards considered, assuming standards of 0.11
or 0.19 are adopted.I/ This should in no way be construed as an
endorsement of these standards but only as a useful indicator of the
potential ijnpact of the alternative emissions standards schedules
on short term air quality levels. By 1990, schedule A is projected to
result in 1302 excursions over the 0.11 level (347 excursions above
0.19) while schedules B, D and E will result in 1569 violations (486 at
0.19) and schedule C will result in 1701 violations (554 at 0.19).
Schedules B, D and E result in about 21% more excursions above than
schedule A (40% more at 0.19) while schedule C results in 31% more
(60% more at 0.19).
This range is similar to a range of standards being examined by the
World Health Organization (WHO).
-------
TABLE 9
COMPARISON OF OXIDANT AIR QUALITY IMPACTS FOR VARIOUS AUTOMOBILE EMISSION STANDARDS
Emission Standard For
Automobiles
Schedule C
Schedule D
Schedule A and B
Schedule I
I & M
Status
Without
With
Without
With
Without
With
Without
With
Mobile Source
Growth Rate
2Z
21
21
2Z
2Z
2Z
2Z
2Z
Average Percent Change
in Oxidant Air Quality
As Compared to 1970
Level
1980
12
15
12
15
13
15
13
15
1985 1990
29 36
33 39
O
30 37
34 40
30 37
34 40
30 37
34 40
2000
45
49
46
50
46
50
46
SO
N*«iber of AQCR's Projected
To be Above Oxidant
Standard Out of 48 AQCR's
Examined
1980 1985
47
47
47
47
47
47
47
47
41
41
41
41
41
41
41
41
1990
40
36
37
36
37
36
37
36
2000
Total Number of Times 8-iicur
Oxidant Standard is Projected
To Be Violated in 48 AQCR's
Examined
1980 1985 1990 2000 \^Q~ 2000"
31 10,308 4,797 3,2531,61254,58278,
27 9
30 10
26 9
30 9
26 9
30 9
26 9
,270 3,976 2,739 1,195 46,522 66,
,308 4,671 3,037 1,433 53,381 75,
,270 3,872 2,549 1,056 45,511 63,
,954 4,551 3;037 1,433 51,992 74,
,101 3,759 2,549 1,056 44,327 61,
,954 4,551 3,033 1,433 51,992 74,
,101 3,759 2.549 1,056 44,327 61.
90
v:
7:
5"
y-
9C
34
90
-------
-30-
TABLE 10
COMPARISON OF LONG-TERM N02 AIR QUALITY FOR VARIOUS AUTO
EMISSION STANDARDS
Emission Standard
Schedule
Average % Change In
Air Quality
No. of AQCR's Above
Annual N02 Standard
Schedule C
Schedule D
Schedule B
Schedule A
Schedule E
1980
-4
-4
-4
-4 '
-4
1985
-6
-4
-3
-1
-3
1990
-10
-6
-6
3
-6
2000
-13
-8
-8
5
-8
1980
5
5
5
5
4
1985
7
5
4
4
4
1990
7
6
6
4
6
2000
7
7 .
7
4
7
it
-------
-31-
TABLE IDA
Comparison of Short-Term N02
Air Quality For Various Auto
Emission Standards
Emission
Standards
Schedule
Schedule C
Schedule D
Schedule B
Schedule A
Schedule E
No. of Times WHO Draft
Level of .11 ppm Exceeded
in worst month
1980
1,544
1,544
1,544
1,544
1,528
1985
1,596
1,524
1,499
1,429
1,499
1990
1,701
1,569
1,569
1,302
1,569
2000
1,700
1,626
1,626
1,224
1,626
No. of Times "HO
Level of .19 ppm
in worst month
1980
473
473
473
473
466
1985
499
464
452
418
452
1990
554
486
486
347
486
Draft
Exceeded
2000
613
517
517
318
517
-------
- 32 -
V. Health Consequences Prolections For Alternative Control Strategies
This section describes certain of the health consequences projections
estimated to result from the implementation of varying levels of mobile
source emission control assuming fixed levels of light duty vehicle growth.
Health consequences projections are estimated for the periods 1980 to 2000.
The projections are for those effects for which dose response relations
have been estimated and do not represent the great bulk of other health
consequences or synergistic effects which have not been quantified (see
section II) and these impacts therefore, should not be construed as
meaningful in absolute terms. In the following paragraphs these health
consequences projections are discussed on a per pollutant basis.
Carbon Monox ide
Estimates of excess cardiac deaths and excess hours of person disability
due to angina attacks resulting from elevated carbon monoxide levels for
each of the automotive emission standards schedules are displayed in
Table 11. These projections assume that only ten percent of the urban
population is exposed to harmful levels of carbon monoxide. They are
based on an average year. For high and low years the effects may vary
fifty or more percent from these projected consequences.
The estimates for the period 1980 to 2000 vary from 45 excess deaths
for schedule C (7 with I/M) to 43 deaths with schedule D (also 7 with I/M)
to 18 deaths with schedules A and B (5 with I/M) to a low of 15 deaths with
schedule E (4 with I/M). On a per year basis the 1990 estimates are lower than
those for 1980 or 2000 which indicates that expected growth will overtake
control between 1990 and 2000.
During the period 1980 to 1990 adverse health effects as indicated by
excess person hours of disability due to angina attacks are projected to
be 3% less under schedule D than schedule C (no difference with I/M).
Introducing the statutory standard (3.4 gpm) according to schedules
A and B reduces angina disability by 45% during this period compared to
schedule C (31% less with I/M) and by 54% with schedule E (41% with
I/M). Most of the health benefit for all scenarios occurs in the near
.future, as vehicles now on the road are replaced with vehicles having
lower emissions.
Photochemical Oxidants
Six health consequences are projected in Table 12 for photochemical oxidant
exposure: excess aggravation of heart and lung disease in elderly patients;
excess aggravation of asthma; excess eye discomfort; excess cough; excess
chest discomfort; and excess headache.
-------
- 34 -
Nitrogen Dioxide
Estimates of excess days of restricted activity due to excess attacks
of lower respiratory disease in children from projected elevated nitrogen
dioxide levels for each of the alternative emissions schedules are displayed
in Table 13.
Significant differences exist over the period 1980 to 2000 for
respiratory attacks projected by continuing with the current 2.0 g/mi
nitrogen oxides emission standard versus implementing either a 1.0 g/mi
standard or the statutory 0.4 g/mi standard. For the total health impact
between 1980 and 2000, a 3 to 4 percent improvement is projected for
schedules B, D, and E over schedule C. The statutory standard schedule A
is projected to provide a 26 percent improvement. The benefits of
implementing the statutory standard are most apparent in the per year
estimates for the year 2000, as a 35% reduction is projected for that
year when the statutory standard is compared with the present nitrogen
oxides emission standard.
While the quantification of health effects and the development of
dose response characteristics is controversial and while different
scientists might raise or lower the impacts, the preceding quantification
reflects the best judgments of EPA's medical staff. (These subjects are
discussed further on pages 10 through 12 above (Chapter II)).
VI. Technological Considerations - Timing Of the Standards
(a) 1978 Model Year
Virtually all automobile manufacturers are planning to meet emission
standards of 1.5 HC, 15 CO, 2.0 NOx for model year 1978. Most of the
automobile manufacturers indicated that their plans for model year 1978 are
based on the 1976 Committee Report on Amendments to the Clean Air Act.
Even though the changes to the Clean Air Act contained in that Report were
subsequently not adopted by Congress, the manufacturers' position appears
to be that the intent of Congress was to adopt emission standards of 1.5 HC,
15 CO, 2.0 NOx for model year 1978.
Because the manufacturers have targeted their development toward meeting
1.5 HC, 15 CO, 2.0 NOx for model year 1978, there is little possibility that
•emission standards much different from these levels could be successfully
implemented for that year. Even for a relatively similar standard like
0.9 HC, 9 CO, 2.0 NOx, for example, some durability vehicles would have to
be rerun, calibration and system modifications for each data vehicle would
have to be reexamined and possibly redeveloped, new or additional supplies
of certain components might be required which are not now planned for.
This leads to the conclusion that at this point there is not enough lead time
to do anything significantly different from what the manufacturers are already
planning to do for the model year 1978.
