Air and Radiation EPA420-P-04-009

April 2004

NR-009c

Exhaust and Crankcase

Emission Factors for

Nonroad Engine Modeling--

Compression-Ignition
EPA420-P-04-009

Revised April 2004

Exhaust and Crankcase Emission Factors for

Nonroad Engine Modeling--Compression-Ignition

NR-009c

Assessment and Standards 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 the exchange of

technical information and to inform the public of technical developments which

may form the basis for a final EPA decision, position, or regulatory action.
1

Exhaust and Crankcase Emission Factors

 for Nonroad Engine Modeling--

Compression-Ignition

Report No. NR-009c

Revised April 2004

Assessment and Standards Division

EPA, Office of Transportation and Air Quality

Purpose

This report describes and documents exhaust emission factors used for compression

ignition (CI) engines in the U.S. Environmental Protection Agency’s (EPA) draft

NONROAD2004 emission inventory model. The term “compression ignition” is synonymous

with “diesel” for the purposes of this report. Pollutants covered include hydrocarbons (HC),

carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter (PM), carbon dioxide (CO2),

and sulfur dioxide (SO2). Brake specific fuel consumption (BSFC), which is a fuel rate

measurement, is also discussed. All PM emissions are assumed to be smaller than 10 microns

(PM10) and 97% of the PM is assumed to be smaller than 2.5 microns (PM2.5). The NONROAD

Reporting Utility allows the user to select which of these two size ranges is reported. 

This report covers zero-hour, steady-state emission factors, transient adjustment factors,

and deterioration factors for all diesel-fueled engines. Adjustments to emission rates due to

variations in fuel sulfur level are also included. There are no additional adjustments to CI

emissions for temperature, altitude, or for other fuel parameters. Crankcase HC emission factors

are also covered in this report. Emission factors for spark ignition engines (including gasoline

and natural gas/propane) are covered in a separate report, NR-010d.

Zero-mile, steady-state emission factors for HC, CO, NOx, PM, and BSFC will be

discussed first, followed by adjustments (where applicable) to account for transient operation,

deterioration, and variations in fuel sulfur level. Derivation of CO2 and SO2 emission factors

follows. Crankcase HC emission factors are then discussed. This is followed by a discussion of

the PM2.5 fraction of PM10 used in the Reporting Utility. Prior estimates were documented in the

previous version of this report. [1]
2

Introduction

The NONROAD model estimates air pollution from more than 80 types of compression

ignition (CI) and spark ignition (SI) nonroad sources including such items as lawnmowers,

motorboats, portable generators and construction equipment. By bringing together information

on equipment populations, equipment use, and emission factors, the NONROAD model

estimates mass emissions of hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx),

sulfur dioxide (SO2), particulate matter (PM) and carbon dioxide (CO2) for specific states and

counties for past and future years, providing a flexible tool that can be applied to a wide variety

of air quality modeling and planning functions.

The NONROAD calculations rely on emission factors--estimates of the amount of

pollution emitted by a particular type of equipment during a unit of use. Typically, emission

factors for nonroad sources are reported in grams per horsepower-hour (g/hp-hr), but they also

may be reported in grams per mile, grams per hour, and grams per gallon. The CI emission

factors in the NONROAD model are reported in g/hp-hr and are based on emissions test data

where available, adjusted when necessary to account for in-use operation that differs from the

typical test conditions. These emission factors are stored in NONROAD’s data input files. 

NONROAD adjusts these emission factors as necessary to account for the effects of fuel sulfur.

Emission changes with the age of the engine, often called ‘deterioration,’are also applied by the

model.

If comments on this document or other information gathered during stakeholder and peer

review cause us to refine the CI emission factors, we will document the changes in a subsequent

report.

Emission Standards

In addition to estimating emissions from uncontrolled engines, the NONROAD model is

designed to account for the effect of federal emissions standards. NONROAD will not cover

California emission standards or proposed federal standards that are not yet final. Draft

NONROAD2004 accounts for emission factors under four regulations that establish four tiers of

emission standards:

C “Determination of Significance for Nonroad Sources and Emission Standards for New

Nonroad Compression Ignition Engines at or above 37 Kilowatts.” This rule establishes

“Tier 1” standards for CI engines at or above 50 hp (37 kW). [2]

C “Control of Emissions from Nonroad Diesel Engines.” This rule lists “Tier 1” and “Tier

2” standards for CI engines below 50 hp, and “Tier 2” and “Tier 3 ” standards for engines

of 50 hp and greater. [3]

C “Control of Emissions From Nonroad Large Spark-Ignition Engines and Recreational

Engines (Marine and Land-Based).” This rule establishes standards for recreational
3

marine diesel engines over 50 hp. [4]

C “Control of Emissions from Nonroad Diesel Engines and Fuel.” This rule establishes

“Tier 4" standards for CI engines covering all hp categories, and also regulates diesel fuel

sulfur content. [5]

The emission standards with the affected model years and the corresponding model tech

types are provided in Table 1. Table 1 covers all CI engines except recreational marine engines

over 50 hp. The standards and emission factors for recreational marine CI engines over 50 hp

are discussed separately. Tech types are defined for unique sets of standards and/or certification

fuel sulfur levels. The certification fuel sulfur levels will be discussed in more detail later in this

report.

Along with the new engine standards listed in Table 1, there are flexibility allowances for

equipment manufacturers. Under the Percentage Phase-in Allowance provision, a manufacturer

may exempt up to a cumulative total of eighty percent of the production over the first seven

years a new standard applies. This applies separately to each regulatory power category. The

engines used in such exempted equipment will only have to meet the previous standard, which is

either the Tier 1 standard in the case of equipment at or above 50 hp, or unregulated in the case

of equipment under 50 hp. For categories of engines where there is an overlap in standards (this

only occurs in equipment at or above 50 hp), the standard for the exempted equipment continues

to be the Tier 1 standard. The following example illustrates the percent exemptions applied

during the introduction of Tier 2 and Tier 3 standards for equipment <100 to 175 hp. For this

example, the standard for the exempted equipment is the Tier 1 standard.

2002 100% Tier 1

2003 20% Tier 1; 80% Tier 2

2004 20% Tier 1; 80% Tier 2

2005 10% Tier 1; 90% Tier 2

2006 10% Tier 1; 90% Tier 2

2007 10% Tier 1; 90% Tier 3

2008 10% Tier 1; 90% Tier 3

2009 100% Tier 3

Total exemption: 80%

For the purposes of emissions modeling, we assumed that the manufacturers took full

advantage of the Percentage Phase-in Allowance provisions. The resulting technology

distributions by hp category and model year are provided in Appendix A, Table A1.
4

Table 1. Nonroad CI Engine Emission Standardsa

Engine Power

(hp) Model Years Regulation Emission Standards (g/hp-hr) NONROAD

HC b NMHC+NO Tech Types x CO NOx PM

<11 2000-2004 Tier 1 7.8 6.0 0.75 T1

2005-2007 Tier 2 5.6 6.0 0.60 T2

2008+ Tier 4 0.30 T4A, T4B e

$11 to <25 2000-2004 Tier 1 7.1 4.9 0.60 T1

2005-2007 Tier 2 5.6 4.9 0.60 T2

2008+ Tier 4 0.30 T4A, T4B e

$25 to <50 1999-2003 Tier 1 7.1 4.1 0.60 T1

2004-2007 Tier 2 5.6 4.1 0.45 T2

2008-2012 Tier 4

transitional

0.22 T4A

2013+ Tier 4 final 3.5 0.02 T4

50 to <75 1998-2003 Tier 1 6.9 T1

2004-2007 Tier 2 5.6 3.7 0.30 T2

2008-2012 Tier 3 c 3.5 3.7 T3

2008-2012 Tier 4

transitional c

0.22 T4A

2013+ Tier 4 final 3.5 0.02 T4

$75 to <100 1998-2003 Tier 1 6.9 T1

2004-2007 Tier 2 5.6 3.7 0.30 T2

2008-2011 Tier 3 3.5 3.7 T3B

2012-2013 Tier 4

transitional

0.14

(50%) d

0.30

(50%)

0.01 50% T4

50% T4N

2014+ Tier 4 final 0.14 0.30 0.01 T4N

$100 to <175 1997-2002 Tier 1 6.9 T1

2003-2006 Tier 2 4.9 3.7 0.22 T2

2007-2011 Tier 3 3.0 3.7 T3

2012-2013 Tier 4

transitional

0.14

(50%)

0.30

(50%)

0.01 50% T4

50% T4N

2014+ Tier 4 final 0.14 0.30 0.01 T4N

$175 to <300 1996-2002 Tier 1 1.0 8.5 6.9 0.4 T1

2003-2005 Tier 2 4.9 2.6 0.15 T2

2006-2010 Tier 3 3.0 2.6 T3

2011-2013 Tier 4

transitional

0.14

(50%)

0.30

(50%)

0.01 50% T4

50% T4N

2014+ Tier 4 final 0.14 0.30 0.01 T4N
Engine Power

(hp) Model Years Regulation Emission Standards (g/hp-hr) NONROAD

HC b NMHC+NO Tech Types x CO NOx PM

5

$300 to <600 1996-2000 Tier 1 1.0 8.5 6.9 0.4 T1

2001-2005 Tier 2 4.8 2.6 0.15 T2

2006-2010 Tier 3 3.0 2.6 T3

2011-2013 Tier 4

transitional

0.14

(50%)

0.30

(50%)

0.01 50% T4

50% T4N

2014+ Tier 4 final 0.14 0.30 0.01 T4N

$600 to #750 1996-2001 Tier 1 1.0 8.5 6.9 0.4 T1

2002-2005 Tier 2 4.8 2.6 0.15 T2

2006-2010 Tier 3 3.0 2.6 T3

2011-2013 Tier 4

transitional

0.14

(50%)

0.30

(50%)

0.01 50% T4

50% T4N

2014+ Tier 4 final 0.14 0.30 0.01 T4N

>750 except

generator sets

2000-2005 Tier 1 1.0 8.5 6.9 0.4 T1

2006-2010 Tier 2 4.8 2.6 0.15 T2

2011-2014 Tier 4

transitional

0.30 2.6 0.075 T4

2015+ Tier 4 final 0.14 2.6 0.03 T4N

Generator sets

>750 to #1200

2000-2005 Tier 1 1.0 8.5 6.9 0.4 T1

2006-2010 Tier 2 4.8 2.6 0.15 T2

2011-2014 Tier 4

transitional

0.30 2.6 0.075 T4

2015+ Tier 4 final 0.14 0.5 0.02 T4N

Generator sets

>1200

2000-2005 Tier 1 1.0 8.5 6.9 0.4 T1

2006-2010 Tier 2 4.8 2.6 0.15 T2

2011-2014 Tier 4

transitional

0.30 0.5 0.075 T4

2015+ Tier 4 final 0.14 0.5 0.02 T4N

a

 These standards do not apply to recreational marine diesel engines over 50 hp. Standards for this category are provided in Table

7.

b

 Tier 4 standards are in the form of NMHC.

c

 For 50 to <75 hp engines, a Tier 3 NOx standard of 3.5 g/hp-hr was promulgated, beginning in 2008. The Tier 4 transitional

standard also begins in 2008; it leaves the Tier 3 NOx standard unchanged and adds a 0.22 g/hp-hr PM standard. d

 Percentages are model year sales fractions required to comply with the indicated NOx and NMHC standards, for model years

where less than 100 percent is required.

e

 The T4A tech type is used in 2008-2012. The T4B tech type is used in 2013+.
6

Methodology for Calculation of Emission Factors in NONROAD

For HC, CO, and NOx, the exhaust emission factor for a given diesel equipment type in a

given model year/age is calculated as follows:

 [Equation 1] EF EF TAF DF adj HC CO NOx ss (,, ) =××

where:

EFadj = final emission factor used in model, after adjustments to account for transient operation

and deterioration (g/hp-hr)

EFss = zero-hour, steady-state emission factor (g/hp-hr)

TAF = transient adjustment factor (unitless)

DF = deterioration factor (unitless)

The zero-hour, steady-state emission factors (EFss) are mainly a function of model year and

horsepower category, which defines the technology type. The transient adjustment factors

(TAFs) vary by equipment type. The deterioration factor (DF) is a function of the technology 

type and age of the engine.

Since PM emissions are dependent on the sulfur content of the fuel the engine is burning,

the equation used for PM is slightly modified from equation [1] as follows:

EF EF TAF DF S adj PM ss PMadj ( ) = × ×− [Equation 2]

where:

SPM adj = adjustment to PM emission factor to account for variations in fuel sulfur content

(g/hp-hr)

PM and SO2 are the only diesel pollutants that are dependent on fuel sulfur content.

For BSFC, there is no deterioration applied, so the equation is simplified to:

EF EF TAF adj BSFC ( ) = × ss [Equation 3]

Emission factors for CO2 and SO2 are calculated based on brake-specific fuel

consumption; therefore, the model does not require CO2 or SO2 emission factor input files. The

equations for computing these emissions are discussed in detail later in this report.

Crankcase HC emissions are simply a fraction (2%) of exhaust HC emissions for Tier 3

and earlier engines. [6] For Tier 4 engines, zero crankcase emissions are assumed. Crankcase

emissions are discussed in more detail later in this report.

For ease of reference, the model inputs for EFss, TAFs, and DFs are included with the
7

technology model year fractions in Appendix A.

Zero-Hour, Steady State Emission Factors (EFss)--HC, CO, NOx , PM, and BSFC

This section describes the steady-state fuel consumption and emission factors for HC,

CO, NOx , and PM. These emission factors are listed in Table A2 in Appendix A. We have used

engine model year and horsepower as categories to group NONROAD emission factors. These

groupings are consistent with emission standards for CI engines with two minor exceptions. One

exception is that the pre-control engines have been split into two groups, pre-1988 MY engines,

and 1988 MY to Tier 1 engines. The pre-1988 MY engines are referred to as “Base” engines

and the 1988 MY to Tier 1 engines are referred to as “Tier 0” engines. This distinction was

made based on data indicating a difference in emission rates. The other exception is a minor

difference in the horsepower categories used in NONROAD versus those used for standard

setting. The NONROAD horsepower categories follow the general formula, x<hp#y, whereas

the CI standards generally follow the formula, x#hp<y. By making this minor modification, the

NONROAD CI horsepower categories are consistent with those used for spark ignition

equipment. Perhaps in the future, emission factors may be distinguished by technologies such as

turbo-charging, fuel metering pumps, and cylinder size; however, there are not enough emissions

data at present to support such distinctions in NONROAD emission factors.

As mentioned previously, fuel sulfur levels affect PM emissions. NONROAD users can

adjust for local (episodic) fuel sulfur levels. The adjustment is made relative to the default

certification fuel sulfur level in the model. NONROAD has a default certification diesel fuel

sulfur level of 0.33 mass percent (3300 ppm), the national average for nonroad diesel estimated

as of 1997 [7], and the Tier 1 and pre-control emission factors in NONROAD’s input files are

adjusted to be consistent with this default fuel sulfur level. The available Tier 2 emission factors

are intended to be consistent with a default fuel sulfur level of 0.20 mass percent, in order to

attain a 0.15 g/hp-hr PM standard. Where emission tests were known to have been performed

with fuels with other sulfur contents, the test results have been adjusted, as described in

Appendix C.

The default certification fuel sulfur levels in the model for Tier 3 and Tier 4 engines are

provided in Table 2. In addition to adjusting for local fuel sulfur levels, the model allows the

user to input alternative default certification diesel fuel sulfur levels for Tier 2 and later engines. 

This option will be described in more detail in a later section of the report.
8

Table 2. Default Certification Diesel Fuel Sulfur Content for Tier 3 and Tier 4 Engines

Engine Power Model Years Regulation NONROAD

Tech Types

Modeled Default Fuel Sulfur

Content (ppm)

hp # 75 2008-2012 Tier 4 transitional T4A 500

2013+ Tier 4 T4B, T4 15

75 < hp # 100 2008-2011 Tier 3 transitional a T3B 500

2012+ Tier 4 transitional

and final T4, T4N 15

100 < hp # 175 2007-2011 Tier 3 T3 2000

2012+ Tier 4 transitional

and final T4, T4N 15

175 < hp # 750 2006-2010 Tier 3 T3 2000

2011+ Tier 4 transitional

and final T4, T4N 15

hp > 750 2011+ Tier 4 transitional

and final T4, T4N 15

a

 Since the Tier 3 standard begins in 2008, it is assumed that this new technology introduction will allow

manufacturers to take advantage of the availability of 500 ppm fuel that year.

Due to lack of data, the brake-specific fuel consumption (BSFC) for the 1988-and-later

pre-control (Tier 0) engines is used for all engines, both earlier pre-control engines and later

engines subject to emissions standards. The derivation of the BSFC values is described in

Appendix C. While it is likely that fuel consumption varies between these categories, there is

not sufficient data available at this time for EPA to specify alternate values.

There is little test data available on nonroad engines. In developing the emission factors

for NONROAD, we have considered data from various sources. The basis for the emission

factors by model year/hp category is described below and summarized in Tables 3-6. Compared

to previous versions of the model, this version has emission factor estimates for Tier 4 engines

that reflect the recent final rulemaking.

Base (Pre-1988), Engines #50 hp:

There are no known tests of pre-1988 CI engines of less than or equal to 50 hp. Thus,

NONROAD will use the same emission factors as for the 1988 through Tier 1 years for engines

of this size described below.

Table 3. Summary of the Basis for the HC Zero-Hour Steady-State CI Emission Factors in Draft
9

NONROAD2004

HP

HC g/hp-hr

Tier 0a T0 Basis Tier 1 T1 Basis Tier 2b T2 Basisc Tier 3b T3 Bas

>0 to 11 1.5 OFFROAD 0.7628 cert 0.5508d (5) 10% default margin from 0.6 equivalent std (since T1 EF exceeds T2 std, cannot be used) na 

>11 to 16 1.7 OFFROAD 0.4380 cert 0.4380 (3) Same as T1 (since T1 EF still below 0.6 T2 equivalent std) na >16 to 25 1.7 OFFROAD 0.4380 cert 0.4380 (3) Same as T1 (since T1 EF still below 0.6 T2 equivalent std) na >25 to 50 1.8 OFFROAD 0.2789 cert 0.2789 (3) Same as T1 (since T1 EF still below 0.6 T2 equivalent std) na >50 to 75 0.99 EF data 0.5213 cert 0.3672d (5) 10% default margin from 0.4 equivalent std (since T1 EF exceeds T2 std, cannot be used) 0.1836d (5) 10% ma

from 0.2 eq

>75 to 100 0.99 EF data 0.5213 cert 0.3672d (5) 10% default margin from 0.4 equivalent std (since T1 EF exceeds T2 std, cannot be used) 0.1836d (5) 10% ma

from 0.2 eq

>100 to 175 0.68 EF data 0.3384 cert 0.3384 (3) Same as T1 (since T1 EF still below 0.4 T2 equivalent std) 0.1836d (5) 10% ma

from 0.2 eq

>175 to 300 0.68 EF data 0.3085 cert 0.3085 (3) Same as T1 (since T1 EF still below 0.4 T2 equivalent std) 0.1836d (5) 10% ma

from 0.2 eq

>300 to 600 0.68 EF data 0.2025 cert 0.1669 cert 0.1669 (3) Same a>600 to 750 0.68 EF data 0.1473 cert 0.1669

(1 and 2) Same as the >300 to 600hp category.Rationale:a) All these HP categories meet same 0.3 HCeqv std. b) The NOx T1 EFs exceed the T2 std. To meetNOx T2, changes are likely to increase HC. c) EF based on actual cert data.

