SEPA
Office of Transportation
and Air Quality
EPA420-S-06-002
March 2006
UMtM
Protection
Diesel
Technology
An Analysis of the
Cost-Effectiveness of Reducing
Participate Matter Emissions
from Heavy-Duty Diesel
Engines Through Retrofits
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EPA420-S-06-002
March 2006
An of the of
Through
Assessment & Standards Division and
Compliance & Innovative Strategies Division
Office of Transportation and Air Quality
U. S. Environmental Protection Agency
NOTICE
This Technical Report does not necessarily represent final EPA decisions or positions,
It is intended to present technical analysis of issues using data that are currently available.
The purpose in the release of such reports is to facilitate an exchange of
technical information and to inform the public of technical developments.
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Executive Summary
The Environmental Protection Agency's (EPA) National Clean Diesel Campaign
(NCDC) is a comprehensive initiative to reduce pollution from diesel engines
throughout the country, including vehicles on highways, city streets, construction
sites, and ports. The NCDC comprises both regulatory programs to address new
engines and voluntary programs to address the millions of diesel engines already
in use. On the regulatory side, EPA is successfully implementing emissions
standards for engines in the 2007 Heavy-Duty Highway Engine Rule and the Tier
4 Nonroad Rule and developing new emission requirements for locomotives and
marine diesel engines, including large commercial marine engines. On the
voluntary side, EPA is addressing engines that are already in use by promoting a
variety of innovative emission reduction strategies such as retrofitting, repairing,
replacing and repowering engines; reducing idling; and switching to cleaner fuels.
The voluntary programs are accomplished in partnership with state and local
governments, environmental groups and industry.
The emissions standards for new engines will reduce both highway and nonroad
engine emissions by roughly 90%. However, these emission reductions occur
over a long period of time as new engines are phased into the fleet. Retrofitting
diesel engines currently in use will allow significant and immediate emission
reductions from diesel engines that would not otherwise be addressed.
The purpose of this technical analysis is to evaluate the cost effectiveness of
retrofitting existing heavy-duty diesel engines to reduce particulate matter (PM).
(The cost effectiveness of the regulatory measures EPA has implemented is
addressed the rulemakings.) Analysts in EPA's Office of Transportation and Air
Quality (OTAQ) evaluated the costs and emissions benefits of retrofitting school
buses, freight trucks, and bulldozers with diesel oxidation catalysts (DOCs) and
catalyzed diesel particulate filters (CDPFs), two of the most common PM
emissions reduction technologies for diesel engines.
For highway vehicles (e.g. school buses and trucks), EPA considered two
overarching methods to estimate the cost effectiveness of diesel retrofit
technology. The first involved using only the current mobile source emission
factors and inventories in EPA's approved MOBILES.2 model. The second
involved using more recent data that OTAQ has collected to use in the future
development of EPA's next highway emissions model, MOVES (Motor Vehicle
Emissions Simulator). EPA chose the second option for this technical paper in
order to better reflect more recent information on highway vehicles.
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EPA obtained the more recent highway vehicle data from states, fleet owners,
and technology and engine manufacturers covering factors such as annual
vehicle miles traveled, vehicle useful life, engine emission rates, retrofit
technology effectiveness, and technology costs. For example, this paper
assumes heavy-duty diesel PM emissions are approximately 2.3 times higher
than predicted in MOBILES.2 based on results from recent chassis dynamometer
testing from the California Air Resources Board, the Coordinated Research
Council, EPA's efforts to update the MOBILE model, and other sources. EPA will
eventually use the more recent highway vehicle data to modify the MOBILES
model as part of a comprehensive effort to create the next generation mobile
model, MOVES. It is important to note, however, that states and local
governments are still using MOBILES.2 to estimate highway vehicle emissions for
State Implementation Plans (SIPs) and transportation conformity purposes.
For nonroad engines (e.g. 250 hp bulldozers), EPA relied primarily on data from
the NONROAD2004 model to determine the cost-effectiveness of DOCs. EPA
also consulted additional data sources where appropriate.
EPA calculated that the cost effectiveness for both school bus diesel oxidation
catalyst (DOC) and catalyzed diesel particulate filter (CDPF) retrofits ranged from
$12,000 to $50,500 per ton of PM reduced. The same type of retrofits for Class
6&7 heavy-duty highway trucks (commonly found on highways and city streets)
ranged from $27,600 to $69,900 per ton of PM reduced. The same type of
retrofits of larger Class 8b trucks (commonly used to transport freight long
distances) ranged from $11,100 to $44,100 per ton of PM reduced. Finally, DOC
retrofits for 250 hp bulldozers ranged from $18,100 to $49,700 per ton of PM
reduced.
The results can be compared to similar estimates for other EPA programs
targeted at reducing diesel particulate matter. For example, EPA estimates that
the cost-effectiveness of the Urban Bus Retrofit and Rebuild program is
$31,500/ton of PM reduced, the 2007 Heavy-Duty diesel emission standards is
$14,200/ton, and the Nonroad Tier 4 emission standards is $11,200/ton.
The findings from this study indicate that retrofits can be a cost effective way to
reduce air pollution.
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Table of Contents
I. INTRODUCTION 1
I.A. NATIONAL CLEAN DIESEL CAMPAIGN 1
I.B. STUDY OBJECTIVE & METHODS 1
II. RETROFIT EFFECTIVENESS FACTORS 2
II.A VEHICLE ACTIVITY 3
II.A. 1 School Bus Activity Analysis 3
II.A.2. Truck Activity Analysis 4
II.A.3 Nonroad Activity Analysis 4
II.B. VEHICLE SURVIVAL RATE 4
II.B.1. Highway Scrappage Analysis 4
II.C. EMISSION RATES 5
II.C.1. Highway Emission Rate Analysis 5
II.C.2 Nonroad Emission Rate Analysis 6
II.D. COMPARISON TO EXISTING HIGHWAY EMISSIONS INVENTORY
MODEL 7
II.E. EFFECTIVENESS OF RETROFIT TECHNOLOGIES 7
II.E.1. Background on Retrofit Technology Verification 7
II.E.2 Analysis 8
II.F COSTS 9
II.F.1. Background 9
II.F.2. Highway Cost Analysis 9
II.F.3. Nonroad Cost Analysis 11
II.F.4. Highway and Nonroad Operating Costs 11
II.G. ESTIMATING LIFETIME EMISSION REDUCTIONS 11
II.G.1. Background 11
II.G.2. Highway Emission Reduction Analysis 12
II.G.3. Nonroad Emission Reduction Analysis 13
III. RESULTS 13
IV. CONCLUSIONS 14
REFERENCES 32
in
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I. INTRODUCTION
I.A. NATIONAL CLEAN DIESEL CAMPAIGN
The Environmental Protection Agency's (EPA's)
National Clean Diesel Campaign (NCDC) is a
comprehensive initiative to reduce pollution from
diesel engines. EPA's Office of Transportation
and Air Quality (OTAQ) manages the NCDC,
which comprises both regulatory programs to
address new engines and voluntary programs to
address the millions of diesel engines already in
use.
Particulate matter (PM), one of the primary
pollutants from diesel exhaust, is associated with
many different types of respiratory and
cardiovascular effects, and premature mortality.
EPA has determined that it is a likely human
carcinogen. Fine particles (smallerthan 2.5
micrometers), in particular, are a significant
health risk as they can pass through the nose
and throat and cause lung damage. People with
existing heart or lung disease, asthma, or other
respiratory problems are most sensitive to the
health effects of fine particles as are children and
the elderly. Children are more susceptible to air
pollution than healthy adults because their
respiratory systems are still developing and they
have a faster breathing rate. EPA expects
reductions in air pollution from diesel engines to
lower the incidence of these health effects, as
well as contribute to reductions in regional haze
in our national parks and cities, lost work days
and reduced worker productivity, and other
environmental and ecological impacts.
New regulations from EPA require stringent
pollution controls on new highway and nonroad
diesel engines, including engines operating in
the freight, transit, construction, agriculture, and
mining sectors. The new regulations will also
slash sulfur content in diesel fuel by 97 percent.
By combining tough exhaust standards with
cleaner fuel requirements, these rules will cut
emission levels from new engines by over 90
percent. The new lower sulfur diesel fuel will
result in reduced PM emissions as soon as the
fuel is introduced into the market. New engines
sold in the US after 2007 for highway use (and
after 2010 for nonroad use) must meet the more
stringent standards, but the effect of these
cleaner engines will be achieved over time as
the existing fleet is gradually replaced. The
benefits of these new rules will not be fully
realized until the 2030 time frame. As a result
EPA is promoting a suite of voluntary programs
to address the emissions from the existing fleet
of diesel vehicles.
The NCDC voluntary programs are designed to
address existing diesel vehicles and equipment
through emission reduction strategies that can
provide immediate air quality and health benefits.
The voluntary programs focus on vehicles and
equipment in the school bus, construction, port,
freight and agricultural sectors. The voluntary
programs work with partners in state and local
government, industry, and environmental
organizations to promote a wide range of
measures to reduce diesel emissions including
retrofitting vehicles with new or improved
emission control equipment, upgrading engines,
replacing older engines with newer/cleaner
engines, reduced idling, and using cleaner fuels.
I.E. STUDY OBJECTIVE & METHODS
Stakeholders - including states that are
developing their plans to achieve the National
Ambient Air Quality Standards for fine particles -
are searching for cost effective ways to reduce
emissions from existing diesel engines in order
to improve air quality and protect public health.
The purpose of this study is to estimate the cost
effectiveness of retrofit strategies.
We chose to evaluate retrofit strategies for four
types of vehicles:
1)school buses
2) combined class 6&7 trucks
3) class 8b trucks, and
4) 250 horsepower (hp) bulldozers
Truck classes are based on the Gross Vehicle
Weight Rating. Class 6 trucks are 19,501 -
26,000 Ibs and Class 7 trucks are 26,001 -
33,000 Ibs. Class 6&7 trucks are commonly
found on highways and on city streets. Class 8b
vehicles are greater than 60,000 Ibs and are
commonly used to transport freight long
distances. 250 hp bulldozers are technically
called Diesel Crawler Tractors or Crawler Dozers
in our NONROAD emissions inventory model,
and are prevalent on construction sites around
the country.
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EPA chose these vehicle types for three
reasons. First, we wanted to evaluate retrofits for
both highway (e.g. school buses and trucks) and
nonroad vehicles (e.g. bulldozers). Second, we
had the best data for these types of vehicles
due, in large part, to our experience with retrofit
projects on-the-ground. Finally, these vehicles
exist in large numbers across the country, so we
believed that cost-effectiveness analysis for
these vehicles would be relevant to a wide
audience.
We decided to evaluate the two most common
diesel retrofit technologies, diesel oxidation
catalysts (DOCs) and catalyzed diesel
particulate filters (CDPFs), for all vehicle types,
except for 250 hp bulldozers, for which we only
analyzed DOC retrofits since CDPFs are not
currently compatible with many bulldozers.
For highway vehicles (e.g. school buses and
Class 6-8b trucks), EPA considered two
overarching methods to estimate the cost
effectiveness of diesel retrofit technology. The
first involved using only the current mobile
source emission factors and inventories in EPA's
approved MOBILE 6 model (version 6.2),
OTAQ's emission factor model for predicting
gram per mile emissions from cars, trucks, and
motorcycles under various conditions. The
second involved using more recent data that
OTAQ has collected to use in the future
development of EPA's next highway emissions
model, MOVES. EPA chose the second option
for this technical paper in order to better reflect
more recent information on highway vehicles.
EPA obtained the more recent highway vehicle
data from states, fleet owners, and technology
and engine manufacturers which impacted
factors such as annual vehicle miles traveled,
vehicle useful life, engine emission rates, retrofit
technology effectiveness, and technology costs.
For example, this paper assumes heavy-duty
diesel PM emissions are approximately 2.3 times
higher than projected in MOBILE6.2 based on
results from recent chassis dynamometer testing
from the California Air Resources Board, the
Coordinated Research Council, EPA's efforts to
update the MOBILE model, and others. EPA will
eventually use the more recent highway vehicle
data to modify the MOBILE6.2 model as part of a
comprehensive effort to create the next
generation mobile model MOVES (Motor Vehicle
Emissions Simulator). It is important to note,
however, that states and local governments are
still using MOBILE 6.2 to estimate highway
vehicle emissions for State Implementation
Plans (SIPs) and transportation conformity
purposes.
For nonroad engines (e.g. 250 hp bulldozers),
EPA relied primarily on data from the
NONROAD2004 model to determine the cost-
effectiveness of DOCs. EPA also consulted
additional data sources where appropriate.
For both highway and nonroad vehicles, we
analyzed annual vehicle miles traveled, vehicle
useful life, engine emission rates, retrofit
technology effectiveness, and technology costs
to calculate the cost-effectiveness of retrofit
strategies, in terms of $ per ton of PM reduced. It
is important to note that, in many cases, heavy-
duty diesel retrofit strategies provide other
emission benefits such as reductions in
hydrocarbons and carbon monoxide. This study
only evaluates the cost-effectiveness of reducing
PM from diesel retrofits.
The following section will detail our methods for
calculating the cost-effectiveness of PM
reductions from retrofits including factors such as
vehicle activity, survival rates, emissions factors,
costs of technologies, and emissions reductions
from retrofit technologies. In Section 3 we will
present our results and in Section 4 we will
provide summary remarks about the relative
cost-effectiveness of diesel retrofits. As
mentioned previously EPA calculates these cost
effectiveness figures based on more recent
information for highway vehicles obtained from
various sources. If EPA chose not to use this
more recent information and instead relied
exclusively on the MOBILE model for these
calculations, the cost effectiveness could range
from approximately $14Kto $160K per ton.