-------
Sunm.-'fy of Two Types of 1'ealth Impacts From Carbon Monoxide Exposure
Emission
Standard For
Automobiles
Schedule C
Schedule D
Schedules A
and B
Schedule E
I & M
Status
Without
With
Without
With
Without
With
Without
With
Excess Cardiac
1980
9
3
9
3
8
3
7
2
1985
2
0
2
0
1
0
0
0
1990
1
0
1
0
0
0
0
0
2000
2
0
2
0
0
0
0
0
Deaths
1980-1990
30
6
30
6
18
5
14
4
Excess Person-Hours of Disability
trom Angina Pectoris
1980-2000
45
7
43
7
18
5
15
4
1«80
116,253
56,343
116,253
56,343
107,597
50,613
95,085
45,294
1985
39,945
5,680
39,945
5,680
14,071
1,571
10.2BO
718
1990
29,881
3,157
20,557
3,156
3,592
131
3,582
131
2000
41,147
5,701
38,018
5,701
4,250
- 166
4,250
166
1980-1990
509,857
137,033
494,317
137,032
279,072
95,047
232.995
80,495
1980-2000
864,997
181,323
787, 192
181,317
318,282
96,532
272,205
81,980
m
l
r.
rb
-------
-35-
Table 12
PROJECTED HEALTH IMPLICATIONS
(2Z LDV Growth) FOR ALTERNATIVE OX SCENARIOS
Projected
Health
Consequence
Emissions
I/M Standards
Status Schedule
1990
W/0 C
W C
W/0 D
W D
W/0 A,B
W A,B
W/0 E .
W E
2000
W/0 C
W C
W/0 D
W D
W/0 A,B
W A,B
W/0 E
W E
1980 to 2000
W/0 C
W C
W/0 D
W D
W/0 A,B
W A,B
W/0 £
W E
Aggra-
vation
of
Elderly
Heart and
Lung Dis-
ease
7,840
6,257
7,163
5,730
Z.163
5,730
7,163
5,730
3,474
2,335
3,128
1,939
3,128
1,939
3,128
1,939
246.298
201,580
236.121
193,236
228,877
199,291
228.877
199,2'.)!
Aggra-
vation
of
Asthma
784
626
716
573
716
573
716
573
347
234
313
194
313
194
313
194
24,631
20,165
23.609
19,320
22.889
19,198
22 ,RS»
1 9 , 1 y 8
Eye
Disease
623,665
512,078
576,577
470,640
. 576,577
470,640
576,577
470,640
316,215
231,882
283,893
199,222
283,893
199,222
283,893
199,222
16,325,167
13,805,164
15,626,915
13,143.797
15,325,601
13,036,313
15.3.25 ,601
3,086.513
Cough
122,829
98,024
112,223
89,767
112,233
89,767
112,233
89,767
54,429
36,584
49,006
30,370
49,006
30,370 '
49,006
30,370
3,814,263
3. 158. 117
3,699,219
3.027,308
3,585,941
3.007,155
3.585.941
5.007.155
Chest
Dis-
comfort
11,533
9,195
10,555
8,354
10,555
8,354
10,555
8,354
4,928
3,270
4,358
2,594
. 4,358
2,594
4,358
2,594
365,608
300,692
350,665
287,194
340,166
285 .171
340 ,166
2 P. S . 1 7 1
Headache
1,862,584
1,669,712
1,790,145
1,592,208
1,790,145
1,592,208
1,790,145
1,592,208
1,352,913
1,157,510
1,267,838
1,057,296
1,267,838
1,057,296
1,267,838
1,057,296 .
40 ,676 ,921
36.706 .496
39,427,490
35.339,066
39 , 138, 70S
35 ,2G6, -'.>.'
39, 138 ,7t)3
35 ,266 . 7'J5
-------
-36-
Table 13
COMPARISON OF LONG-TERM N02 HEALTH EFFECTS FOR VARIOUS
AUTO EMISSIONS STANDARDS
Emission Standards
Schedule
Schedule C
Schedule D
Schedule B
Schedule A
Schedule E
Mobile Source
Growth Rate
2%
2%
2%
2%
2%
Excess Days of Restricted Activity
In Due to Lower Respiratory Disease in
1000's Children
1980 1990 2000 1990 - 2000
2398 2326 3066 55,8.93
2398 2693 3053 54,076
2398 2693 3053 54,076
2398 1989 2002 41,186
2344 2693 3053 53,896
-------
-37-
(b) Post 1978
Estimates of the earliest dates that more stringent emission standards
could be achieved from an emission control technology standpoint are
provided in the table below. A discussion of each of the standards
considered follows:
Emission Standard Earliest
Model Year
Hydrocarbons Carbon Monoxide Nitrogen Oxides
0.41 9.0 2.0 1979
0.41 3.4 2.0 1980
0.41 3.4 1.0 1981
0.41 3.4 0.4 1982
*
(i) .41 HC, 9 CO, 2.0 NOx
Achievement of this standard can be accomplished in 1979 if the
industry knows by July 1, 1977 it will be required. This is when final
decision must be made regarding control systems for the 1979 model year
design. Any additional delay in establishing the 1979 standard will
seriously jeopardize its achievement. Those companies that may have
been working toward another set of standards as a 1979 goal could delay
the introduction of their 1979 models until January 1, 1979 to gain
additional time for development.
At this level of emissions control the greatest challenge is the
0.41 HC. This will have to be achieved with well designed air injection,
bigger catalysts, and exhaust heat conservation techniques such as port
liners. At the 2.0 NOx level there would be no increase in HC from
tighter NOx control, as there could be at 1.5 or less NOx. The 9.0 CO
would come along with the .41 HC.
(ii) 0.41 HC, 9 CO, 1.5 NQx
These standards are numerically the same as the standards for California
for model year 1977. While extension of technology developed for California
to Federal application might seem at first to be relatively straightforward,
there are differences between California and Federal certification protocols
- that complicate the issue somewhat. Therefore, the California experience
is not directly translatable into projections of compliance with Federal
emission standards that are numerically the same.
-------
-38-
Time and effort are required to develop emission control systems to
meet 0.41 HC while retaining good fuel economy calibrations. This is borne
out by the experience in California where fuel economy of the California
fleet has lagged the Federal fleet (on a equal model mix basis) by 1-2
years largely as a result of the less than optimum systems and calibrations
used to meet the more stringent California standards. However, it should
be noted that even though there was a difference in fuel economy between
California and Federal fleets when computed on an identical or equal
sales mix, the fact that California buyers elected to purchase lighter
and more fuel efficient vehicles resulted in no significant difference
in fuel economy between the California and Federal fleets on an actual
sales mix in 1976.
The 0.41 HC, 9 CO, 1.5 NOx standards would tend to encourage the
development and introduction of 3-way catalyst systems if these levels
are followed in succeeding model years by lower NOx standards.
(iii) 0.41 HC, 3.4 CO, 2.0 NOx
In the 1979-1980 time period, the 3.4 CO level will be difficult
to meet while retaining good fuel economy even with the use of advanced
oxidation catalyst systems. These systems would be similiar to current
Federal systems but to optimize fuel economy would utilize larger more
efficient oxidation catalysts, air injection, heat conservation techniques
(port liners, insulated manifolds) and start catalysts or lean thermal
reactors (on the heavy cars). If NOx standards more stringent than 2.0 gpm
are eventually going to be required, 3-way catalysts may also be used to
meet these more stringent standards. However, the 3.4 CO would be a tough
target for 3-way catalysts in the 1979-80 time frame and therefore this
standard may not permit or encourage the early phase-in of the 3-way
catalyst technology that will be needed to meet tighter NOx standards
with little or no fuel economy penalty.
(XV) 0.41 HC, 3.4 CO, 1.0 NOx
These standards can be met in 1981. The most difficult pollutant to
control at the 0.41 HC, 3.4 CO, 1.0 NOx level will be CO, if 3-way
catalyst systems are used. The addition of a downstream oxidation catalyst
and air injection might be required on some vehicles. Without the use of
3-way catalysts, control of both HC and NOx to these levels will be
difficult.
(v) 0.41 HC, 3.4 CO, 0.4 NOx
.The timetable for introduction of the 0.41 HC, 3.4 CO, 0.4 NOx standards
could be as early as 1983 and would allow time to incorporate good fuel
economy calibrations. One of the more important pacing items for this
standard is the lead time necessary to develop and adopt the sophisticated.
fuel metering systems that may be required. Feedback carburetion may not
be good enough, and fuel injection systems of.some type may be needed.
-------
-39-
VII. Cost and Fuel Economy and Fuel Consumption Impacts of Various
Levels of Emissions Standards
Estimates of the changes in vehicle first cost, lifetime maintenance
cost, and fuel economy associated with meeting various levels of emission
standards are summarized in Table 14. The Base Case from which all of
the changes are estimated is achievement of 1.5/15/2.0 standards using
Optimal Cost technology. 1977 model year vehicles using optimal cost
technology (high energy ignition proportional exhaust gas recirculation
and oxidation catalysts) but adjusted for optimal fuel economy served
as the Base Case. These same vehicles with the addition of electronics
are assumed to improve by about 2% in fuel economy.