0.1669 (3) Same a

>750 except

gen sets 0.68 EF data 0.2861 cert 0.1669 na 

Gen sets

>750 to 1200 0.68 EF data 0.2861 cert 0.1669 na 

Gen sets

>1200 0.68 EF data 0.2861 cert 0.1669 na 

a Tier 0 represents 1988+ MY engines for MYs prior to Tier 1. Separate EFs are also provided for Base (pre-1988 MY) engines. For #50hp en

>50hp engines, the Base EFs vary by application, so are not provided in this table. b The Tier 2 and Tier 3 standards are expressed as a combined NMHC + NOx standard. The NMHC assumed fractions of these combined stand

The resulting NMHC portion of the combined standard is referred to here as the “equivalent” standard.

c Numbers in parentheses correspond to the option selected, which is briefly described here. For more details regarding the options, consult the d An adjustment of 1.02 (1/0.984) is also applied to convert from NMHC to THC, since the standards apply to NMHC. This adjustment is desce For >750 hp engines, there is also a transitional Tier 4 NMHC standard of 0.30 g/hp-hr in 2011-2014. The corresponding HC EF in NONROAf Tier 4 emission factors are considered to be transient, rather than steady-state.
10

Table 4. Summary of the Basis for the CO Zero-Hour Steady-State CI Emission Factors in Draft NONR

HP CO g/hp-hr Tier 0a T0 Basis Tier 1 T1 Basis Tier 2 T2 Basisb Tier 3 T3 Bas

>0 to 11 5 OFFROAD 4.1127 cert 4.1127 Same as T1 (since T1 EF still below T2 std) na 

>11 to 16 5 OFFROAD 2.1610 cert 2.1610 Same as T1 (since T1 EF still below T2 std) na >16 to 25 5 OFFROAD 2.1610 cert 2.1610 Same as T1 (since T1 EF still below T2 std) na >25 to 50 5 OFFROAD 1.5323 cert 1.5323 Same as T1 (since T1 EF still below T2 std) na >50 to 75 3.49 EF data 2.3655 cert 2.3655 Same as T1 (since T1 EF still below T2 std) 2.3655 Same as 

>75 to 100 3.49 EF data 2.3655 cert 2.3655 Same as T1 (since T1 EF still below T2 std) 2.3655 Same as 

>100 to 175 2.7 EF data 0.8667 cert 0.8667 Same as T1 (since T1 EF still below T2 std) 0.8667 Same as >175 to 300 2.7 EF data 0.7475 cert 0.7475 Same as T1 (since T1 EF still below T2 std) 0.7475 Same as >300 to 600 2.7 EF data 1.3060 cert 0.8425 cert 0.8425 Same as >600 to 750 2.7 EF data 1.3272 cert 1.3272 Same as T1 (since T1 EF still below T2 std) 1.3272 Same as 

>750 except

gen sets 2.7 EF data 0.7642 cert 0.7642 Same as T1 (since T1 EF still below T2 std) na 

Gen sets

>750 to 1200 2.7 EF data 0.7642 cert 0.7642 Same as T1 (since T1 EF still below T2 std) na 

Gen sets

>1200 2.7 EF data 0.7642 cert 0.7642 Same as T1 (since T1 EF still below T2 std) na 

a Tier 0 represents 1988+ MY engines for MYs prior to Tier 1. Separate EFs are also provided for Base (pre-1988 MY) engines. For #50hp en

For >50hp engines, the Base EFs vary by application, so are not provided in this table.b The Tier 2 and Tier 3 CO emission factors are based on application of option 2, the carryover of emission factors derived from nonroad certifregarding this option, consult the text.c For >25 to 75 hp engines, CO emissions for engines meeting the Tier 4 transitional PM standard of 0.22 g/hp-hr in 2008-2012 are unchanged 

the Tier 4 PM standard of 0.02 g/hp-hr takes effect, the corresponding CO EFs are reduced by 90 percent.d Tier 4 emission factors are considered to be transient, rather than steady-state.
11

Table 5. Summary of the Basis for the NOx Zero-Hour Steady-State CI Emission Factors in Draft NONR

HP

NOx g/hp-hr

Tier 0a T0 Basis Tier 1 T1 Basis Tier 2b T2 Basisc Tier 3b T3 Bas

>0 to 11 10 OFFROAD 5.2298 cert 4.3 (4) 14% hwy margin from 5.0 equivalent std (since T1 EF exceeds T2 std, cannot be used) na 

>11 to 16 8.5 OFFROAD 4.4399 cert 4.4399 (3) Same as T1 (since T1 EF still below 5.0 T2 equivalent std) na >16 to 25 8.5 OFFROAD 4.4399 cert 4.4399 (3) Same as T1 (since T1 EF still below 5.0 T2 equivalent std) na >25 to 50 6.9 OFFROAD 4.7279 cert 4.7279 (3) Same as T1 (since T1 EF still below 5.0 T2 equivalent std) na >50 to 75 8.30 EF data 5.5988 cert 4.7 (5) 10% default margin from 5.2 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) 3.0 (5) 10% m

from 3.3 eq

>75 to 100 8.30 EF data 5.5988 cert 4.7 (5) 10% default margin from 5.2 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) 3.0 (5) 10% m

from 3.3 eq

>100 to 175 8.38 EF data 5.6523 cert 4.1 (5) 10% default margin from 4.5 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) 2.5 (5) 10% m

from 2.8 eq

>175 to 300 8.38 EF data 5.5772 cert 4.0 (4) 10.5% hwy margin from 4.5 T2 equivalent std 2.5 (4) 10.5% 

margin fro

>300 to 600 8.38 EF data 6.0153 cert 4.3351 cert (real data preferred even though margin from 4.5 eqv T2 std <10%) 2.5 (5) 10% m

from 2.8 eq

>600 to 750 8.38 EF data 5.8215 cert 4.1 (5) 10% default margin from 4.5 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) 2.5 (5) 10% m

from 2.8 eq

>750 except

gen sets 8.38 EF data 6.1525 cert 4.1 (5) 10% default margin from 4.5 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) na 

Gen sets

>750 to 1200 8.38 EF data 6.1525 cert 4.1 (5) 10% default margin from 4.5 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) na 

Gen sets

>1200 8.38 EF data 6.1525 cert 4.1 (5) 10% default margin from 4.5 T2 equiv std (since T1 EF exceeds T2 std, cannot be used) na 

a Tier 0 represents 1988+ MY engines for MYs prior to Tier 1. Separate EFs are also provided for Base (pre-1988 MY) engines. For #50hp en

For >50hp engines, the Base EFs vary by application, so are not provided in this table. b The Tier 2 and Tier 3 standards are expressed as a combined NMHC + NOx standard. The NOx assumed fractions of these combined standard

resulting NOx portion of the combined standard is referred to here as the “equivalent” standard.

c Numbers in brackets correspond to the option selected, which is briefly described here. For more details regarding the options, consult the tex

highway-based compliance margins are discussed in Appendix E.

d For generator sets >750 to 1200hp, there is also a transitional Tier 4 NOx standard of 2.6 g/hp-hr in 2011-2014. The corresponding NOx EF is e Tier 4 emission factors are considered to be transient, rather than steady-state.
12

Table 6. Summary of the Basis for the PM10 Zero-Hour Steady-State CI Emission Factors in Draft NONR

HP

PM10 g/hp-hr

Tier 0a T0 Basis Tier 1 T1 Basis Tier 2 T2 Basisb Tier 3 T3 Basi

>0 to 11 1 OFFROAD 0.4474 cert 0.50

(1) The NOx T1 EF exceeds the T2 std. Tomeet NOx T2, changes are likely to increasePM. The T2 PM EF is therefore expected to begreater than 0.44 (T1 EF) and less than 0.60(T2 std); 0.50 chosen as a reasonable value.

na 

>11 to 16 0.9 OFFROAD 0.2665 cert 0.2665 (3) Same as T1 (since T1 EF still below T2 std) na >16 to 25 0.9 OFFROAD 0.2665 cert 0.2665 (3) Same as T1 (since T1 EF still below T2 std) na >25 to 50 0.8 OFFROAD 0.3389 cert 0.3389 (3) Same as T1 (since T1 EF still below T2 std) na >50 to 75 0.722 EF data 0.4730 0.24 (4) 20% highway-based margin from std (since T1 EF exceeds T2 std, cannot be used) 0.30 (1) T3 st

>75 to 100 0.722 EF data 0.4730 0.24 (4) 20% highway-based margin from std (since T1 EF exceeds T2 std, cannot be used) 0.30 (1) T3 st

>100 to 175 0.402 EF data 0.2799 0.18 (4) 20% highway-based margin from std (since T1 EF exceeds T2 std, cannot be used) 0.22 (1) T3 st>175 to 300 0.402 EF data 0.2521 cert 0.1316

(2) T2 EF for >300 to 600hp category applied tothese hp categories. Rationale: All four hpcategories meet same PM std. Also, T2 EF of0.1316 based on actual certification data.

0.15 (1) T3 st

>300 to 600 0.402 EF data 0.2008 cert 0.1316 0.15 (1) T3 st>600 to 750 0.402 EF data 0.2201 cert 0.1316 0.15 (1) T3 st

>750 except

gen sets 0.402 EF data 0.1934 cert 0.1316 na 

Gen sets

>750 to 1200 0.402 EF data 0.1934 cert 0.1316 na 

Gen sets

>1200 0.402 EF data 0.1934 cert 0.1316 na 

a Tier 0 represents 1988+ MY engines for MYs prior to Tier 1. Separate EFs are also provided for Base (pre-1988 MY) engines. For #50hp en

For >50hp engines, the Base EFs vary by application, so are not provided in this table.

b Numbers in brackets correspond to the option selected, which is briefly described here. For more details regarding the options, consult the tex

highway-based compliance margins are discussed in Appendix E.

c For >25 to 75 hp engines, there is also a transitional Tier 4 PM standard of 0.22 g/hp-hr in 2008-2012. The corresponding PM EF in NONROd For all engines >750 hp, there is also a transitional Tier 4 PM standard of 0.075 g/hp-hr in 2011-2014. The corresponding PM EF in NONROe Tier 4 emission factors are considered to be transient, rather than steady-state.
13

Base (Pre-1988), Engines > 50 hp:

 For pre-1988 CI engines of greater than 50 hp, NONROAD’s steady-state emission

factors are based on the emission factors used in the Nonroad Engine and Vehicle Emission

Study (NEVES) [6]. The sources of the emission factors used in NEVES are described in

Appendix B. The emission factors vary by application. However, NEVES includes an

adjustment for in-use operation. Since NONROAD uses a different in-use adjustment factor

than NEVES (see Appendix F), the NEVES adjustment is removed to determine pre-1988

average steady-state emissions.

Because the testing fuel is generally unknown, we assume that the NEVES PM factors

are 

appropriate for the default fuel sulfur content of 0.33 wt.% sulfur used in NONROAD.

A conversion from gram per gallon to gram per horsepower-hr was made to NEVES

emission rates for the greater than 50 horsepower engines for the diesel recreational marine

categories; inboard, outboard, and sailboat auxiliary. Outboard and sailboat auxiliary engines

above 50 hp were converted from the NEVES gram per gallon to gram per horsepower using the

higher fuel consumption of 0.408 lbs/hp-hr and 7.1 lbs/gallon fuel density because these engines

are primarily less than 100 hp. The NEVES emission rate for inboard engines was converted

using the lower fuel consumption rate of 0.367 lbs/hp-hr because these engines are primarily

above 100 horsepower.

Tier 0 (1988 to Tier 1), Engines #50 hp

For 1988-and-later pre-control engines less than or equal to 50 hp, we will use the

emission factors described in the documentation for ARB’s OFF-ROAD model. [8] We have

combined the direct injection and indirect injection factors using the technology fractions listed

in the Regulatory Impact Analysis (RIA) for the emission standards. [9] Again, because the

sulfur content of fuels used in generating these emission factors is unknown, we have assumed

that the PM emission factors are appropriate for the default fuel sulfur level of 0.33 weight

percent.

Tier 0 (1988 to Tier 1), Engines >50 hp

Recent studies have indicated that, in general, emission rates from Tier 0 engines greater

than 50 hp are lower than for Tier 0 engines less than or equal to 50 hp. For these engines, we

will use emission factors calculated from recent studies. A summary of the emission data from

these studies is provided in Appendix C. As explained in Appendix C, a correction for fuel

sulfur content is applied.

Tier 1 Engines , all hp categories

The NONROAD model’s emission factors for Tier 1 engines are based on EPA

certification data. The certification data are described in Appendix D.

Tier 2 Engines, >300 to 600 hp

Since EPA certification data are available for this hp category, the emission factors are
14

based on analysis of the certification data, as described in Appendix D.

Tier 2 Engines #300 hp and > 600 hp and Tier 3 Engines

Since the Tier 2 standard for the 600 to 750 hp category began in 2002, and the Tier 2

standard for the 100 to 300 hp category began in 2003, Tier 2 certification data for these

categories are now available; however, these recent certification data were not yet available at

the time these emission factors were developed. As a result, we developed five alternative

options for calculating zero mile, steady-state emission factors for these engines. These options

were considered in the order they are presented here.

(1) Examine likely impacts of expected technology changes. In this option, we consider

offsetting changes to PM and HC with implementation of stricter emission standards for

NOx. This includes assigning the applicable standard as the PM emission factor without

applying a compliance margin. The compliance margin is the percent difference between

a standard and average emissions at certification for engines manufactured under that

standard.

(2) Assign an emission factor from another hp category. In this option, we assume that an

emission factor based on certification data is applicable to another hp category and is

preferable to applying a compliance margin to the applicable nonroad standard.

(3) Continue to use the Tier 1 or Tier 2 emission factors derived from the nonroad

certification data. In this option, we assume that manufacturers will maintain current

emission levels, e.g., design technologies, if they appear adequate to achieve compliance

while maintaining some margin of safety. Under this option, we would assume that

emission factors remain at the same levels used for Tier 1 or Tier 2 engines.

This option was only considered if the compliance margin (percent difference) between

the proposed emission factor and the applicable nonroad standard was at least 10%. We

based this lower bound (10%) on average highway-certification compliance margins for

NOx, assuming that it represents progressive highway certification experience for a

“controlling pollutant,” i.e., a pollutant for which the necessity to achieve compliance

drives innovation in engine design or control technology.

(4) Reduce the applicable nonroad standard by a compliance margin derived from

certification test results for analogous highway engines. We expect that the control of

emissions from nonroad engines will follow a course similar to that experienced for

highway engines, since we believe that as standards for nonroad engines become more

stringent, manufacturers will adopt technologies similar to those already introduced in

highway engines. Based on this expectation, we calculated compliance margins using

highway standards and corresponding highway certification test results. In this

discussion, we will refer to compliance margins calculated for highway engines as

“highway-certification compliance margins” (HCCM). The derivation of the HCCMs is

discussed in detail in Appendix E. An HCCM is only considered for use if it is greater
15

than or equal to 10% and less than 75%.

(5) Apply a default compliance margin of 10%. In this option, we assume that on average,

manufacturers will maintain a minimum compliance margin. This margin is based on

average highway certification compliance margins for NOx, the pollutant appearing to

drive measures to achieve compliance in highway diesel engines. A default compliance

margin was considered when the highway-based compliance margins were outside the

acceptable range. With this option, the applicable nonroad standard is simply reduced by

10%.

The Agency regulates HC and NOx under a combined standard for all Tier 2 and Tier 3

engines. Thus, in order to apply compliance margins for these pollutants, where applicable, we

split the combined standard into pollutant-specific components for HC and NOx. These are

presented in Table 7.

For each pollutant in Tiers 2 and 3, we evaluated one or more of these five options for

each horsepower category. The specific options selected for each pollutant and Tier are

presented in Tables 3-6 and summarized below:

HC: Tier 2: For categories less than 300 hp, we continued to use the Tier 1 nonroad

certification results (option 3) or applied the default compliance margin (option 5) on an

individual basis by horsepower category to give nonroad compliance margins of at least

10%. We did not use the highway-certification compliance margins because the highway

HC standards have not driven technology development; as a result, the HC standards are

unrelated to the certification values.

For the two hp categories greater than 600 hp, we assigned the emission factor for the

300-600 hp category. The rationale, which applies options 1 and 2, is threefold: 1) all

three hp categories meet the same HC equivalent standard, 2) the use of certification data

is preferable to applying a compliance margin, and 3) changes necessary to meet the Tier

2 NOx standard for the 600-750 hp category are likely to increase HC, so a slight increase

in HC emissions from Tier 1 to Tier 2 for this hp category is not unexpected.

Tier 3: We continued to use the Tier 2 nonroad certification results (option 3) or applied

the default compliance margin (option 5) to give nonroad compliance margins of at least

10%. We ruled out use of highway-certification compliance margins (option 4) for the

same reason as for Tier 2.

CO: Tiers 2 and 3: We continued to use the Tier 1 nonroad certification results (option 2) for

all horsepower categories in Tiers 2 and 3. Highway-certification compliance margins

(option 4) were very large (>90%), and as with HC, give implausibly low emission

factors in Tiers 2 and 3.
16

Table 7. Tier 2 and Tier 3 Combined and Estimated Pollutant-Specific Emissions

Standards for Nonroad Diesel Engines1

Power Range

(hp)

Combined Standard

HC+NOx

(g/hp-hr)

Estimated 

Pollutant-Specific

 HC 

(g/hp-hr)

Estimated 

Pollutant-Specific

 NOx

(g/hp-hr)

Tier 2 Tier 3 Tier 2 Tier 3 Tier 2 Tier 3

< 11 5.6 0.6 5.0

$11 to <25 5.6 0.6 5.0

$25 to <50 5.6 0.6 5.0

$50 to <100 5.6 3.5 0.4 0.2 5.2 3.3

$100 to <175 4.9 3.0 0.4 0.2 4.5 2.8

$175 to <300 4.9 3.0 0.4 0.2 4.5 2.8

$300 to <600 4.8 3.0 0.3 0.2 4.5 2.8

$600 to <750 4.8 3.0 0.3 0.2 4.5 2.8

$750 4.8 0.3 4.5

1

 Pollutant-specific components have no regulatory significance and are derived to facilitate

modeling analyses.

Basis for Pollutant-Specific HC and NOx Emission Standards:

Tier 2 <50 hp: As in the RIA [9], EPA assumes minimum HC emissions of 0.6 g/hp-hr based on

ARB data on indirect injection (IDI) engines under 25 hp. This rate is then subtracted from the

combined HC+NOx standard to split the standard into single pollutant emission factors.

Tier 2 $50 hp: As in the RIA [9], the proposed European NOx standard is used to split the

combined HC+NOx standard into single pollutant emission factors.

Tier 3: NONROAD follows the RIA [9] in using engineering judgment to assume minimum HC

emissions of 0.2 g/hp-hr. This rate is then subtracted from the combined HC+NOx standard to

split the standard into single pollutant emission factors.
17

NOx: Tier 2: We applied highway-certification compliance margins (option 4), continued to

use the Tier 1 nonroad certification results (option 3) or applied the default compliance

margin (option 5) on an individual basis by horsepower category to give compliance

margins of at least 10%.

Tier 3: We applied the highway certification compliance margin (option 4) or the default

compliance margin (option 5) for all horsepower categories. Nonroad certification

results (option 3) did not provide adequate compliance margins.

 PM: Tier 2: We applied the first four options on an individual basis by horsepower category to

give compliance margins of at least 10%. The highway-certification compliance margin

used for the 50-100 hp and 100-175 hp categories was 20%.

Tier 3: Tier 3 PM emission factors were set equal to the appropriate nonroad standards. 

To meet the NOx Tier 3 standards, technological changes are likely to increase PM;

therefore, compliance margins were not applied to PM (option 1).

Tier 4 Engines

For these engines, an 8% compliance margin was applied to the standards. This

compliance margin was derived from data for highway diesel vehicles and used in the HD2007

rulemaking.

The resulting zero-hour, steady-state emission factors for all Tiers and pollutants are

shown in Table A2 in Appendix A.

Recreational Marine and Underground Mining Emission Factors

Recreational marine CI engines over 50 hp were recently subject to EPA emission

regulations [5], so the emission factor inputs used for these engines do not exactly follow those

presented in Tables 2 - 5. The emission factors reflecting the standards for this equipment

category are now included in this version of the model. The emission standards for this category

are provided in Table 8. Table 9 shows the base and controlled recreational marine emission

factors now in draft NONROAD2004.

Although underground mining equipment emissions are not controlled by EPA, there

have been controls imposed by the Occupational Safety and Health Administration (OSHA). 

The OSHA standards do not directly follow the form used for the NONROAD model, but they

are considered approximately equivalent to the EPA Tier 2 standards for land-based CI

equipment. Therefore, the NONROAD model simply uses the NEVES uncontrolled emission

factors for Base, Tier 0, and Tier 1 underground mining inputs, and then applies the Tier 2

emission factors from Tables 3 - 6 for all newer engines.
18

Table 8. Emission Standards for Recreational Marine Diesel Engines Over 50 Hp

Engine Size (based on displacent

in liters per cylinder)

Model

Year

Model

Tech

Type

Emission Standards (g/hp-hr)

HC+NOx CO PM

0.5 L/cyl # disp < 0.9 L/cyl 2007 T2M 5.6 3.7 0.30

0.9 L/cyl # disp < 1.2 L/cyl 2006 T2M 5.4 3.7 0.22

1.2 L/cyl # disp < 2.5 L/cyl 2006 T2M 5.4 3.7 0.15

disp $ 2.5 L/cyl 2009 T2M 5.4 3.7 0.15

Table 9. NONROAD Model EF Inputs for Recreational Marine Diesel Engines Over 50 Hp

Engine Power

(hp)

Model

Years Tech Type

Emission Factor Modeling Inputs (g/hp-hr)

HC CO NOx PM

50 < hp # 100 Pre-2007 Base 0.22 0.95 6.67 0.16

2007 T2M 0.14 0.95 4.99 0.16

100 < hp # 175 Pre-2006 Base 0.22 0.95 6.67 0.16

2006 T2M 0.14 0.95 4.78 0.16

175 < hp # 300 Pre-2006 Base 0.22 0.95 6.67 0.16

2006 T2M 0.14 0.95 4.78 0.11

300 < hp # 750 Pre-2006 Base 0.22 0.95 6.67 0.16

2006 T2M 0.14 0.95 4.79 0.12

>750 Pre-2009 Base 0.22 0.95 6.67 0.16

2009 T2M 0.14 0.95 4.79 0.12

Transient Adjustment Factors--HC, CO, NOx, PM, and BSFC

Nonroad engines are primarily tested with steady-state tests. However, the steady-state

operation typically used for emission testing is not always representative of the operation of

engines in many nonroad applications. Some of the differences can be due to load or engine

speed, and other differences can be due to transient demands. We will apply “transient

adjustment factors” (“TAFs”) to the steady-state emission factors previously described. TAFs

are applied to the Base, Tier 0, Tier 1, Tier 2, and Tier 3 emission factors. Transient emission

control is expected to be an integral part of all Tier 4 engine design considerations. As a result,

TAFs are not applied to the emission factors for Tier 4 engines (i.e., the model applies a TAF of

1.0).
19

TAF

EF

EF trans

ss

=

We calculate the TAF as the ratio of the transient emission factor (EFtrans) to the

corresponding steady-state (ISO-C1) emission factor (EFss):

Transient adjustment factors may be greater than or less than 1.0.

The derivation and application of the TAFs, including the test data used, are described in

more detail in Appendix F. Appendix F also compares the TAF methodology and data used for

draft NONROAD2004 with previous versions of the model.