II. RETROFIT EFFECTIVENESS FACTORS
In order to estimate the relative cost
effectiveness of various PM retrofit strategies, it
is necessary to estimate a number of factors,
including:
-vehicle activity
-vehicle survival rates
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-emissions rates of vehicles
-effectiveness of DOCs and CDPFs
-costs of retrofits
The following sections 2.A - 2.G outline our
methodologies for estimating each of these
factors.
II.A VEHICLE ACTIVITY
One of the first steps in estimating emission
reductions from retrofit strategies is to develop
an estimate of annual vehicle activity. This
requires identifying nominal values for vehicle
miles traveled for representative vehicle
samples, in the case of highway vehicles (e.g.
trucks and school buses), and operating hours
and load for nonroad vehicles (e.g. bulldozers).
This information can then be used to estimate
annual vehicle emissions and emission
reductions from retrofits.
II.A.1 School Bus Activity Analysis
The default MOBILE 6.2 Vehicle Miles Traveled
(VMT) for school buses is 9,939 miles per year
1. Anecdotal reports suggest that average school
bus VMT has increased overtime. This increase
is attributed to suburban growth around many
communities at a time when budget-strapped
school districts cannot afford to expand their
school bus fleets.
As a test of this anecdotal information, we
reviewed detailed school bus fleet data that
school districts submitted to EPA in response to
a request for applications for Clean School Bus
USA grant funding over the summer of 2003.
The Clean School Bus USA demonstration
grants program attracted 120 applications from
diverse programs around the country seeking to
retrofit or replace aging school bus fleets. Of
these, 72 applications contained data that were
relevant to this exercise and that were in a
format that could be analyzed. Most of the
applications provided actual fleet VMT data from
the 2002-2003 school year, with the others
submitting data from 2001-2002. The data
represent several hundred school districts, and
more than 34,000 school buses from 31 states
plus Puerto Rico.
We analyzed the average school bus activity
only for diesel school buses.
We took the average per-bus VMT for each fleet
directly from the application, or, if not provided,
calculated it by dividing the annual fleet mileage
by the number of buses in the fleet. If a fleet's
total mileage included diesel and non-diesel
school buses, we weighted the annual mileage
by the technology ratio to reflect only the diesel
portion of the fleet. If applicants provided only
total mileage and age for each bus in the fleet,
we calculated an average VMT for each bus by
dividing mileage by age, and then created a fleet
average by averaging the VMTs from individual
buses.
To determine a representative VMT mix across
the population of buses considered for this
analysis, we calculated a fleet fraction for each
school bus fleet by dividing the number of buses
in that fleet by the total population. We then
multiplied that fraction of the population by the
fleet's average VMT to create a weighted fleet
fraction of the fleet's VMT. We determined the
average VMT for the total population by adding
the weighted fleet fractions.
The method described above yielded an average
annual VMT of 13,248 miles per bus. This is an
increase of approximately 3,309 miles per year
from the default value currently in the
MOBILE6.2 model and is used to represent
average VMT for school buses independent of
vehicle age. That is, school bus VMT is
estimated to be the same in the first year and all
subsequent years of the vehicles life. Although
this represents a simplification of real-world
practices, we believe that, given the fixed routes
defined for many school buses, this is a
reasonable assumption. However, there are no
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independent data available to test the
assumption from this analysis.
the typical load factor for a 250 hp bulldozer is
0.59 (average cycle power/rated power).3
It is important to note that the annual school bus
VMT used in our analysis represents a relatively
large increase over the school bus VMT estimate
from the Vehicle Inventory and Use Survey
(VIUS) study (the basis for the values used in the
development of MOBILE6.2).
I.A.2. Truck Activity Analysis
We used an estimate of annual VMT from
MOBILE 6.2 for Class 6-8b trucks which declines
with vehicle age. This estimate can be found in
EPA report, Fleet Characterization Data for
MOBILE6: Development and Use of Age
Distributions, Average Annual Mileage
Accumulation Rates and Projected Vehicle
Counts for Use in MOBILE 6.2 (see Table 1
Annual Accumulation).2
II.A.3 Nonroad Activity Analysis
Our methodology for estimating emission
reductions from nonroad equipment is similar to
that for highway vehicles in that we first needed
to estimate annual and lifetime activity (use
patterns). We estimated this activity based on
data from the technical documentation for the
NONROAD inventory emissions mode (see
www.epa.gov/otaq/nonrdmdl.htm for a
description of the NONROAD model). Nonroad
engine activity is expressed in terms of hours of
operation (annual and lifetime) and load factor
(average engine operating power as a
percentage of rated engine power). The estimate
for annual hours of operation for a 250 hp
bulldozer is 936 hours per year. The estimate for
II.B. VEHICLE SURVIVAL RATE
The scrappage rate describes the fraction of
vehicles (relative to the total number originally
sold) that are no longer in the fleet from one year
to the next. This factor reflects vehicle loss
through accidents, deterioration, and export.
From a retrofit perspective, scrappage is a
necessary component of cost effectiveness
analysis because it dictates how long older
vehicles will stay on the road, and hence the
potential benefit which will accrue from a retrofit
at a certain point in time.
II.B.1. Highway Scrappage Analysis
An analysis of scrappage rates for selected
model years of Heavy-Duty vehicles is published
by Oak Ridge National Laboratory in the
Transportation Energy Data Book (TEDB), based
on registration data and a scrappage model
developed by Greenspan and Cohen4. The latest
model year for which TEDB published data on
scrappage rates is 1990, but we did not use
these data for our analysis because they
seemed unrealistically high - for example, they
projected a 45 percent survival rate for 30
year-old trucks. While limited data exist to
confirm this judgement, a snapshot of 5-year
survival rates can be derived from the VIUS for
1992 and 1997 for comparison. According to
VIUS, the average survival rate for model years
1988-1991 between the 1992 and 1997 surveys
was 88 percent. The comparable survival rate for
1990 model year Heavy-Duty vehicles from the
TEDB was 96 percent, while the rate for 1980
model year trucks was 91 percent. Based on this
analysis, we determined that 1980 model year
survival rates are more in line with available
data, and these rates are used in the analysis
instead of the 1990 rates. The resulting median
life estimate (the age at which 50% of vehicles
have been scrapped) is 18.5 years. This
contrasts with a median life estimated in the
MOBILE6.2 emission model of approximately 12
years. The difference between the two data
values indicates that there is some degree of
uncertainty regarding survival rates. Survival
Rates are shown in Table 2.
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II.B.2 Nonroad Scrappaqe Analysis
Like the MOBILE model, the NONROAD model
has intrinsic scrappage rates built into the model.
These rates are used to project the distribution of
nonroad equipment in a population by age. We
chose to use a simplified nonroad scrappage
rate estimate for this analysis. We use the
resulting median life estimate for nonroad
equipment in the NONROAD model. This
number is the number of hours of rated engine
operation that the median example of nonroad
diesel engine is expected to operate. Dividing
that number by the load factor (discussed
previously) converts the median life from hours
of operation at rated power to hours of operation
at typical operating power levels (i.e., it converts
it to actual hours of operation). The median life
for a 250 hp diesel engine from the NONROAD
model is 4,667 hours at rated power. Dividing
this number by the typical load factor found
previously (4,667 hours rated / 0.59) returns a
median life at typical operating conditions of
7,910 hours. Given annual operating hours of
936 hours, the expected lifetime for the median
250hp nonroad bulldozer can be found as 8.5
years. While this represents the expected
median operating life, it should be recognized
that significant variation about this median can
be expected in practice with many pieces of
nonroad equipment being used for periods well
in excess of 8.5 years.
II.C. EMISSION RATES
MOBILE6.2 is the current, approved highway
emission factor model used by States and local
governments for State Implementation Plans
(SIPs) and planning purposes. When the
analysis portion of MOBILE6.2 was completed in
1998, there were little heavy-duty chassis
dynamometer data available, therefore the
emission rates in MOBILE6.2 are based on
engine dynamometer test data from engine
certification tests. With chassis dynamometer
testing, the engine remains in its vehicle
(chassis) and the vehicle's tires drive rollers that
produce a load in the dynamometer. This
produces a more realistic test of the engine in
this application than an engine dynamometer
test where the engine is removed from the
vehicle and connected directly to a
dynamometer. The analysis for highway vehicles
in this report uses more recent data, which EPA
is planning to incorporate into EPA's next
highway emissions model, MOVES, when it is
developed.
II.C.1. Highway Emission Rate Analysis
OTAQ completed a large data collection effort in
2002 and 2003 on Heavy-Duty Highway vehicle
emissions rates. There have been several
Heavy-Duty chassis dynamometer test programs
completed in recent years which we obtained
from EPA's Mobile Source Observation
Database (MSOD) for this study.
While there is a significant number of Heavy-
Duty diesel Class 8 chassis dynamometer tests
in the MSOD, there is a lack of school bus
chassis dynamometer emissions tests and
limited tests for Heavy-Duty diesel Class 6&7
vehicles (which are similar in size to many
school buses). For this analysis we developed a
ratio metric correlation for Heavy-Duty diesel
Class 8 emissions from chassis dynamometer
tests to engine dynamometer test data
represented in MOBILE6.2, and applied this ratio
to Heavy-Duty diesel Class 6-8 MOBILE6.2
emissions to estimate emission rates for those
vehicle classes. We made this estimate by
applying the correlation described below to the
current emission factors for Class 6-8 vehicles
from the MOBILE 6.2 model to create new
emission factors that should more closely match
actual emission rates in use. This approach
inherently assumes the ratio relevant to Class 8
vehicles applies to Class 6 and 7. While we
believe this approach is reasonable, we do not
have independent data to validate this
assumption.
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The available chassis data set consisted of 39
vehicles tested on 20 different cycles for a total
of 315 tests. The bulk of the data used federal
diesel grade 2 or California diesel fuels. We
eliminated other fuel types from the analysis.
See 3 for a description of the data set by
cycles, model years, and fuel type. 4
shows a brief description of the cycles. More
detailed plots of the test cycles are available
upon request by contacting MOBILE@epa.gov.
We performed an analysis to determine if there
was a trend by model year for the chassis to
engine test results comparison. We did not find
any obvious trend, and a weighted regression
did not prove to be statistically significant. We
compiled average PM emission rates for each
model year on each of the two fuels used from
the chassis data set. We computed the ratio for
each model year of the chassis data set to the
MOBILE6.2 emission rate, for each fuel type.
When we took an average - including both fuels -
weighted by sample size, over each model year,
which resulted in a ratio of 2.3 for chassis
dynamometer emissions to engine dynamometer
emissions. This ratio reflects the effects of real
world driving, in-use deterioration, and in-use
fuels. See 5 for the emission rates and
ratios by model year for the data set described
above versus MOBILE6.2. In order to make a
conclusion on impacts of these in-use factors on
actual PM inventories from highway vehicles, we
would have to conduct a detailed analysis
isolating the effects of cycles, fuel, and
deterioration to estimate the effects over the
range of model years and vehicle classes
available in MOBILE6.2. We felt, however, that
the use of the ratio approach (described above)
to determine emission rates is appropriate for
this cost effectiveness analysis. EPA will
consider this information as it develops its future
emissions models that are to be used in the
future for official SIP or conformity purposes.
It is important to note that the ratio we use in this
analysis also does not appear in the newly
released Retrofit benefits calculation module of
the National Mobile Inventory Model (NMIM)
which is based on MOBILE 6.2 emission rates.
The benefits in the NMIM model come from a
percentage tagged to each different technology
used for retrofit. EPA would need to analyze a
substantial amount of additional data to update
the emission rates used in MOBILE 6.2.
For school buses we made one additional
change. The PM emission factors in MOBILE6.2
are based on inputs from an earlier mobile
source model called PARTS. The PARTS model
did not specifically identify emission factors for
school buses, but it does contain an estimate for
"buses", a category which would include urban
transit buses, coach buses, and school buses.
MOBILE6.2 does have an emission factor for
school buses but that factor is simply a carryover
from the bus emission factor in PARTS. The bus
emission factor in PARTS, and hence, the school
bus emission factor in MOBILE6.2 is based
primarily on data and emission standards for
urban buses. This causes two problems for
school buses. First, older school buses have
emission factors that are likely to overestimate
PM emissions by approximately 50 percent due
to the use of the higher emission conversion
factor for urban buses. Second, emission factors
attributed to new school buses are too low due to
the use of the lower urban bus emission
standard to project future emission rates even
though school buses do not need to meet the
lower standard (the current PM standard for
school buses is twice that of urban buses, 0.1
g/bhp-hr versus 0.05 g/bhp-hr). Therefore, in this
analysis we have chosen to model the school
bus emission factor the same as combined Class
6&7 trucks. Class 6&7 trucks are most similar to
diesel school buses using the same engines
meeting the same emission standards.
DOC on construction equipment
II.C.2 Nonroad Emission Rate Analysis
The NONROAD engine model uses emission
rates for nonroad diesel engines based on the
emission standards, historic engine certification
data, and projections of in-use deterioration of
emissions over the lifetime of the equipment.
Additionally, the nonroad model includes a factor
to correct for observed differences in emissions
production between in-use operating cycles and
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the steady-state emissions test results. The
projected in-use emissions rates are therefore
the product of the expected new certification
emissions level, the ratio of transient emission
rates to steady-state emission rates, and
projected deterioration rates overtime (i.e., as
the equipment ages EPA projects emissions will
increase). The result of this methodology is that
new (beginning of life) nonroad equipment is
estimated to have a lower emission rate than the
same equipment would after a period of
operation. In order to simplify the analysis in this
paper, we have combined the adjustment for
transient emissions and deterioration into a
single static number of 1.5 (i.e., a 50% increase
in emissions over the certification levels) which
roughly approximates the combined factors for a
bulldozer in the nonroad model. This approach
may undercount the emissions from a typical
piece of nonroad equipment when compared to
the NONROAD model where the transient
adjustment factor ranges from 1.23 to 1.97 and
the deterioration factor varies from 0 at 0 hours
to 0.473 at full useful life.5 Hence, the
NONROAD model adjustment would range from
1.2 to 2.9 (1.0 X 1.23 to 1.473 X 1.97) over the
range of engines and through the equipment life.