Separate estimates are given in Table 15 for the 1980, 1983, and 1985
model years. These estimates for different model years, which differ
from one another to only a small degree, were made by computing weighted
average cost increments and fuel economy penalties for each of the model
years using the separate estimates derived for light and heavy cars and
estimated fractions of light and heavy cars in the new vehicle fleet of
each model year. Light cars (defined in this study as having emission
test weights of 3000 Ibs. or less) were assumed to make up 35% of the new
vehicle fleet in the 1980 model year, 45% in 1983, and 50% in 1985; heavy
cars (greater than 3000 Ibs. test weight) make up the remainder of the
new vehicle fleet in each model year. The cost in Table 15 generally
decline with time because of this assumed reduction in heavy car sales.
(a) Cost/Fuel Economy Impact *
Table 14 indicates that achievement of emission standards as stringent
as 0.41/3.4/1.0 is judged to be achieveable in the early 1980's with no
sacrifice in fuel economy from the levels which could be obtained under
current (1.5/15/2.0) standards. However, this will require the application
of technology significantly more sophisticated than that typically used
on today's cars. In particular, the use of sophisticated electronic
control of engine parameters such as spark timing and exhaust gas recir-
culation rate and the use of three-way catalysts at the more stringent NOx
emission levels have been assumed. These technologies are currently under
intensive development and evaluation by major automobile manufacturers
and are either already being used on a trial basis on some production
models or are planned for such limited use on some 1978 models. It is
proposed, however, that if these more sophisticated technologies are not
used, there would probably be some fuel economy penalty.
The use of this more sophisticated emission control technology is
estimated to increase the average sticker price of new cars by approxi-
mately $250 at the 0.41/3.4/1.0 standards level and by lesser amounts at
less stringent standards. Lifetime maintenance.costs (excluding
maintenance that would be done solely to keep emission levels low, such
as in response to an inspection/maintenance program) are estimated to
increase by about $80 at the 0.41/3.4/1.0.standards (see Table 16).
-------
Revised 4/13/77
Emissions
Level
HC/CO/NOx
Table 14
Cost & Fuel Economy Estimates *
(1977 $)
Cost Optimal I/
Fuel Optimal 2/
Light Cars
Cost FE Maint
Heavy Cars V
Cost FE Maint
Light Cars
Cost FE Maint
Heavy Cars 3/
Cost FE Maint
i
o
(gm/mi)
1.5/15/2.0
0.41/9/2.0
0.41/3.4/2.0
0.41/9/1.5
0.41/3.4/1.5
0.41/9/1.0
0.41/3.4/1.0
0.41/9/0.4
0.41/3.4/0.4
Base
$35 -2% $0
$35 -2% $0
$85 -3% $15
$105 -3% $15
$105 -4% $15
$175 -4% $15
$185 0 to $70
-8%
$195 0 to $90
-8%
V V 6/
Base
$35 -4% $0
$35 -4% $0
$95 -2% $55
$95 -2% $55
$170 -3% $55
$220 -3% $55
$210 0 to $90
-8%
$285 0 to $90
-8%
4/ 5/
6/
4/
6/
I/Minimum cost design to meet emission levels.
2_/Maximum fuel economy design to meet emission levels,
3_/More than 3,000 Ibs.
^/Additional sticker price above base case.
J>/Change in fuel economy relative to base case.
6/Maintenance costs over 100,000 miles.
$90
$90
$110
$150
$145
$220
$220
$300
+2% $15
+2% $15
+2% $15
+2% $15
+2% $70
+2% $70
0 to $70
+2%
0 to $90
+2%
$125 +2% $15
$140 +2% $15
$145 +2% $70
$220 +2% $70 ^>
$220 +2% $70 °
$285 +2% $70
$330 0 to $90
+2%
$360 0 to $110
+2%
*Note that emission control technology
changes for the different emission
levels as detailed in Appendix A
-------
Revised 4/13/77
1980
Table 15
WEIGHTED INITIAL COST
(1977 S)
1983
1985
Emission Optimum
Levels Cost I/
i
>H
^
. (gm/mi)
0.41/9/2.0
0.41/3.4/2.0
0.41/9/1.5
0.41/3.4/1.5
0.41/9/1.0
0.41/3.4/1.0
0.41/9/0.4
0.41/3.4/0.4
$35
$35
$90
$100
$145
$200
$200
$250
Optimum
Fuel 2/
$110
$125
$135 •
s 200
$190
$260
$290
$340
Optimum Optimum
Cost I/ Fuel 2/
$35
$35
$90
$100
$140
$200
$200
$245
$110
$115
$130
$190
$185
$255
$280
$335
Optimum
Cost I/
$35
$35
$90
$100
$140
$190
$200
$240
Optimum
Fuel 2/
$110
$115
$130
$185
— r\
-j>
$185 »_<
$250
$275
$330
I/Minimum cost design to meet emission levels.
2/Maximum fuel economy design to meet emission levels.
-~ • • V «*»"<.'.pfl-jArtSMgf ••••••rJ.
'
-------
.V
Revised A/13/77
i
CM
Table US
WEIGHTED MAINTENANCE COST I/
1980
Emission
Level
(gm/mi)
0.4./9/2.0
0.41/3.4/2.0
0.41/9/1.5
0.41/3.4/1.5
0.41/9/1.0
0.41/3.4/1.0
0.41/9/0.4
0.41/3.4/0.4
Optimum
Cost 2/
$ 0
$ 0
$40
$40
$40
$40
$85
$90
Optimum
Fuel 3/
$17
$17
$50
$50
$70
$70
$85
$100
(1977 S)
1983
Optimum
Cost 2/
$ 0
$ 0
$35
o
$35
$35
$35
$80
$90
Optimum
Fuel 3/
$17
$17
$45
$45
$70
$70
'$80
$100
198
Optimum
Cost 2/
$ 0
$ 0
$35
$35
$35
$35
$80
$90
5
Optimum
Fuel 3/
$17
$17
$45
$45
$70
$70 .
$80
$100
I/Over 100,000 miles without Inspection and Maintenance
2/Minimum cost design to meet emission levels.
3/Maximum fuel economy design to meet emission levels.
-------
-43-
In addition, other techniques are being developed to obtain fuel
economy increases by making the engine work harder on the average.
These techniques include dual displacement engines, unproved transmissions,
and higher compression ratio engines with knock-sensitive spark advance.
The relation between fuel economy and emissions for complete engine
systems based on these new techniques is not known.
Alternatively, these standards could be met by manufacturers using
less sophisticated, and less costly, emission control technology, but at
the cost of some loss in.fuel economy. With a sacrifice of 3% to 4% in
fuel economy, systems costing $40 to $65 less (depending on the level of
the emission standards) could be used. Still greater cost reductions
(with larger fuel economy losses) are possible, but this analysis assumed
that manufacturers would not be willing to accept substantially larger
fuel economy penalties because of the need to comply with manufacturer
fleet-average fuel economy standards.
The estimates for the most stringent emission standards considered
in this analysis (0.41/9.0/0.4 and 0.41/3.4/0.4) are substantially more
uncertain because of the general lack of empirical test data for the
types of systems judged likely to be required to meet such standards.
With this caveat EPA estimates that achievement of the current statutory
emission standards (0.41/3.4/0.4) is possible with little or no fuel
economy penalty/ and with an average increase in Vehicle sticker price
of about $330 relative to today's cars.
At present, the distinction between Optimal Cost and Optimal Fuel
Economy systems at the 0.41/3.4/0.4 standards is probably somewhat
artificial. The technolgy for meeting those standards is uncertain
enough to make an accurate definition of the technology likely to allow
a full range of models to comply with those standards rather difficult.
Nevertheless, there appears to be significant potential for meeting those
standards with little or no fuel economy penalty through the further
improvement and application of emission control technologies. (Detailed
in Appendix A.)
Additional detailed discussion of the cost/fuel/economy/system design
relationships is provided in Appendix A. Tables A-l through A-8 provide
a detailed description of the control systems under consideration for the .
various levels of emission standards.
(b) Fuel Consumption Impacts
The potential impact on total fuel consumption of the various emission
standards is shown in Table 17. The figures given represent the change
(in barrels per day) in lifetime new car fleet fuel consumption estimates.