Table A3 presents the resulting TAFs assigned to each equipment application. The

steady-state emission factors given in Table A2 were then multiplied by the appropriate TAFs to

create NONROAD’s emission factor input files for CI engines.

In the previous version of the model, the Tier 3 NOx and PM TAFs were mistakenly

applied for equipment having steady-state operation. Equipment having steady-state operation

should have TAF values of 1.0. This has been corrected in draft NONROAD2004.

Deterioration Factors--HC, CO, NOx, and PM

The NONROAD model addresses the effects of deterioration in the inventory calculation

by multiplying a zero hour emission factor for each category of engine by a deterioration factor,

DF (see equation 1 above). DF varies as a function of engine age. The following equation is

used to calculate DF as a function of engine age:

DF = 1 + A * (Age Factor)b for Age Factor # 1 [Equation 4]

DF = 1 + A for Age Factor > 1

where: Age Factor = fraction of median life expended = (cumulative hours * load factor)

 median life at full load, in hours

A, b = constants for a given pollutant/technology type; b# 1.

Deterioration is capped at the end of an engine’s median life (age factor =1), under the

assumption that an engine deteriorates to a point where any increased deterioration is offset by

maintenance.

The constants A and b can be varied to approximate a wide range of deterioration

patterns. “A” can be varied to reflect differences in maximum deterioration. For example,

setting A equal to 2.0 would result in emissions at the engine’s median life being three times the

emissions when new (DF = 1 + 2). The shape of the deterioration function is determined by the
20

second constant, “b.” This constant can be set at any level between zero and 1.0. For

compression-ignition engines, b is always equal to 1.0. This results in a linear deterioration

pattern, in which the rate of deterioration is constant throughout the median life of an engine.

Due to lack of deterioration data for nonroad compression-ignition engines, the

deterioration factors are based on data derived from highway engines. The derivation of the

constant “A” for compression-ignition engines is described in Appendix G and the resulting

deterioration factors (i.e., the constants “A”) are given in Table A4.

Sulfur Adjustment for PM Emissions (SPMadj)

Since PM emissions are dependent on the sulfur content of the fuel, an adjustment (SPM

adj) is subtracted from the PM emission factor to account for variations in fuel sulfur content (see

equation 2 above). SPM adj corrects PM emissions from the default fuel sulfur level to the episodic

fuel sulfur level and is calculated using the following equation:

SPM adj = BSFC * 453.6 * 7.0 * soxcnv * 0.01 * (soxbas - soxdsl) [Equation 5]

where: SPM adj = PM sulfur adjustment (g/hp-hr)

BSFC = in-use adjusted brake-specific fuel consumption (lb fuel/hp-hr)

453.6 = conversion from lb to grams

7.0 = grams PM sulfate/grams PM sulfur

soxcnv = grams PM sulfur/grams fuel sulfur consumed

0.01= conversion from percent to fraction

soxbas = default certification fuel sulfur weight percent

soxdsl = episodic fuel sulfur weight percent (specified by user)

The soxcnv term represents the fraction of diesel fuel sulfur converted to PM. This

varies by technology type. Soxcnv is equal to 0.02247 for the Base, T0, T1, T2, T3, T3B, T4A,

and T4B technology types. For Tier 4 engines meeting stringent PM standards below 0.1 g/hphr, soxcnv is equal to 0.30. This applies to the T4 and T4N technology types. If the soxcnv

value for a technology type is not provided in the opt file, the default value used in the model is

0.02247. Derivation of the soxcnv term is described in Appendix C.

Values for the soxbas term vary by technology type and were discussed previously. If

the soxbas value for a technology type is not provided in the opt file, the default value used in

the model is 0.33 weight percent for diesel engines.

This version of the model also allows the user to input alternative default certification

diesel fuel sulfur levels (soxbas) for Tier 2 and Tier 3 engines. This is a feature added to the opt

file, but not available through the GUI; therefore, this feature can only be exercised by changing

the opt file.

Sample Calculation--EF adj
21

The following example illustrates how emission factors are calculated in NONROAD.

Example: Calculate the PM emission factor for a three year old 100-175 hp diesel excavator in

2003. The episodic diesel fuel sulfur level is 2500 ppm. (In NONROAD, three year old

equipment in 2003 translates to equipment made in model year 2001, since the calendar year of

interest is assigned age =1 year).

Needed inputs: For 100-175 hp, MY2001 = Tier 1 (from Table 1)

100-175 hp, Tier 1 PM EFss = 0.2799 g/hp-hr (from Table A2)

Excavator, Tier 1 PM TAF = 1.23 (from Table A3)

Tier 1 PM Deterioration “A” = 0.473 (from Table A4)

The deterioration factor, DF, is calculated as:

 DF = 1 + A*(cumulative hours * load factor) [Equation 4]

 median life at full load, in hours

where: Diesel excavator activity = 1092 hours/year (from activity.dat input file)

Diesel excavator load factor = 0.59 (from activity.dat input file)

Diesel excavator median life = 4667 hours (from us.pop input file)

Cumulative hours = age * activity = 3*1092 = 3276 hours

Substituting the above values into the equation yields:

DF = 1 + 0.473*(3276 * 0.59) = 1 + 0.473 * 0.414 = 1.196

 4667

The sulfur adjustment factor, SPM adj, is calculated as:

SPM adj = BSFC * 453.6 * 7.0 * soxcnv * 0.01 * (soxbas - soxdsl) [Equation 5]

where: BSFC = 100-175 hp BSFCss * Excavator BSFC TAF = 0.367*1.01 = 0.371

(BSFCss from Table A2 and BSFC TAF from Table A3)

soxcnv = 0.02247

soxbas = 0.3300

soxdsl = 0.2500

Substituting the values into the equation yields:

SPM adj = 0.371* 453.6 * 7.0 * 0.02247 * 0.01 * (0.33 - 0.25) = 0.0212 g/hp-hr

The resulting adjusted emission factor is calculated as follows:
22

EF adj(PM) = EFss * TAF * DF - SPMadj

 = (0.2799 * 1.23 * 1.196) - 0.0212

 = 0.39 g/hp-hr

Emission Factors--CO2 and SO2

Emission factors for CO2 and SO2 are rarely measured, instead they typically are

calculated based on brake-specific fuel consumption (BSFC).

The NONROAD model uses in-use adjusted BSFC to compute CO2 emissions directly, as

shown in the equation below. The carbon that goes to exhaust HC emissions is subtracted as the

correction for unburned fuel. This does not require a CO2 emission factors input file.

 CO2 = (BSFC * 453.6 - HC) * 0.87 * (44/12) [Equation 6]

where

CO2 is in g/hp-hr

BSFC is the in-use adjusted fuel consumption in lb/hp-hr

453.6 is the conversion factor from pounds to grams

HC is the in-use adjusted hydrocarbon emissions in g/hp-hr

0.87 is the carbon mass fraction of diesel

44/12 is the ratio of CO2 mass to carbon mass

The model does not require an SO2 emission factors input file either. EPA will calculate

SO2 emission factors as shown in the equation below.

 SO2 = (BSFC * 453.6* (1 - soxcnv) - HC) * 0.01 * soxdsl * 2 [Equation 7]

where

SO2 is in g/hp-hr

BSFC is the in-use adjusted fuel consumption in lb/hp-hr

453.6 is the conversion factor from pounds to grams

soxcnv is the fraction of fuel sulfur converted to direct PM

HC is the in-use adjusted hydrocarbon emissions in g/hp-hr

0.01 is the conversion factor from weight percent to weight fraction

soxdsl is the episodic weight percent of sulfur in nonroad diesel fuel

2 is the grams of SO2 formed from a gram of sulfur

This equation includes corrections for the fraction of sulfur that is converted to direct PM

and for the fraction of sulfur remaining in unburned fuel. This equation assumes that the

unburned fuel, as indicated by HC emissions, has the same sulfur level as the base fuel.

Note that BSFC for the pre-control (Tier 0) engines is used for all engines in the model. 

As a result, related emissions of CO2 and SO2 will change very little with the advent of new
23

emission reduction technologies. Minor changes will result as HC emissions are changed, since

the carbon that goes to exhaust HC is subtracted in the CO2 and SO2 equations. For diesel

engines, this adjustment is insubstantial.

Crankcase HC Emission Factors

Crankcase emissions are those emissions that escape from the combustion chamber past

the piston rings into the crankcase. For diesel engines with open crankcases, NONROAD

assumes the crankcase HC emission factor is equal to 2.0% of the exhaust HC emission factor. 

This applies for all Tier 3 and prior engines. This estimate was obtained from NEVES [6], and is

based on data from on-highway engines. These percentages are applied to the final calculated

exhaust emission factors, so the resulting crankcase emission factors include the same

percentage deterioration as used for exhaust HC. For Tier 4 engines, zero crankcase emissions

are assumed. Crankcase emission factors for all fuel types are discussed in NR-012b, “Basic

Evaporative Emission Rates for Nonroad Engine Modeling.”

PM2.5 Fraction of PM10

The NONROAD PM emission factor files and PM model output include all PM. For

diesel engines, all PM emissions are assumed to be smaller than 10 microns (PM10). The

NONROAD Reporting Utility allows the user to select whether to report results for PM10 or

PM2.5 (smaller than 2.5 microns). If PM2.5 is selected, an adjustment of 0.97 is applied to the

PM10 output. This is an updated estimate, based on an analysis of size distribution data for diesel

engines. [10]
24

References

[1] EPA, “Exhaust Emission Factors for Nonroad Engine Modeling–Compression-Ignition,”

Report No. NR-009b, November 27, 2002.

[2] EPA, “Control of Air Pollution; Determination of Significance for Nonroad Sources and

Emission Standards for New Nonroad Compression Ignition Engines At or Above 37 Kilowatts,”

59 FR 31306, June 17, 1994.

[3] EPA, “ Control of Emissions of Air Pollution From Nonroad Diesel Engines,” 63 FR 56967,

October 23, 1998.

[4] EPA, “Control of Emissions From Nonroad Large Spark-Ignition Engines and Recreational

Engines (Marine and Land-Based); Final Rule,” 67 FR 68241, November 8, 2002.

[5] EPA, “Control of Emissions of Air Pollution From Nonroad Diesel Engines and Fuel; Final

Rule,” April, 2004.

[6] EPA, “Nonroad Engine and Vehicle Emission Study” (NEVES), U.S. EPA, Office of Air

and Radiation, 21A-2001. November, 1991.

[7] Korotney, David. “Estimates for In-Use Nonroad Diesel Fuel Levels,” Memorandum to

Docket A-96-40. July 1, 1997.

[8] EEA, “Documentation of Input Factors for the New Off-Road Mobile Source Emissions

Inventory Model,” (“Inputs...”) Energy and Environmental Analysis, Inc. for California Air

Resources Board. February, 1997.

[9] EPA, “Final Regulatory Impact Analysis: Control of Emissions from Nonroad Diesel

Engines,” August, 1998.

[10] Cantrell, Bruce. “Recommended Revision of the Fraction of Diesel Particulate Emissions

Mass Less Than 2.5 Microns in Size,” Memorandum to Docket A-2001-28, Document IV-B-21. 

October 17, 2003.
A1

Appendix A

CI Inputs for Draft NONROAD2004:

Technology Distributions

Zero-Hour, Steady-State Emission Factors

Transient Adjustment Factors

Deterioration Factors
A2

Table A1. Nonroad CI Technology Distributions by HP Category and Model Yeara

Engine

Power (hp)

Model

Year

Fraction of Population in Each Technology Type

Baseb Tier 0b Tier 1 Tier 2 Tier 3 Tier 3B Tier 4A Tier 4B Tier 4 Tier 4N

#25 Pre-1988 1.000

1988-1999 1.000

2000-2001 0.200 0.800

2002-2004 0.100 0.900

2005 0.100 0.900

2006-2007 1.000

2008-2012 1.000

2013+ 1.000

>25 to 50 Pre-1988 1.000

1988-1998 1.000

1999-2000 0.200 0.800

2001-2003 0.100 0.900

2004 0.100 0.900

2005-2007 1.000

2008-2012 1.000

2013+ 1.000

>50 to 75 Pre-1998 1.000

1988-1997 1.000

1998-2003 1.000

2004-2005 0.200 0.800

2006-2007 0.100 0.900

2008-2009 0.100 0.900

2010-2012 1.000

2013+ 1.000
 Table A1 Nonroad CI Technology Distributions by HP Category and Model Year (cont.)a

Engine

Power (hp)

Model

Year

Fraction of Population in Each Technology Type

Baseb Tier 0b Tier 1 Tier 2 Tier 3 Tier 3B Tier 4A Tier 4B Tier 4 Tier 4N

A3

>75 to 100 Pre-1998 1.000

1988-1997 1.000

1998-2003 1.000

2004-2005 0.200 0.800

2006-2007 0.100 0.900

2008-2009 0.100 0.900

2010-2011 1.000

2012-2013 0.500 0.500

2014+ 1.000

>100 to 175 Pre-1998 1.000

1988-1996 1.000

1997-2002 1.000

2003-2004 0.200 0.800

2005-2006 0.100 0.900

2007-2008 0.100 0.900

2009-2011 1.000

2012-2013 0.500 0.500

2014+ 1.000

>175 to 300 Pre-1988 1.000

1988-1995 1.000

1996-2002 1.000

2003-2004 0.200 0.800

2005 0.100 0.900

2006-2008 0.100 0.900

2009-2010 1.000

2011-2013 0.500 0.500

2014+ 1.000
 Table A1 Nonroad CI Technology Distributions by HP Category and Model Year (cont.)a

Engine

Power (hp)

Model

Year

Fraction of Population in Each Technology Type

Baseb Tier 0b Tier 1 Tier 2 Tier 3 Tier 3B Tier 4A Tier 4B Tier 4 Tier 4N

A4

>300 to 600 Pre-1988 1.000

1988-1995 1.000

1996-2000 1.000

2001-2002 0.200 0.800

2003-2005 0.100 0.900

2006 0.100 0.900

2007-2010 1.000

2011-2013 0.500 0.500

2014+ 1.000

>600 to 750 Pre-1988 1.000

1988-1995 1.000

1996-2001 1.000

2002-2003 0.200 0.800

2004-2005 0.100 0.900

2006-2007 0.100 0.900

2008-2010 1.000

2011-2013 0.500 0.500

2014+ 1.000

>750 Pre-1988 1.000

1988-1999 1.000

2000-2005 1.000

2006-2007 0.300 0.700

2008 0.200 0.800

2009-2010 1.000

2011-2014 1.000

2015+ 1.000

a

 Used in the draft 2004 version of NONROAD. The technology fractions are contained in the tech.dat model

file. Blank cells have a technology fraction of 0.000. b

 Base = pre-control, pre-1988 MY engines. Tier 0 = pre-control 1988+ MY engines prior to Tier 1.
A5

Table A2. Zero-Hour, Steady-State Emission Factors for Nonroad CI Enginesa

Engine

Power (hp)

Technology

Type

BSFC 

(lb/hp-hr)

Emission Factors (g/hp-hr)

HC CO NOx PM

>0 to 11 Base 0.408b 1.5 5.0 10.0 1.0

Tier 0 1.5 5.0 10.0 1.0

Tier 1 0.7628 4.1127 5.2298 0.4474

Tier 2 0.5508 4.1127 4.3 0.50

Tier 4A 0.5508 4.1127 4.3 0.28

Tier 4B 0.5508 4.1127 4.3 0.28

>11 to 16 Base 0.408b 1.7 5.0 8.5 0.9

Tier 0 1.7 5.0 8.5 0.9

Tier 1 0.4380 2.1610 4.4399 0.2665

Tier 2 0.4380 2.1610 4.4399 0.2665

Tier 4A 0.4380 2.1610 4.4399 0.28

Tier 4B 0.4380 2.1610 4.4399 0.28

>16 to 25 Base 0.408b 1.7 5.0 8.5 0.9

Tier 0 1.7 5.0 8.5 0.9

Tier 1 0.4380 2.1610 4.4399 0.2665

Tier 2 0.4380 2.1610 4.4399 0.2665

Tier 4A 0.4380 2.1610 4.4399 0.28

Tier 4B 0.4380 2.1610 4.4399 0.28

>25 to 50 Base 0.408b 1.8 5.0 6.9 0.8

Tier 0 1.8 5.0 6.9 0.8

Tier 1 0.2789 1.5323 4.7279 0.3389

Tier 2 0.2789 1.5323 4.7279 0.3389

Tier 4A 0.2789 1.5323 4.7279 0.20

Tier 4 0.1314 0.153 3.0000 0.0184
Engine

Power (hp)

Technology

Type

BSFC 

(lb/hp-hr)

Emission Factors (g/hp-hr)

HC CO NOx PM

A6

>50 to 75 Base 0.408 Vary by application, see NEVES

Tier 0 0.99 3.49 6.9 0.722

Tier 1 0.5213 2.3655 5.5988 0.4730

Tier 2 0.3672 2.3655 4.7 0.24

Tier 4A 0.1836 2.3655 3.0 0.20

Tier 4 0.1314 0.237 3.00 0.0184

>75 to 100 Base 0.408 Vary by application, see NEVES

Tier 0 0.99 3.49 6.9 0.722

Tier 1 0.5213 2.3655 5.5988 0.4730

Tier 2 0.3672 2.3655 4.7 0.24

Tier 3B 0.1836 2.3655 3.0000 0.30

Tier 4 0.1314 0.237 3.00 0.0092

Tier 4N 0.1314 0.237 0.276 0.0092

>100 to 175 Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.3384 0.8667 5.6523 0.2799

Tier 2 0.3384 0.8667 4.1 0.18

Tier 3 0.1836 0.8667 2.5 0.22

Tier 4 0.1314 0.087 2.50 0.0092

Tier 4N 0.1314 0.087 0.276 0.0092

>175 to 300 Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.3085 0.7475 5.5772 0.2521

Tier 2 0.3085 0.7475 4.0 0.1316

Tier 3 0.1836 0.7475 2.5 0.15

Tier 4 0.1314 0.075 2.50 0.0092

Tier 4N 0.1314 0.075 0.276 0.0092
Engine

Power (hp)

Technology

Type

BSFC 

(lb/hp-hr)

Emission Factors (g/hp-hr)

HC CO NOx PM

A7

>300 to 600 Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.2025 1.3060 6.0153 0.2008

Tier 2 0.1669 0.8425 4.3351 0.1316

Tier 3 0.1669 0.8425 2.5 0.15

Tier 4 0.1314 0.084 2.50 0.0092

Tier 4N 0.1314 0.084 0.276 0.0092

>600 to 750 Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.1473 1.3272 5.8215 0.2201

Tier 2 0.1669 1.3272 4.1 0.1316

Tier 3 0.1669 1.3272 2.5 0.15

Tier 4 0.1314 0.133 2.50 0.0092

Tier 4N 0.1314 0.133 0.276 0.0092

>750 except

generator

sets

Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.2861 0.7642 6.1525 0.1934

Tier 2 0.1669 0.7642 4.1 0.1316

Tier 4 0.2815 0.076 2.392 0.069

Tier 4N 0.1314 0.076 2.392 0.0276

Gen sets

>750 to

1200

Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.2861 0.7642 6.1525 0.1934

Tier 2 0.1669 0.7642 4.1 0.1316

Tier 4 0.2815 0.076 2.392 0.069

Tier 4N 0.1314 0.076 0.460 0.0184
Engine

Power (hp)

Technology

Type

BSFC 

(lb/hp-hr)

Emission Factors (g/hp-hr)

HC CO NOx PM

A8

Gen sets

>1200

Base 0.367 Vary by application, see NEVES

Tier 0 0.68 2.70 8.38 0.402

Tier 1 0.2861 0.7642 6.1525 0.1934

Tier 2 0.1669 0.7642 4.1 0.1316

Tier 4 0.2815 0.076 0.460 0.069

Tier 4N 0.1314 0.076 0.460 0.0184

a

Prior to listing in NONROAD input files, these ISO-C1 emission factors are adjusted for in-use

operation as explained in Appendix F. The emission factors in the input files are rounded to two

decimal places. These emission factors do not apply to recreational marine CI engines over 50

hp. The emission factors for recreational marine CI engines over 50 hp are provided in Table 9. 