We believe the use of a simplified single value of
1.5 is appropriate for this analysis since our goal
is to estimate a nominal ratio of emission
reductions and cost. EPA has developed a
retrofit modeling function within NMIM that fully
incorporates the features of the NONROAD
model and will allow states and local authorities
to more accurately estimate the potential for
emission reductions through retrofits.
II.D. COMPARISON TO EXISTING HIGHWAY
EMISSIONS INVENTORY MODEL
As mentioned above, MOBILE6.2 is EPA's
official emissions factor model for highway
Heavy-Duty engines and vehicles. A complete
description of MOBILE 6.2 can be found on
EPA's web site at
www.epa.gov/otaq/mobile.htm.
In the previous sections (II.A - II.C), we analyzed
a number of factors to estimate emissions from
highway Heavy-Duty engines (Class 6&7, Class
8b, and school buses) and newly developed
estimates based on the most recent data, where
appropriate. These factors are annual VMT for
school buses, scrappage rates for Heavy-Duty
vehicles, and a new engine-to-chassis
conversion factor. Table 6 is a comparison of the
estimates we developed for this paper and the
emissions inventory values in MOBILE6.2.
Table 6. Comparison of MOBILE6.2 Values to
Retrofit Cost Effectiveness Study Values
Factor
School Bus
VMT
Scrappage
Engine
Based PM
Emission
Factor3
Engine-to-
Chassis
Conversion
MOBILE6.2
value
9,939
12 year median
life
1991 MY 1.948
2000MY0.163
1
(no factor used)
Retrofit
Analysis
value
13,248
18.5 year
median life
1991 MY 0.51 8
2000MY0.158
2.3
a The engine based PM emission factors change for each
model year, two example years are shown here.
When considered as a whole, the estimated
values of lifetime emissions that we developed
for this analysis (detailed in Sections II.A- II.C)
are approximately 3 times greater for newer
school buses and 2.3 times greater for Class 6-8
vehicles than the values used in MOBILE6.2.
This general characteristic does not hold for
model year 1993 and older school buses due to
the much higher emission factors in MOBILE6.2
for these vehicles when compared to this
analysis. The results for 1993 and older school
buses are approximately 20 percent lower in this
analysis when compared to estimates from
MOBILE6.2. Section 3.Ci explains our rational
for using alternative emission factors for school
buses in this analysis.
II.E. EFFECTIVENESS OF RETROFIT
TECHNOLOGIES
II.E.1. Background on Retrofit Technology
Verification
The NCDC voluntary programs encourage air
quality agencies and owners of fleets of diesel
powered vehicles and equipment to implement
-------
clean diesel strategies such as installing new or
enhanced emission control technology and using
cleaner fuels. To help these organizations make
informed decisions regarding which retrofit
technologies are appropriate for their fleets and
what emission reductions can be expected, EPA
created the Retrofit Technology Verification
Process. This process evaluates the emission
reduction performance of retrofit technologies,
including their durability, and identifies engine
operating criteria and conditions that must exist
for these technologies to achieve those
reductions.
Under this program, companies can apply for
EPA verification of the effectiveness of their
emission control technology. The verification
protocol requires the same tests as defined by
the Code of Federal Regulations (CFR) for new
engine family certification before sale in the U.S.
The protocol tests the stand-alone engine, and
then the engine with the emission control
technology. Both new and aged devices must be
tested. The emission reduction percentage that
EPA verifies will reflect the performance of the
new and used devices. Once a technology is
verified, the company receives an official EPA
verification letter, and the technology is listed on
EPA's web site as a verified technology. There is
no restriction on who may apply for verification.
To date, EPA has verified nearly 20 technologies
from different emission control technology
companies.
The measures that EPA verifies can be very
general - for example, an emission control
technology company may receive verification for
a diesel oxidation catalyst (DOC) technology that
can reduce particulate matter from any
uncontrolled or Tier 1 nonroad diesel engine by
20 percent - or the verification can be specific to
an engine model made over specific model
years.
While retrofit technologies are the most common
clean diesel strategy verified by EPA, there is a
wide range of measures that can reduce diesel
emissions. For example, the replacement of
older engines or vehicles may be more beneficial
in many cases than using retrofit technologies. If
a fleet manager is concerned that exhaust
emissions from their vehicles may overwhelm
current retrofit technologies, or they are
interested in having more up-to-date safety
equipment, the fleet manager may prefer to
replace older vehicles with newer models rather
than retrofit their existing vehicles.
II.E.2 Analysis
We took the retrofit technology applications and
emissions reduction information in this cost
effectiveness study directly from EPA's List of
Verified Technologies. We are focusing only on
emission reduction figures for DOCs and CDPFs
verified for Class 6&7 Heavy-Duty engines.
The estimated reduction in PM:
1) from adding a DOC to a highway engine is
20%
2) from adding a DOC to a nonroad engine and
changing to highway fuel (< 500 ppm S) is
20%
3) from adding a CDPF to a highway engine and
changing to ultra low sulfur diesel (ULSD) fuel
from regular highway diesel fuel is 90%
One requirement of the verification process is
that applicants must test their systems after they
have been installed fora period of time. The
manufacturer must begin in-use testing after they
have sold a certain number of units of the
verified system. EPA must approve the
manufacturer's sampling plan to gather units to
be tested. The manufacturer must test units
aged in the field to a minimum fraction of the
designated durability testing period in two
different phases. Manufacturers are given wide
latitude in the type of emissions testing
equipment they use, although test cycles are
well defined. The manufacturer must test at least
four units in each phase. Individual failures lead
to additional testing or possible removal from the
Verified Technology List. This part of the
verification process is still in its infancy and, as
such, EPA has not yet received any in-use test
results from retrofit technology manufacturers.
Once EPA receives these additional in-use test
results, EPA will examine them and use them to
help quantify real world retrofit benefits.
The reduction of other criteria air pollutants by
aftertreatment devices should also be
recognized. A DOC or CDPF may reduce
hydrocarbon and carbon monoxide emissions on
the order of 20 to 90 percent.
-------
11.F COSTS
II.F.1. Background
Several sources of information are available on
the current price of retrofit technologies. These
include a December 2000 survey by the
Manufacturers of Emission Controls
Associations (MECA) and current price
information for grant recipients in EPA's Clean
School Bus Program.6 Those sources give
ranges for CDPF prices of $3,000 to $7,500
depending on size, expected product sales
volumes, and configuration (i.e., in-line or muffler
replacement). Similarly, these sources suggest
DOCs will range in price from $425 to $1,750
depending on size, sales volume and
configuration. While we believe these ranges are
reflective of current prices for PM retrofit
technologies applied to Class 6&7 trucks and
school buses, we also believe that future retrofit
costs are likely to drop substantially as a result of
the Heavy-Duty 2007 emission standards and
the Nonroad Tier 4 emission standards.
II.F.2. Highway Cost Analysis
For this report, EPA has conducted a review of
available information on the cost of PM retrofit
technologies and has made a new projection for
the future cost of PM retrofit technologies in
2007. Beginning in 2007, all new Heavy-Duty
diesel engines are required to meet a PM
emissions standard of 0.01 g/bhp-hr. EPA
projected in the 2007 rule-making that this
emission standard would be met through the use
of CDPFs. Our recent Highway Diesel Progress
Review Report #2 confirms that all Heavy-Duty
diesel engine manufacturers are planning to
comply with these regulations through the use of
CDPF technologies.7 This means that, beginning
in the 2007 model year, the market - and
therefore production volumes - for CDPFs will
increase from a few thousand units a year in the
United States to almost a million units a year. At
the same time, there is increasing demand in
Japan and Europe spurred by retrofit programs
and new emission standards. In the aggregate,
CDPF production volumes are expected to
increase by almost two orders of magnitude (i.e.,
from tens of thousands annually to more than a
million annually). In manufacturing, substantial
cost savings can typically be found with
increasing production volumes, especially when
those production volumes change by orders of
magnitude. Therefore, we expect the cost for
CDPFs to decrease significantly after 2007
compared to today's costs. For this analysis of
the cost effectiveness of future retrofit programs,
we feel it is appropriate to make an estimate of
the future cost of retrofit technologies rather than
relying on today's costs.
EPA has recently made an estimate of the
production cost for CDPFs in the Nonroad Tier 4
rule-making.8 The analysis in that rule-making
was based on preliminary data available to EPA
regarding the actual manufacturing costs for
CDPF and DOC technologies. We decided to
use that analysis as a basis for our projection of
the future retrofit cost for Class 6&7 trucks and
school buses. We have made a number of
additions and modifications to the Tier 4 analysis
to account for differences between high volume
engine manufacturing and retrofit applications.
Specifically, we have added additional costs to
account for the instrumentation and testing
necessary to qualify candidate retrofit vehicles
for CDPFs and for the installation of the retrofit
technologies. We have also accounted for
additional canning and packaging costs specific
to retrofit technologies and for the differences
between projected manufacturing costs in 2007
(the period for this analysis) and the Tier 4 time
frame (post 2010).
In order to ensure successful application of
passive CDPF technologies, retrofit companies
typically instrument a sample of candidate
vehicles from a retrofit fleet to confirm that
operating conditions and exhaust temperatures
are appropriate for CDPF regeneration. Absent
such testing, CDPFs can inadvertently be
installed on vehicles for which passive
regeneration is not assured, potentially leading
to CDPF failure. We estimated the cost for this
testing at approximately $2,000 dollars per
twenty vehicles retrofitted (i.e., the cost for the
testing is estimated as $2,000 dollars and the
results from the test are assumed to be, on
average, applicable to twenty vehicles within a
fleet). Thus, we estimated an average cost of
$100 per CDPF vehicle retrofit to account for the
total cost of this testing.
The labor associated with installing a catalyst
technology in a vehicle on a production line is
quite small and not substantially different from
the cost of installing an exhaust system.
-------
Installing a catalyst may entail more labor if the
catalyst weighs more than an exhaust system or
needs additional fasteners, or connection points.
The labor cost for installing retrofit technologies,
however, can be a significant fraction of the
overall cost. Installing a retrofit catalyst may
entail removing a portion of the existing exhaust
system, on-site fabrication or welding of
connections to the exhaust system, and then
remounting of the exhaust system. The facilities
available for retrofit installation, typically vehicle
service facilities, are also not designed as
efficiently as vehicle assembly lines when it
comes to installing a single component on
vehicles. For these reasons, we felt that it was
necessary to account for the additional
installation cost (primarily labor) of retrofit
technologies in this analysis. To accomplish this,
we used data from the grant proposals provided
to EPA under the Clean School Bus USA
program. A number of the grant proposals
included a cost for installation of the retrofit
technologies. The average installation cost from
these grant proposals was $193. We have used
this average as an estimate for the installation of
both CDPFs and DOCs for Class 6&7 trucks and
school buses. Although, it might be reasonable
to assume this cost will decrease in the future,
we do not have adequate information to project
the degree to which this average cost might
change.
CDPF Installation
In addition to higher labor costs related to
installing retrofit technologies (relative to the
volume of vehicle production) we also expect
there to be additional hardware costs associated
with unique fastening and mounting systems for
retrofit technologies. This reflects the fact that
older vehicles were not designed to
accommodate PM control after-treatment
technologies. We have estimated the cost for
these additional hardware components
(additional fasteners and perhaps unique
exhaust tubing and fittings) at $87 per vehicle for
DOC retrofits and $300 per vehicle for CDPF
retrofits. It may be possible in the more distant
future that these components will reach a degree
of commonality that will lead to lower costs,
however, at this time we did not have enough
information to estimate the degree to which
these costs may change.
In order to apply the Nonroad Tier 4 Regulatory
Impact Analysis estimate of CDPF and DOC
costs for retrofit vehicles, we needed to address
the difference in time horizons for the two future
projections. This analysis is intended to project
the cost for retrofit technologies in the year 2007,
while the Nonroad Tier 4 analysis focused on
technology cost in 2011 and beyond. Reflecting
a start date beyond 2010, the Nonroad Tier 4
analysis incorporated a 20 percent learning
curve effect into its estimate of future CDPF
costs (no learning curve effect was applied for
DOCs). For this analysis, we have removed that
learning curve effect in order to correlate the
estimate to an earlier time period, specifically
2007. The resulting cost for a CDPF (without the
other costs noted previously) is $1,920 for a
diesel engine of 8 liter engine displacement. The
DOC cost (again without the additional costs
listed previously) is $260 for Class 6&7 trucks
and school buses.
7 summarizes the total estimate we have
made for the cost of PM retrofit technologies in
the 2007 time frame. The table shows a
projected cost for DOCs of $540 per Class 6&7
truck and school bus retrofitted and a projected
cost for CDPFs of $2,500. These projections
represent our best estimate of the nominal cost
for retrofitting vehicles with diesel engines of 8
liter displacement. In practice, we would expect
significant variability above and below these
price estimates due to a wide range of other
factors that we did not account for in this
analysis (e.g., retrofit fleet size, profit margin
differences, etc.). Nevertheless, we believe
these estimates adequately reflect the nominal
cost for future PM retrofit technologies.