These changes for each model year vehicle are also expressed as a percent
of total gasoline consumption over the same period (10 years).
v-r-7
-------
I
RtVISED i/24/77
•• TAflU 17
of Hex Car Fleet Connmptlon CltfmtUi |/|/ '
-
l!
ii-
Bin fuil Increiia
fade! Conjunction V to Dm Co
Y««r (1000 8/0) (1000 B/OT (C
,
i
1978 ; 36? j
1979 i . . 343
1990 • • 326 ; ]'*
1981 ! '.303 !•' ''']
1982 283 • = ; ''{•
1983 • 266 «.j
1984 251
198S 237 ";'-.
A .
0/0
01/-6.8
M1/-6.5
>9.$/-s.;
421/-5.J
»20/-5.0
419/-4.7
0
0/0
M1/-6.8
(9.6/-J.7
I9.0/-5.3
"8.8/-S.O
.8.3/-U
Conjumpi tor
jollne Com
ojt_ppuiml
i Centre n
ci
0/0
0/0
MOM.I
•i.6/-5.7
•9.0/-5.J
»7.S/-S.O
,7,1>-U
RiUttv*
/fuel dptlnalT
chedulo
D
0/0
0/0.
410/-6.1
•9.6/-S.7
«9.0/-5.J
•0.8/-S.O
•8.3M.7
t
fyo
411/-6.8
UO/-S.1
I9.6/-5.7
(9.0/-S.J
»8.8/-5.0.
»8.3/-4.7
KT Totilt 2371- 4101.6/ 467. 7/ 4S4.2/ 4S8.7/ W.7/
1976-198$ -40.1 -40.1 -33.3 -33.3 -40.1
fmtt
t» To]
Em
A
0/0
».»«/-. to
MS/-. 09
M4/-.08
».30/-:07
KZ9/-.07
».27/-.07
it Ch»ns« in
il Gasoline
Ifojt00t1n!
sjlon Contr
8 • '
0/0
4.16/-.10
M4/-.09
M4/-.OB
4.13/-.07
M3/-.07
4.I2/..07
Consiimptit
Consumptlc
siyFuel Op
ol TcKc3ut
C
0/0
0/0
M5/-.09
».14/-.09
M4/-.08
M1/-.07
MO/-.07
m (5c)»tive
m 2/4/
u(mal)
0
0/0
0/0
M5/-.09
O4/-.09
4.14/-.08
4.13/-.07
+.13/-.07
4.12/-.07
41.4/-.S7 4.97/-.S7 *.77/-.47 *.81/-.*7
i
0/0
».!«/-. 10
M5/-.09
O4/-.08
M3/-.07
O2/-.07
4.97/-.S7
Fuel Consumption for given model year with base emission. standards (1.5 IIC, 15 CO, 2.0 NOx) and cost optimal tech-
ld fllJt average fuel economy equal to the fuel economy standards for that model year.
J/ Based on average annual gasoline consumption of 7.0;MMB/D between now and 1985..
i/ RA«.,I on tales weighted average penalty (saving*) < for light and heavy cars. Where a range in fuel economy ostimateo
1 is given in Toble 1? the maximum penalty was assumed fo^ptimal technology, and the maximum savings for fuel
optimal technology. ^ I £?.?.*•
4/ Negatlva numbers Indicate fuel savings relotlve tp base.
»5/ Based on 10 milUon new vehicles per model year and 10,000 milea per y«!.u.
-------
: _45-
Other Technological Considerations
(a) Rhodium
The three way catalyst system developed to date by Volvo uses a Platinum
(Pt)-Rhodium (Rh) mixture that is different from the Platinum-Palladium (Pd)
mixture used in oxidation catalysts. Because of its use of a high percentage
of RH (relative to Pt)/ the 3-way catalyst has raised questions about the
availability of Rh.
An EPA analysis of this issue shows that the short-term (2-3 years)
supply of Rhodium is probably adequate to meet demand if all cars were to
use a 3-way catalyst with the Volvo mixture (high proportion of Rhodium
relative to Platinum). However, other industrial users might have to find
substitutes for Rhodium. In the long-term, whether the additional demand
for Rhodium could be met, at least from South African mines, if all cars
use the Volvo mixture, depends to a large extent on finding additional
markets for Platinum that is mined along with Rhodium. On the other hand,
if all cars were to use 3-way catalysts with a "natural" ratio of Rhodium
to Platinum and Palladium (about 5% of the total loading), the South African
mines would have no trouble meeting the demand for Rhodium.
(b) Fuel Economy/NOx Relationship for Low Power to Weight Ratio Vehicles
Questions have been raised about whether underpowered vehicles which
tend to be high fuel economy cars have to work harder during the Federal
Test Procedure and thus make higher emissions than cars with traditional
weight to horse-power ratios. How much harder they have to work is an
important issue. If they use maximum power the use of current carburetor
designs generally involves crude means of power enrichment. This would
tend to lower NOx emissions. CD, however, could then be higher and difficult
to control. However, if the purpose for going to underpowered vehicles is
to improve fuel economy they would not likely be designed to operate with
crude means of power enrichment during the test. Power enrichment would
degrade fuel economy not improve it, compared to a vehicle operating without
-power enrichment. Electronic feedback carburetors currently under develop-
ment should help solve this proolem.
Even with proper control of the fuel enrichment, higher power conditions
might cause NOx to increase, if nothing was done to attempt to control the
NOx. Under these conditions, the system would obviously have to be
recalibrated or redesigned to attempt to improve NOx control. If the
engine is operating at a higher load factor, its EGR tolerance could be •
actually improved, and the EGR calibration could be retailored to account
for the higher load condition. Alternatively, other design approaches
could be used to control NOx by increasing EGR tolerance of the basic
engine, as has been demonstrated by Nissan. (The Nissan 2 spark plug car
with oxidation catalyst).
An additional consideration that works in favor of a lighter-weight
vehicle is the fact that they produce, less exhaust volume during the test,
so mass emission (proportional to exhaust volume times concentration)- can
be less at a'given exhaust concentration. For vehicles that "work harder"
during the cycle, catalyst light-off characteristics may also be improved,
thus leading to lower HC and 00 emissions.
-------
•-46-
(c) Diesel Vehicle Emissions
It has-been argued by industry that Diesel powered vehicles will
not be able to meet a NOx standard of 1.0 gpm. These arguments must be
considered in light of the weight of vehicles being discussed and the control
technology (e.g., EGR) being used. The lightest-weight Diesel-powered
automobiles would likely be able to meet a 1.0 gpm NOx emission standard
without the use of Exhaust Gas Recirculation (EGR). Volkswagen (VW),
results show that current Diesels of this type are about 0.34 HC, 1.0 CO,
0.96 NOx (average of 4K and 50K cert results - VW durability car). A
modified VW "fuel economy" version of the above vehicle tested at EPA
had 0.78 HC, 1.0 CO, 0.80 NOx (including DF) with fuel economy of 50 MPG
city and 65 MPG highway.
Heavier Diesel-powered vehicles may require EGR. A GM 4500 IW
vehicle being certified for 1978 (average of 5 to 30 K durability results)
was 0.93 HC, 1.8 CO, 1.35 NOx without EGR. The NOx and the HC were above
the 1.0 and 0.41 levels. EGR for Diesels has been indicated as one part
of an emission control system to get to low NOx (below 1.0 NOx) levels
(SAE 760211, SAE 770430), and the above-mentioned technical papers predict
that control to below 1.0 NOx is possible (SAE 770430 predicts NOx
control below 0.4 NOx). Chrysler Corp. has also indicated that some
Diesel concepts have potential for NOx levels below 1.0 NOx.
When NOx is controlled to low levels with EGR, particulate emissions
and HC and CO tend to increase. Fuel economy is affected only slightly,
if at all, by some calibrations and control technique that yield low NOx
emissions.
Preliminary evidence indicates that some diesel EGR systems may
plug with extended use. This problem is considered to be solvable given
sufficient lead time. Since HC and CO emissions (especially HC emissions)
can tend to be degraded with the use of EGR, more work will be needed
to provide acceptable performance at low HC, CO, and NOx levels. Com-
bustion chamber and injection system design are two areas in which work
is expected to be done. Technological improvements in these two areas
are likely, with HC improvements possible.
The particulate emissions from Diesels are also of concern to EPA
because of the potential significant contribution to air quality control
regions particulate problems. EPA is studying the total mass and other
aspects of Diesel particulate, but as yet no firm guidelines on allowable
Diesel particulate emissions have been set. Control of .Diesel parti-
culates if needed, is expected to be a formidable technical task.
-------
-47-
VIII. Economic Impacts of Standards
New car sales are projected to rise to approximately 12.3 million
cars per year by 1985. This increase in sales will also substantially
increase the size of the labor force employed directly in automobile
manufacturing and original equipment parts supply industries.