Underground mining equipment inputs are just the Base (NEVES) and Tier 2 values from this

table.

b

BSFC for engines <50 hp is assumed to be the same as 50-100 hp engines
A9

Table A3. Transient Adjustment Factors by Equipment Type for Nonroad CI Equipment a

SCC Equipment Type Cycle TAF Assignment HC CO NOx PM 

Base-T3 Base-T3 Base, T0-T2 Tier 3 Base, T0-T2 Tie

2270001000 Recreational Vehicles All Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270001020 Recreational Vehicles Snowmobiles None None 1.00 1.00 1.00 1.00 1.00 1.02270001030 Recreational Vehicles All Terrain Vehicles None None 1.00 1.00 1.00 1.00 1.00 1.02270001040 Recreational Vehicles Minibikes None None 1.00 1.00 1.00 1.00 1.00 1.02270001050 Recreational Vehicles Golf Carts None None 1.00 1.00 1.00 1.00 1.00 1.02270001060 Recreational Vehicles Speciality Vehicle Carts Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270002003 Construction Equipment Pavers Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002006 Construction Equipment Tampers/Rammers None None 1.00 1.00 1.00 1.00 1.00 1.02270002009 Construction Equipment Plate Compactors None None 1.00 1.00 1.00 1.00 1.00 1.02270002015 Construction Equipment Rollers Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002018 Construction Equipment Scrapers Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002021 Construction Equipment Paving Equipment Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002024 Construction Equipment Surfacing Equipment Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002027 Construction Equipment Signal Boards None None 1.00 1.00 1.00 1.00 1.00 1.02270002030 Construction Equipment Trenchers Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002033 Construction Equipment Bore/Drill Rigs None None 1.00 1.00 1.00 1.00 1.00 1.02270002036 Construction Equipment Excavators Excavator Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002039 Construction Equipment Concrete/Industrial Saws Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002042 Construction Equipment Cement & Mortar Mixers None None 1.00 1.00 1.00 1.00 1.00 1.02270002045 Construction Equipment Cranes None None 1.00 1.00 1.00 1.00 1.00 1.02270002048 Construction Equipment Graders Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002051 Construction Equipment Off-highway Trucks Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002054 Construction Equipment Crushing/Proc. Equipment None None 1.00 1.00 1.00 1.00 1.00 1.02270002057 Construction Equipment Rough Terrain Forklifts RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002060 Construction Equipment Rubber Tire Loaders RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002063 Construction Equipment Rubber Tire Dozers Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002066 Construction Equipment Tractors/Loaders/Backhoes Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270002069 Construction Equipment Crawler Dozer Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002072 Construction Equipment Skid Steer Loaders SSLoader Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270002075 Construction Equipment Off-Highway Tractors Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270002078 Construction Equipment Dumpers/Tenders Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270002081 Construction Equipment Other Construction

Equipment

Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.4

2270003010 Industrial Equipment Aerial Lifts Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270003020 Industrial Equipment Forklifts RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.4
Table A3. Transient Adjustment Factors by Equipment Type for Nonroad CI Equipment a

SCC Equipment Type Cycle TAF Assignment HC CO NOx PM 

Base-T3 Base-T3 Base, T0-T2 Tier 3 Base, T0-T2 Tie

A10

2270003030 Industrial Equipment Sweepers/Scrubbers None None 1.00 1.00 1.00 1.00 1.00 1.02270003040 Industrial Equipment Other General Industrial

Equipment

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270003050 Industrial Equipment Other Material Handling

Equipment

Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.3

2270003060 Industrial Equipment AC\Refrigeration None None 1.00 1.00 1.00 1.00 1.00 1.02270003070 Terminal Tractors Crawler Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270004000 Lawn & Garden Equipment ALL None None 1.00 1.00 1.00 1.00 1.00 1.02270004010 Lawn & Garden Equipment Lawn mowers

(Residential)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004011 Lawn & Garden Equipment Lawn mowers

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004015 Lawn & Garden Equipment Rotary Tillers < 6 HP None None 1.00 1.00 1.00 1.00 1.00 1.02270004016 Lawn & Garden Equipment Rotary Tillers < 6 HP

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004020 Lawn & Garden Equipment Chain Saws < 6 HP None None 1.00 1.00 1.00 1.00 1.00 1.02270004021 Lawn & Garden Equipment Chain Saws < 6 HP

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004025 Lawn & Garden Equipment Trimmers/Edgers/Brush

Cutters

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004026 Lawn & Garden Equipment Trimmers/Edgers/Brush

Cutters (Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004030 Lawn & Garden Equipment Leafblowers/Vacuums None None 1.00 1.00 1.00 1.00 1.00 1.02270004031 Lawn & Garden Equipment Leafblowers/Vacuums

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004035 Lawn & Garden Equipment Snowblowers None None 1.00 1.00 1.00 1.00 1.00 1.02270004036 Lawn & Garden Equipment Snowblowers 

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004040 Lawn & Garden Equipment Rear Engine Riding

Mowers

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004041 Lawn & Garden Equipment Rear Engine Riding

Mowers (Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004045 Lawn & Garden Equipment Front Mowers None None 1.00 1.00 1.00 1.00 1.00 1.02270004046 Lawn & Garden Equipment Front Mowers

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004050 Lawn & Garden Equipment Shredders < 6 HP None None 1.00 1.00 1.00 1.00 1.00 1.02270004051 Lawn & Garden Equipment Shredders < 6 HP

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0
Table A3. Transient Adjustment Factors by Equipment Type for Nonroad CI Equipment a

SCC Equipment Type Cycle TAF Assignment HC CO NOx PM 

Base-T3 Base-T3 Base, T0-T2 Tier 3 Base, T0-T2 Tie

A12

2270004055 Lawn & Garden Equipment Lawn & Garden Tractors None None 1.00 1.00 1.00 1.00 1.00 1.02270004056 Lawn & Garden Equipment Lawn & Garden Tractors

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004060 Lawn & Garden Equipment Wood Splitters None None 1.00 1.00 1.00 1.00 1.00 1.02270004061 Lawn & Garden Equipment Wood Splitters

(Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004065 Lawn & Garden Equipment Chippers/Stump

Grinders

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004066 Lawn & Garden Equipment Chippers/Stump

Grinders (Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004071 Lawn & Garden Equipment Commercial Turf

Equipment (Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004075 Lawn & Garden Equipment Other Lawn & Garden

Equipment

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270004076 Lawn & Garden Equipment Other Lawn & Garden

Equipment (Commercial)

None None 1.00 1.00 1.00 1.00 1.00 1.0

2270005010 Farm Equipment 2-Wheel Tractors AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005015 Farm Equipment Agricultural Tractors AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005020 Farm Equipment Combines AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005025 Farm Equipment Balers AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005030 Farm Equipment Agricultural Mowers AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005035 Farm Equipment Sprayers AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005040 Farm Equipment Tillers > 6 HP AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005045 Farm Equipment Swathers AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005050 Farm Equipment Hydro Power Units None None 1.00 1.00 1.00 1.00 1.00 1.02270005055 Farm Equipment Other Agricultural Equipment AgTractor Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270005060 Farm Equipment Irrigation Sets None None 1.00 1.00 1.00 1.00 1.00 1.02270006000 Light Commercial ALL None None 1.00 1.00 1.00 1.00 1.00 1.02270006005 Light Commercial Generator Sets None None 1.00 1.00 1.00 1.00 1.00 1.02270006010 Light Commercial Pumps None None 1.00 1.00 1.00 1.00 1.00 1.02270006015 Light Commercial Air Compressors None None 1.00 1.00 1.00 1.00 1.00 1.02270006020 Light Commercial Gas Compressors None None 1.00 1.00 1.00 1.00 1.00 1.02270006025 Light Commercial Welders ArcWelder Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270006030 Light Commercial Pressure Washers None None 1.00 1.00 1.00 1.00 1.00 1.02270007005 Logging Equipment Chain Saws > 6 HP RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270007010 Logging Equipment Shredders > 6 HP RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.4
Table A3. Transient Adjustment Factors by Equipment Type for Nonroad CI Equipment a

SCC Equipment Type Cycle TAF Assignment HC CO NOx PM 

Base-T3 Base-T3 Base, T0-T2 Tier 3 Base, T0-T2 Tie

A9

2270007015 Logging Equipment Forest Equipment RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.42270008005 Airport Service Equipment Airport Support

Equipment

RTLoader Hi LF 1.05 1.53 0.95 1.04 1.23 1.4

2270009010 Other Underground Mining Equipment Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.32270010010 Other Oil Field Equipment None None 1.00 1.00 1.00 1.00 1.00 1.02282020005 Recreational Pleasure Craft, Inboards None None 1.00 1.00 1.00 1.00 1.00 1.02282020010 Recreational Pleasure Craft, Outboards None None 1.00 1.00 1.00 1.00 1.00 1.02282020015 Recreational Pleasure Craft, Personal Water Craft None None 1.00 1.00 1.00 1.00 1.00 1.02282020025 Recreational Pleasure Craft, Sailboat Aux.

Outboard

None None 1.00 1.00 1.00 1.00 1.00 1.0

2285002015 Railway Maintenance Backhoe Lo LF 2.29 2.57 1.10 1.21 1.97 2.3

a TAFs are not applied to the emission factors for Tier 4 engines (i.e., the model applies a TAF of 1.0). “Base-T3” in this table refers to Tier 3 
A10

Table A4. Deterioration Factors for Nonroad Diesel Engines

Pollutant

Relative Deterioration Factor (A) 

(% increase/%useful life)

Base/Tier 0 Tier 1 Tier 2 Tier 3+

HC 0.047 0.036 0.034 0.027

CO 0.185 0.101 0.101 0.151

NOx 0.024 0.024 0.009 0.008

PM 0.473 0.473 0.473 0.473

DF =1+A*(fraction of useful life expended)B

B = 1 for diesel nonroad engines
B1

Appendix B

Sources of Previous Emission Factors for

Nonroad Compression Ignition Engines

There is little test data available on nonroad engines. Table B1 lists the data sources used

for EPA’s Nonroad Engine and Vehicle Study’s (NEVES) diesel emission factors. Published in

November, 1991, NEVES was mandated by Congress to determine whether nonroad sources

made a significant contribution to urban air pollution. It covers HC, CO, NOx, PM, SOx and

other pollutants. It provides inventories for 19 ozone and 16 CO nonattainment areas.

Table B1. Data sources for NEVES Diesel Emission Factors

Application Emissions Test 

Data Source

Notes

Lawn and Garden and

Light Commercial

None NEVES emission factors

were based on factors for

“continuous service diesel <

50 hp” SwRI, 1991, which

are based on Radian, 1988

factors for truck/container

refrigeration units.

Agriculture Cal/ERT, 1982

Construction EMA 

SwRI, 1973

Cal/ERT, 1982

NEVES emission factors

were based on EMA when

possible. For PM and for

applications not available

from EMA, factors were

taken from AP-42, which

relies on Cal/ERT for most

emission factors and on

SwRI, 1973 for PM and

SOx.

Logging (skidders) EMA 

Industrial and

Airport Service Equipment

SwRI, 1973

Recreational Marine

(Inboard)

NMMA
B2

Table B2 lists the data sources used for California’s Air Resources Board (ARB)

OFFROAD diesel emission factors. OFFROAD is designed to estimate nonroad emissions for

the state of California only. A version of this model was released in late summer 1997. It covers

HC, CO, NOx, PM, SO2, and CO2. The studies listed in the tables are described below. 

Table B2. Data sources for ARB OFFROAD Diesel Emission Factors

Horsepower Class Emissions Test 

Data Source

Notes

0-15 hp Manufacturers’ data--

2 Yanmar engines

1 Deutz engine

15-25 hp Manufacturers (ARB OffRoad Equipment Study,

1990)

25-50 hp Manufacturers Submissions

(ARB Off-Road Equipment

Study, 1990 )

50-125 hp Manufacturers (CA HD

Construction Study, 1988)

125-250

250+

Manufacturers (CA HD

Construction Study, 1988)

ARB factors on all engines

from 125 hp and above are

based on the same data, but

the weighting between turbocharged and naturally

aspirated engines is different

in the two horsepower

categories listed here.

Description and Citations of Sources used for Previous Emission Factors

Radian, 1988. Radian’s estimates of HC, CO, NOx and PM for truck/container

refrigeration units are not based on testing, but on Radian’s estimates for “typical small

direct injection and indirect injection diesel engines.” (Weaver, C.S., “Feasibility and

Cost Effectiveness of Controlling Emissions from Diesel Engines in Rail, Marine,

Construction, Farm and Other Mobile Off-Highway Equipment.” Final Report by Radian

Corporation for U.S. EPA, Office of Policy Analysis, under contract 68-01-7288,

February, 1988.) 

SwRI, 1973. Southwest Research Institute tested 8 diesel engines for HC, CO, NOx and
B3

PM. Emissions of SOx were calculated for no. 2 diesel fuel assuming sulfur content of

0.22%. BSFC is not stated. The emissions tests were given different weightings to

estimate industrial, construction and farm equipment emission factors. (Hare, C.T and

K.J. Springer. Exhaust Emission from Uncontrolled Vehicles and Related Equipment

Using Internal Combustion Engines, Final Report, Part 5, Heavy Duty Farm,

Construction and Agricultural Engines. San Antonio TX: Southwest Research Institute,

October 1973.)

EMA. Emission factors for 17 applications based on unknown number of tests, unknown

horsepower engines. Engine vintage unknown, but data was submitted by the Engine

Manufacturers Association to EPA prior to NEVES (1991). (Listed in NEVES table I06.)

Cal/ERT, 1982. Data from 13 engine manufacturers representing 391 models of

construction equipment. Raw data was aggregated by an accounting firm prior to

analysis and reporting. (Environmental Research and Technology, Inc. “Feasibility, Cost

and Air Quality Impact of Potential Emission Control Requirements on Farm,

Construction and Industrial Equipment in California”, Document PA841, sponsored by

the Farm and Industrial Equipment Institute, Engine Manufacturers Association, and

Construction Industry Manufacturers Association, May 1982.)

NMMA. The National Marine Manufacturers Association submitted data to EPA on HC,

CO, NOx and BSFC for 3 diesel inboard motors. Engine vintage unknown, but data was

submitted to EPA prior to NEVES (1991). (NEVES, Table I-11(e).)

ARB Off-Road Study, 1990. A study of lawn and garden and utility emissions. 

(Manufacturer Submissions to ARB on Exhaust Emission Standards for Utility and Lawn

and Garden Equipment Engines. California ARB, October 1990. EPA requests

assistance in locating this study)

ARB Heavy Duty Construction Study, 1988.1

 Reports HC, NOx and PM emission factors

based on emission information from four manufacturers. Does not include information

on test programs. It is not clear how data collected in the study was used to create the

inputs for the ARB model. (Energy and Environment Analysis, Inc. “ Feasibility of

Controlling Emissions from Off-Road, Heavy-Duty Construction Equipment.” Final

Report to the California Air Resources Board. Arlington, VA, December 1988.)
C1

Appendix C

1988-1995 (Tier 0) Zero-Hour, Steady-State Emission Factors and 

Fuel Sulfur Adjustment for Nonroad Compression Ignition Engines

Introduction

EPA’s 1991 Nonroad Engine and Vehicle Emission Study (NEVES) (1) used emission

factors for diesel engines based primarily on tests of older engines. All the NEVES particulate

matter (PM) emission factors are from tests conducted in 1972 and many of the other emissions

factors in NEVES are based on data from tests prior to 1982.

To better characterize emissions from more recent, pre-control engines, EPA analyzed

available emission test data on 1988-1995 nonroad diesel engines. This analysis provides the

basis for NONROAD pre-control emission factors for 1988-and-later engines greater than 50 hp,

as described in the main body of this report. The analysis indicated a significant difference in

emissions based on engine power. Engines between 50 and 100 horsepower in general had

higher emissions and fuel consumption than engines larger than 100 horsepower. Table C1

summarizes these results.

Table C1. Average Emission Test Results for 1988 to 1995 Model Year Engines

Engine

(Reference)

HC 

(g/hp-hr)

CO

(g/hp-hr)

NOx

(g/hp-hr)

PM 

(g/hp-hr)

BSFC 

(lb/hp-hr)

Average (50

to 100 hp)

0.99 3.49 8.30 0.722 0.408

Average

(>=100 hp)

0.68 2.70 8.38 0.402 0.367

A summary of test results for individual engines is presented in Table C2. Note that

testing was conducted using the current certification test procedure, also known as ISO-C1. The

procedure uses eight steady-state modes weighted by time to produce one number in units such

as grams per horsepower-hour. EPA adjusted this test data to account for differences between

the test fuel and typical in-use fuel sulfur levels of 0.33 wt. percent as explained below.
C2

Table C2. Summary of ISO-C1 Emission Results for 1988 through 1995 Engines

Engine

(Reference)

Model

Year

Age

(Hrs)

Fuel

Sulfur

(wt. %)

Power

Level

(hp)

HC 

(g/hp-hr)

CO 

(g/hp-hr)

NOx

(g/hp-hr)

PM 

(g/hp-hr)

BSFC

(lb/hp-hr)

Ford New

Holland (2)

1991 0 0.26 127 1.02 7.70 7.48 1.10 0.358

John Deere

7068T (2)

1990 0 0.26 139 0.45 2.98 11.74 0.41 0.349

Volvo TD

71G (avg. of

2) (3)

1984 0 0.046 144 0.47 1.64 12.68 0.149 0.373

Volvo TD73

KBE (avg. of

2) (3)

1992 0 0.046 139 0.64 0.85 4.52 0.12 0.386

Weterbeke

32BEDA (4)

1995 0 0.033 95 1.95 7.43 7.99 1.50 0.484

Caterpillar

3176B (4)

1995 0 0.033 451 0.09 2.94 6.37 0.213 0.358

Cummins

KTA19-M3

(4)

1995 0 0.033 599 0.68 3.26 8.78 0.257 0.359

Caterpillar

3306

(Nonroad) (5)

1990 0 0.26 285 1.1 1.4 6.5 0.18 0.354

Cummins 4BT

(Nonroad) (5)

1990 0 0.26 100 0.8 2.1 11 0.39 0.365

John Deere

4039D (6)

1991 0 0.25 72 0.6 3.5 7.2 0.59 0.385

Caterpillar

3116 (7)

1991 2,511 0.28 201 0.07 2.51 9.38 0.406 0.352

0.035 0.350

Caterpillar

3054 (7)

1991 1,964 0.28 85 0.66 1.00 7.53 0.387 0.393

0.035 0.340

John Deere 

4039 (7)

1994 2,265 0.28 86 0.41 2.17 11.22 0.384 0.389

0.035 0.256

John Deere 

7076 (7)

1993 3,300 0.28 174 0.53 2.05 10.22 0.250 0.385

0.035 0.205
(table continued from previous page)

Engine

(Reference)

Model

Year

Age

(Hrs)

Fuel

Sulfur

(wt. %)

Power

Level

(hp)

HC 

(g/hp-hr)

CO 

(g/hp-hr)

NOx

(g/hp-hr)

PM 

(g/hp-hr)

BSFC

(lb/hp-hr)

C3

Consolidated

Diesel

6TA-830 (7)

1990 4,370 0.28 226 0.86 1.50 6.53 0.397 0.365

0.035 0.338

John Deere

6619 (7)

1993 4,970 0.28 275 0.82 4.69 7.29 0.662 0.397

0.035 0.556

Consolidated

Diesel 4039

(7)

1988 3,570 

 

0.28 71 1.32 3.37 7.57 0.581 0.389

0.035 0.484

Caterpillar

3306 (7)

1990 6,700 0.28 278 1.27 1.46 6.52 0.248 0.373

0.035 0.245

Average 

(50 to 100 hp)

0.33 0.99 3.49 8.30 0.722* 0.408

Average

(>=100 hp)

0.33 0.68 2.70 8.38 0.402* 0.367

* Adjusted to the national average fuel sulfur level of 0.33 weight percent

Fuel Sulfur Adjustment

PM emissions from diesel engines are highly dependent on the sulfur content of the fuel

the engine is burning. PM emissions from diesel engines are generally comprised of unburned or

partially burned fuel, engine oil, and sulfur compounds. When the engine burns fuel, the fuel

sulfur is oxidized to both sulfur dioxide and sulfur trioxide. The sulfur trioxide rapidly absorbs

water to form hydrated sulfuric acid which condenses and is collected on filters as particulate

matter (PM) during emission testing. 

Because the sulfur content of diesel fuel can vary considerably, it is important to account

for fuel sulfur in establishing emission factors for PM. To adjust emission test data to the default

sulfur level used in NONROAD (0.33 wt. percent), EPA followed the approach described below.

 EPA measured particulate emissions from nine nonroad diesel engines using fuel with

two different sulfur levels, a typical highway diesel fuel at a sulfur level of 0.035 weight percent

and a typical nonroad diesel fuel doped to a sulfur level of 0.28 weight percent to simulate more

closely the average nonroad diesel fuel sulfur level of 0.33 weight percent. (8) Data from eight

of the engines is listed in Table C2, above. In addition, the study included a 1997 John Deere

nonroad engine. This engine is not shown in Table C2 because it is certified for the Tier 1

emission regulations and should not be used to determine an overall emission factor for pre-
C4

control engines. Test results from this study (including all 9 engines tested) were used to

determine the emission adjustment associated with fuel sulfur level. Other fuel parameter

differences such as cetane and fuel distillation that might also have affected particulate emissions

were ignored for this analysis. 

The study found that emissions of all pollutants were reduced by using highway fuel as

compared to the nonroad fuel; however, only the average PM reduction was statistically

significant at the 90% confidence level.

The particulate sulfur emission rate should be proportional to the fuel consumption and

the fuel sulfur level. By dividing the difference in particulate emissions by the difference in fuel

sulfur consumption, EPA calculated the average effect of fuel sulfur levels on PM emissions for

the nine engines, as shown in Table C3 below.

Table C3. Effects of Fuel Sulfur on PM Emissions

Engine MY

Fuel Sulfur PM BSFC Delta

PM

Delta Fuel

Sulfur

Consumed*

Delta PM

(wt percent) (g/hp-hr) (lb/hp-hr) (g/hp-hr) (g/hp-hr) / Delta

Sulfur

Cat 3116 1991 0.280 0.406 0.352 0.056 0.391 0.143

Cat 3116 1991 0.035 0.350 0.352

Cat 3054 1991 0.280 0.387 0.393 0.047 0.437 0.107

Cat 3054 1991 0.035 0.340 0.393

Deere 4039 1994 0.280 0.384 0.389 0.128 0.432 0.296

Deere 4039 1994 0.035 0.256 0.389

Deere 7076 1993 0.280 0.250 0.385 0.045 0.428 0.105

Deere 7076 1993 0.035 0.205 0.385

ConDsl 6TA-830 1990 0.280 0.397 0.365 0.059 0.405 0.146

ConDsl 6TA-830 1990 0.035 0.338 0.365

Deere 6619 1993 0.280 0.662 0.397 0.106 0.441 0.240

Deere 6619 1993 0.035 0.556 0.397

Con Dsl 4039 1988 0.280 0.581 0.389 0.097 0.432 0.225

Con Dsl 4039 1988 0.035 0.484 0.389

Cat 3306 1990 0.280 0.248 0.373 0.003 0.415 0.007

Cat 3306 1990 0.035 0.245 0.373

Deere 6101 1997 0.280 0.186 0.350 0.057 0.389 0.147

Deere 6101 1997 0.035 0.129 0.350

Average: 0.1573

* Delta fuel sulfur consumed (g S/hp-hr) = 0.01*(0.280-0.035)*BSFC*453.6 g/lb 
C5

The value of 0.1573 is the average change in PM emissions per change in grams of fuel

sulfur consumed. The change in PM emissions would be due to PM sulfate, so this can also be

expressed as the change in PM sulfate emissions per change in grams of fuel sulfur consumed. 