10
-------
The cost analysis described above is specific to
engines with displacements of 8 liters applied to
Class 6&7 trucks and school buses. In order to
estimate the cost to retrofit larger Class 8b
vehicles powered by engines with displacements
typically between 11 and 16 liters, we have
scaled this analysis by a ratio of 13:8 (i.e., we
have increased the cost by 62 percent). This
increase implicitly assumes that the retrofit cost
is directly proportional to engine displacement
and that 13 liters is a typical Class 8b engine
displacement. Because many of the retrofit
components are sized in direct proportion to
engine displacement, we believe this
approximation is robust. The resulting cost
estimates for Class 8b retrofits are $880 per
DOC retrofit and $4,100 per CDPF retrofit. As
noted above, this estimate represents a nominal
cost and a number of factors could result in costs
that are lower or higher than those we have
estimated.
II.F.3. Nonroad Cost Analysis
For our nonroad example application (250 hp
bulldozer), we have taken a different approach to
estimating the cost for future retrofit application.
We have used a nominal average cost based on
our current experience with nonroad retrofits.
That typical cost is $800 per DOC retrofit on
nonroad equipment. We have not made a future
projection of reductions in this cost, because of
the greater diversity and smaller retrofit fleet
sizes typical of nonroad equipment. We expect
nonroad retrofits to occur one piece of
equipment at a time, even in relatively high
volumes. We believe using today's nominal cost
as a future cost estimate is very conservative,
but given the uncertainty in the nonroad retrofit
market we do not attempt to predict future cost
reductions.
II.F.4. Highway and Nonroad Operating Costs
We do not account for operating costs related to
the application of PM retrofit technologies in this
analysis. Operating costs could include the
differential cost for using 15 ppm sulfur fuel, fuel
economy impacts related to increased exhaust
backpressure, or changes to maintenance
practices related to the use of retrofit
technologies. We have not accounted for a 15
ppm sulfur fuel premium in this analysis because
in 2007 (the time frame of this analysis) 15 ppm
sulfur highway diesel fuel will be the predominant
diesel fuel used in highway applications. At the
same time nonroad engines must switch to fuel
with less than 500 ppm sulfur. We have not
accounted for a change in fuel consumption
related to the use of PM retrofits in this analysis
because current data from existing retrofits show
no significant difference in fuel economy for
vehicles with and without PM retrofit
technologies.9 In practice, the impact of retrofit
technologies on fuel consumption is strongly
related to engine load and therefore varies
significantly depending upon the vehicle
application.
In the HD2007 rulemaking, we made estimates
of the lifetime operating costs for maintenance
related to cleaning accumulated oil ash from
CDPFs. Those costs reflect a net present value
calculation (in the year of sale) for a future
maintenance cost that would occur after 150,000
miles of trap operation. We project, however,
that only a limited number of retrofitted vehicles
in Classes 6&7 will accumulate 150,000 miles of
operation after the CDPF retrofit. In most cases,
we project that vehicles will be scrapped prior to
the time when this maintenance would be
necessary. Therefore, while some vehicles will
receive this maintenance (for example, vehicles
with higher annual VMTthan projected in this
analysis), we have not accounted for these
maintenance costs for school buses and Class
6&7 trucks in this analysis. For Class 8b trucks,
which tend to accumulate many more miles, we
have included the maintenance cost estimated in
the HD2007 rulemaking of $208.
II.G. ESTIMATING LIFETIME EMISSION
REDUCTIONS
II.G.1. Background
In order to compare the relative cost
effectiveness (i.e., tons of emissions reduced per
dollars spent) of PM retrofit programs to other
PM emission control programs, it is necessary to
estimate the lifetime emissions reduction we
project will occur with PM retrofits. In concept,
estimating the emission reductions is simple and
can be viewed as the product of the lifetime
vehicle miles traveled (VMT), the baseline
emission rate for the vehicle (grams/mile) and
the emission reduction potential of the retrofit
technology (e.g., 90% for CDPFs). In practice,
11
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the estimation is more complicated since we
must account for vehicle scrappage, variations in
vehicle miles traveled as the vehicle ages, and
the relative value of emission reductions realized
in the current year versus a future time.
Furthermore, estimates of the lifetime emission
reductions for retrofit technologies must address
the age of the vehicle when the retrofit is
installed (i.e., retrofitting a one year old vehicle
would be expected to result in a larger emission
reduction compared to a ten year old vehicle).
We have accounted for these factors in our
analysis for the nominal case, but it should be
recognized that factors such as annual vehicle
miles traveled can vary significantly between
different vehicles.
II.G.2. Highway Emission Reduction Analysis
Earlier in this report, we provided an estimate of
the average annual VMT for school buses
participating in the Clean School Bus USA
program and for vehicles with Class 6-8 Heavy-
Duty engines. These estimates for annual VMT
reflect the mileage a vehicle may travel in each
full 12 month period of its operating life.
However, some vehicles will invariably be
scrapped prior to reaching their total potential
lifetime VMT. So while we estimate that a 20
year old school bus may have an average VMT
of 13,248 miles per year in this analysis, we
would only expect a small percentage of school
buses to remain in operation after 20 years. In a
previous section, we described the methodology
used to estimate the fraction of vehicles that
survive to a particular age based on historic
registration data. Those data show, for example,
that after 10 years 83% of trucks are expected to
be in operation and conversely that
approximately 17% will have been scrapped.
Using this information, we can weight the annual
VMT (and hence emission reductions) of a ten
year old vehicle by the likelihood that the vehicle
is still in use and generating those emissions or
emission reductions. We accomplish this by
multiplying the annual VMT of a ten year old
vehicle and the survival fraction often year old
vehicles. We make a similar calculation for every
year of a nominal vehicle's life.
This approach allows us to estimate the
emissions of a group of newly built vehicles, but
it is somewhat problematic for retrofits of older
vehicles. This is because the subset of retrofit
vehicles represent a surviving fraction from
which the scrapped vehicles have already been
removed, and for this analysis scrappage must
be tracked for the retrofitted fleet according to
when the retrofits were performed. For example,
if we retrofitted a fleet often year old vehicles the
scrappage rate for those vehicles in their first
year of operation would be the age one
scrappage rate of 0%, rather than the age ten
scrappage rate of 17%. In order to account for
the fact that retrofits of older vehicles begin with
a subset of the survivors, we have created
separate survival curves for retrofit vehicles of
various ages from one year old to 28 years old at
the time of the retrofit. We generated these
survival curves by normalizing the survival
fraction to 100% in the first year of operation,
thus maintaining the general characteristics of
the survival curve while reflecting the fact that
retrofit vehicle groups are assured to have
survived to the first year of their retrofit. Table 8
shows the survival fractions based on vehicle
age and vehicle age at time of retrofit.
Using the information in Table 8 and the annual
VMT estimates for school buses and Class 6-8
Heavy-Duty trucks, it is possible to make an
estimate of weighted annual VMT for retrofit
vehicles accounting for the survival fraction and
the age of the vehicle at the time of retrofit.
These estimates are presented in 9, 10
and 11.
Based on the estimate of the nominal annual
VMT for retrofit vehicles and weighting this VMT
by the surviving fraction of a subset of vehicles
retrofitted at a certain age, we can use this
information to estimate the annual emission
reductions for retrofit technologies as the product
of the weighted annual VMT (Tables 9-11), the
emission rate per mile, and the emission
reduction (percent reduction) realized from the
retrofit for each year of a retrofit vehicle's life.
12-17 show the results of these
calculations. 12 -17 are organized
showing the base emission rates from
MOBILE6.2 on a gram/mile basis. The adjusted
emissions rates on a grams/mile basis are
shown across the top of the table in summary
form for retrofitted vehicles of model years 1990
- 2006. The main body of the tables shows the
annual emission reductions estimated as
described above in each year of a retrofit
vehicles life beginning with retrofit in 2007.
12
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Those annual estimates can then be brought
back to a net present value at a defined discount
rate (3 percent) to give a discounted lifetime
emission reduction. This result is shown in the
second row of the lower half of Tables 12-17.
The ratio of the cost for the retrofit technology
and the discounted lifetime emissions reductions
represents the relative cost per ton reduction for
the retrofit technology. These results are shown
in the last row of the upper half of tables 12-17.
Because vehicles retrofitted at different ages will
have different lifetime emission reductions, we
have made estimates for retrofits for various
vehicle model years as if the vehicles were
retrofitted in calendar year 2007. Hence a 2006
model year vehicle retrofitted in model year 2007
would be one year old, and a 2001 model year
vehicle retrofitted in model year 2007 would be
six years old. Tables 12-17 organize the
vehicles of different ages by column designating
both the model year of the retrofitted vehicle
(e.g., 2001) and the age of the vehicle when
retrofitted in 2007 (e.g., 6 years old).
II.G.3. Nonroad Emission Reduction Analysis
We have followed a similar process for the 250
hp bulldozer, using inputs from the NONROAD
inventory model and the simplifying assumptions
described earlier in this paper. EPA has
developed a retrofit modeling module within
NMIM that will enable states and other interested
parties to directly estimate the emission
reduction potential of nonroad retrofits.
III. RESULTS
Table 18 below, summarizes the range of cost
effectiveness ratios we estimated for the
selected retrofit cases in this paper. As noted
previously, these estimates represent a nominal
projection of the future cost per ton of emission
reduction. These cost effectiveness estimates
have not factored in the co-benefits from
reducing other pollutants such as HC. The cost
effectiveness of retrofitted programs can vary
significantly depending on a number of factors,
including actual annual average activity (i.e.,
annual vehicle miles traveled for highway or
annual operating hours for nonroad).
Table 18 Summary of Cost Effectiveness for
Various Diesel PM Retrofit Scenarios
Vehicle
School
Bus
Class
6&7
Truck
Class 8b
Truck
250 hp
Bulldozer
Retrofit
Technology
DOC
CDPF
DOC
CDPF
DOC
CDPF
DOC
CDPF
Range of $/ton PM
Emission Reduced
$12,000
$12,400
$27,600
$28,400
$11,100
$12,100
$18,100
n/a
$49,100
$50,500
$67,900
$69,900
$40,600
$44,100
$49,700
n/a
The results summarized in Table 18 can be
compared to similar estimates for other EPA
programs targeted at reducing diesel particulate
matter. For example, EPA's Urban Bus Retrofit
and Rebuild program of $31,500/ton, EPA's
2007 Heavy-Duty diesel emission standards of
$14,200/ton, for and EPA's Nonroad Tier 4
emission standards of $11,200/ton.10
The results summarized in Table 18 above and
given in more detail in Tables 12 -17 are
characterized by increasing cost per ton of
emission reduction for the retrofit of older
vehicles in comparison to newer vehicles.
This characteristic is to be expected as older
vehicles will have a shorter remaining lifetime
and hence lower remaining emissions (or
emission reductions) prior to vehicle scrappage.
In some cases, the cost per ton of emission
reductions decreases with older vehicles
because of older vehicles' relatively high
emissions level. That is, retrofitting an emission
control technology on an older engine that, due
to historically more lenient emission standards
has higher emissions, may lead to a larger
emission reduction for the same retrofit cost.
This benefit from retrofitting older dirtier vehicles
is offset by the shorter remaining life of the older
vehicles.
13
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IV. CONCLUSIONS
Our analysis demonstrates that diesel retrofit
strategies can be a cost effective way to reduce
air pollution. We calculated that the
cost-effectiveness of DOC and CDPF retrofits for
school buses, Class 6-8b trucks, and 250 hp
bulldozers range from roughly $11,000 to
$70,000 per ton of PM reduced, depending on
number of factors such as vehicle activity,
survival rates, emissions rates, effectiveness of
DOCs and CDPFs and their costs. These
findings indicate that retrofits of diesel engines
can be as cost-effective as recent EPA
rule-makings to address diesel particulate
matter, such as the 2007 Heavy-Duty rule and
the Nonroad Tier 4 standards which EPA
estimates will cost $14,200/ton of PM reduced
and $11,200/ton of PM reduced, respectively.
It is important to note that, while we based our
cost effectiveness estimates on robust and
recent data sources, there is a significant
amount of variability in both the costs and the
emissions reductions from retrofit technologies in
the field. We believe our analysis adequately
represents the cost effectiveness of DOC and
CDPF retrofits for the average school bus, Class
6-8b truck, and 250 hp bulldozer, but the
cost-effectiveness of retrofits for specific engines
and vehicle fleets may differ in certain situations.
EPA has developed a module as part of the
National Mobile Inventory Model that will allow
users to predict the impact of retrofitting their
particular fleets. The new module will be able to
generate national, county-level, or fleet-specific
mobile source emissions inventories and then
use these inventories to estimate emissions
reductions from retrofit technologies.
Contact:
Carl Wick
U.S. EPA - Office of Transportation and Air
Quality. E-mail:
14
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Table 1. Average Annual Mileage Accumulation (Curve Fit Data)1
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HDDV Heavy ctwty die-ie! vehicle
HDDS Heavy craty dieseJ bu-?
(a) Aveuge sclicul bai mileage for all ages = &.9S9
1 Fleet for MOBILES: and of Age
Annual and Counts, Table 6 page 16, EPA420-R-01-047,
September 2001 (www.epa.gov/otaq/models/mobile6/r01047.pdf).