Although changes in the sales volume of new cars is determined
primarily by the overall health of the economy, I/ changes in the
sticker prices of new cars will also have a quantifiable, if considerably
less significant, impact on new car sales. The 1985 sales and employ-
ment impacts related to two alternative sets of emissions standards are
shown in the table below.
TABLE 18
1985 Emissions Standards
.41/3.4/1.0 .41/9.0/1.0
New Car Sales (000) -73 -50
Auto Manufacturer and
OEM Jobs (000) -15 -10
*>
This estimate does not take into account the partially
offsetting increases in employment in (1) the service and replacement
parts industries that would occur as a result of owners driving their
older cars longer and (2) the emissions control equipment industry. The
data indicate that standards of .41/9.0/1.0 will reduce "potential"
sales in 1985 by about 50,000 cars (four-tenths of one percent of total
sales) resulting in reductions in the "potential" labor force 2/ of
approximately 10,000 jobs. Moving to a standard of .41/3.4/1.0 would
reduce potential sales by another 23,000 cars (total reductions of six-
tenth of one percent) with potential employment dropping another 5,000
jobs. 3/4/
I/ The econometric model used in this projection shows a decrease in new
car sales of .5 million cars from 1984 to 1985 because of changes
in basic economic conditions.
2/ Actual employment will still increase substantially over today's levels.
3/ These additional sales and labor force reduction estimates for 1985
would be 56,000 to 82,000 cars and 12,000 to 17,000 jobs respectively
if the .4 NOx standard is ultimately adopted.
4/ The employment and sales impacts are based on long-term elasticities. The
first year impact will be greater.
-------
-48-
Changes in the Consumer Index Impact (CPI)
The Report by the Federal Task Force on Motor Vehicle Goals Beyond 1980
considered the CPI changes of emissions control, safety and fuel economy
programs using standards for HC/CO/NOx of .41/3.4/2.0. That study concluded
that these aggregate costs have an "insignificant" impact on the CPI. Based
on the incremental sticker price increases for 1985 cited in Table 15 above,
the approximated average annual price effects of alternative emissions standards
alone are shown in Table 19 below.
TABLE 19
Change in Consumer Price
Index (CPI) I/ 2/
STANDARDS ALTERNATIVES A B
.035 .026 .012 .019 .026
V Using the nighest sticker price (Optional Fuel Economy technology).
2/ These estimates overstate the CPI impact of emissions controls because
emissions control costs are considered quality adjustments and therefore
do not directly affect the CPI.
Here again the impact of the emissions standards alone on the CPI must be
viewed as insigificant with no set of standards changing the CPI by more than
four one-hundreths of one percentage point.
-------
-49-
APPENDIX A
Fuel Economy/Cost/System Design Relationship
A vehicle can be designed with emission control technology that
Will have poor fuel economy at a given emission standard if the control
technology relies on non-optimal engine calibrations or is short of
emission control capability. To compensate for the shortcoming in
emission control capability, engine calibrations may have to be set so
as to reduce emissions in a manner that compromises fuel economy, and
fuel economy penalties can result.
However, if the emission control system has excess capability to
control emissions, the use of engine calibrations that provide good fuel
economy performance is feasible and emission standards can be met with
no fuel economy penalty. In model year 1975, for example, the use of
new emission control tecnnology (i.e. catalysts) allowed better fuel
economy calibrations to be used on the engine. This permitted fuel
economy gains over model year 1974, even though the emission standards
for model 1975 were substantially more stringent than those for model
year 1974.
However, the use of even the best emission control technology does
not guarantee good fuel economy, since fuel economy is determined princi-
pally by certain basic engine calibrations. If these basic engine cali-
brations deviate from the good fuel economy calibrations, fuel economy
losses can result, regardless of the emission control technology usea.
The calibrations that result in good fuel economy for a given engine are
a complicated combination of, for example, spark timing, air-fuel ratio,
and EGR rate as a function of engine speed and load, touch experimental
work is now underway to determine these calibrations for the engines
planned for use in future moael years. Considering the three calibration
variables of spark timing, air-fuel ratio, and EGR rate, it appears
that a good fuel economy calibration can be obtained over a range of air-
fuel ratios. However, if EGR is not used, the air-fuel ratio calibration
for good fuel economy is known to be slightly lean of stoichiometry.
This means that if an engine is operated at the stoichiometric
air-fuel ratio, without EGR, as could be the case for a 3-way catalyst
emission control system, a fuel economy loss would result when compared
to slightly lean operation without EGR. Even though the emission control
might be satisfactory without EGR, the desire to obtain good fuel economy.
calibrations might require the use of EGR and concomitant spark timing
recalibration. This could tend, to improve the NOx control while making
HC control more difficult.
This sensitivity of fuel economy to engine calibrations and the still-
evolving understanding of the interrelationships among the calibration
variables often lead to a wide divergence of technical opinion about the
fuel economy potential of a new emission control technology. This is
particularly true during the early stages of development when emphasis is
placed on determining the emission performance. • . .
-------
-50-
Historically, new emission control systems have improved in fuel economy
over the years as more experience has been gained in system optimization.
The improvement in fuel economy of the 1976 models over the iy?b models
was to some degree due to the continued optimization of engine calibrations.
Further, the fuel economy penalties apparent at the more stringent California
emission standards is an illustration of compromises in engine calibration
when an emission control system (e.g. the oxidation catalyst) approaches
its limit of control capability.
In order to meet future, more stringent emission standards while retaining
good fuel economy calibrations, emission control systems will have to be used
that have improved emission control capability over systems currently in
production. These improved systems will need emission control capability be-
yond that just required to meet the emission standards. Such improved systems
are now being developed by the automobile industry.
The development of technology to control emissions and permit good fuel
economy calibrations to be maintained is expected to take longer than just
the development of technology solely for the purpose of controlling emissions.
For example, the use of electronic controls which have the potential to
be an important part of future low emission, fuel efficient systans will
require the generation and analysis of significant quantities of new engine
data in order to determine more optimal calibrations.
» *
Certain automobile manufacturers have indicated that, given time, future
emission standards as stringent as u.41 HC, 3.4 CO, l.u NOx can be met with
little or no loss in fuel economy. Other manufacturers, however, maintain that
fuel economy penalties will exist at these emission levels. Although the
capability to meet the statutory emission standards (0.41 HC, 3.4 CO, 0.4 NOx)
while retaining good fuel economy caliorations is also possible, little data
have been reported by the automobile manufacturers on complete, improved emission
control systems targeted toward these standards. The reason for this lack of
data may be that the automobile industry has not considered 0.4 NOx to be a real
target. This lack of data will probably continue to exist until 0.4 NOx is made
a firm standard.
The impact of future emission standards on fuel economy should also be
considered in relationship to other technological approaches for improving fuel
economy. Taken in combination, reduced vehicle weight, improved rolling
resistance, lower friction, drivetrain improvanents, improved accessory drives;
improved aerodynamics, and vehicle power-to-weight ration changes can have a
much larger impact on fuel economy than the fuel economy penalties reported
by some as being due to emission control.
... J
-------
Revised 4/13/77
HC/CO/NOx
Emission
Standards
(e/ai)
0.41/9.0/2.0
Tal.le A-J.
Impacts of Various Standards Levels on Automotive Technology, Costs, and Fuel Economy
Optimal Cost Assumptions
(1977 S)
Optimal Fuel Economy Assumptions
Control Technologies Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Air Injection (AIR)
Oxidation Catalyst (PC)
Heavier Weight Cars Use;
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Air Injection (AIR)
Cold Spark Retard
Oxidation Catalyst (PC)
Sticker Maintenance
Price I/ Cost 2J
Increase Increase
(Base)
(Base)
($35)
(Base)
$ 35
(Base)
(Base)
($ 0)
(Base)
$ 0
Fuel
Economy3/
Penalty
-2Z
Control Technologies Used
S 35
$ 0
Lighter Weight Cars Use;
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGP. Control (EEGR)
Air Injection (AIR)
Oxidation Catalyst (OC)
Simple Elec. Control Unit (SECU)
Heavier Weight Curs Use:
High Energy Ignition (HEI)
Electronic Spark Coutroi (ESC)
Electronic EGR Control (EEGR)
Air Injection (AIR)
Start Catalyst (SC)
Oxidation Catalyst (OC)
Simple Elec. Control Unit (S-ECU)
Sticker Maintenance Fuel
Price I/ Cost 21 Economy^/
Increase Increase Penalty
(Base)
($ 7)
($13)
($35)
(Base)
($35)
$ 90
(Base)
($ 7)
($13)
($35)
($35)
(Base)
($35)
(Base)
($ 0)
($17)
(S 0)
(Base)
($ °>
$ 17
(Base)
($ 0)
($17)
(? 0)
($ 0)
(Base)
($ 0)
+2Z
/)
I
$125
$ 17
-------
TaMc A-2
HC/CO/NOx
Emission
Standards
(?/ml)
0.41/3.4/2.0
I
CM
m
i
Revised 4/13/77
Impacts of Various Standards Levels on Automotive Technology, Costs, and Fuel Economy
(1977 S)
Optimal Cost Assumptions Optimal Fuel Economy Assumptions
Control Technologies Used
Lighter Weight Cara Use;
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Air Injection (AIR)
Oxidation Catalyst (PC)
Heavier Weight Cara Use;
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Air Injection (AIR)
Cold Spark Retard
Oxidation Catalyst (PC)
Sticker Maintenance
Price I/ Cost TJ
Increase Increase
(Base)
(Base)
(S35)
(Ease)
$ 35
$ 35
(Base)
(Base)
(? 0)
(Base)
$ 0
$ 0
Fuel
EconomyS/
Penalty
-21
Control Technologies Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic ECR Control (EEGR)
Air Injection (AIR)
Pxldation Catalyst (OC)
Simple Flee. Control Unit (SECU)
Heavier Weight Cars Use!