We assume that PM sulfate is H2SO4:7H20 (sulfuric acid hydrated seven times). For PM

sulfate, there is 7.0 grams sulfate per gram sulfur. Therefore, 0.1573 ÷7 = 0.02247 grams PM

sulfur per gram fuel sulfur consumed, which is the fraction of fuel sulfur converted to PM. In

the NONROAD model, the change in PM emissions per change in grams of fuel sulfur

consumed is expressed as the term, “soxcnv * 7,” where soxcnv is the fraction of fuel sulfur

converted to PM and 7 is the grams sulfate PM per gram sulfur. Soxcnv is equal to 0.02247 and

soxcnv * 7 is equal to 0.157 for diesel equipment not equipped with advanced oxidation catalyst

technologies. This applies to the Base, Tier 0, Tier 1, Tier 2, Tier 3, Tier 3B, Tier 4A, and Tier

4B technology types in NONROAD.

Consistent with our analysis in the Heavy-Duty (HD) 2007 highway rule, we have

assumed that the conversion of fuel sulfur to sulfate emissions for engines equipped with

advanced oxidation catalyst technologies (e.g., catalyzed diesel particulate filters) will be 30

percent. As a result, soxcnv is equal to 0.30 for the Tier 4 and Tier 4N technology types in

NONROAD. The balance (70 percent) of the fuel sulfur is assumed to be emitted as SO2. The

memo to EPA Air Docket A-99-06 Item II-B-32 documents the analysis from the HD 2007

rulemaking. Extensive discussion of diesel fuel sulfur oxidation to sulfate PM can be found in

Chapter 3 of the HD 2007 Final Regulatory Impact Analysis (RIA) and in Chapter 4 of the

nonroad Tier 4 RIA. The 30 percent conversion of fuel sulfur to sulfate represents an assumed

average rate; sulfur conversion rates can vary widely depending upon operating conditions and

catalyst technology.

The above analysis of engine test data provided the constant “A” in the equation below,

which describes the adjustment made to correct PM emissions from the test fuel sulfur level to

the default sulfur level of 0.33 weight percent.

PMBase = PM + BSFC * A * (0.0033 - Fuel Sulfur)

where

PMBase = PM emissions with default fuel, in g/hp-hr

PM = PM emissions with test fuel, in g/hp-hr

BSFC = Brake Specific Fuel Consumption in g/hp-hr

A = 0.157 g PM/hp-hr/Weight Fraction sulfur/BSFC

0.0033= the default weight fraction of fuel sulfur for nonroad diesel

 Fuel Sulfur = Weight Fraction of sulfur in test fuel

EPA then used this equation for all tests listed in Table C2 to correct PM emissions from

the test-fuel sulfur level to a fuel sulfur level of 0.33 wt.% before computing the averages listed

in Table C1 and at the bottom of Table C2. Since the engines tested are pre-Tier 4 technologies,

the constant “A” value of 0.157 was used in the equation. 
C6

References

(1)“Nonroad Engine and Vehicle Emission Study” (NEVES), U.S. EPA, Office of Air and

Radiation, 21A-2001. November, 1991.

(2) Doorlag, M. and M. Samulski. “Heavy-Duty Engine Testing Report: Non-Road Engine

Configurations, Test Results 1991" EPA Technical Report, 1991.

(3) Hedbom, A. “Emission tests of two Volvo//VME Heavy Duty Off Road Engines.”

Motortestcenter, Hanige, Sweden. MTC 9307A. March. 1994.

(4) Carroll, J.N. and C. M. Urban. “Emission Testing of Nonroad Compression Ignition

Engines.” Draft Final Report. Southwest Research Institute, 6886-802. September 1995.

(5) Fritz, S. G., “Dynamometer Testing of Heavy-Duty Diesel Engines to Support 

Non-Road Regulations,” SwRI Report No. 08-3426-010, Work Assignment 0-10 of 

EPA Contract No. 68-C0-0014 (September 1991).

(6) Smith, Michael. “Dynamometer Testing of Nonroad Diesel Engines to Support Nonroad

Regulations.” Southwest Research Institute, 08-4855-150, EPA Docket A-91-24, June 1992.

(7) Fritz, S. G. and M.E. Starr, “Emission Factors for Compression Ignition Nonroad Engines

Operated on Number 2 Highway and Nonroad Diesel Fuel,” Southwest Research Institute. EPA

contract # 68-C5-0077, SwRI 08-7601-822, March 1998.

(8) Korotney, David. “Estimates for In-Use Nonroad Diesel Fuel Levels,” Memorandum to

Docket A-96-40. July 1, 1997.
D1

Appendix D

Certification Data for Nonroad Compression Ignition Engines

Certification data were available and therefore used to develop zero-mile, steady-state

emission factors for Tier 1 engines in all hp categories and Tier 2 engines in the >300 to 600 hp

category. Certification data were extracted from the database as of October, 2001. Official test

results (OTR values) obtained with the nonroad 8-mode test procedure were used. Note that

emissions for some engines exceed the applicable standards if the engine families are part of the

Average Banking and Trading (ABT) program.

Tests were conducted with fuel meeting either diesel nonroad or diesel on-highway

specifications. For tests conducted on the Tier 1 engines with diesel on-highway fuel, the PM

emissions were adjusted from 350 ppm to 3300 ppm sulfur (the default diesel sulfur level used in

NONROAD), using the equation described in Appendix C. For tests conducted on the Tier 2

engines with diesel on-highway fuel, the PM emissions were adjusted from 350 ppm to 2000

ppm. An estimate of brake-specific fuel consumption is required to calculate the adjustment. If

the fuel rate for a certification test was reported, the engine-specific BSFC was calculated and

used directly. If the fuel rate was not reported, the default BSFC values in NONROAD were

used to calculate the adjustment.

The certification data were grouped by model year and by hp category. Sales-weighted

emission averages were calculated for each model year/hp category. Then, for each hp category,

a straight average of the applicable model year data were used. 

For categories less than 50 hp, the Tier 1 standard for HC and NOx is expressed as a

combination of HC and NOx (HC+NOx, refer to Table 1). As a result, most of the certification

data for these engines is provided as the sum of HC and NOx, although there are some data

reported for HC and NOx separately. To obtain separate HC and NOx emission factors for

categories less than 50 hp, HC fractions of HC+NOx emissions were calculated for those tests

which reported both HC and HC+NOx emission factors. The average HC fraction was then

calculated and multiplied by the sales-weighted average HC+NOx emission factor to obtain an

HC emission factor (referred to as HC calc in the tables). The remaining fraction of the

HC+NOx emission factor was assigned as the NOx emission factor (referred to as NOx calc in the

tables). This was done for each model year and for each of the hp categories less than 50 hp

(i.e., 0-11 hp, 11-25 hp, 25-50 hp).

Table D1 presents a summary of the results, as well as the sample sizes for each

pollutant/model year/hp category. The numbers in bold are those used in the model. Tables D2-

D7 present the individual engine emissions data and sales weightings for each model year and hp

category. The engine identification and specific sales information have been removed. For

categories less than 50 hp, the HC fractions, HC calc emission factors, and NOx calc emission

factors are also provided. The HC calc and NOx calc emission factors are used in the model.
D2

Table D1. Summary of Certification Data for Nonroad Compression Ignition Engines*

>0 to 11 hp

g/hp-hr HC NOx HC+NOx CO PM HC frac HC calc NOx calc

2000 0.692103 5.170337 5.966223 4.051366 0.452858 0.113196 0.675351 5.290871

2001 0.828378 5.073763 6.018891 4.174066 0.44201 0.141247 0.850153 5.168738

average 0.760241 5.12205 5.992557 4.1127 0.4474 0.7628 5.2298

sample size HC NOx HC+NOx CO PM

2000 4 6 20 20 20

2001 5 5 19 19 19

total 9 11 39 39 39

>11 to 25 hp

g/hp-hr HC NOx HC+NOx CO PM HC frac HC calc NOx calc

2000 0.489983 3.749647 4.9489 2.207041 0.289982 0.081156 0.401631 4.547269

2001 0.447831 4.109521 4.80692 2.114884 0.242992 0.09869 0.474395 4.332525

average 0.468907 3.929584 4.87791 2.1610 0.2665 0.4380 4.4399

sample size HC NOx HC+NOx CO PM

2000 9 10 40 39 40

2001 16 16 43 43 43

total 25 26 83 82 83

>25 to 50 hp

g/hp-hr HC NOx HC+NOx CO PM HC frac HC calc NOx calc

1999 0.496458 4.558405 4.983359 1.54213 0.35614 0.047095 0.23469 4.748669

2000 0.452946 4.893606 5.083919 1.522782 0.331337 0.056039 0.284899 4.79902

2001 0.472917 4.469647 4.952901 1.532028 0.329222 0.064006 0.317014 4.635887

average 0.474107 4.640553 5.006726 1.5323 0.3389 0.2789 4.7279

sample size HC NOx HC+NOx CO PM

1999 11 15 72 72 72

2000 14 22 95 96 96

2001 25 35 103 104 104

total 50 72 270 272 272
D3

Table D1. Summary of Certification Data for Nonroad Compression Ignition Engines

(cont)*

>50 to 100 hp

g/hp-hr HC NOx HC+NOx CO PM

1998 0.528845 5.682411 4.235576 2.753546 0.472055

1999 0.517642 5.613376 6.569501 2.34687 0.452553

2000 0.46289 5.494892 4.235576 2.047055 0.460428

2001 0.575867 5.604515 5.976957 2.314372 0.506824

average 0.5213 5.5988 5.254402 2.3655 0.4730

sample size HC NOx HC+NOx CO PM

1998 18 71 1 21 19

1999 27 91 3 33 31

2000 35 104 1 38 36

2001 40 127 3 47 43

total 120 393 8 139 129

>100 to 175 hp

g/hp-hr HC NOx HC+NOx CO PM

1997 0.297479 5.599201 0.745072 0.281314

1998 0.355336 5.743938 0.961288 0.276378

1999 0.35159 5.749792 0.93731 0.270345

2000 0.33246 5.593736 0.68581 0.282059

2001 0.355107 5.574714 1.003922 0.28934

average 0.3384 5.6523 0.8667 0.2799

sample size HC NOx HC+NOx CO PM

1997 29 43 0 29 25

1998 25 52 0 27 24

1999 25 59 0 27 25

2000 27 61 0 29 28

2001 34 69 0 37 36

total 140 284 0 149 138

>175 to 300 hp

g/hp-hr HC NOx HC+NOx CO PM

1996 0.331633 5.667602 0.834876 0.239994

1997 0.307044 5.723983 0.819777 0.24542

1998 0.316321 5.574079 0.722968 0.262486

1999 0.314974 5.549376 0.695869 0.257528

2000 0.26631 5.441729 4.54 0.666725 0.240685

2001 0.314765 5.506545 4.203295 0.744633 0.266622

average 0.3085 5.5772 4.371648 0.7475 0.2521

sample size HC NOx HC+NOx CO PM

1996 44 44 0 44 44

1997 43 43 0 43 43

1998 72 72 0 72 72

1999 71 71 0 71 71

2000 64 64 2 64 64

2001 86 86 6 88 88

total 380 380 8 382 382
D4

Table D1. Summary of Certification Data for Nonroad Compression Ignition Engines

(cont)*

>300 to 600 hp

g/hp-hr HC NOx HC+NOx CO PM

1996 0.260521 6.264393 1.353145 0.195978

1997 0.1553 5.865363 1.431343 0.213156

1998 0.209071 6.126551 1.289223 0.198893

1999 0.201521 6.04976 1.201752 0.192703

2000 0.186024 5.77026 5.24 1.254546 0.203148

average 0.2025 6.0153 5.24 1.3060 0.2008

2001Tier 2 0.1669 4.3351 4.345348 0.8425 0.1316

sample size HC NOx HC+NOx CO PM

1996 40 40 0 40 40

1997 35 35 0 35 35

1998 48 48 0 48 48

1999 55 55 0 55 55

2000 51 51 1 51 51

2001 14 14 35 35 35

total 243 243 36 264 264

>600 to 750 hp

g/hp-hr HC NOx HC+NOx CO PM

1996 0.174804 6.063537 1.502117 0.242149

1997 0.135125 5.872338 1.571034 0.236991

1998 0.190719 5.866023 1.277422 0.205116

1999 0.118392 5.723896 1.361031 0.227162

2000 0.126821 5.790567 1.368105 0.225632

2001 0.138065 5.612418 3.975047 0.883305 0.183773

average 0.1473 5.8215 3.975047 1.3272 0.2201

sample size HC NOx HC+NOx CO PM

1996 11 11 0 11 11

1997 10 10 0 10 10

1998 12 12 0 12 12

1999 13 13 0 13 13

2000 15 15 0 15 15

2001 16 16 3 17 17

total 77 77 3 78 78
D5

Table D1. Summary of Certification Data for Nonroad Compression Ignition Engines

(cont)*

>750 hp

g/hp-hr HC NOx HC+NOx CO PM

2000 0.25906 6.252638 0.727419 0.183308

2001 0.313093 6.052394 0.800887 0.203589

average 0.2861 6.1525 0.7642 0.1934

sample size HC NOx HC+NOx CO PM

2000 16 16 0 16 16

2001 18 18 0 18 18

total 34 34 0 34 34

* Values in bold are used in NONROAD. All are Tier 1 emission factors, with the exception

that both Tier 1 and Tier 2 emission factors are provided for the >300 to 600 hp category.
D6

Table D2. 1996 MY Certification Data

175 to 300 hp Emission Factors (g/hp-hr)

Rated HP HC NOx CO PM Sales wgt

261 0.47 6.06 0.89 0.27 0.0005

248 0.34 5.31 1.04 0.35 0.0005

215 0.32 5.51 0.55 0.33 0.0628

260 0.44 5.81 0.70 0.27 0.0398

240 0.29 5.38 0.49 0.27 0.0545

260 0.37 5.73 1.30 0.31 0.0177

225 0.41 5.70 0.84 0.15 0.0862

275 0.11 4.56 1.25 0.18 0.0174

258 0.05 6.34 0.89 0.22 0.0064

275 0.08 4.93 1.80 0.25 0.0034

220 0.11 6.16 0.89 0.20 0.0563

200 0.26 5.12 0.60 0.22 0.0910

215 0.32 5.51 0.55 0.33 0.1054

260 0.44 5.80 0.70 0.27 0.0652

240 0.29 5.38 0.49 0.27 0.0362

255 0.46 6.11 0.52 0.20 0.0014

296 0.31 6.41 0.96 0.18 0.0005

196 0.28 5.44 0.65 0.21 0.0074

287 0.33 5.94 1.16 0.21 0.1080

263 0.43 6.13 2.68 0.24 0.0322

275 0.46 6.51 1.19 0.15 0.0273

216 0.59 6.20 1.55 0.20 0.0262

293 0.09 6.20 0.46 0.12 0.0018

261 0.30 4.38 0.69 0.23 0.0050

194 0.30 6.26 0.80 0.17 0.0024

280 0.25 4.03 0.56 0.18 0.0005

241 0.41 6.44 1.11 0.26 0.0036

193 0.60 6.69 0.85 0.28 0.0025

215 0.32 5.51 0.55 0.33 0.0136

240 0.29 5.38 0.49 0.27 0.0362

189 0.31 5.40 0.92 0.16 0.0020

252 0.22 6.23 0.30 0.17 0.0058

273 0.31 4.46 0.48 0.08 0.0009

248 0.34 5.31 1.04 0.35 0.0005

275 0.10 4.14 0.78 0.13 0.0028

210 0.16 6.85 1.47 0.17 0.0043

225 0.11 6.63 0.57 0.06 0.0014

228 0.36 5.45 0.59 0.21 0.0504

182 0.42 6.43 0.87 0.32 0.0072

207 0.44 6.59 1.15 0.36 0.0045

188 0.37 5.51 0.63 0.18 0.0018

235 0.31 6.18 0.52 0.13 0.0018

201 0.42 5.38 0.63 0.16 0.0018

255 0.43 6.43 0.76 0.20 0.0027

Sales-wgt EF 0.331633 5.667602 0.834876 0.239994 1.0000

Sample Size 44 44 44 44
D7

Table D2. 1996 MY Certification Data (cont.)

300 to 600 hp Emission Factors (g/hp-hr)

Rated HP HC NOx CO PM Sales wgt

335 0.27 5.51 0.74 0.28 0.0013

543 2.24 5.66 0.54 0.24 0.0010

300 0.28 6.13 0.81 0.28 0.0249

330 0.34 5.27 1.07 0.28 0.0075

362 0.16 5.49 1.57 0.13 0.3220

425 0.09 6.38 2.18 0.08 0.0155

500 0.17 8.19 2.24 0.13 0.0078

455 0.12 5.48 0.82 0.17 0.0039

542 0.07 6.05 1.43 0.31 0.0959

300 0.08 5.78 0.43 0.05 0.0093

397 0.19 4.65 1.35 0.19 0.0216

535 0.08 5.79 2.10 0.34 0.0186

515 0.05 6.05 1.44 0.21 0.0180

300 0.31 5.50 0.41 0.22 0.0052

480 0.17 6.85 1.16 0.17 0.0833

525 0.25 6.36 0.45 0.15 0.0104

375 0.40 6.03 1.51 0.20 0.0339

337 0.41 5.99 1.31 0.22 0.0170

300 0.51 8.03 1.28 0.21 0.1823

313 0.10 6.55 0.49 0.14 0.0039

440 0.39 6.55 0.43 0.18 0.0052

568 0.37 6.46 2.17 0.37 0.0124

350 0.78 6.32 1.30 0.37 0.0357

400 0.10 6.28 0.49 0.14 0.0129

412 0.35 6.51 1.76 0.30 0.0039

322 0.23 5.00 0.87 0.23 0.0026

563 0.18 4.56 0.48 0.18 0.0078

305 0.24 6.29 0.72 0.29 0.0044

335 0.19 5.78 0.41 0.10 0.0003

349 0.20 5.41 0.34 0.15 0.0016

526 0.17 6.06 0.60 0.16 0.0003

493 0.16 5.89 0.95 0.20 0.0005

573 0.14 5.86 0.62 0.17 0.0005

571 0.31 3.98 0.48 0.11 0.0026

308 0.28 5.68 0.45 0.18 0.0021

335 0.27 5.51 0.74 0.28 0.0023

543 0.22 5.66 0.54 0.25 0.0037

300 0.07 4.54 0.51 0.15 0.0052

300 0.07 6.35 0.52 0.04 0.0078

369 0.24 5.43 0.51 0.14 0.0052

Sales-wgt EF 0.260521 6.264393 1.353145 0.195978 1.0000

Sample Size 40 40 40 40
D8

Table D2. 1996 MY Certification Data (cont.)