15
-------
Table 2. Transportation Energy Data Book 1980 Model Year Heavy-Duty Survival Rate
Age
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Survival
Rate
1.00
1.00
1.00
1.00
0.99
0.97
0.95
0.92
0.89
0.86
0.83
0.79
0.75
0.72
0.68
0.64
0.60
0.56
0.52
0.48
0.44
0.41
0.37
0.34
0.31
0.28
0.25
0.22
0.20
0.18
0.16
16
-------
Table 3. Heavy-Duty Diesel Class 8 Chassis Dynamometer Test Data Set
Vehicle Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Model Year
1997
1997
1997
1997
1982
1992
1997
1985
1994
1998
1998
1998
1998
1996
1997
1997
1996
1995
1996
1996
1991
1991
1991
1991
1991
2000
1999
1998
Cycle
OCRTC2
OCRTC2
NYGTC3
NYGTC3
5 Mile
CSHVR
TEST D
WVU-5P
CSHVR
HIWAY
CSHVR
HIWAY
5 Mile
TEST D
CSHVR
HIWAY
CSHVR
CSHVR
CSHVR
CSHVR
3CBD
WHM
3CBD
WHM
3CBD
WHM
2-5 Mile
CSHVR
CSHVR
2-5 Mile
CSHVR
2-5 Mile
CSHVR
14R
CBD
CBD
CBD
14C
14R
CBD
CBD-RT
14R
CBD
CSHVR
HIWAY
CSHVR
HIWAY
CSHVR
Number of Tests
6
6
5
6
3
4
2
10
3
1
1
1
4
13
2
2
3
3
3
3
3
3
3
3
3
3
11
12
6
3
9
5
6
1
10
7
19
1
4
15
1
2
5
1
1
2
1
2
Fuel Type
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
California
California
California
California
Federal Grade 2 Diesel
Federal Grade 2 Diesel
California
California
California
California
California
California
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
California
California
California
California
California
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
California
California
California
California
California
17
-------
Vehicle Number
29
30
31
32
33
34
35
36
37
38
39
Model Year
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1992
Cycle
HIWAY
2-5 Mile
CSHVR
HVDUTY
CSHVR
CSHVR
2-5 Mile
CSHVR
CSHVR
CSHVR
CSHVR
2-5 Mile
CSHVR
CSHVR
20_mph
30_mph
40 mph
5 Mile
CSCYC
CSHVR
TEST D
WVU-5P
YARD
CSHVR
HIWAY
Number of Tests
1
8
7
1
3
6
3
4
3
6
4
3
4
3
1
2
5
4
1
15
1
3
1
2
1
315
Fuel Type
California
California
California
California
California
California
California
California
California
California
California
California
California
California
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
Federal Grade 2 Diesel
California
California
18
-------
Table 4. Test Cycle Descriptions of Class 8 Heavy-Duty Diesel Chassis Dynamometer Tests
Cycle
20_MPH
30_MPH
40_MPH
5 Mile
2-5MIL
CBD
CBD-RT
3CBD
14C
14R
CSCYC
CSHVR
CSHVR
HI WAY
HVDUTY
NYGTC3
OCRTC2
TEST_D
WHM
WVU-5P
YARD
Cycle Description
20 mile per hour steady state driving
30 mile per hour steady state driving
40 mile per hour steady state driving
Heavy-Duty vehicle drive cycle over 5 miles.
The SMILE Heavy-Duty drive cycle-twice.
Central Business District
Routized CBD
Triple Central Business District
Modified CBD
Modified and routized CBD
City Suburban Cycle
Heavy-Duty vehicle drive cycle.
Heavy-Duty vehicle drive cycle.
Triple Length New York Garbage Truck Cycle
Orange County Refuse Truck Cycle-twice
UDD for Heavy-Duty Vehicles
Number of
Vehicles
1
1
1
3
6
5
1
3
1
3
1
24
2
7
1
2
2
3
3
2
1
Model Year
Range
1998
1998
1998
1982-1998
1996-1998
1991
1991
1996-1997
1991
1991
1998
1992-2000
1982-1998
1992-2000
1998
1997
1997
1982-1998
1996-1997
1982-1998
1998
Number of
Tests
1
2
5
11
33
56
1
9
1
7
1
98
19
8
1
11
12
16
9
13
1
315
19
-------
Table 5. Emission Rates, and Ratios of Chassis Dynamometer Emissions to Engine Dynamometer
Emissions by Model Year
Model Year
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Totals:
New MSOD Data
D2 fuel GARB fuel
N PM10(g/mi) N PM10(g/mi)
19 3.95
17 3.12
65 3.82
7 0.97
4 0.57
6 0.81
6 0.58 46 0.75
35 1.06 2 0.245
33 0.51 70 0.37
3 0.71
2 0.46
175 140
MOBILE6.2
PM10(g/mi)
2.09
2.09
2.01
2.00
2.00
1.99
1.98
2.06
1.75
1.73
1.18
0.64
0.63
0.63
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0.23
Weighted Ratic
Ratios
D2fuel GARB fuel
Ratio Ratio
1.97
1.57
5.97
1.54
2.45
3.53
2.57 3.31
4.69 1.08
2.27 1.63
3.12
2.03
)= 2.3
20
-------
Table 7. Calendar Year 2007 Estimated Retrofit Costs for Combined Class 6&7 and School Buses, and for
Class 8b
Cost Component
Substrate/Coating/Canning
Additional exhaust tubing and
mounting hardware
Datalogging and testing for
CDPF regeneration
Installation
Class 6-7 and School Buses
Total (2 significant figures)
Ratio Class 6&7 to Class 8b
Class 8b Retrofit Cost
(2 significant figures)
Class 8b Maintenance Cost
Total Class 8b Cost
(2 significant figures)
Diesel Oxidation Catalyst
(DOC)
$260
$87
-
$193
$540
13/8 times
$880
Catalyzed Diesel Particulate Filter
(CDPF)
$1,920
$300
$100
$193
$2,500
1 3/8 times
$4,100
$208
$4,300
21
-------
Table 8. Retrofit Survival Fractions as a Function of Vehicle Age at Time of Retrofit
Scrappage Table Survival Fraction (based on 1980 vehicles)
Vehicle Age
From New
Years
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Age at Retrofit
New
(survival %)
100%
100%
100%
98.5%
96.7%
94.5%
92.0%
89.1%
86.0%
82.7%
79.1%
75.4%
71.6%
67.7%
63.7%
59.7%
55.7%
51.8%
47.9%
44.2%
40.6%
37.1%
33.7%
30.6%
27.6%
24.8%
22.2%
19.8%
17.6%
15.5%
1
(survival %)
0%
1 00%
1 00%
98.5%
96.7%
94.5%
92.0%
89.1%
86.0%
82.7%
79.1%
75.4%
71 .6%
67.7%
63.7%
59.7%
55.7%
51 .8%
47.9%
44.2%
40.6%
37.1%
33.7%
30.6%
27.6%
24.8%
22.2%
19.8%
17.6%
15.5%
2
(survival %)
0%
0%
1 00%
98.5%
96.7%
94.5%
92.0%
89.1%
86.0%
82.7%
79.1%
75.4%
71 .6%
67.7%
63.7%
59.7%
55.7%
51 .8%
47.9%
44.2%
40.6%
37.1%
33.7%
30.6%
27.6%
24.8%
22.2%
19.8%
17.6%
15.5%
3
(survival %)
0
0
0
100.0%
98.2%
96.0%
93.5%
90.6%
87.5%
84.2%
80.6%
76.9%
73.1%
69.2%
65.2%
61.2%
57.2%
53.3%
49.4%
45.7%
42.1%
38.6%
35.2%
32.1%
29.1%
26.3%
23.7%
21.3%
19.1%
17.0%
4
(survival %)
0
0
0
0
100.0%
97.8%
95.3%
92.4%
89.3%
86.0%
82.4%
78.7%
74.9%
71.0%
67.0%
63.0%
59.0%
55.1%
51.2%
47.5%
43.9%
40.4%
37.0%
33.9%
30.9%
28.1%
25.5%
23.1%
20.9%
18.8%
5
(survival %)
0
0
0
0
0
100.0%
97.5%
94.6%
91 .5%
88.2%
84.6%
80.9%
77.1%
73.2%
69.2%
65.2%
61 .2%
57.3%
53.4%
49.7%
46.1%
42.6%
39.2%
36.1%
33.1%
30.3%
27.7%
25.3%
23.1%
21 .0%
6
(survival %)
0
0
0
0
0
0
100.0%
97.1%
94.0%
90.7%
87.1%
83.4%
79.6%
75.7%
71 .7%
67.7%
63.7%
59.8%
55.9%
52.2%
48.6%
45.1%
41 .7%
38.6%
35.6%
32.8%
30.2%
27.8%
25.6%
23.5%
7
(survival %)
0
0
0
0
0
0
0
100.0%
96.9%
93.6%
90.0%
86.3%
82.5%
78.6%
74.6%
70.6%
66.6%
62.7%
58.8%
55.1%
51 .5%
48.0%
44.6%
41 .5%
38.5%
35.7%
33.1%
30.7%
28.5%
26.4%
8
(survival %)
0
0
0
0
0
0
0
0
100.0%
96.7%
93.1%
89.4%
85.6%
81 .7%
77.7%
73.7%
69.7%
65.8%
61 .9%
58.2%
54.6%
51.1%
47.7%
44.6%
41 .6%
38.8%
36.2%
33.8%
31 .6%
29.5%
9
(survival %)
0
0
0
0
0
0
0
0
0
100.0%
96.4%
92.7%
88.9%
85.0%
81 .0%
77.0%
73.0%
69.1%
65.2%
61 .5%
57.9%
54.4%
51 .0%
47.9%
44.9%
42.1%
39.5%
37.1%
34.9%
32.8%
10
(survival %)
0
0
0
0
0
0
0
0
0
0
100.0%
96.3%
92.5%
88.6%
84.6%
80.6%
76.6%
72.7%
68.8%
65.1%
61.5%
58.0%
54.6%
51.5%
48.5%
45.7%
43.1%
40.7%
38.5%
36.4%
11
(survival %)
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.2%
92.3%
88.3%
84.3%
80.3%
76.4%
72.5%
68.8%
65.2%
61.7%
58.3%
55.2%
52.2%
49.4%
46.8%
44.4%
42.2%
40.1%
12
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.1%
92.1%
88.1%
84.1%
80.2%
76.3%
72.6%
69.0%
65.5%
62.1%
59.0%
56.0%
53.2%
50.6%
48.2%
46.0%
43.9%
13
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.0%
92.0%
88.0%
84.1%
80.2%
76.5%
72.9%
69.4%
66.0%
62.9%
59.9%
57.1%
54.5%
52.1%
49.9%
47.8%
14
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.0%
92.0%
88.1%
84.2%
80.5%
76.9%
73.4%
70.0%
66.9%
63.9%
61.1%
58.5%
56.1%
53.9%
51.8%
15
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.0%
92.1%
88.2%
84.5%
80.9%
77.4%
74.0%
70.9%
67.9%
65.1%
62.5%
60.1%
57.9%
55.8%
16
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.1%
92.2%
88.5%
84.9%
81 .4%
78.0%
74.9%
71 .9%
69.1%
66.5%
64.1%
61 .9%
59.8%
17
(survival %)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
96.1%
92.4%
88.8%
85.3%
81 .9%
78.8%
75.8%
73.0%
70.4%
68.0%
65.8%
63.7%
22
-------
Table 9. Annual VMT for Class 6&7 Trucks Weighted by the Survival Fraction from the Age at Retrofit
VU&t Classes?
\*hde/^
1
£.