High Energy Ignition (HEI)
Electronic Spark Central (ESC)
Electronic EGR Control (EEGR)
Improved Fuel Metering (IFM)
Air Injection (AIR)
Start Catalyst. Unswitched (SC)
Pxidation Catalyst (OC)
Simple Elec. Control Unit (SECU)
Sticker Maintenance Fuel
Price \j Cost 21 Economy3_/
Increase Increase Penalty
(Base)
($ 7)
($13)
(535)
(Base)
$ SO
$142
(Base)
($ 0)
($17)
($ 0)
(Base)
($ 0)
$ 17
$ 17
+2Z
+2Z
-------
Revised 4/13/77
Table A-3
Impacts of Various Standards Levels on Automotive Technology, Ccsts, and Fuel Economy
U977 S)
"HC/CO/MOx
Emission
Standards
(g/ci)
0.41/9.0/
1.5
in
I
Optimal Cost Assumptions
Control Technologies Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic EGR Control (EEGR)
Air Injection (AIR)
Oxidation Catalyst (OC)
Simple Elec. Control Unit
(SECU)
i
Heavier Weight Cars Use :
High Energy Ignition (HEI)
Proportional ECR (PEGR)
Improved Fuel Metering (IFM)
Oxygen Sensor (OS)
Electronic A/F Ratio 'Control
(EA/F)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Simple Elec. Control Unit
(SECU)
Sticker
Prir.ei In-
crease I/
(Base)
($ 13)
($ 35)
(Base)
($ 35)
$ B3
(Base)
(Base)
($ 20)
($ 10)
($ 13)
($115)
-($100)
($ 35)
$ 93
Maintenance
Cost In-
crease 21
(Base)
($ 17)
($ 0)
(Base)
($ 0)
$ 17
(Base)
(Base)
($ 0)
<$ 30)i/
($23)
($ 0)
-($ 0)
($ 0)
$ 53
Optimal Fuel Economy Assumptions
Fuel
Economy Control Technologies
PenaltvS/ Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic Spark Con-
trol (ESC)
Electronic EGR Control
(EEGR)
Improved Fuel Metering
' (IFK)
-3Z Air Injection (Air)
Oxidation Catalyst (OC)
Simple Elec. Control
Unit (SECU)
Heavier Weight Cars Use:
High Energy Igni t ion (HEI)
Electronic Spark Control
(KSC)
Electronic EGR Control
(EEGR)
IriproveJ Fuel Metering
(IFM)
Oxygen Sensor (OS)
Electronic A/F Ratio
Control (EA/F)
Three-Way Catalyst (TWC)
-22 Oxidation Catalyst Re-
moved -
Complex Elec. Control
Unit (CECU)
Sticker
?rice In-
creasel/
(Base)
($ 7)
($ 13
($ 20)
($ 35)
(Base)
($ 351
$110
(Base)
($ 7)
($ 13)
($ 20;
($ 10)
($ 13)
($115)
($100) .
iL-«i
$143
Maintenance:' Fuel
Cost In- :Economy
crease 11 :Penalty 3/
(Base)
($ 0)
($ 17)
($ 0)
($ 0)
(Base)
$ 17 +2Z
(Base) i
($ 0)
($ 17)
($ o) :
($ 30) «y i
($ 23)
($ 0)
-($ 0)
($ oj.
$ 70 +2:
-------
Revised 4/13/77
HC/CO/NOx
Emission
Standards
(g/mi)
0.41/3.4/1.5
in
I
Tab IP. A-4
Imparts of Various Standards Levels on AutomQtJva Technology, Costs, and Fuel Economy
• (1977 $)
Optimal Cost Assumptions
Optimal Fuel Economy Assumptions
Control Technologies Used
Lighter Wclfeht Cars Use:
High Energy Ignition (HEI)
Electronic EGR Control (EEGR)
Improved Fuel Metering (IFM)
Air Injection (AIR)
Oxidation Catalyst (OC)
Simple Elec. Control Unit (SECU)
Heavier Weight Cars Use:
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Improved Fuel Metering (IFM)
Switched Air Aspirator (SAA)
Oxygen Sensor (OS)
Electronic A/F Ratio Control (EA/F)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Simple Elec. Control Unit (SECU)
Sticker Maintenance Fuel
Price I/ Cost j
Increase" Increase" Penalty"
(Base)
($1?)
($20)
($ 35)
(Base)
($ 35)
$103
(Base)
(Bane)
($ 17)
($ 7)
($ 10)
($ 13)
($115)
-($100)
($ 35)
(Base)
($ 17)
($ 0)
($ 0)
(Base)
<;$ o)
$ 17
(Base)
(Base)
($ 0)
($ 0)
($ 30)i;
($ 23)
($ 0)
-($ 0)
($ 0)
$ 97
$ 53
Control Technologies Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EECR)
Improved Fuel Metering (IFM)
Air Injection (AIR)
Electronic AIR Control (EAIR)
Oxidation Catalyst (OC)
-3Z Complex Elec. Control Unit (CECU)
Heavier Weight Cars Use:
High tnergy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Improved Fuel Metering (IFM)
Electronic Air Aspirator (EAA)
Oxygen Sensor (03)
Electronic A/F Ratio Control (EA/F)
Start Catalyst, Switched (SC)
-2Z Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Complex Elec. Control Unit (CECU)
Sticker Maintenance Fuel
Price j. Cost 2/ Economy.,
Increase- Increase— Penalty
(Base)
($ 7)
($ 13)
($ 20)
($ 35)
($ 7)
(Base)
($ 65)
S148
(Base)
($ 7)
($ 13)
($ 20)
($ 7)
($ 10)
($ 13)
($ 70)
($115)
-($100)
($' 65)
(Base)
($ 0)
($ 17)
($ 0)
($ 0)
($ 0)
(Base)
($ 0)
$ 17
(Base)
($ 0)
($ 17)
($ 0)
($ 0),
($ 30)-'
(S 23)
($ 0)
($ 0)
-($ 0)
($ 0)
+2%
$220
$ 70
-------
Emission
Standards
0.41/9-0/1.0
I
in
in
i
Impact;? of Various Standards Levels on Automotive Technology, Casts, and Fuel Econoriy
Cotjjtal Cost Assumptions (1977 $) Optimal Fuel Assumptions
Sticker
Price j
Control Technologies Used Increase
Maintenance Fuel '.'•.
Cost 2/ Economy . ^i ,
Increase Penalty '
Sticker Maintenance Fuel
Price Cost Economy^
Control Technologies Used Increased/Increase^/- Penal t-y.