600 to 750 hp Emission Factors (g/hp-hr)

Rated HP HC NOx CO PM Sales wgt

750 0.07 5.90 1.29 0.22 0.1010

750 0.07 5.84 0.90 0.16 0.0056

750 0.08 6.01 1.92 0.30 0.1330

750 0.35 5.80 1.48 0.29 0.0859

660 0.05 6.24 0.83 0.14 0.1627

740 0.10 5.53 1.63 0.33 0.1324

640 0.10 5.62 0.83 0.19 0.0056

730 0.05 5.04 0.99 0.18 0.0960

600 0.46 6.86 1.46 0.23 0.1403

710 0.25 6.64 2.42 0.27 0.1347

740 0.24 5.85 1.37 0.21 0.0028

Sales-wgt EF 0.174804 6.063537 1.502117 0.242149 1.0000

Sample Size 11 11 11 11
D9

Table D3. 1997 MY Certification Data

100 to 175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

100 0.35 6.08 0.70 0.28 0.0015 0.0011 0.0015 0.0015

125 0.23 6.21 0.47 0.16 0.0087 0.0069 0.0087 0.0090

165 0.36 4.95 0.75 0.31 0.1552 0.1226 0.1552 0.1597

110 6.06 0.0000 0.0174 0.0000 0.0000

165 6.24 0.0000 0.0915 0.0000 0.0000

166 4.95 0.0000 0.0022 0.0000 0.0000

100 0.35 6.08 0.70 0.30 0.0102 0.0080 0.0102 0.0104

125 0.23 6.21 0.47 0.16 0.1001 0.0790 0.1001 0.1030

165 0.36 4.95 0.75 0.31 0.2320 0.1833 0.2320 0.2388

114 0.39 4.88 0.88 0.0038 0.0030 0.0038 0.0000

141 0.39 4.97 2.30 0.0057 0.0045 0.0057 0.0000

134 0.33 6.59 1.15 0.17 0.0218 0.0172 0.0218 0.0224

168 0.43 6.52 1.25 0.17 0.0044 0.0034 0.0044 0.0045

110 0.75 6.18 2.60 0.41 0.0058 0.0046 0.0058 0.0060

158 0.51 6.26 1.28 0.38 0.0247 0.0195 0.0247 0.0254

153 5.65 0.0000 0.0206 0.0000 0.0000

134 6.51 0.0000 0.0041 0.0000 0.0000

103 6.26 0.0000 0.0069 0.0000 0.0000

106 6.01 0.0000 0.0018 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0022 0.0017 0.0022 0.0022

125 0.23 6.21 0.47 0.16 0.0015 0.0011 0.0015 0.0015

165 0.36 4.95 0.75 0.31 0.0537 0.0424 0.0537 0.0552

162 0.62 6.11 0.90 0.29 0.0035 0.0028 0.0035 0.0036

130 5.58 0.0000 0.0115 0.0000 0.0000

134 6.08 0.0000 0.0183 0.0000 0.0000

131 5.18 0.0000 0.0115 0.0000 0.0000

157 0.12 6.55 1.15 0.13 0.0125 0.0099 0.0125 0.0128

168 0.11 6.63 0.57 0.06 0.0091 0.0072 0.0091 0.0094

108 0.17 5.99 0.37 0.17 0.0242 0.0191 0.0242 0.0249

166 0.38 6.21 0.56 0.22 0.0182 0.0143 0.0182 0.0187

121 0.68 6.11 1.22 0.18 0.0085 0.0067 0.0085 0.0087

108 0.20 5.63 0.70 0.32 0.2393 0.1890 0.2393 0.2463

103 6.19 0.0000 0.0128 0.0000 0.0000

172 0.13 5.31 0.45 0.25 0.0258 0.0204 0.0258 0.0266

130 0.64 6.70 1.23 0.36 0.0004 0.0003 0.0004 0.0004

102 6.68 0.0000 0.0023 0.0000 0.0000

172 6.23 0.0000 0.0069 0.0000 0.0000

117 6.23 0.0000 0.0023 0.0000 0.0000

173 0.54 6.57 1.83 0.42 0.0029 0.0023 0.0029 0.0030

122 0.07 5.75 1.06 0.34 0.0029 0.0023 0.0029 0.0030

122 0.12 4.12 0.64 0.0030 0.0024 0.0030 0.0000

161 0.23 5.96 0.83 0.0160 0.0126 0.0160 0.0000

161 0.34 5.26 1.05 0.19 0.0029 0.0023 0.0029 0.0030

Sales-wgt EF 0.297479 5.599201 0.745072 0.281314 1.0000 1.0000 1.0000 1.0000

Sample Size 29 43 29 25
D10

Table D3. 1997 MY Certification Data (cont.)

175 to 300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

261 0.47 6.06 0.89 0.27 0.0048 0.0048 0.0048 0.0048

248 0.34 5.31 1.04 0.35 0.0060 0.0060 0.0060 0.0060

280 0.47 5.47 0.52 0.23 0.1439 0.1439 0.1439 0.1439

260 0.37 5.73 1.30 0.39 0.0282 0.0282 0.0282 0.0282

246 0.34 5.27 1.07 0.36 0.0056 0.0056 0.0056 0.0056

225 0.41 5.70 0.84 0.22 0.1444 0.1444 0.1444 0.1444

220 0.11 6.16 0.89 0.27 0.1523 0.1523 0.1523 0.1523

275 0.11 4.56 1.25 0.26 0.0489 0.0489 0.0489 0.0489

205 0.19 5.96 1.73 0.25 0.0060 0.0060 0.0060 0.0060

260 0.08 6.48 0.82 0.29 0.0854 0.0854 0.0854 0.0854

275 0.08 4.93 1.80 0.32 0.0116 0.0116 0.0116 0.0116

280 0.47 5.47 0.52 0.23 0.0059 0.0059 0.0059 0.0059

260 0.46 6.11 0.52 0.27 0.0104 0.0104 0.0104 0.0104

188 0.50 5.29 1.31 0.37 0.0045 0.0045 0.0045 0.0045

296 0.23 4.78 0.72 0.21 0.0013 0.0013 0.0013 0.0013

264 0.64 6.38 2.37 0.41 0.0085 0.0085 0.0085 0.0085

250 0.10 6.41 0.54 0.12 0.0040 0.0040 0.0040 0.0040

189 0.43 6.65 1.04 0.34 0.0053 0.0053 0.0053 0.0053

261 0.30 4.38 0.69 0.23 0.0240 0.0240 0.0240 0.0240

194 0.30 6.26 0.80 0.17 0.0133 0.0133 0.0133 0.0133

189 0.37 5.87 0.76 0.28 0.0069 0.0069 0.0069 0.0069

241 0.41 6.44 1.11 0.26 0.0115 0.0115 0.0115 0.0115

227 0.51 6.72 1.07 0.31 0.0101 0.0101 0.0101 0.0101

193 0.60 6.69 0.85 0.28 0.0051 0.0051 0.0051 0.0051

296 0.42 5.77 0.82 0.25 0.0008 0.0008 0.0008 0.0008

234 0.31 4.22 0.51 0.08 0.0027 0.0027 0.0027 0.0027

248 0.34 5.31 1.04 0.35 0.0044 0.0044 0.0044 0.0044

247 0.57 6.13 0.69 0.17 0.0011 0.0011 0.0011 0.0011

240 0.35 5.36 0.54 0.23 0.0053 0.0053 0.0053 0.0053

225 0.14 6.73 0.64 0.16 0.0008 0.0008 0.0008 0.0008

228 0.36 5.45 0.59 0.21 0.1289 0.1289 0.1289 0.1289

253 0.55 4.64 1.10 0.29 0.0133 0.0133 0.0133 0.0133

182 0.42 6.43 0.87 0.29 0.0027 0.0027 0.0027 0.0027

207 0.44 6.59 1.15 0.36 0.0027 0.0027 0.0027 0.0027

183 0.54 6.63 0.81 0.34 0.0016 0.0016 0.0016 0.0016

227 0.35 0.63 0.51 0.27 0.0016 0.0016 0.0016 0.0016

272 0.35 6.44 1.09 0.23 0.0027 0.0027 0.0027 0.0027

255 0.25 5.85 0.40 0.13 0.0373 0.0373 0.0373 0.0373

255 0.25 6.22 1.10 0.14 0.0250 0.0250 0.0250 0.0250

188 0.37 5.51 0.60 0.18 0.0053 0.0053 0.0053 0.0053

235 0.31 6.41 0.54 0.13 0.0053 0.0053 0.0053 0.0053

201 0.42 5.38 0.63 0.16 0.0053 0.0053 0.0053 0.0053

255 0.43 6.43 0.76 0.20 0.0053 0.0053 0.0053 0.0053

Sales-wgt EF 0.307044 5.723983 0.819777 0.245420 1.0000 1.0000 1.0000 1.0000

Sample Size 43 43 43 43
D11

Table D3. 1997 MY Certification Data (cont.)

300 to 600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

335 0.27 5.51 0.74 0.28 0.0004 0.0004 0.0004 0.0004

543 0.22 5.66 0.54 0.24 0.0035 0.0035 0.0035 0.0035

425 0.09 6.38 2.18 0.16 0.0282 0.0282 0.0282 0.0282

300 0.28 6.13 0.81 0.36 0.0339 0.0339 0.0339 0.0339

397 0.19 4.65 1.35 0.19 0.0261 0.0261 0.0261 0.0261

362 0.16 5.49 1.57 0.21 0.4232 0.4232 0.4232 0.4232

373 0.17 8.19 2.24 0.21 0.0141 0.0141 0.0141 0.0141

455 0.12 5.48 0.82 0.17 0.0023 0.0023 0.0023 0.0023

599 0.04 6.59 2.67 0.33 0.1521 0.1521 0.1521 0.1521

492 0.05 6.24 0.83 0.14 0.0052 0.0052 0.0052 0.0052

535 0.08 5.79 2.10 0.34 0.0065 0.0065 0.0065 0.0065

559 0.07 5.84 0.90 0.16 0.0004 0.0004 0.0004 0.0004

300 0.08 5.78 0.43 0.13 0.0173 0.0173 0.0173 0.0173

307 0.10 6.52 0.51 0.14 0.0069 0.0069 0.0069 0.0069

430 0.38 6.58 0.43 0.18 0.0177 0.0177 0.0177 0.0177

425 0.08 6.44 0.76 0.16 0.0355 0.0355 0.0355 0.0355

413 0.35 6.51 1.76 0.29 0.0140 0.0140 0.0140 0.0140

590 0.34 6.40 0.72 0.23 0.0002 0.0002 0.0002 0.0002

313 0.18 4.56 0.48 0.18 0.0121 0.0121 0.0121 0.0121

305 0.24 6.29 0.72 0.29 0.0089 0.0089 0.0089 0.0089

493 0.16 4.26 1.04 0.30 0.0024 0.0024 0.0024 0.0024

426 0.31 3.98 0.48 0.11 0.0040 0.0040 0.0040 0.0040

308 0.28 5.68 0.45 0.20 0.0019 0.0019 0.0019 0.0019

335 0.27 5.51 0.74 0.28 0.0115 0.0115 0.0115 0.0115

543 0.22 5.66 0.54 0.16 0.0275 0.0275 0.0275 0.0275

308 0.38 5.70 0.39 0.18 0.0002 0.0002 0.0002 0.0002

330 0.07 5.07 0.44 0.12 0.0270 0.0270 0.0270 0.0270

320 0.12 7.41 0.51 0.08 0.0008 0.0008 0.0008 0.0008

300 0.08 5.62 0.45 0.12 0.0121 0.0121 0.0121 0.0121

381 0.21 6.55 0.61 0.08 0.0403 0.0403 0.0403 0.0403

496 0.13 6.12 0.28 0.07 0.0379 0.0379 0.0379 0.0379

369 0.24 6.50 0.51 0.14 0.0081 0.0081 0.0081 0.0081

526 0.45 5.59 0.67 0.11 0.0081 0.0081 0.0081 0.0081

315 0.34 5.48 0.79 0.13 0.0081 0.0081 0.0081 0.0081

362 0.37 5.29 0.82 0.12 0.0016 0.0016 0.0016 0.0016

Sales-wgt EF 0.155300 5.865363 1.431343 0.213156 1.0000 1.0000 1.0000 1.0000

Sample Size 35 35 35 35
D12

Table D3. 1997 MY Certification Data (cont.)

600 to 750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

740 0.04 5.67 1.57 0.25 0.3355 0.3355 0.3355 0.3355

750 0.08 6.01 1.92 0.30 0.0205 0.0205 0.0205 0.0205

740 0.10 5.53 1.63 0.33 0.0169 0.0169 0.0169 0.0169

640 0.10 5.62 0.83 0.19 0.0319 0.0319 0.0319 0.0319

743 0.05 5.04 0.99 0.18 0.1004 0.1004 0.1004 0.1004

750 0.07 5.90 1.29 0.22 0.0771 0.0771 0.0771 0.0771

600 0.26 6.02 1.78 0.24 0.1597 0.1597 0.1597 0.1597

710 0.25 6.64 2.42 0.27 0.1643 0.1643 0.1643 0.1643

750 0.13 5.89 1.07 0.13 0.0479 0.0479 0.0479 0.0479

748 0.30 6.04 0.45 0.24 0.0456 0.0456 0.0456 0.0456

Sales-wgt EF 0.135125 5.872338 1.571034 0.236991 1.0000 1.0000 1.0000 1.0000

Sample Size 10 10 10 10
D13

Table D4. 1998 MY Certification Data

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt CO wgt PM wgt

67 6.40 0.0000 0.0071 0.0000 0.0000

79 5.74 0.0000 0.0024 0.0000 0.0000

96 5.81 0.0000 0.0006 0.0000 0.0000

80 0.48 7.61 4.32 0.56 0.2600 0.0914 0.2581 0.0000

67 0.75 6.35 1.96 0.34 0.1418 0.0499 0.1408 0.0000

80 0.72 5.78 3.26 0.51 0.2786 0.0979 0.2765 0.0000

98 0.71 6.30 1.68 0.21 0.0009 0.0003 0.0009 0.0000

62 6.23 0.0000 0.0012 0.0000 0.0000

57 6.20 0.0000 0.0012 0.0000 0.0000

59 6.56 0.0000 0.0310 0.0000 0.0000

84 5.74 0.0000 0.0413 0.0000 0.0000

64 5.92 0.0000 0.0049 0.0000 0.0000

82 5.23 0.0000 0.0605 0.0000 0.0000

53 6.32 0.0000 0.0175 0.0000 0.0000

72 6.30 0.0000 0.0006 0.0000 0.0000

78 6.22 0.0000 0.0001 0.0000 0.0000

52 4.59 0.0000 0.0208 0.0000 0.0000

50 4.14 0.0000 0.0036 0.0000 0.0000

51 0.60 6.68 3.04 0.63 0.0004 0.0001 0.0004 0.0000

55 0.39 6.16 0.98 0.28 0.0118 0.0042 0.0117 0.0000

64 0.43 5.62 2.17 0.60 0.0254 0.0089 0.0252 0.0000

73 0.29 5.35 1.08 0.52 0.0118 0.0042 0.0117 0.0000

56 0.48 4.88 0.46 0.27 0.0016 0.0006 0.0016 0.0000

79 0.55 5.25 2.47 0.55 0.0258 0.0091 0.0256 0.0000

91 0.42 6.63 1.32 0.54 0.0133 0.0047 0.0132 0.0000

59 6.65 0.0000 0.0170 0.0000 0.0000

62 6.23 0.0000 0.0012 0.0000 0.0000

80 0.72 5.78 3.26 0.51 0.0051 0.0018 0.0050 0.0000

98 0.71 6.30 1.68 0.21 0.0009 0.0003 0.0009 0.0000

59 4.37 0.0000 0.0042 0.0000 0.0000

56 4.18 0.0000 0.0148 0.0000 0.0000

86 5.42 0.0000 0.0047 0.0000 0.0000

93 4.71 0.0000 0.0030 0.0000 0.0000

72 4.31 0.0000 0.0059 0.0000 0.0000

54 0.55 6.31 2.42 0.0077 0.0027 0.0076 0.0000

65 0.05 4.18 4.24 0.90 0.0010 0.0003 0.0010 1.0000

54 2.62 0.0000 0.0057 0.0000 0.0000

50 4.38 0.0000 0.0190 0.0000 0.0000

89 5.98 0.0000 0.0066 0.0000 0.0000

72 4.63 0.0000 0.0145 0.0000 0.0000

78 6.05 0.0000 0.0101 0.0000 0.0000

52 6.32 0.0000 0.0060 0.0000 0.0000

67 0.14 4.94 1.07 0.45 0.1213 0.0426 0.1204 0.0000

92 0.27 5.62 0.99 0.27 0.0834 0.0293 0.0828 0.0000

55 2.62 0.0000 0.0015 0.0000 0.0000

85 2.18 0.0000 0.0018 0.0000 0.0000

59 5.90 0.0000 0.0006 0.0000 0.0000
Table D4. 1998 MY Certification Data

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D14

58 3.23 0.0000 0.0297 0.0000 0.0000

52 6.62 0.0000 0.0125 0.0000 0.0000

64 5.13 0.0000 0.0064 0.0000 0.0000

60 6.06 0.0000 0.0297 0.0000 0.0000

96 5.09 0.0000 0.0861 0.0000 0.0000

72 6.30 0.0000 0.0025 0.0000 0.0000

68 5.85 0.0000 0.0772 0.0000 0.0000

68 6.44 0.0000 0.0504 0.0000 0.0000

80 0.86 5.40 4.00 0.64 0.0091 0.0032 0.0091 0.0000

59 4.33 0.0000 0.0036 0.0000 0.0000

84 6.14 0.0000 0.0012 0.0000 0.0000

94 5.75 0.0000 0.0003 0.0000 0.0000

82 4.84 1.22 0.44 0.0000 0.0011 0.0032 0.0000

60 5.87 3.96 0.39 0.0000 0.0006 0.0017 0.0000

62 6.19 1.69 0.30 0.0000 0.0009 0.0026 0.0000

75 3.87 0.0000 0.0046 0.0000 0.0000

58 3.91 0.0000 0.0069 0.0000 0.0000

54 5.40 0.0000 0.0003 0.0000 0.0000

67 4.89 0.0000 0.0148 0.0000 0.0000

80 4.80 0.0000 0.0006 0.0000 0.0000

60 4.12 0.0000 0.0042 0.0000 0.0000

70 5.59 0.0000 0.0006 0.0000 0.0000

56 5.23 0.0000 0.0018 0.0000 0.0000

58 5.12 0.0000 0.0033 0.0000 0.0000

Sales-wgt

EF

0.528

845

5.682

411

4.23557

6

2.7535

46

0.4720

55 1.0000 1.0000 1.0000 1.0000

Sample

Size 18 71 1 21 19
D15

Table D4. 1998 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

167 0.34 5.26 1.05 0.18 0.0003 0.0003 0.0003 0.0003

108 6.47 0.0000 0.0009 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.1104 0.0940 0.1101 0.1112

125 0.23 6.21 0.47 0.16 0.0041 0.0035 0.0041 0.0042

165 0.36 4.95 0.75 0.31 0.0647 0.0551 0.0645 0.0652

110 6.06 0.0000 0.0062 0.0000 0.0000

165 6.24 0.0000 0.0336 0.0000 0.0000

166 4.95 0.0000 0.0029 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.1765 0.1504 0.1760 0.1779

125 0.23 6.21 0.47 0.16 0.0537 0.0457 0.0535 0.0541

165 0.36 4.95 0.75 0.31 0.1891 0.1611 0.1886 0.1906

158 6.53 0.0000 0.0018 0.0000 0.0000

109 6.41 0.0000 0.0018 0.0000 0.0000

133 6.44 0.0000 0.0018 0.0000 0.0000

172 6.48 0.0000 0.0018 0.0000 0.0000

114 0.52 6.54 1.18 0.0014 0.0012 0.0014 0.0000

141 3.71 0.0000 0.0018 0.0000 0.0000

135 0.40 5.70 1.75 0.29 0.2535 0.2160 0.2528 0.2555

155 6.39 0.0000 0.0021 0.0000 0.0000

124 6.60 0.0000 0.0068 0.0000 0.0000

103 6.22 0.0000 0.0310 0.0000 0.0000

158 6.26 0.0000 0.0077 0.0000 0.0000

103 0.57 6.26 1.58 0.39 0.0033 0.0028 0.0033 0.0033

153 0.51 5.65 0.49 0.26 0.0126 0.0108 0.0126 0.0127

106 6.01 0.0000 0.0095 0.0000 0.0000

144 6.61 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0085 0.0072 0.0085 0.0086

125 0.23 6.21 0.47 0.16 0.0012 0.0010 0.0012 0.0012

165 0.36 4.95 0.75 0.31 0.0140 0.0119 0.0140 0.0141

114 5.87 0.0000 0.0049 0.0000 0.0000

148 0.16 6.58 0.70 0.13 0.0003 0.0003 0.0003 0.0003

168 0.34 6.17 0.63 0.13 0.0002 0.0002 0.0002 0.0002

162 0.62 6.11 0.90 0.28 0.0006 0.0005 0.0006 0.0006

108 6.11 0.0000 0.0137 0.0000 0.0000

113 4.41 0.0000 0.0020 0.0000 0.0000

108 0.17 5.99 0.37 0.17 0.0555 0.0473 0.0553 0.0559

121 0.68 6.11 1.22 0.18 0.0117 0.0100 0.0117 0.0118

166 0.38 6.21 0.56 0.22 0.0196 0.0167 0.0195 0.0197

118 6.30 0.0000 0.0006 0.0000 0.0000

103 6.19 0.0000 0.0070 0.0000 0.0000

103 0.53 5.30 1.24 0.51 0.0018 0.0015 0.0018 0.0018

100 0.57 5.50 1.35 0.47 0.0024 0.0020 0.0023 0.0024

102 6.68 0.0000 0.0027 0.0000 0.0000

127 5.38 0.0000 0.0009 0.0000 0.0000

117 6.23 0.0000 0.0009 0.0000 0.0000

172 6.23 0.0000 0.0027 0.0000 0.0000

173 0.54 6.57 1.83 0.42 0.0032 0.0027 0.0032 0.0032
Table D4. 1998 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D16