^
^
£
£
7
£
c
1C
11
12
c
V
E
ie
17
1£
«
Z
21
22
Z
2
Z
Z
27
Z
Z
3C
67
total irilesgE
45681
338/2
3342D
33ZJ1
27,45
24825
225EB
Z3443
18,529
13795
15222
13737
12535
11,335
1Q273
9312
§40
7,653
6,933
6,234
56BS
5163
4679
4241
3844
3454
3153
2862
2594
2352
Nw
276,638
43,681
33,872
33420
29,837
23543
ZJ516
2Q73I
13215
15935
13883
12041
1Q433
§954
7,674
6544
5533
4701
3933
3321
2778
2313
1,915
1,577
1,293
1,031
864
701
537
457
335
Ivsrdd
244237
0
33,872
33420
29,837
23543
23,516
20,751
13215
15935
13833
12041
10433
3954
7,674
3544
5533
4701
3933
3321
2778
2313
1,915
1,577
1,293
1,031
864
701
537
457
335
2vsrdd
214743
0
0
33433
23837
23549
23516
2Q751
13215
15935
13839
12041
1Q433
3954
7,674
3544
5553
4,701
3933
3321
2778
2313
1,915
1,577
126
1,031
864
701
537
457
335
Svsrdd
191,325
0
0
0
33291
23931
23833
21,039
13521
13213
14141
12Z8
1Q610
9,141
7,844
3693
5633
4,828
4,077
3425
2872
2333
1,933
1,647
1,331
1,119
916
743
610
435
433
4veerdd
17Q627
0
0
0
0
27,455
24333
21,435
13833
13543
14444
12543
1Q853
9333
3048
3833
5837
4930
4215
3550
2935
2531
2036
1,731
1,433
1,188
979
805
631
542
442
Svsrdd
152538
0
0
0
0
0
24,835
21,931
19,333
13954
14,813
12378
11,162
9641
8237
7,103
3071
5165
4333
3702
3123
2623
2193
1,834
1,531
1,272
1,053
875
724
533
434
ia501-3aOOOIb3)WITT£tie
Svsrdd
133,573
0
0
0
0
0
0
22555
19,833
17,417
15233
13253
11,537
9954
8531
7,333
33X
5376
45/5
3876
3ZO
2763
2323
1,951
1,637
1,333
1,143
954
793
634
553
7vsrdd
122633
0
0
0
0
0
0
0
23,443
17,955
15733
13703
11,937
1Q317
8933
7,634
3574
5621
4797
4077
3432
2933
2478
2037
1,783
1,430
1,244
1,045
879
733
621
Svsrdd
11Q238
0
0
0
0
0
0
0
0
18523
16241
14,172
12335
1Q704
9,231
7,932
3833
5833
5034
4,232
3657
3110
2633
2232
1,831
1,533
1,332
1,143
937
833
634
9veerdd
93224
0
0
0
0
0
0
0
0
0
13795
14674
12733
11,117
9,635
8321
7,170
3161
5233
4,533
3885
3233
2803
2383
2031
1,723
1,437
1247
1,062
935
771
10vsrdc
83,435
0
0
0
0
0
0
0
0
0
0
15222
13237
11,537
1Q043
8631
7,535
34=5
5522
47/0
4091
3533
2935
2555
2184
1,864
1,532
1,331
1,165
933
853
Hveerdd
SQ723
0
0
0
0
0
0
0
0
0
0
0
13797
12033
10432
9071
7,850
3777
586
5023
4323
3714
3183
2723
2341
2037
1,721
1,478
1,271
1,035
943
12vsrdd
72,807
0
0
0
0
0
0
0
0
0
0
0
0
12535
1Q833
9431
8204
7,093
3135
5233
4532
3933
3382
2903
2502
2153
1,853
1,593
1,379
1,193
1,033
13vsrdd
65635
0
0
0
0
0
0
0
0
0
0
0
0
0
11,335
9832
8537
7,427
3434
5530
4807
4152
3533
3038
2633
2333
1,939
1,721
1,431
1,234
1,124
14vsrdc
53,181
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1Q273
8940
7,735
3743
5838
5053
4,330
3793
3275
2837
2453
2123
1,8(7
1,633
1,333
1218
15vsrdd
53257
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
9312
8102
7,043
3115
5310
4633
3933
3432
3037
2610
2Z8
1,974
1,723
1,532
1,312
ISvsrdd
47,818
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8440
7,332
3332
5531
4,833
4203
3650
3177
2734
2437
2100
1,835
1,633
1,433
17veerdd
42,768
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7,633
3633
5803
5053
44X
3832
3342
2914
2543
2223
1,943
1,707
1,433
23
-------
Table 10. Annual VMT for School Buses weighted by the Survival Fraction from the Age at Retrofit
School Bus VMT Table
Vehicle Age
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
School Bus
[VMT
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
13,248
New
176,671
13,248
13,248
13,248
13,049
12,811
12,519
12,188
11,804
11,393
10,956
10,479
9,989
9,486
8,969
8,439
7,909
7,379
6,862
6,346
5,856
5,379
4,915
4,465
4,054
3,656
3,286
2,941
2,623
2,332
2,053
1 year old
168,723
0
13,248
13,248
13,049
12,811
12,519
12,188
1 1 ,804
11,393
10,956
10,479
9,989
9,486
8,969
8,439
7,909
7,379
6,862
6,346
5,856
5,379
4,915
4,465
4,054
3,656
3,286
2,941
2,623
2,332
2,053
2 year old
160,537
0
0
13,248
13,049
12,811
12,519
12,188
1 1 ,804
11,393
10,956
10,479
9,989
9,486
8,969
8,439
7,909
7,379
6,862
6,346
5,856
5,379
4,915
4,465
4,054
3,656
3,286
2,941
2,623
2,332
2,053
3 year old
155,747
0
0
0
13,248
13,010
12,718
12,387
12,003
11,592
11,155
10,678
10,188
9,684
9,168
8,638
8,108
7,578
7,061
6,545
6,054
5,577
5,114
4,663
4,253
3,855
3,484
3,140
2,822
2,530
2,252
4 year old
151,435
0
0
0
0
13,248
12,957
12,625
12,241
11,830
11,393
10,916
10,426
9,923
9,406
8,876
8,346
7,816
7,300
6,783
6,293
5,816
5,352
4,902
4,491
4,094
3,723
3,378
3,060
2,769
2,491
5 year old
147,805
0
0
0
0
0
13,248
12,917
12,533
12,122
11,685
11,208
10,718
10,214
9,698
9,168
8,638
8,108
7,591
7,074
6,584
6,107
5,644
5,193
4,783
4,385
4,014
3,670
3,352
3,060
2,782
6 year old
144,600
0
0
0
0
0
0
13,248
12,864
12,453
12,016
11,539
11,049
10,545
10,029
9,499
8,969
8,439
7,922
7,406
6,915
6,439
5,975
5,524
5,114
4,716
4,345
4,001
3,683
3,391
3,113
7 year old
142,007
0
0
0
0
0
0
0
13,248
12,837
12,400
11,923
11,433
10,930
10,413
9,883
9,353
8,823
8,306
7,790
7,300
6,823
6,359
5,909
5,498
5,100
4,730
4,385
4,067
3,776
3,497
8 year old
139,565
0
0
0
0
0
0
0
0
13,248
12,811
12,334
11,844
11,340
10,824
10,294
9,764
9,234
8,717
8,201
7,710
7,233
6,770
6,319
5,909
5,511
5,140
4,796
4,478
4,186
3,908
9 year old
137,243
0
0
0
0
0
0
0
0
0
13,248
12,771
12,281
11,777
11,261
10,731
10,201
9,671
9,154
8,638
8,148
7,671
7,207
6,756
6,346
5,948
5,577
5,233
4,915
4,624
4,345
1 0 year old
135,208
0
0
0
0
0
0
0
0
0
0
13,248
12,758
12,254
11,738
11,208
10,678
10,148
9,631
9,115
8,624
8,148
7,684
7,233
6,823
6,425
6,054
5,710
5,392
5,100
4,822
1 1 year old
133,037
0
0
0
0
0
0
0
0
0
0
0
13,248
12,745
12,228
11,698
11,168
10,638
10,121
9,605
9,115
8,638
8,174
7,724
7,313
6,915
6,545
6,200
5,882
5,591
5,312
12 year old
130,704
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,731
12,201
11,671
11,142
10,625
10,108
9,618
9,141
8,677
8,227
7,816
7,419
7,048
6,703
6,386
6,094
5,816
13 year old
128,180
0
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,718
12,188
11,658
11,142
10,625
10,135
9,658
9,194
8,744
8,333
7,936
7,565
7,220
6,902
6,611
6,333
14 year old
125,433
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,718
12,188
11,671
11,155
10,665
10,188
9,724
9,274
8,863
8,465
8,095
7,750
7,432
7,141
6,862
15 year old
122,275
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,718
12,201
11,685
11,195
10,718
10,254
9,804
9,393
8,995
8,624
8,280
7,962
7,671
7,392
16 year old
118,681
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,731
12,215
1 1 ,724
11,248
10,784
10,333
9,923
9,525
9,154
8,810
8,492
8,201
7,922
17 year old
114,488
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13,248
12,731
12,241
11,764
11,301
10,850
10,439
10,042
9,671
9,327
9,009
8,717
8,439
24
-------
Table 11. Annual VMT for Class 8b Trucks weighted by the Survival Fraction from the Age at Retrofit
Weight ClassSB (>60,000 Ibs) VMT Table
Vehicle Age
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
8b
total mileage
124,208
112,590
102,060
92,514
83,861
76,017
68,907
62,462
56,620
51,324
46,523
42,172
38,228
34,652
31,411
28,473
25,810
23,396
21,208
19,224
17,426
15,796
14,319
12,979
1 1 ,765
10,665
9,667
8,763
7,944
7,201
New
845,176
124,208
112,590
102,060
91,126
81,094
71,836
63,394
55,654
48,693
42,445
36,800
31,798
27,371
23,459
20,009
16,998
14,376
12,119
10,159
8,497
7,075
5,860
4,826
3,972
3,247
2,645
2,146
1,735
1,398
1,116
1 year old
746,324
0
112,590
102,060
91,126
81,094
71,836
63,394
55,654
48,693
42,445
36,800
31,798
27,371
23,459
20,009
16,998
14,376
12,119
10,159
8,497
7,075
5,860
4,826
3,972
3,247
2,645
2,146
1,735
1,398
1,116
2 year old
656,123
0
0
102,060
91,126
81,094
71,836
63,394
55,654
48,693
42,445
36,800
31,798
27,371
23,459
20,009
16,998
14,376
12,119
10,159
8,497
7,075
5,860
4,826
3,972
3,247
2,645
2,146
1,735
1,398
1,116
3 year old
584,624
0
0
0
92,514
82,352
72,976
64,428
56,591
49,543
43,215
37,498
32,430
27,945
23,979
20,480
17,425
14,763
12,470
10,477
8,785
7,336
6,097
5,040
4,166
3,424
2,805
2,291
1,867
1,517
1,224
4 year old
521,427
0
0
0
0
83,861
74,345
65,668
57,715
50,562
44,139
38,335
33,189
28,633
24,603
21,045
17,938
15,228
12,891
10,858
9,131
7,650
6,382
5,298
4,400
3,635
2,997
2,465
2,024
1,660
1,354
5 year old
466,192
0
0
0
0
0
76,017
67,184
59,089
51,807
45,268
39,358
34,117
29,474
25,365
21,736
18,564
15,796
13,406
1 1 ,325
9,554
8,033
6,729
5,613
4,685
3,894
3,231
2,678
2,217
1,835
1,512
6 year old
417,456
0
0
0
0
0
0
68,907
60,651
53,223
46,551
40,522
35,171
30,429
26,232
22,522
19,276
16,441
13,991
1 1 ,855
10,035
8,469
7,124
5,971
5,010
4,188
3,498
2,919
2,436
2,034
1,692
7 year old
374,959
0
0
0
0
0
0
0
62,462
54,865
48,039
41,871
36,394
31,538
27,236
23,433
20,102
17,189
14,669
12,470
10,592
8,974
7,582
6,386
5,386
4,530
3,807
3,200
2,690
2,264
1,901
8 year old
337,100
0
0
0
0
0
0
0
0
56,620
49,630
43,313
37,702
32,723
28,311
24,406
20,985
17,990
15,395
13,128
11,188
9,515
8,072
6,830
5,789
4,894
4,138
3,499
2,962
2,510
2,124
9 year old
303,366
0
0
0
0
0
0
0
0
0
51,324
44,848
39,093
33,985
29,454
25,443
21,924
18,841
16,167
13,828
11,823
10,090
8,593
7,303
6,217
5,282
4,490
3,818
3,251
2,772
2,362
10 year old
273,648
0
0
0
0
0
0
0
0
0
0
46,523
40,612
35,361
30,702
26,574
22,949
19,770
17,009
14,591
12,515
10,717
9,162
7,818
6,684
5,706
4,874
4,166
3,567
3,058
2,621
1 1 year old
246,851
0
0
0
0
0
0
0
0
0
0
0
42,172
36,775
31,984
27,736
24,003
20,725
17,875
15,376
13,226
1 1 ,362
9,746
8,348
7,164
6,141
5,269
4,524
3,891
3,352
2,888
1 2 year old
222,664
0
0
0
0
0
0
0
0
0
0
0
0
38,228
33,301
28,930
25,085
21,706
18,764
16,182
13,957
12,024
10,346
8,892
7,658
6,588
5,674
4,892
4,224
3,654
3,161
13 year old
200,809
0
0
0
0
0
0
0
0
0
0
0
0
0
34,652
30,155
26,195
22,713
19,676
17,009
14,706
12,704
10,962
9,451
8,164
7,047
6,090
5,269
4,566
3,964
3,442
14 year old
181,036
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31,411
27,334
23,745
20,612
17,857
15,475
13,401
11,594
10,023
8,683
7,518
6,516
5,655
4,916
4,282
3,730
15 year old
162,919
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
28,473
24,778
21,548
18,705
16,244
14,098
12,226
10,596
9,202
7,988
6,943
6,042
5,267
4,600
4,018
16 year old
146,293
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
25,810
22,484
19,554
17,013
14,795
12,858
11,169
9,721
8,459
7,370
6,429
5,617
4,917
4,306
17 year old
130,855
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
23,396
20,381
17,763
15,474
13,474
11,727
10,227
8,918
7,785
6,806
5,959
5,227
4,587
25
-------
Table 12. Class 6&7 Truck DOC Cost per Ton Estimates
Class 6&7 Estimates (2007 Calendar Year Retrofits)
Class 6&7 DOC Cost $540
Class 6&7 DOC Efficiency 20%
Model Year 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
Mobile 6 Emission Rate [g/mile] 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.261 0.264 0.265 0.267 0.516 0.517 0.518 0.775
Adjusted Rate 2.3 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.601 0.606 0.611 0.614 1.187 1.190 1.192 1.783
DOC Cost Effectless $27,600 $31,400 $35,200 $39,500 $44,200 $49,300 $54,900 $61,100 $67,900 $45,600 $50,100 $55,100 $60,800 $34,900 $38,700 $43,000 $32,100
Weight Class 6&7 (19,501-33,000 Ibs
Year
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
6-7