Lighter Height Cars Use:
Hiah Energv Ignition (HEI) (Base) (Base)
Electronic"BGR Control (EEGR) ($ 13) ($ 17)
Improved Fuel JJecering (IFM) ($ 20) ($ 0)
Air Injection (AIR) (S 35) ($ 0)
Oxidation Catalyst (OC) (Base) (Base)
Simple Elec. Control Unit (SECUH$_35) ($ 0)
$103 $17 - 4%
Heavier Weight Cars Use;
Hiqh Energy Ignition (HEI) (Base) (Base)
Proportional BGR (PEGR) (Base) (Base)
Improved Fuel Metering (IFM) ($ 20) ($ 0)
Electronic Air Aspirator (EAA) . ($ 7) ($ 0)
Oxygen Sensor (OS) ($ 10) ($ 30)4/
Electronic A/F Ratio Control (EA/F$ 13) ($ 23)
Start Catalyst, Switched (SC) ($ 70) ($ 0)
Three-Way Catalyst (TWG) ($115) ($ 0)
Oxidation Catalyst Removed -($100) -($ 0)
Sinyle Elec. Control Unit (SECO) $ 35) ($ 0)
$1.70 $ 53 -3%
(Base)
($ 7)
($13)
(I 20)
($ 10)
• Lighter ^.-feight Cars Use;
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGH Control (EEGR)
Improved Fuel Meterinq (IFM)
Oxygen Sensor (OS) '
Electronic A/F Ratio Cc-ntrol (EA/F$ 13)
. Three-Vfay Catalyst (TWC) ($115)
Oxidation Catalyst Ranaved -($100)
-Complex Elec. Control Unit (CBCmS 65
$143
Heavier Vteight Cars Use;
High Hnergy Ignition (HEI)
Electronic Spark Control (ESC).
Electronic EGR Control (EFHR)
Improved Fuel F'-ntering (33^1)
(Base)
($ 7)
($ 13)
($ 20)
Electronic Air Aspirator (EAA)($ 7)
Start Catalyst, Switched (SC) ($ 70)
Three-Way Catalyst (TOC) ($115)
Oxidation Catalyst Removed -($100)
ConDlex Elec. Control Unit (CECU) (S 65)
Oxygen Sensor (OS) ($ 10)
Electronic A/F Ratio Control
_ - (EA/F) _ ($ 10)
(Base)
($ 0 )
($ 17)
($ 23)
($ 0)
0)
f$ .PL
$ 70
-($
(Base)
($ 0)
($ 17)
($ 0)
($ 0)
($ 0)
($ 0)
-($ 0)
($ OK.
($ 30)-'
($ 23)
+2%
$217
$ 70.
+2Z
-------
Table A-6
Revised 4/13//7
EC/CO/NOx
End usion
Standards
(q/mi)
0.41/3.4/1.0
O
f>
I
Impacts of Various Standards Levels on Automotive Technology, CcstG, and Fuel Economy
(1977 $)
—Opclmal Cost Assumptions — Optimal Fuel Economy 7issumptions~
Control Technologies Used
Sticker Maintenance Fuel
Price Cost Economy
Increase!/ Increase!/ Penalty^/
Lighter Weight Cars 'Use;
High Energy Ignition (HEI) (Base)
Electronic EGR Control (EEGR) (S 13)
Improved Fuel Metering (IFM) ($ 20)
Air Injection (AIR) {$ 35)
Start Catalyst Switched (SC) ($ 70)
Oxidation Catalyst (OC) (Base)
Simple Elec. Control Unit (SECU)($ 35)
S173
Heavier Weight Cars Use:
High Energy Ignition (HEI)
Proportional EGR (PEGR)
Improved Fuel Metering (IFM)
Oxygen Sensor (OS)
Electronic A/F Ratio Control
(EA/F)
Three-way Catalyst (TWC+OC)
Air Injection (AIR)
Oxidation Catalyst Reooved
(Base)
(Base)
($ 20)
<$ 10)
• ($ 13)
($205)
($ 35)
-($100)
Simple Elec. Control Unit (SECU) ($ 35)
$218
(Base)
(Base)
($ o>4/
($ 30)-'
($ 23)
($ 0)
($ 0)
($ 0)
($ 0)
$ 53
-4%
•3%
Control Technologies Used
Lighter l.'eiqht Cars Use;
High Energy Ignition (HEI) (Base)
Electronic Spark Control (ESC) (S 7)
Electronic EGR Control (EEGR) ($ 13)
Improved Fuel Metering (IFM) ($ 20)
Electronic Air Aspirator (EAA) !$ 7)
Oxygen Sensor (OS) ($ 10)
Electronic A/F Ratio Control ($ 13)
(EA/F)
Start Catalyst, Stitched (SC) (S 70)
Three-way Catalyst (TWC) ($115)
Oxidation Catalyst Removed -($100)
Complex Elec. Contorl Unit (S 65)
(CECU) ____
$220
Heavier Weight Vehicles Use;
High Energy Ignition (HEI) (Base)
Electronic Spark Control (ESC) ($ 7)
Electronic EGR Control (EEGR) ($ 13)
Improved Fuel Metering (IFM) ($ 20)
Oxygen Sensor (OS) ($ 10)
Electronic A/F Ratio Control ($ 13)
(EA/F)
Three-way Catalyst (TWC) ($115)
Air Injection (AIR) ($ 35)
Electronic Air Control (EAIB) ($ 7)
Oxidation Catalyst (OC) (Base)
Complex Elec. Control Unit (S 65)
(CECU)
$285
Sticker Maintenance Fuel
Price Cost Economy
Increase^/ Increase j/ Penalty* 3/
(Base)
<$ 0)
<$ 17)
($ 0)
($ 0)
($ 30)
($ 23)
($ 0)
($ 0)
($ 0)
($ 0)
$ 70
(Base)
($ 0)
($ 17)
($ 0)
($ 30)^
(5 23)
($ 0)
($ 0)
($ 0)
(Base)
($ 0)
5 70
-1-2%
O
) <
cr
+2%
-------
(X
V,
RC/CQ/HOx.
Emission
Standards
(a/mi)
0.41/9.0/0.4
in
i
Table A-7
Impacts of Various Standards Levels on Automotive Technology, Costs, and Fuel Economy
(1977 S)
Optimal Coat Assumptions
Optimal Fuel Economy Assumptions
Control Technologies Used
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic EGR Control (EEGR)
Improved Fuel Metering (IFM)
Switched Air Aspirator (SAA)
Oxygen Sensor (OS)
Electronic A/F Ratio Control (EA/F)
St*rt Catalyst, Switched (SC)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Simple Elec. Control Unit (SECU)
Heavier Veip.ht Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Mechanical Fuel Injection (MFI)
Oxygen Sensor (OS)
Three-Way Catalyst (TWC) '
Oxidation Catalyst Removed
Complex Elec. Control Cnlt (CECU)
Sticker Maintenance Fuel
Price . Cost Economy
IncreaSei'Increase2-' Penalty—'
(Rase)
($ 13)
($ 20)
($ 7)
($ 10)
($ 13)
($ 70)
($115)
-($100)
($ 35)
$183
(Base)
($ 7)
($ 13)
($100)
($ 10)
($115)
-($100)
($65)
$210
(Base)
($ 17)
($ 0)
($ 0)
($ 30)1/
($ 23)
$ 70
(Base)
($ 0)
($ 17)
($ 45)
($ 30)i'
($ 0)
-($ 0)
_($ 0)
$ 92
OZ to
-8Z
OZ to
-8Z
Control Technologies Used
Lighter Weight Cars Use:
Hluh Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Improved Fuel Metering (IFM)
Electronic Air Aspirator (EAA)
Oxygen Sensor (OS)
Electronic A/F Ratio Control (EA/F)
Start Catalyst, Switched (SC)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Complex Control Unit (CECU)
Heavier Weight Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Electronic Fuel Injection (EFI)
Electronic Air Aspirator (EAA)
Oxygen Sensor (OS)
Start Catalyst, Switched (SC)
Three-way Catalyst (TWC)
Oxidation Catalyst Removed
(Complex Elec. Control Unit (CECU)
Sticker Maintenance Fuel
Price Cost Economy
Increasei' Increase2.'Penalty—
(Base)
($ 7)
($ 13)
(S 20)
($ 7)
($ 10)
($ 13)
($ 70)
($115)
($100)
($ 65)
$220
(Base)
($ 7)
($ 13)
($140)
($ 7)
($ 10)
($ 70)
($115)
•($100)
($ 65)
$327
(Base)
($ 0)
($ 17)
($ 0)
($ 0)
($ 30)i/
(9 23)
($ 0)
($ 0)
-($ 0)
($ 0)
OZ to
$ 70 +2Z
(Base)
($ 0)
($ 17)
($ 45)
($ 0)
($ 30)4/
($ 0)
($ 0)
-($ 0)
($ 0)
0% to
$ 92 +22
TJ
I <
c:
-------
HC/CO/NOx
Emission
Standards
(q/ml)
0.41/3.4/0.4
I
00
in
I
Table A-8
Impacts of Various Standards Levels on Automotive Technology, Costs, and Fuel Economy
(1977 $)
Optimal Cost Assumptions Optimal Fuel Economy Assumptions
Control Technologies Used
Sticker
Price
Increase
Heavier Height Cars Use;
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Mechanical Fuel Injection (MFI)
Switched Air Aspirator (SAA)
Oxygen Sensor (OS)
Start Catalyst, Switched (SC)
Three-Way Catalyst {TWC)
Oxidation Catalyst Recoved
Complex Elec. Control Unit (CECU)
(Base)
($. 7)
($ 13)
($100)
($ 7)
($ 10)
($ 70)
($115)
-($100)
J$65)
$287
Maintenance
Cost
Increase
!/ ?con^3/
Lighter Weight Cars Use:
High Energy Ignition (HEI)
Electronic EGR Control (EEGR)
Mechanical Fuel Injection (MFI)
Oxygen Sensor (OS)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Complex Elec. Control Unit (CECO)
9
(Base)
(S 13)
($ 90)
($ 10)
($115)
-($100)
($ 65)
S193
(Base)
<$ 17)
(5 45>4/
($ 30)1'
<$ 0)
-($ 0)
($ 0)
$ 92
0 to -8%
0 to -8%
Control Technologies
Lighter Heigh1: Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC)
Electronic EGR Control (EEGR)
Electronic Fuel Injection (EFI)
Electronic Air Aspirator (EAA)
Oxygen Sensor (OS)
Start Catalyst Switched (SC)
Three-Way Catalyst (TWC)
Oxidation Catalyst Removed
Complex Elec. Control Unit (CECU)
Heavier Weight Cars Use:
High Energy Ignition (HEI)
Electronic Spark Control (ESC).