123 4.12 0.64 0.0000 0.0015 0.0018 0.0018

122 0.07 5.75 1.06 0.44 0.0021 0.0018 0.0021 0.0022

142 5.92 1.33 0.31 0.0000 0.0010 0.0011 0.0011

138 6.68 0.0000 0.0004 0.0000 0.0000

161 0.23 5.96 0.83 0.0092 0.0078 0.0092 0.0000

Sales-wgt

EF 0.355336 5.743938 0.961288 0.276378 1.0000 1.0000 1.0000 1.0000

Sample

Size 25 52 27 24
D17

Table D4. 1998 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

257 0.43 6.43 0.76 0.20 0.0002 0.0002 0.0002 0.0002

261 0.47 6.06 0.89 0.27 0.0013 0.0013 0.0013 0.0013

248 0.34 5.31 1.04 0.35 0.0011 0.0011 0.0011 0.0011

200 0.26 5.13 0.60 0.22 0.0124 0.0124 0.0124 0.0124

215 0.32 5.51 0.55 0.32 0.0184 0.0184 0.0184 0.0184

260 0.44 5.82 0.70 0.27 0.0222 0.0222 0.0222 0.0222

240 0.29 5.38 0.49 0.27 0.0222 0.0222 0.0222 0.0222

278 0.13 4.70 0.51 0.15 0.0061 0.0061 0.0061 0.0061

280 0.47 5.47 0.52 0.23 0.0160 0.0160 0.0160 0.0160

275 0.11 4.56 1.26 0.26 0.0049 0.0049 0.0049 0.0049

205 0.19 5.96 1.73 0.25 0.0056 0.0056 0.0056 0.0056

260 0.17 6.48 0.82 0.29 0.0108 0.0108 0.0108 0.0108

290 0.10 5.60 2.19 0.32 0.0030 0.0030 0.0030 0.0030

260 0.42 6.16 1.30 0.39 0.0018 0.0018 0.0018 0.0018

225 0.41 5.70 0.84 0.22 0.0253 0.0253 0.0253 0.0253

275 0.04 4.76 0.31 0.14 0.0013 0.0013 0.0013 0.0013

200 0.26 5.13 0.60 0.22 0.0726 0.0726 0.0726 0.0726

215 0.32 5.51 0.55 0.32 0.0749 0.0749 0.0749 0.0749

260 0.44 5.82 0.70 0.27 0.0616 0.0616 0.0616 0.0616

240 0.29 5.38 0.49 0.27 0.0738 0.0738 0.0738 0.0738

284 0.41 5.76 0.52 0.22 0.0042 0.0042 0.0042 0.0042

200 0.19 4.05 0.92 0.28 0.0016 0.0016 0.0016 0.0016

253 0.34 6.58 0.57 0.21 0.0016 0.0016 0.0016 0.0016

188 0.50 5.29 1.31 0.37 0.0007 0.0007 0.0007 0.0007

256 0.46 6.11 0.52 0.27 0.0016 0.0016 0.0016 0.0016

296 0.23 4.78 0.72 0.21 0.0002 0.0002 0.0002 0.0002

261 0.47 6.06 0.89 0.27 0.0002 0.0002 0.0002 0.0002

220 0.20 5.87 0.72 0.27 0.0050 0.0050 0.0050 0.0050

234 0.19 5.45 0.62 0.25 0.0104 0.0104 0.0104 0.0104

196 0.28 5.44 0.65 0.28 0.3023 0.3023 0.3023 0.3023

197 0.23 5.52 0.75 0.29 0.0074 0.0074 0.0074 0.0074

263 0.43 6.13 2.68 0.31 0.0040 0.0040 0.0040 0.0040

294 0.38 5.99 0.95 0.23 0.1154 0.1154 0.1154 0.1154

280 0.49 6.14 2.52 0.31 0.0157 0.0157 0.0157 0.0157

294 0.64 6.38 2.37 0.40 0.0007 0.0007 0.0007 0.0007

283 0.09 6.38 0.51 0.12 0.0020 0.0020 0.0020 0.0020

196 0.35 6.52 0.95 0.36 0.0006 0.0006 0.0006 0.0006

240 0.29 4.88 0.73 0.23 0.0056 0.0056 0.0056 0.0056

187 0.26 5.99 0.73 0.15 0.0026 0.0026 0.0026 0.0026

189 0.37 5.87 0.76 0.35 0.0016 0.0016 0.0016 0.0016

241 0.41 6.44 1.11 0.34 0.0028 0.0028 0.0028 0.0028

227 0.51 6.72 1.07 0.33 0.0006 0.0006 0.0006 0.0006

193 0.60 6.69 0.85 0.28 0.0010 0.0010 0.0010 0.0010

296 0.38 6.19 0.54 0.22 0.0002 0.0002 0.0002 0.0002

255 0.42 5.77 0.82 0.26 0.0006 0.0006 0.0006 0.0006

200 0.26 5.13 0.60 0.22 0.0036 0.0036 0.0036 0.0036

215 0.32 5.51 0.55 0.32 0.0049 0.0049 0.0049 0.0049
Table D4. 1998 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D18

240 0.29 5.38 0.49 0.27 0.0052 0.0052 0.0052 0.0052

189 0.31 5.40 0.92 0.21 0.0010 0.0010 0.0010 0.0010

252 0.22 6.23 0.30 0.23 0.0027 0.0027 0.0027 0.0027

211 0.37 5.42 0.57 0.22 0.0004 0.0004 0.0004 0.0004

253 0.23 5.28 0.47 0.27 0.0002 0.0002 0.0002 0.0002

231 0.32 4.69 0.46 0.15 0.0005 0.0005 0.0005 0.0005

260 0.18 6.35 0.73 0.15 0.0016 0.0016 0.0016 0.0016

275 0.14 5.38 0.48 0.14 0.0002 0.0002 0.0002 0.0002

248 0.34 5.31 1.04 0.35 0.0001 0.0001 0.0001 0.0001

247 0.57 6.13 0.69 0.17 0.0004 0.0004 0.0004 0.0004

225 0.11 6.63 0.57 0.13 0.0028 0.0028 0.0028 0.0028

210 0.12 6.55 1.15 0.20 0.0048 0.0048 0.0048 0.0048

225 0.14 6.73 0.64 0.16 0.0018 0.0018 0.0018 0.0018

228 0.37 5.46 0.60 0.21 0.0294 0.0294 0.0294 0.0294

190 0.66 6.08 1.56 0.40 0.0005 0.0005 0.0005 0.0005

268 0.44 6.50 0.50 0.30 0.0024 0.0024 0.0024 0.0024

182 0.42 6.43 0.87 0.30 0.0004 0.0004 0.0004 0.0004

207 0.44 6.59 1.15 0.36 0.0004 0.0004 0.0004 0.0004

217 0.36 5.49 1.00 0.22 0.0004 0.0004 0.0004 0.0004

183 0.54 6.63 0.81 0.34 0.0002 0.0002 0.0002 0.0002

227 0.35 0.63 0.51 0.27 0.0002 0.0002 0.0002 0.0002

244 0.19 6.30 1.66 0.36 0.0016 0.0016 0.0016 0.0016

272 0.35 6.44 1.09 0.23 0.0016 0.0016 0.0016 0.0016

255 0.25 5.89 0.40 0.13 0.0056 0.0056 0.0056 0.0056

255 0.25 6.22 1.10 0.14 0.0033 0.0033 0.0033 0.0033

Sales-wgt

EF 0.316321 5.574079 0.722968 0.262486 1.0000 1.0000 1.0000 1.0000

Sample 

Size 72 72 72 72
D19

Table D4. 1998 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

310 0.34 5.48 0.79 0.13 0.0011 0.0011 0.0011 0.0011

373 0.24 6.50 0.51 0.14 0.0011 0.0011 0.0011 0.0011

335 0.27 5.51 0.74 0.28 0.0002 0.0002 0.0002 0.0002

543 0.22 5.66 0.54 0.24 0.0016 0.0016 0.0016 0.0016

300 0.08 5.78 0.43 0.13 0.0036 0.0036 0.0036 0.0036

425 0.90 6.38 2.17 0.16 0.0514 0.0514 0.0514 0.0514

300 0.28 6.13 0.81 0.36 0.0118 0.0118 0.0118 0.0118

330 0.33 5.28 1.07 0.36 0.0111 0.0111 0.0111 0.0111

397 0.19 5.24 1.35 0.29 0.0040 0.0040 0.0040 0.0040

362 0.16 5.49 1.57 0.21 0.2369 0.2369 0.2369 0.2369

500 0.13 6.10 1.67 0.17 0.0257 0.0257 0.0257 0.0257

455 0.12 5.48 0.82 0.17 0.0029 0.0029 0.0029 0.0029

599 0.04 6.59 2.67 0.33 0.0715 0.0715 0.0715 0.0715

350 0.22 6.52 1.17 0.20 0.1676 0.1676 0.1676 0.1676

525 0.25 6.36 0.45 0.15 0.0032 0.0032 0.0032 0.0032

480 0.17 6.85 1.16 0.18 0.1718 0.1718 0.1718 0.1718

336 0.14 5.48 0.45 0.15 0.0070 0.0070 0.0070 0.0070

375 0.40 6.03 2.02 0.28 0.0012 0.0012 0.0012 0.0012

336 0.41 5.99 1.31 0.30 0.0084 0.0084 0.0084 0.0084

399 0.18 5.33 0.91 0.14 0.0285 0.0285 0.0285 0.0285

339 0.21 5.72 0.92 0.15 0.0020 0.0020 0.0020 0.0020

517 0.17 5.74 0.37 0.13 0.0630 0.0630 0.0630 0.0630

401 0.23 6.02 0.50 0.14 0.0090 0.0090 0.0090 0.0090

313 0.13 6.38 0.59 0.15 0.0077 0.0077 0.0077 0.0077

420 0.36 6.65 0.47 0.18 0.0118 0.0118 0.0118 0.0118

425 0.08 6.44 0.76 0.15 0.0193 0.0193 0.0193 0.0193

567 0.28 5.65 2.26 0.33 0.0010 0.0010 0.0010 0.0010

586 0.20 4.64 0.45 0.18 0.0029 0.0029 0.0029 0.0029

329 0.26 6.38 0.61 0.19 0.0018 0.0018 0.0018 0.0018

590 0.34 6.40 0.72 0.23 0.0001 0.0001 0.0001 0.0001

306 0.24 6.29 0.72 0.37 0.0086 0.0086 0.0086 0.0086

493 0.16 4.26 1.04 0.30 0.0037 0.0037 0.0037 0.0037

335 0.19 5.78 0.41 0.18 0.0002 0.0002 0.0002 0.0002

375 0.22 5.72 0.32 0.20 0.0014 0.0014 0.0014 0.0014

525 0.17 6.06 0.60 0.23 0.0002 0.0002 0.0002 0.0002

493 0.16 5.89 0.95 0.28 0.0004 0.0004 0.0004 0.0004

572 0.14 5.86 0.62 0.24 0.0004 0.0004 0.0004 0.0004

571 0.31 3.98 0.48 0.17 0.0021 0.0021 0.0021 0.0021

531 0.36 5.01 0.40 0.16 0.0021 0.0021 0.0021 0.0021

327 0.22 6.39 0.46 0.14 0.0021 0.0021 0.0021 0.0021

327 0.24 6.11 0.48 0.13 0.0021 0.0021 0.0021 0.0021

308 0.30 5.67 0.45 0.18 0.0018 0.0018 0.0018 0.0018

335 0.27 5.51 0.74 0.28 0.0027 0.0027 0.0027 0.0027

543 0.02 5.66 0.54 0.24 0.0064 0.0064 0.0064 0.0064

330 0.07 5.07 0.44 0.10 0.0068 0.0068 0.0068 0.0068

330 0.04 5.64 0.40 0.16 0.0114 0.0114 0.0114 0.0114

381 0.21 6.55 0.61 0.08 0.0167 0.0167 0.0167 0.0167
Table D4. 1998 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D20

496 0.13 6.12 0.28 0.07 0.0021 0.0021 0.0021 0.0021

Sales-wgt

EF 0.209071 6.126551 1.289223 0.198893 1.0000 1.0000 1.0000 1.0000

Sample

Size 48 48 48 48

Table D4. 1998 MY Certification Data (cont.)

600-750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

660 0.10 6.03 0.54 0.13 0.0630 0.0630 0.0630 0.0630

640 0.11 5.62 0.83 0.19 0.0132 0.0132 0.0132 0.0132

740 0.10 5.53 1.62 0.33 0.0350 0.0350 0.0350 0.0350

600 0.26 6.02 1.78 0.24 0.2955 0.2955 0.2955 0.2955

606 0.16 6.01 0.58 0.12 0.1128 0.1128 0.1128 0.1128

725 0.16 5.88 0.84 0.12 0.0855 0.0855 0.0855 0.0855

750 0.07 5.84 0.90 0.16 0.0210 0.0210 0.0210 0.0210

750 0.07 5.90 1.29 0.22 0.1089 0.1089 0.1089 0.1089

750 0.06 4.48 1.43 0.24 0.0389 0.0389 0.0389 0.0389

750 0.35 5.80 1.48 0.30 0.1322 0.1322 0.1322 0.1322

750 0.13 5.89 1.06 0.13 0.0855 0.0855 0.0855 0.0855

740 0.24 5.85 1.37 0.28 0.0086 0.0086 0.0086 0.0086

Sales-wgt

EF 0.190719 5.866023 1.277422 0.205116 1.0000 1.0000 1.0000 1.0000

Sample 

Size 12 12 12 12
D21

Table D5. 1999 MY Certification Data

25-50 hp Emission Factors (g/hp-hr) Sales Weighting

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

34 5.21 1.44 0.38 0.0000 0.0000 0.0107 0.0107 0.0107

36 3.12 1.31 0.40 0.0000 0.0000 0.0011 0.0011 0.0011

45 5.95 0.48 0.26 0.0000 0.0000 0.0011 0.0011 0.0011

50 6.14 0.0000 0.1061 0.0000 0.0000 0.0000

38 6.69 1.92 0.32 0.0000 0.0000 0.0113 0.0113 0.0113

35 5.68 1.74 0.21 0.0000 0.0000 0.0282 0.0282 0.0282

39 6.58 1.84 0.11 0.0000 0.0000 0.0068 0.0068 0.0068

47 5.84 1.35 0.09 0.0000 0.0000 0.0056 0.0056 0.0056

28 3.76 1.24 0.20 0.0000 0.0000 0.0025 0.0025 0.0025

33 3.65 0.87 0.17 0.0000 0.0000 0.0033 0.0033 0.0033

40 4.50 0.62 0.20 0.0000 0.0000 0.0013 0.0013 0.0013

47 3.38 0.87 0.27 0.0000 0.0000 0.0007 0.0007 0.0007

27 5.66 1.62 0.56 0.0000 0.0000 0.0008 0.0008 0.0008

29 4.11 1.16 0.35 0.0000 0.0000 0.0310 0.0310 0.0310

40 2.78 1.62 0.42 0.0000 0.0000 0.0507 0.0507 0.0507

45 4.04 0.87 0.38 0.0000 0.0000 0.0158 0.0158 0.0158

28 3.57 2.65 0.43 0.0000 0.0000 0.0017 0.0017 0.0017

27 0.17 4.29 4.46 1.25 0.52 0.038763 0.0019 0.0014 0.0003 0.0003 0.0003

37 0.16 3.56 3.72 2.30 0.60 0.043011 0.0027 0.0020 0.0004 0.0004 0.0004

32 0.26 4.22 4.49 1.61 0.54 0.058036 0.0360 0.0262 0.0048 0.0048 0.0048

27 0.09 3.95 4.04 0.82 0.42 0.022277 0.0046 0.0034 0.0006 0.0006 0.0006

39 0.14 4.59 4.74 0.90 0.45 0.029598 0.0115 0.0084 0.0016 0.0016 0.0016

34 0.16 3.30 3.46 0.68 0.30 0.046243 0.0028 0.0020 0.0004 0.0004 0.0004

35 0.56 4.54 5.10 1.52 0.48 0.109804 0.8386 0.6112 0.1127 0.1127 0.1127

34 0.08 4.56 4.64 0.90 0.40 0.017241 0.0616 0.0449 0.0083 0.0083 0.0083

40 0.69 6.18 6.88 1.62 0.25 0.100868 0.0046 0.0034 0.0006 0.0006 0.0006

34 4.59 0.92 0.42 0.0000 0.0000 0.0001 0.0001 0.0001

46 3.79 0.68 0.33 0.0000 0.0000 0.0008 0.0008 0.0008

34 3.80 0.98 0.54 0.0000 0.0000 0.0058 0.0058 0.0058

47 0.12 6.71 6.83 0.74 0.30 0.01757 0.0042 0.0031 0.0006 0.0006 0.0006

38 6.16 1.66 0.41 0.0000 0.0000 0.0451 0.0451 0.0451

26 4.64 1.30 0.28 0.0000 0.0000 0.0011 0.0011 0.0011

31 3.80 1.16 0.36 0.0000 0.0000 0.0163 0.0163 0.0163

42 3.84 0.77 0.24 0.0000 0.0000 0.0047 0.0047 0.0047

26 4.46 0.96 0.35 0.0000 0.0000 0.0417 0.0417 0.0417

41 4.81 0.75 0.25 0.0000 0.0000 0.0008 0.0008 0.0008

31 5.27 0.74 0.19 0.0000 0.0000 0.0118 0.0118 0.0118

31 5.11 0.80 0.26 0.0000 0.0000 0.0662 0.0662 0.0662

37 4.47 0.80 0.29 0.0000 0.0000 0.1936 0.1936 0.1936

40 0.18 4.99 5.17 0.94 0.48 0.034632 0.0315 0.0230 0.0042 0.0042 0.0042

30 2.79 3.06 0.46 0.0000 0.0000 0.0013 0.0013 0.0013

38 3.62 2.13 0.51 0.0000 0.0000 0.0025 0.0025 0.0025

25 5.78 3.66 0.43 0.0000 0.0000 0.0045 0.0045 0.0045

33 2.37 1.58 0.53 0.0000 0.0000 0.0017 0.0017 0.0017

30 5.29 1.50 0.33 0.0000 0.0000 0.0008 0.0008 0.0008

35 5.48 1.61 0.36 0.0000 0.0000 0.0025 0.0025 0.0025
Table D5. 1999 MY Certification Data

25-50 hp Emission Factors (g/hp-hr) Sales Weighting

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D22

40 5.53 2.57 0.22 0.0000 0.0000 0.0025 0.0025 0.0025

44 5.56 1.69 0.34 0.0000 0.0000 0.0017 0.0017 0.0017

44 5.96 2.39 0.19 0.0000 0.0000 0.0017 0.0017 0.0017

38 6.00 1.25 0.36 0.0000 0.0000 0.0001 0.0001 0.0001

30 6.51 3.22 0.50 0.0000 0.0000 0.0034 0.0034 0.0034

39 4.73 1.01 0.34 0.0000 0.0000 0.0021 0.0021 0.0021

35 6.27 2.35 0.48 0.0000 0.0000 0.0118 0.0118 0.0118

44 6.19 1.09 0.53 0.0000 0.0000 0.0225 0.0225 0.0225

34 3.53 3.55 1.22 0.54 0.0000 0.0458 0.0085 0.0085 0.0085

49 3.20 3.31 1.29 0.40 0.0000 0.0917 0.0169 0.0169 0.0169

49 4.85 0.0000 0.0275 0.0000 0.0000 0.0000

28 5.78 3.61 0.40 0.0000 0.0000 0.0152 0.0152 0.0152

30 5.82 2.93 0.35 0.0000 0.0000 0.0026 0.0026 0.0026

33 5.76 2.74 0.28 0.0000 0.0000 0.0596 0.0596 0.0596

41 5.97 1.35 0.49 0.0000 0.0000 0.0006 0.0006 0.0006

29 5.82 2.82 0.25 0.0000 0.0000 0.0070 0.0070 0.0070

37 6.76 1.71 0.40 0.0000 0.0000 0.0007 0.0007 0.0007

37 6.03 2.59 0.35 0.0000 0.0000 0.0098 0.0098 0.0098

30 6.07 3.01 0.38 0.0000 0.0000 0.0169 0.0169 0.0169

45 5.85 3.21 0.45 0.0000 0.0000 0.0423 0.0423 0.0423

38 5.79 3.23 0.39 0.0000 0.0000 0.0011 0.0011 0.0011

48 6.00 1.56 0.44 0.0000 0.0000 0.0001 0.0001 0.0001

34 5.94 1.87 0.34 0.0000 0.0000 0.0507 0.0507 0.0507

46 6.01 2.54 0.20 0.0000 0.0000 0.0039 0.0039 0.0039

41 5.76 2.79 0.33 0.0000 0.0000 0.0041 0.0041 0.0041

48 6.25 1.59 0.28 0.0000 0.0000 0.0002 0.0002 0.0002

27 3.04 0.98 0.40 0.0000 0.0000 0.0036 0.0036 0.0036

39 5.53 1.96 0.26 0.0000 0.0000 0.0015 0.0015 0.0015

Sales-wgt

EF 0.4965 4.5584 4.9834 1.5421 0.3561 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 11 15 72 72 72 0.047095

Calc HC* 0.2347

Calc NOx* 4.7487

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D23

Table D5. 1999 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx CO wgt PM wgt