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
1 year old
0.020
0.0030
0.0027
0.0024
0.0021
0.0019
0.0017
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
0.0000
0.0000
scrapped
2 year old
0.017
0.0027
0.0024
0.0021
0.0019
0.0017
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
0.0000
0.0000
scrapped
3 year old
0.015
0.0024
0.0022
0.0019
0.0017
0.0015
0.0013
0.0011
0.0010
0.0009
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
0.0000
0.0000
scrapped
4 year old
0.014
0.0022
0.0020
0.0017
0.0015
0.0013
0.0012
0.0010
0.0009
0.0008
0.0006
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
0.0000
scrapped
5 year old
0.012
0.0020
0.0018
0.0015
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
0.0000
6 year old
0.011
0.0018
0.0016
0.0014
0.0012
0.0011
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
scrapped
scrapped
Annual PM Reductions DOC
7 year old
0.010
0.0016
0.0014
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0000
scrapped
8 year old
0.009
0.0015
0.0013
0.0011
0.0010
0.0009
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
9 year old
0.008
0.0013
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
scrapped
scrapped
10 year old
0.012
0.0020
0.0018
0.0015
0.0013
0.0011
0.0010
0.0009
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
0.0001
0.0001
tons reduction
1 1 year olc
0.011
0.0018
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0001
0.0001
scrapped
scrapped
12 year olc
0.010
0.0017
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
0.0001
scrapped
13 year olc
0.009
0.0015
0.0013
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
scrapped
14 year olc
0.015
0.0027
0.0023
0.0020
0.0018
0.0015
0.0013
0.0011
0.0010
0.0009
0.0007
0.0006
0.0006
0.0005
0.0004
0.0004
0.0003
scrapped
15 year old
0.014
0.0024
0.0021
0.0018
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
16 year olc
0.013
0.0022
0.0019
0.0017
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0006
0.0005
0.0004
0.0004
scrapped
scrapped
17 year old
0.017
0.0030
0.0026
0.0023
0.0020
0.0017
0.0015
0.0013
0.0011
0.0010
0.0009
0.0008
0.0007
0.0006
scrapped
26
-------
Table 13. Class 6&7 Truck CDPF Cost per Ton Estimates
Class 6&7 Estimates (2007 Calendar Year Retrofits)
Class 68,7 CDPF Cost $2,500
Class 68,7 CDPF Efficiency 90%
Model Year 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
Mobile 6 Emission Rate [g/mile] 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.261 0.264 0.265 0.267 0.516 0.517 0.518 0.775
Adjusted Rate 2.3 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.601 0.606 0.611 0.614 1.187 1.190 1.192 1.783
DOC Cost Effectless $28,400 $32,300 $36,200 $40,600 $45,500 $50,800 $56,500 $62,900 $69,900 $46,900 $51,600 $56,700 $62,500 $35,900 $39,800 $44,300 $33,100
Weig
Year
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
6-7
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
-
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
-
1 year old
0.088
0.0133
0.0121
0.0108
0.0096
0.0085
0.0075
0.0066
0.0057
0.0050
0.0043
0.0038
0.0032
0.0028
0.0024
0.0020
0.0017
0.0014
0.0012
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
scrapped
2 year old
0.077
0.0121
0.0108
0.0096
0.0085
0.0075
0.0066
0.0057
0.0050
0.0043
0.0038
0.0032
0.0028
0.0024
0.0020
0.0017
0.0014
0.0012
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
scrapped
ht Class 6&7 (19,501-33,000 Ibs) Annual PM Reductions CDPF (tons reduction)
3 year old
0.069
0.0109
0.0097
0.0086
0.0076
0.0067
0.0058
0.0051
0.0044
0.0038
0.0033
0.0028
0.0024
0.0021
0.0017
0.0015
0.0012
0.0010
0.0009
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
scrapped
4 year old
0.062
0.0099
0.0088
0.0078
0.0068
0.0060
0.0052
0.0045
0.0039
0.0034
0.0029
0.0025
0.0021
0.0018
0.0015
0.0013
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0004
0.0003
0.0002
0.0002
0.0002
scrapped
5 year old
0.055
0.0090
0.0079
0.0070
0.0061
0.0053
0.0046
0.0040
0.0035
0.0030
0.0026
0.0022
0.0019
0.0016
0.0013
0.0011
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
scrapped
6 year old
0.049
0.0081
0.0072
0.0063
0.0055
0.0048
0.0041
0.0036
0.0031
0.0027
0.0023
0.0019
0.0016
0.0014
0.0012
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
scrapped
7 year old
0.044
0.0074
0.0065
0.0057
0.0049
0.0043
0.0037
0.0032
0.0028
0.0024
0.0020
0.0017
0.0015
0.0012
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
scrapped
8 year old
0.040
0.0067
0.0059
0.0051
0.0044
0.0039
0.0033
0.0029
0.0025
0.0021
0.0018
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0003
scrapped
9 year old
0.036
0.0061
0.0053
0.0046
0.0040
0.0035
0.0030
0.0026
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0009
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
scrapped
10 year ok
0.053
0.0091
0.0079
0.0069
0.0060
0.0052
0.0045
0.0038
0.0033
0.0028
0.0024
0.0021
0.0018
0.0015
0.0013
0.0011
0.0009
0.0008
0.0007
0.0006
0.0005
scrapped
1 1 year ok
0.048
0.0083
0.0072
0.0063
0.0054
0.0047
0.0041
0.0035
0.0030
0.0026
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
scrapped
1 2 year ok
0.044
0.0076
0.0066
0.0057
0.0050
0.0043
0.0037
0.0032
0.0028
0.0024
0.0020
0.0018
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
scrapped
1 3 year ok
0.040
0.0069
0.0060
0.0052
0.0045
0.0039
0.0034
0.0029
0.0025
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
scrapped
14 year ok
0.070
0.0121
0.0105
0.0091
0.0079
0.0069
0.0060
0.0052
0.0045
0.0039
0.0033
0.0029
0.0025
0.0022
0.0019
0.0016
0.0014
scrapped
1 5 year ok
0.063
0.0110
0.0096
0.0083
0.0072
0.0063
0.0054
0.0047
0.0041
0.0035
0.0031
0.0027
0.0023
0.0020
0.0018
0.0015
scrapped
1 6 year olc
0.056
0.0100
0.0087
0.0076
0.0066
0.0057
0.0050
0.0043
0.0038
0.0033
0.0028
0.0025
0.0022
0.0019
0.0017
scrapped
1 7 year old
0.076
0.0135
0.0118
0.0103
0.0089
0.0078
0.0068
0.0059
0.0051
0.0045
0.0039
0.0034
0.0030
0.0026
scrapped
27
-------
Table 14. School Bus DOC Cost per Ton Estimates
School Bus Estimates (2007 Calendar Year Retrofits)
School Bus DOC Cost
School Bus DOC Efficiency
$540
20%
Model Year 2007
Mobile 6 Emission Rate kj/mile]
Adjusted Rate 2.3
DOC Cost Effectiveness
2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.261 0.264 0.265 0.267 0.516 0.517 0.518 0.775
0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.601 0.606 0.611 0.614 1.187 1.190 1.192 1.783
$39,900 $42,000 $43,300 $44,500 $45,600 $46,600 $47,500 $48,300 $49,100 $30,200 $30,400 $30,700 $31,100 $16,500 $16,900 $17,300 $12,000
School Bus Annual PM Reductions DOC (tons reduction)
Calendar Yr
(age)
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
School Bus
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
1 year old
0.014
0.0011
0.0011
0.0010
0.0010
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
scrapped
2 year old
0.013
0.0011
0.0010
0.0010
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0002
0.0002
0.0002
0.0002
scrapped
3 year old
0.012
0.0011
0.0010
0.0010
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0006
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0003
0.0002
0.0002
0.0002
scrapped
4 year old
0.012
0.0011
0.0010
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0002
0.0002
0.0002
scrapped
5 year old
0.012
0.0011
0.0010
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0002
0.0002
scrapped
6 year old
0.012
0.0011
0.0010
0.0010
0.0010
0.0009
0.0009
0.0008
0.0008
0.0008
0.0007
0.0007
0.0006
0.0006
0.0006
0.0005
0.0005
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
0.0003
0.0002
scrapped
7 year old
0.011
0.0011
0.0010
0.0010
0.0010
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0004
0.0003
0.0003
0.0003
scrapped
8 year old
0.011
0.0011
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0004
0.0003
0.0003
scrapped
9 year old
0.011
0.0011
0.0010
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
0.0007
0.0006
0.0006
0.0005
0.0005
0.0005
0.0004
0.0004
0.0004
0.0004
0.0003
scrapped
10 year ok
0.018
0.0018
0.0017
0.0016
0.0016
0.0015
0.0014
0.0013
0.0013
0.0012
0.0011
0.0011
0.0010
0.0010
0.0009
0.0008
0.0008
0.0008
0.0007
0.0007
0.0006
scrapped
1 1 year ok
0.018
0.0018
0.0017
0.0016
0.0016
0.0015
0.0014
0.0014
0.0013
0.0012
0.0012
0.0011
0.0010
0.0010
0.0009
0.0009
0.0008
0.0008
0.0007
0.0007
scrapped
1 2 year ok
0.018
0.0018
0.0017
0.0016
0.0016
0.0015
0.0014
0.0014
0.0013
0.0012
0.0012
0.0011
0.0011
0.0010
0.0009
0.0009
0.0009
0.0008
0.0008
scrapped
1 3 year ok
0.017
0.0018
0.0017
0.0016
0.0016
0.0015
0.0014
0.0014
0.0013
0.0012
0.0012
0.0011
0.0011
0.0010
0.0010
0.0009
0.0009
0.0009
scrapped
1 4 year ok
0.033
0.0035
0.0033
0.0032
0.0031
0.0029
0.0028
0.0027
0.0025
0.0024
0.0023
0.0022
0.0021
0.0020
0.0019
0.0019
0.0018
scrapped
1 5 year ok
0.032
0.0035
0.0033
0.0032
0.0031
0.0029
0.0028
0.0027
0.0026
0.0025
0.0024
0.0023
0.0022
0.0021
0.0020
0.0019
scrapped
1 6 year ok
0.031
0.0035
0.0033
0.0032
0.0031
0.0030
0.0028
0.0027
0.0026
0.0025
0.0024
0.0023
0.0022
0.0022
0.0021
scrapped
1 7 year old
0.045
0.0052
0.0050
0.0048
0.0046
0.0044
0.0043
0.0041
0.0039
0.0038
0.0037
0.0035
0.0034
0.0033
scrapped
28
-------
Table 15. School Bus CDPF Cost per Ton Estimates
School Bus Estimates (2007 Calendar Year Retrofits)
School Bus CDPF Cost $2,500
School Bus CDPF Efficiency 90%
Model Year 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
Mobile 6 Emission Rate [g/mile] 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.158 0.261 0.264 0.265 0.267 0.516 0.517 0.518 0.775
Adjusted Rate 2.3 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.364 0.601 0.606 0.611 0.614 1.187 1.190 1.192 1.783
DOCCost Effectiveness $41,100 $43,200 $44,500 $45,800 $46,900 $47,900 $48,800 $49,700 $50,500 $31,100 $31,300 $31,600 $32,000 $16,900 $17,300 $17,800 $12,400
School Bus Annual PM Reductions CDPFs (tons reduction)
Vehicle Ag
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
School Bus
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
-
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
-
1 year old
0.061
0.0048
0.0048
0.0047
0.0046
0.0045
0.0044
0.0043
0.0041
0.0040
0.0038
0.0036
0.0034
0.0032
0.0030
0.0029
0.0027
0.0025
0.0023
0.0021
0.0019
0.0018
0.0016
0.0015
0.0013
0.0012
0.0011
0.0009
0.0008
0.0007
scrapped
2 year old
0.058
0.0048
0.0047
0.0046
0.0045
0.0044
0.0043
0.0041
0.0040
0.0038
0.0036
0.0034
0.0032
0.0030
0.0029
0.0027
0.0025
0.0023
0.0021
0.0019
0.0018
0.0016
0.0015
0.0013
0.0012
0.0011
0.0009
0.0008
0.0007
scrapped
3 year old
0.056
0.0048
0.0047
0.0046
0.0045
0.0043
0.0042
0.0040
0.0039
0.0037
0.0035
0.0033
0.0031
0.0029
0.0027
0.0025
0.0024
0.0022
0.0020
0.0018
0.0017
0.0015
0.0014
0.0013
0.0011
0.0010
0.0009
0.0008
scrapped
4 year old
0.055
0.0048
0.0047
0.0046
0.0044
0.0043
0.0041
0.0039
0.0038
0.0036
0.0034
0.0032
0.0030
0.0028
0.0026
0.0024
0.0023
0.0021
0.0019
0.0018
0.0016
0.0015
0.0013
0.0012
0.0011
0.0010
0.0009
scrapped
5 year old
0.053
0.0048
0.0047
0.0045
0.0044
0.0042
0.0040
0.0039
0.0037
0.0035
0.0033
0.0031
0.0029
0.0027
0.0026
0.0024
0.0022
0.0020
0.0019
0.0017
0.0016
0.0014
0.0013
0.0012
0.0011
0.0010
scrapped
6 year old
0.052
0.0048
0.0046
0.0045
0.0043
0.0042