Electronic EGR Control (EEGR)
Electronic Fuel Injection (EFI)
Advanced Gr.ygen Sensor (AOS)
Three-Way Catalyst (TWC)
Air Injection (AIR)
Electronic AIR Control (EAIR)
Small Oxidation Catalyst (SOC)
Oxidation Catalyst Removed
Complex Elec. Control Unit (CECU)
Sticker Maintenance Fuel
Price . Cost fconoa
Increase— Increase-/ Penaltv
(Base)
($ 7)
($ 13)
($110)
($ 7)
($ 10)
($ 70)
($115)
-($100)
($ 65)
$297
(Base)
($ 7)
($ 13)
($1*0)
($ 13)
($110)
($ 35)
($ 7)
<$ 70)
-<$100)
($ 65)
$360
(Base)
($ 0)
($ 17)
($ 45)
($ 0)
(S 30)V
($ 0)
($ 0)
-($ 0)
($ 0)
$ 92
(Base)
($ 0)
($ 17)
(S 45)A/
($ 45)1'
($ 0) .-.
($ 0)
($ 0)
($ 0)
-<$ 0)
($ 0)
$167
0 to -t-2%
i (
c:
0 to +2%
-------
Revised 4/13/77
in
I
Impacts of Various Standards Levels on Automotive Technology. Costs, -and Fuel Economy
HOTES!
I/ Equivalent sticker price and maintenance cost Increases are in 1977 dollars and are relative to the Optimal Cost Assumptions for the 1.5/15/2.0
levels.
Zf Maintenance cost Increased are for a 100,000 mile vehicle lifetime, are expressed in undlscounted 1975 dollars, and are relative to the Optimal
~ Cost Assumptions for the 1.5/15/2.0 levels. Maintenance Cost are assumed to be those that would occur without Inspection/Maintenance programs
in place.
31 Fuel economy penalty is average estimated for near-term implementation of standards (1979 to 1983 period) and is relative to the Optimal Cost
Assumptions for the 1.5/15/2.0 levels. Negative numbers are penalties, positive" numbers are gains.
if Oxygen sensor replacement interval of 30,000 miles (three changes over 100,000 miles) assumed.
''*
-------
-60- x sj
Key to Control Technology Acronyms
AIR Air injection system including air pump, check valve, and
manifold for injection of air at exhaust ports. For start
catalysts and other systems where switching of air injection
location is required after warm up extra components would
be included to accomplish this function.
AO£5 Advanced oxygen sensor. Exhaust oxygen sensor capable of
providing an analog signal proportional to the actual excess
oxygen concentration.
CSCU Complex electronic control unit. Digital electronic control
unit capable of handling control of three or four engine
parameters. Includes basic engine condition sensors. Sensors
and actuators for specific control functions are separately
itemized.
EAA. Electronically-controlled air aspirator. Reed valve type
air induction system for providing extra air to start catalyst
during warm up. Includes catalyst temperature sensor (if any)
and actuator for control by central electronic control unit.
EAIR Electronically-controlled air injection. Valve and actuator
for proportional control of air injection rate by electonic
control unit. «
EA/F Electronic control of air/fuel ratio. Position sensor and
actuator for modulation of carburetor air/fuel ratio by
central electronic control unit.
EEGR Electronically-controlled exhaust gas recirculation. Position
sensor and actuator for modulation of egr valve postion by
central electonic control unit.
EFI Electronic fuel injection. Electronically-controlled fuel
injection system including electronic control unit and basic
engine condition sensors. Replaces functions of CECU and
EA/F.
ESC Electronic spark timing control. Firing circuits for control
of ignition timing by central electronic control unit.
HEI High energy ignition. Ignition system capable of providing
high energy discharge to spark plugs to minimize misfire.
IFM Improved fuel metering. Improved carburetor capable of
more precise control of air/fuel ratio during transient
driving conditions.
IOC Improved oxidation catalyst. Kigher efficiency (75% HC
conversion efficiency over FTP at 50,000 miles vs. 70%
efficiency assumed for standard oxidation catalyst) oxidation
catalyst assumed in "High Range" system of 3 Agency Study
at 0.41/3.4/1.5 levels.
"10 ••'••
-------
-61-
Table 3 (Continued)
Key to Control Technology Acronyms
MFI Mechanical fuel injection. Mechanically (pressure)
modulated fuel injection system. Assumed to include
electronic signal processing and actuator to permit
feedback control of air/fuel ratio from an exhaust
oxygen sensor, but not to have the full electronic
monitoring and control capabilities of a central
electronic control unit.
OC Oxidation catalyst.
OS Oxygen sensor. Exhaust oxygen sensor used in three-
way catalyst system to provide step function (rich or
lean) indication of exhaust condition to fuel metering
control system (EA/F, EFI, or MFI).
PEGR Proportional exhaust gas recirculation. Exhaust gas
recirculation system which provided for mechanical
modulation of EGR flow rate based on intake manifold
vacuum or other engine condition signal.
PL Port liners. Insulation of exhaust ports on cylinder
head to conserve exhaust heat for purposes of greater
thermal oxidation of HC and CO in exhaust manifold and
quicker warm up of catalysts (especially start catalyst)
and oxygen sensor.
SAA Switched air aspirator. Mechanically or electrically
(solenoid) operated reed valve type air induction system
for providing extra air to start catalyst during warm up.
SECU Simple electronic control unit. Digital electronic
control unit capable of handling control of one or two
engine parameters. Includes basic engine condition
sensors. Sensors and actuators for specific control
functions are separately itemized.
SC Start catalyst. Small oxidation 'catalyst located close
to exhaust manifold where it will come quickly to operating
temperature after engine starting, so as to provide
catalytic control of high start up HC and CO emissions
before main oxidation catalyst reaches operating temperature
As used in 3 Agency and 5 Agency studies, start catalyst
is assumed to include any air aspirator needed to provide
extra air during warm up (engine is running rich because
of choke) and any switching mechanism to remove start
catalyst from exhaust gas flow path after warm up so
as to conserve catalyst efficiency.
-------
-62-
Table 3 (Continued)
Key to Control Technology Acronyms
SOC Small oxidation catalyst. A smaller volume oxidation
catalyst included in the EPA Study Optimal Fuel Economy
'system for heavier cars at the 0.41/3.4/0.4 levels.
This catalyst, together with AIR and EAIR would be
used downstream of the three-way catalyst to provide
additional HC and CO control under certain driving •
conditions.
SSC Switched start catalyst. Start catalyst (see SC) provided
with a means for diverting the exhaust flow around the
start catalyst after main catalyst reaches operating
temperature.
TWC Three-way catalyst. Catalyst formulated to provide
efficient simultaneous control of HC, CO, and NOx when
operated at a stoichiometric air/fuel ratio. In the
3 Agency and 5 Agency studies the acronym TWC is used
for a complete three-way catalyst system, including the
oxygen sensor (OS), electronic air/fuel ratio control
(EA/F) and electronic control unit (PFCU).
TWC/OC Combined three-way and oxidation catalyst unit with
provisions for air injection between Oseparate catalyst
elements. :
USC Unswitched start catalyst. Start catalyst (see SC)
which remains in the exhaust flow stream at all times.
Less expensive than switched start catalyst, but has
lower high mileage efficiency because of additional
catalyst deterioration caused by continuous contact
with exhaust gases.
------- |