0.0040
0.0038
0.0036
0.0034
0.0032
0.0030
0.0029
0.0027
0.0025
0.0023
0.0022
0.0020
0.0018
0.0017
0.0016
0.0014
0.0013
0.0012
0.0011
scrapped
7 year old
0.051
0.0048
0.0046
0.0045
0.0043
0.0041
0.0039
0.0038
0.0036
0.0034
0.0032
0.0030
0.0028
0.0026
0.0025
0.0023
0.0021
0.0020
0.0018
0.0017
0.0016
0.0015
0.0014
0.0013
scrapped
8 year old
0.050
0.0048
0.0046
0.0044
0.0043
0.0041
0.0039
0.0037
0.0035
0.0033
0.0031
0.0030
0.0028
0.0026
0.0024
0.0023
0.0021
0.0020
0.0019
0.0017
0.0016
0.0015
0.0014
scrapped
9 year old
0.049
0.0048
0.0046
0.0044
0.0042
0.0041
0.0039
0.0037
0.0035
0.0033
0.0031
0.0029
0.0028
0.0026
0.0024
0.0023
0.0021
0.0020
0.0019
0.0018
0.0017
0.0016
scrapped
10 year ok
0.080
0.0079
0.0076
0.0073
0.0070
0.0067
0.0064
0.0060
0.0057
0.0054
0.0051
0.0049
0.0046
0.0043
0.0041
0.0038
0.0036
0.0034
0.0032
0.0030
0.0029
scrapped
1 1 year ok
0.080
0.0080
0.0077
0.0073
0.0070
0.0067
0.0064
0.0061
0.0058
0.0055
0.0052
0.0049
0.0046
0.0044
0.0042
0.0039
0.0037
0.0035
0.0034
0.0032
scrapped
1 2 year ok
0.079
0.0080
0.0077
0.0074
0.0071
0.0067
0.0064
0.0061
0.0058
0.0055
0.0053
0.0050
0.0047
0.0045
0.0043
0.0041
0.0039
0.0037
0.0035
scrapped
1 3 year ok
0.078
0.0081
0.0077
0.0074
0.0071
0.0068
0.0065
0.0062
0.0059
0.0056
0.0053
0.0051
0.0048
0.0046
0.0044
0.0042
0.0040
0.0039
scrapped
14 year ok
0.148
0.0156
0.0150
0.0143
0.0137
0.0131
0.0125
0.0120
0.0114
0.0109
0.0104
0.0100
0.0095
0.0091
0.0087
0.0084
0.0081
scrapped
1 5 year ok
0.144
0.0156
0.0150
0.0144
0.0138
0.0132
0.0126
0.0121
0.0116
0.0111
0.0106
0.0102
0.0098
0.0094
0.0090
0.0087
scrapped
1 6 year olc
0.140
0.0157
0.0150
0.0144
0.0139
0.0133
0.0127
0.0122
0.0117
0.0113
0.0108
0.0104
0.0100
0.0097
0.0094
scrapped
1 7 year old
0.202
0.0234
0.0225
0.0216
0.0208
0.0200
0.0192
0.0185
0.0177
0.0171
0.0165
0.0159
0.0154
0.0149
scrapped
29
-------
Table 16. Class 8b Truck DOC Cost per Ton Estimates
Class 8b Estimates (2007 Calendar Year Retrofits)
Class 8b DOC Cost $880
Class 8b DOC Efficiency 20%
Model Year 2007
Mobile 6 Emission Rate [g/mile]
Adjusted Rate 2.3
DOC Cost Effectless
2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.211 0.213 0.579 0.584 0.589 1.084
0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.486 0.489 1.332 1.343 1.356 2.494
$11,100 $12,600 $14,200 $15,900 $17,800 $19,900 $22,100 $24,600 $27,300 $30,300 $33,600 $37,000 $40,600 $16,600 $18,300 $20,100 $12,200
Weight Class 8b (>60,000 Ibs) Annual PM Reductions DOC (tons reduction)
Year
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
8b
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
1 year old
0.079
0.0119
0.0108
0.0097
0.0086
0.0076
0.0067
0.0059
0.0052
0.0045
0.0039
0.0034
0.0029
0.0025
0.0021
0.0018
0.0015
0.0013
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
0.0001
scrapped
2 year old
0.070
0.0108
0.0097
0.0086
0.0076
0.0067
0.0059
0.0052
0.0045
0.0039
0.0034
0.0029
0.0025
0.0021
0.0018
0.0015
0.0013
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
0.0001
scrapped
3 year old
0.062
0.0098
0.0087
0.0077
0.0068
0.0060
0.0053
0.0046
0.0040
0.0034
0.0030
0.0025
0.0022
0.0018
0.0016
0.0013
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0004
0.0003
0.0002
0.0002
0.0002
0.0001
scrapped
4 year old
0.055
0.0089
0.0079
0.0070
0.0061
0.0054
0.0047
0.0041
0.0035
0.0030
0.0026
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0001
scrapped
5 year old
0.049
0.0081
0.0071
0.0063
0.0055
0.0048
0.0042
0.0036
0.0031
0.0027
0.0023
0.0020
0.0017
0.0014
0.0012
0.0010
0.0009
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
0.0002
scrapped
6 year old
0.044
0.0073
0.0064
0.0056
0.0049
0.0043
0.0037
0.0032
0.0028
0.0024
0.0020
0.0017
0.0015
0.0013
0.0011
0.0009
0.0008
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
0.0002
scrapped
7 year old
0.040
0.0066
0.0058
0.0051
0.0044
0.0039
0.0033
0.0029
0.0025
0.0021
0.0018
0.0016
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0002
0.0002
scrapped
8 year old
0.036
0.0060
0.0053
0.0046
0.0040
0.0035
0.0030
0.0026
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0009
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
0.0002
scrapped
9 year old
0.032
0.0054
0.0048
0.0041
0.0036
0.0031
0.0027
0.0023
0.0020
0.0017
0.0015
0.0013
0.0011
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
0.0003
0.0003
scrapped
1 0 year olc
0.029
0.0049
0.0043
0.0038
0.0033
0.0028
0.0024
0.0021
0.0018
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
0.0003
scrapped
1 1 year olc
0.026
0.0045
0.0039
0.0034
0.0029
0.0025
0.0022
0.0019
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
0.0003
scrapped
1 2 year olc
0.024
0.0041
0.0036
0.0031
0.0027
0.0023
0.0020
0.0017
0.0015
0.0013
0.0011
0.0010
0.0008
0.0007
0.0006
0.0005
0.0005
0.0004
0.0003
scrapped
1 3 year olc
0.022
0.0037
0.0033
0.0028
0.0024
0.0021
0.0018
0.0016
0.0014
0.0012
0.0010
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0004
scrapped
1 4 year olc
0.053
0.0092
0.0080
0.0070
0.0060
0.0052
0.0045
0.0039
0.0034
0.0029
0.0025
0.0022
0.0019
0.0017
0.0014
0.0013
0.0011
scrapped
1 5 year olc
0.048
0.0084
0.0073
0.0064
0.0055
0.0048
0.0042
0.0036
0.0031
0.0027
0.0024
0.0021
0.0018
0.0016
0.0014
0.0012
scrapped
1 6 year olc
0.044
0.0077
0.0067
0.0058
0.0051
0.0044
0.0038
0.0033
0.0029
0.0025
0.0022
0.0019
0.0017
0.0015
0.0013
scrapped
17 year old
0.072
0.0129
0.0112
0.0098
0.0085
0.0074
0.0064
0.0056
0.0049
0.0043
0.0037
0.0033
0.0029
0.0025
scrapped
30
-------
Table 17. Class 8b Truck CDPF Cost per Ton Estimates
Class 8b Estimates (2007 Calendar Year Retrofits)
Class 8b CDPF Cost $4,300
Class 8b CDPF Efficiency 90%
Model Year 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990
Mobile 6 Emission Rate [g/mile] 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.209 0.211 0.213 0.579 0.584 0.589 1.084
Adjusted Rate [g/mile] 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.482 0.486 0.489 1.332 1.343 1.356 2.494
DOC Cost Effectivness [$/ton] $12,100 $13,700 $15,400 $17,300 $19,300 $21,600 $24,000 $26,700 $29,700 $32,900 $36,500 $40,100 $44,100 $18,000 $19,800 $21,900 $13,300
Weight Class 8b (>60,000 Ibs) Annual PM Reductions CDPF (tons reduction)
Year
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
6-7
Lifetime Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
Annual Tons
-
New
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
-
1 year old
0.356
0.0538
0.0487
0.0435
0.0387
0.0343
0.0303
0.0266
0.0232
0.0203
0.0176
0.0152
0.0131
0.0112
0.0096
0.0081
0.0069
0.0058
0.0048
0.0041
0.0034
0.0028
0.0023
0.0019
0.0016
0.0013
0.0010
0.0008
0.0007
0.0005
scrapped
2 year old
0.313
0.0487
0.0435
0.0387
0.0343
0.0303
0.0266
0.0232
0.0203
0.0176
0.0152
0.0131
0.0112
0.0096
0.0081
0.0069
0.0058
0.0048
0.0041
0.0034
0.0028
0.0023
0.0019
0.0016
0.0013
0.0010
0.0008
0.0007
0.0005
scrapped
3 year old
0.279
0.0442
0.0393
0.0348
0.0308
0.0270
0.0237
0.0206
0.0179
0.0155
0.0133
0.0114
0.0098
0.0083
0.0070
0.0060
0.0050
0.0042
0.0035
0.0029
0.0024
0.0020
0.0016
0.0013
0.0011
0.0009
0.0007
0.0006
scrapped
4 year old
0.249
0.0400
0.0355
0.0314
0.0276
0.0241
0.0211
0.0183
0.0158
0.0137
0.0117
0.0100
0.0086
0.0073
0.0062
0.0052
0.0044
0.0037
0.0030
0.0025
0.0021
0.0017
0.0014
0.0012
0.0010
0.0008
0.0006
scrapped
5 year old
0.223
0.0363
0.0321
0.0282
0.0247
0.0216
0.0188
0.0163
0.0141
0.0121
0.0104
0.0089
0.0075
0.0064
0.0054
0.0046
0.0038
0.0032
0.0027
0.0022
0.0019
0.0015
0.0013
0.0011
0.0009
0.0007
scrapped
6 year old
0.199
0.0329
0.0290
0.0254
0.0222
0.0193
0.0168
0.0145
0.0125
0.0108
0.0092
0.0078
0.0067
0.0057
0.0048
0.0040
0.0034
0.0029
0.0024
0.0020
0.0017
0.0014
0.0012
0.0010
0.0008
scrapped
7 year old
0.179
0.0298
0.0262
0.0229
0.0200
0.0174
0.0151
0.0130
0.0112
0.0096
0.0082
0.0070
0.0060
0.0051
0.0043
0.0036
0.0030
0.0026
0.0022
0.0018
0.0015
0.0013
0.0011
0.0009
scrapped
8 year old
0.161
0.0270
0.0237
0.0207
0.0180
0.0156
0.0135
0.0117
0.0100
0.0086
0.0073
0.0063
0.0053
0.0045
0.0039
0.0033
0.0028
0.0023
0.0020
0.0017
0.0014
0.0012
0.0010
scrapped
9 year old
0.145
0.0245
0.0214
0.0187
0.0162
0.0141
0.0121
0.0105
0.0090
0.0077
0.0066
0.0056
0.0048
0.0041
0.0035
0.0030
0.0025
0.0021
0.0018
0.0016
0.0013
0.0011
scrapped
1 0 year olc
0.131
0.0222
0.0194
0.0169
0.0147
0.0127
0.0110
0.0094
0.0081
0.0070
0.0060
0.0051
0.0044
0.0037
0.0032
0.0027
0.0023
0.0020
0.0017
0.0015
0.0013
scrapped
1 1 year olc
0.118
0.0201
0.0176
0.0153
0.0132
0.0115
0.0099
0.0085
0.0073
0.0063
0.0054
0.0047
0.0040
0.0034
0.0029
0.0025
0.0022
0.0019
0.0016
0.0014
scrapped
1 2 year ok
0.107
0.0184
0.0160
0.0139
0.0121
0.0104
0.0090
0.0078
0.0067
0.0058
0.0050
0.0043
0.0037
0.0032
0.0027
0.0024
0.0020
0.0018
0.0015
scrapped
13 year ok
0.097
0.0168
0.0146
0.0127
0.0110
0.0095
0.0083
0.0071
0.0062
0.0053
0.0046
0.0040
0.0034
0.0030
0.0026
0.0022
0.0019
0.0017
scrapped
14 year ok
0.239
0.0415
0.0361
0.0313
0.0272
0.0236
0.0204
0.0177
0.0153
0.0132
0.0115
0.0099
0.0086
0.0075
0.0065
0.0057
0.0049
scrapped
15 year olc
0.217
0.0379
0.0330
0.0287
0.0249
0.0216
0.0188
0.0163
0.0141
0.0123
0.0106
0.0092
0.0080
0.0070
0.0061
0.0054
scrapped
16 year ok
0.197
0.0347
0.0302
0.0263
0.0229
0.0199
0.0173
0.0150
0.0131
0.0114
0.0099
0.0086
0.0075
0.0066
0.0058
scrapped
17 year old
0.323
0.0578
0.0504
0.0439
0.0383
0.0333
0.0290
0.0253
0.0220
0.0192
0.0168
0.0147
0.0129
0.0113
scrapped
31
-------
REFERENCES
1. Bobit Publications, "School Bus Fleet 1997 Fact Book", EPA420-R-01-047, September 2001 and
Federal Transit Authority 1997 facts.
2. Fleet Characterization Data for MOBILE 6: Development and Use of Age Distributions, Average
Annual Mileage Accumulation Rates and Projected Vehicle Counts for Use in MOBILE6, EPA420-
P-99-011 April 1999 M6.FIT.007 available on EPA's website at
www.epa.gov/otaq/models/mobile6/m6tech.htm
3. Median Life, Annual Activity, and Load Factor Values for Nonroad engine Emissions Modeling,
NR-005c (EPA420-P-004-005, April 2004), available at www.epa.gov/otaq/nonrdmdl.htmftechrept
4. Alan Greenspan and Darrel Cohen, "Motor Vehicle Stocks, Scrappage, and Sales", Federal
Reserve Board, October 30, 1996 available at
5. Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling -Compression-Ignition,
NR-009c (EPA420-P-04-009, April 2004), available at www.epa.gov/otaq/nonrdmdl.htmftechrept
6. MECA Independent Cost Survey for Emission Control Retrofit Technologies, Manufacturers of
Emission Control Association, December 5, 2000 available on EPA's Retrofit Website,
www.epa.gov/otaq/retrofit
7. Highway Diesel Progress Review Report 2, March 2004 EPA420-R-04-004 available at
www.epa.gov/otaq/highway-diesel/index.htm
8. Nonroad Tier 4 Regulatory Impact Analysis (RIA), (EPA420-R-04-007, May 2004)
http://www.epa.gov/nonroad-diesel/2004fr.htm
9. LeTavec, Chuck, et al, "Year-Long Evaluation of Trucks and Buses Equipped with Passive Diesel
Particulate Filters," SAE 2002-01-0433.
10. Control of Emissions of Air Pollution From Nonroad Diesel Engines and Fuel, Table IV.D-4 page
FR 39133, Federal Register Volume 69, No. 124 June 29, 2004.
32
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