67 6.40 0.0000 0.0035 0.0000 0.0000 0.0000

79 5.74 0.0000 0.0007 0.0000 0.0000 0.0000

96 5.81 0.0000 0.0005 0.0000 0.0000 0.0000

80 0.48 7.61 4.32 0.56 0.1942 0.0652 0.0000 0.1802 0.1814

67 0.75 6.35 1.96 0.34 0.1177 0.0395 0.0000 0.1092 0.1100

75 0.70 5.68 2.28 0.49 0.1618 0.0544 0.0000 0.1502 0.1512

80 0.72 5.78 3.26 0.51 0.0647 0.0217 0.0000 0.0601 0.0605

56 0.46 5.71 2.19 0.29 0.0309 0.0104 0.0000 0.0287 0.0289

75 0.70 5.68 2.28 0.49 0.0486 0.0163 0.0000 0.0451 0.0454

98 0.71 6.30 1.68 0.21 0.0008 0.0003 0.0000 0.0008 0.0008

62 6.23 0.0000 0.0010 0.0000 0.0000 0.0000

57 6.20 0.0000 0.0010 0.0000 0.0000 0.0000

55 5.80 0.0000 0.0010 0.0000 0.0000 0.0000

59 6.56 0.0000 0.0216 0.0000 0.0000 0.0000

84 5.74 0.0000 0.0306 0.0000 0.0000 0.0000

59 0.89 8.82 3.55 0.84 0.0099 0.0033 0.0000 0.0092 0.0092

74 5.82 0.0000 0.0045 0.0000 0.0000 0.0000

82 5.23 0.0000 0.0552 0.0000 0.0000 0.0000

53 6.32 0.0000 0.0280 0.0000 0.0000 0.0000

56 6.70 2.22 0.34 0.0000 0.0000 0.9552 0.0655 0.0660

60 6.16 0.0000 0.0173 0.0000 0.0000 0.0000

72 6.30 0.0000 0.0018 0.0000 0.0000 0.0000

56 5.21 0.0000 0.0040 0.0000 0.0000 0.0000

70 5.02 0.0000 0.0005 0.0000 0.0000 0.0000

96 6.32 0.0000 0.0006 0.0000 0.0000 0.0000

74 3.22 0.0000 0.0049 0.0000 0.0000 0.0000

78 6.22 0.0000 0.0000 0.0000 0.0000 0.0000

52 4.59 0.0000 0.0148 0.0000 0.0000 0.0000

50 4.14 0.0000 0.0030 0.0000 0.0000 0.0000

52 0.17 5.22 1.18 0.45 0.0049 0.0016 0.0000 0.0045 0.0045

54 0.69 4.15 1.45 0.36 0.0183 0.0062 0.0000 0.0170 0.0171

51 0.60 6.68 3.04 0.63 0.0003 0.0001 0.0000 0.0003 0.0003

61 0.46 6.07 1.33 0.32 0.0121 0.0041 0.0000 0.0112 0.0113

64 0.43 5.62 2.17 0.60 0.0056 0.0019 0.0000 0.0052 0.0052

73 0.24 4.79 0.87 0.52 0.0110 0.0037 0.0000 0.0102 0.0103

56 0.48 4.88 0.46 0.27 0.0003 0.0001 0.0000 0.0003 0.0003

63 0.52 6.27 1.67 0.57 0.0118 0.0040 0.0000 0.0109 0.0110

71 0.55 5.27 2.17 0.57 0.0236 0.0079 0.0000 0.0219 0.0221

91 0.42 6.63 1.32 0.54 0.0287 0.0096 0.0000 0.0266 0.0268

59 6.65 0.0000 0.0230 0.0000 0.0000 0.0000

80 0.72 5.78 3.26 0.51 0.0044 0.0015 0.0000 0.0041 0.0041

98 0.71 6.30 1.68 0.21 0.0008 0.0003 0.0000 0.0008 0.0008

56 0.46 5.71 2.19 0.29 0.0002 0.0001 0.0000 0.0002 0.0002

59 4.37 0.0000 0.0022 0.0000 0.0000 0.0000

56 4.18 0.0000 0.0148 0.0000 0.0000 0.0000

86 5.42 0.0000 0.0089 0.0000 0.0000 0.0000

93 4.71 0.0000 0.0074 0.0000 0.0000 0.0000
Table D5. 1999 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx CO wgt PM wgt

D24

72 4.31 0.0000 0.0119 0.0000 0.0000 0.0000

54 0.55 6.31 2.42 0.0060 0.0020 0.0000 0.0056 0.0000

58 0.08 3.32 3.41 0.89 0.0011 0.0004 0.0149 0.0010 0.0000

59 3.34 0.0000 0.0002 0.0000 0.0000 0.0000

54 2.62 0.0000 0.0047 0.0000 0.0000 0.0000

79 5.06 0.0000 0.0002 0.0000 0.0000 0.0000

50 4.09 0.80 0.25 0.0000 0.0000 0.0299 0.0020 0.0021

57 4.46 0.0000 0.0061 0.0000 0.0000 0.0000

55 2.91 0.0000 0.0014 0.0000 0.0000 0.0000

51 5.35 0.0000 0.0083 0.0000 0.0000 0.0000

87 5.92 0.0000 0.0058 0.0000 0.0000 0.0000

52 6.32 0.0000 0.0050 0.0000 0.0000 0.0000

89 6.40 0.0000 0.0005 0.0000 0.0000 0.0000

67 0.14 4.94 1.07 0.45 0.1378 0.0463 0.0000 0.1279 0.1288

92 0.27 5.62 0.99 0.27 0.0902 0.0303 0.0000 0.0837 0.0842

58 3.00 0.0000 0.0012 0.0000 0.0000 0.0000

85 2.18 0.0000 0.0013 0.0000 0.0000 0.0000

59 5.90 0.0000 0.0010 0.0000 0.0000 0.0000

58 3.23 0.0000 0.0247 0.0000 0.0000 0.0000

81 5.43 0.0000 0.0059 0.0000 0.0000 0.0000

52 6.62 0.0000 0.0104 0.0000 0.0000 0.0000

64 5.13 0.0000 0.0049 0.0000 0.0000 0.0000

60 6.06 0.0000 0.0247 0.0000 0.0000 0.0000

96 5.09 0.0000 0.1503 0.0000 0.0000 0.0000

68 5.85 0.0000 0.0652 0.0000 0.0000 0.0000

68 6.34 0.0000 0.0420 0.0000 0.0000 0.0000

80 0.83 6.00 3.19 0.63 0.0063 0.0021 0.0000 0.0059 0.0059

80 0.86 5.40 4.00 0.64 0.0079 0.0027 0.0000 0.0074 0.0074

59 4.33 0.0000 0.0030 0.0000 0.0000 0.0000

84 6.14 0.0000 0.0010 0.0000 0.0000 0.0000

94 5.75 0.0000 0.0003 0.0000 0.0000 0.0000

82 4.84 1.22 0.44 0.0000 0.0010 0.0000 0.0029 0.0029

62 6.06 3.96 0.39 0.0000 0.0000 0.0000 0.0001 0.0001

100 6.27 0.87 0.41 0.0000 0.0003 0.0000 0.0007 0.0007

62 6.19 1.69 0.30 0.0000 0.0003 0.0000 0.0007 0.0007

75 3.87 0.0000 0.0020 0.0000 0.0000 0.0000

58 3.91 0.0000 0.0022 0.0000 0.0000 0.0000

54 5.40 0.0000 0.0001 0.0000 0.0000 0.0000

67 4.89 0.0000 0.0163 0.0000 0.0000 0.0000

80 4.80 0.0000 0.0005 0.0000 0.0000 0.0000

56 5.23 0.0000 0.0020 0.0000 0.0000 0.0000

58 5.12 0.0000 0.0004 0.0000 0.0000 0.0000

60 4.12 0.0000 0.0025 0.0000 0.0000 0.0000

70 5.59 0.0000 0.0049 0.0000 0.0000 0.0000

93 5.35 0.0000 0.0005 0.0000 0.0000 0.0000

100 5.73 0.0000 0.0002 0.0000 0.0000 0.0000
Table D5. 1999 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx CO wgt PM wgt

D25

Sales-wgt

EF

0.5176

42

5.6133

76

6.56950

1

2.34

687

0.452

553 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 27 91 3 33 31
D26

Table D5. 1999 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

167 0.34 5.26 1.05 0.18 0.0004 0.0003 0.0004 0.0004

108 6.47 0.0000 0.0005 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.1343 0.1074 0.1342 0.1355

125 0.23 6.21 0.47 0.16 0.0048 0.0039 0.0048 0.0049

155 0.38 4.23 0.75 0.35 0.1246 0.0996 0.1245 0.1257

110 6.06 0.0000 0.0014 0.0000 0.0000

165 6.24 0.0000 0.0373 0.0000 0.0000

166 4.95 0.0000 0.0030 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.2077 0.1660 0.2075 0.2095

125 0.23 6.21 0.47 0.16 0.1179 0.0942 0.1178 0.1189

158 6.53 0.0000 0.0020 0.0000 0.0000

109 6.41 0.0000 0.0020 0.0000 0.0000

133 6.50 0.0000 0.0020 0.0000 0.0000

141 4.97 0.0000 0.0020 0.0000 0.0000

172 4.83 0.0000 0.0020 0.0000 0.0000

168 0.11 6.17 0.63 0.13 0.0004 0.0003 0.0004 0.0004

162 0.62 6.11 0.90 0.29 0.0004 0.0003 0.0004 0.0004

135 0.40 5.70 1.75 0.29 0.2486 0.1987 0.2483 0.2507

155 6.39 0.0000 0.0022 0.0000 0.0000

108 6.55 0.0000 0.0102 0.0000 0.0000

157 6.65 0.0000 0.0074 0.0000 0.0000

103 0.57 6.26 1.58 0.39 0.0071 0.0056 0.0070 0.0071

144 0.53 6.08 0.55 0.28 0.0187 0.0150 0.0187 0.0189

144 6.61 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0100 0.0080 0.0100 0.0101

125 0.23 6.21 0.47 0.16 0.0014 0.0011 0.0014 0.0014

155 0.38 4.23 0.75 0.35 0.0165 0.0132 0.0165 0.0166

114 5.87 0.0000 0.0010 0.0000 0.0000

103 5.94 0.0000 0.0001 0.0000 0.0000

151 5.60 0.0000 0.0002 0.0000 0.0000

120 5.50 0.0000 0.0200 0.0000 0.0000

144 5.80 0.0000 0.0121 0.0000 0.0000

118 5.52 0.0000 0.0007 0.0000 0.0000

113 4.41 0.0000 0.0050 0.0000 0.0000

173 5.79 0.0000 0.0005 0.0000 0.0000

108 0.17 5.99 0.37 0.17 0.0515 0.0411 0.0514 0.0519

116 0.62 5.36 1.39 0.18 0.0101 0.0081 0.0101 0.0102

168 0.37 5.68 0.54 0.17 0.0257 0.0206 0.0257 0.0260

118 6.30 0.0000 0.0006 0.0000 0.0000

164 5.92 0.0000 0.0161 0.0000 0.0000

103 6.19 0.0000 0.0125 0.0000 0.0000

120 5.55 0.0000 0.0453 0.0000 0.0000

173 6.05 0.0000 0.0050 0.0000 0.0000

115 5.77 0.0000 0.0002 0.0000 0.0000

135 0.45 6.68 0.92 0.24 0.0009 0.0007 0.0009 0.0009

150 0.50 5.74 1.06 0.49 0.0009 0.0007 0.0009 0.0009

103 0.53 5.30 1.24 0.51 0.0021 0.0017 0.0021 0.0022
Table D5. 1999 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D27

130 0.63 6.61 1.21 0.36 0.0015 0.0012 0.0015 0.0015

100 0.57 5.50 1.35 0.47 0.0028 0.0022 0.0028 0.0028

114 6.39 0.0000 0.0030 0.0000 0.0000

127 5.38 0.0000 0.0010 0.0000 0.0000

117 6.23 0.0000 0.0010 0.0000 0.0000

172 6.23 0.0000 0.0030 0.0000 0.0000

173 0.54 6.57 1.83 0.42 0.0013 0.0010 0.0013 0.0013

123 4.12 0.64 0.0000 0.0003 0.0003 0.0000

122 0.07 5.75 1.06 0.43 0.0010 0.0008 0.0010 0.0010

142 5.92 1.33 0.31 0.0000 0.0005 0.0007 0.0007

138 6.68 0.0000 0.0005 0.0000 0.0000

161 0.23 5.96 0.83 0.0094 0.0075 0.0093 0.0000

Sales-wgt

EF 0.351590 5.749792 0.937310 0.270345 1.0000 1.0000 1.0000 1.0000

Sample

Size 25 59 27 25
D28

Table D5. 1999 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

257 0.43 6.43 0.76 0.20 0.0002 0.0002 0.0002 0.0002

200 0.26 5.13 0.60 0.22 0.0290 0.0290 0.0290 0.0290

215 0.32 5.51 0.55 0.32 0.0136 0.0136 0.0136 0.0136

260 0.44 5.82 0.70 0.27 0.0091 0.0091 0.0091 0.0091

240 0.29 5.38 0.49 0.27 0.0091 0.0091 0.0091 0.0091

280 0.47 5.47 0.52 0.23 0.0207 0.0207 0.0207 0.0207

275 0.11 4.56 1.26 0.26 0.0012 0.0012 0.0012 0.0012

205 0.19 5.96 1.73 0.25 0.0041 0.0041 0.0041 0.0041

255 0.08 6.20 0.96 0.27 0.0108 0.0108 0.0108 0.0108

294 0.09 5.45 2.19 0.34 0.0041 0.0041 0.0041 0.0041

260 0.36 5.73 1.30 0.39 0.0009 0.0009 0.0009 0.0009

225 0.41 5.70 0.84 0.22 0.0252 0.0252 0.0252 0.0252

240 0.10 5.06 0.38 0.15 0.0414 0.0414 0.0414 0.0414

200 0.26 5.13 0.60 0.22 0.0746 0.0746 0.0746 0.0746

215 0.32 5.51 0.55 0.32 0.0787 0.0787 0.0787 0.0787

260 0.44 5.82 0.70 0.27 0.0575 0.0575 0.0575 0.0575

240 0.29 5.38 0.49 0.27 0.0828 0.0828 0.0828 0.0828

280 0.47 5.47 0.52 0.23 0.0083 0.0083 0.0083 0.0083

200 0.25 5.43 1.23 0.35 0.0015 0.0015 0.0015 0.0015

253 0.34 6.58 0.57 0.20 0.0015 0.0015 0.0015 0.0015

296 0.31 6.41 0.96 0.25 0.0015 0.0015 0.0015 0.0015

261 0.47 6.06 0.89 0.27 0.0002 0.0002 0.0002 0.0002

248 0.34 5.31 1.04 0.35 0.0002 0.0002 0.0002 0.0002

275 0.14 5.38 0.48 0.14 0.0002 0.0002 0.0002 0.0002

220 0.20 5.87 0.72 0.27 0.0043 0.0043 0.0043 0.0043

234 0.19 5.45 0.62 0.25 0.0108 0.0108 0.0108 0.0108

196 0.28 5.44 0.65 0.28 0.2781 0.2781 0.2781 0.2781

197 0.23 5.52 0.75 0.29 0.0097 0.0097 0.0097 0.0097

294 0.38 5.99 0.95 0.23 0.0988 0.0988 0.0988 0.0988

285 0.46 6.51 1.19 0.22 0.0146 0.0146 0.0146 0.0146

216 0.59 6.20 1.55 0.28 0.0260 0.0260 0.0260 0.0260

285 0.47 4.59 0.73 0.26 0.0040 0.0040 0.0040 0.0040

237 0.78 6.32 1.31 0.38 0.0002 0.0002 0.0002 0.0002

196 0.35 6.52 0.95 0.36 0.0017 0.0017 0.0017 0.0017

187 0.26 5.99 0.73 0.15 0.0039 0.0039 0.0039 0.0039

186 0.34 6.28 0.69 0.23 0.0017 0.0017 0.0017 0.0017

189 0.37 5.87 0.76 0.35 0.0011 0.0011 0.0011 0.0011

249 0.48 6.37 1.08 0.24 0.0002 0.0002 0.0002 0.0002

243 0.40 5.88 1.67 0.37 0.0001 0.0001 0.0001 0.0001

241 0.41 6.44 1.11 0.34 0.0008 0.0008 0.0008 0.0008

227 0.51 6.72 1.07 0.33 0.0034 0.0034 0.0034 0.0034

193 0.60 6.69 0.85 0.21 0.0004 0.0004 0.0004 0.0004

200 0.26 5.13 0.60 0.22 0.0034 0.0034 0.0034 0.0034

215 0.32 5.51 0.55 0.32 0.0046 0.0046 0.0046 0.0046

240 0.29 5.38 0.49 0.27 0.0049 0.0049 0.0049 0.0049

280 0.47 5.47 0.52 0.23 0.0005 0.0005 0.0005 0.0005

189 0.31 5.40 0.92 0.21 0.0009 0.0009 0.0009 0.0009
Table D5. 1999 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D29

252 0.22 6.23 0.30 0.23 0.0026 0.0026 0.0026 0.0026

211 0.37 5.42 0.57 0.22 0.0003 0.0003 0.0003 0.0003

253 0.23 5.28 0.47 0.27 0.0002 0.0002 0.0002 0.0002

244 0.39 6.24 0.74 0.18 0.0005 0.0005 0.0005 0.0005

247 0.57 6.13 0.69 0.17 0.0003 0.0003 0.0003 0.0003

184 0.30 6.70 0.61 0.18 0.0010 0.0010 0.0010 0.0010

280 0.19 5.68 0.51 0.18 0.0017 0.0017 0.0017 0.0017

298 0.37 6.32 1.16 0.30 0.0012 0.0012 0.0012 0.0012

225 0.11 6.63 0.57 0.13 0.0001 0.0001 0.0001 0.0001

210 0.13 6.73 1.77 0.21 0.0019 0.0019 0.0019 0.0019

210 0.12 6.55 1.15 0.20 0.0017 0.0017 0.0017 0.0017

225 0.14 6.73 0.64 0.16 0.0017 0.0017 0.0017 0.0017

286 0.39 5.07 0.50 0.20 0.0246 0.0246 0.0246 0.0246

190 0.66 6.08 1.56 0.40 0.0005 0.0005 0.0005 0.0005

268 0.44 6.50 0.50 0.22 0.0013 0.0013 0.0013 0.0013

177 0.34 6.20 0.89 0.28 0.0004 0.0004 0.0004 0.0004

182 0.42 6.43 0.87 0.30 0.0004 0.0004 0.0004 0.0004

207 0.44 6.59 1.15 0.36 0.0004 0.0004 0.0004 0.0004

217 0.36 5.49 1.00 0.22 0.0004 0.0004 0.0004 0.0004

183 0.54 6.63 0.81 0.34 0.0002 0.0002 0.0002 0.0002

227 0.35 6.34 0.51 0.27 0.0002 0.0002 0.0002 0.0002

244 0.19 6.30 1.66 0.36 0.0015 0.0015 0.0015 0.0015

272 0.35 6.44 1.09 0.23 0.0015 0.0015 0.0015 0.0015

255 0.25 5.89 0.40 0.13 0.0055 0.0055 0.0055 0.0055

Sales-wgt

EF 0.314974 5.549376 0.695869 0.257528 1.0000 1.0000 1.0000 1.0000

Sample

Size 71 71 71 71
D30

Table D5. 1999 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

310 0.34 5.48 0.79 0.13 0.0011 0.0011 0.0011 0.0011

415 0.10 4.65 0.40 0.08 0.0036 0.0036 0.0036 0.0036

340 0.12 3.91 0.56 0.17 0.0271 0.0271 0.0271 0.0271

300 0.08 5.78 0.43 0.13 0.0036 0.0036 0.0036 0.0036

425 0.90 6.38 2.17 0.16 0.0522 0.0522 0.0522 0.0522

300 0.28 6.13 0.81 0.36 0.0049 0.0049 0.0049 0.0049

330 0.33 5.28 1.07 0.36 0.0060 0.0060 0.0060 0.0060

397 0.19 4.65 1.35 0.19 0.0027 0.0027 0.0027 0.0027

362 0.16 5.49 1.57 0.21 0.1859 0.1859 0.1859 0.1859

500 0.13 6.10 1.67 0.17 0.0260 0.0260 0.0260 0.0260

455 0.12 5.48 0.82 0.17 0.0036 0.0036 0.0036 0.0036

599 0.04 6.59 2.67 0.33 0.0763 0.0763 0.0763 0.0763

535 0.08 5.79 2.10 0.34 0.0060 0.0060 0.0060 0.0060

350 0.22 6.52 1.17 0.20 0.0597 0.0597 0.0597 0.0597

430 0.14 6.29 0.34 0.13 0.0199 0.0199 0.0199 0.0199

480 0.17 6.85 1.16 0.18 0.1809 0.1809 0.1809 0.1809

525 0.16 6.52 0.65 0.16 0.0109 0.0109 0.0109 0.0109

336 0.14 5.48 0.45 0.15 0.0071 0.0071 0.0071 0.0071

422 0.15 4.97 0.40 0.11 0.0007 0.0007 0.0007 0.0007

563 0.14 5.11 0.40 0.11 0.0004 0.0004 0.0004 0.0004

308 0.28 5.68 0.45 0.20 0.0016 0.0016 0.0016 0.0016

335 0.27 5.51 0.74 0.28 0.0027 0.0027 0.0027 0.0027

543 0.22 5.66 0.54 0.25 0.0099 0.0099 0.0099 0.0099

336 0.37 4.65 0.68 0.25 0.0282 0.0282 0.0282 0.0282

336 0.41 5.99 1.31 0.30 0.0072 0.0072 0.0072 0.0072

339 0.21 5.72 0.92 0.15 0.0035 0.0035 0.0035 0.0035

399 0.18 5.33 0.91 0.15 0.0047 0.0047 0.0047 0.0047

517 0.17 5.74 0.37 0.13 0.0575 0.0575 0.0575 0.0575

401 0.23 6.02 0.50 0.14 0.0158 0.0158 0.0158 0.0158

431 0.17 5.59 0.43 0.15 0.0071 0.0071 0.0071 0.0071

361 0.20 5.77 0.62 0.16 0.0061 0.0061 0.0061 0.0061

350 0.08 5.74 2.10 0.15 0.0089 0.0089 0.0089 0.0089

313 0.13 6.38 0.59 0.14 0.0116 0.0116 0.0116 0.0116

430 0.35 6.64 0.56 0.19 0.0022 0.0022 0.0022 0.0022

425 0.08 6.44 0.76 0.16 0.0689 0.0689 0.0689 0.0689

586 0.20 4.64 0.45 0.18 0.0043 0.0043 0.0043 0.0043

329 0.26 6.38 0.61 0.19 0.0025 0.0025 0.0025 0.0025

590 0.34 6.40 0.72 0.24 0.0001 0.0001 0.0001 0.0001

335 0.26 6.17 1.05 0.32 0.0004 0.0004 0.0004 0.0004

306 0.24 6.29 0.72 0.37 0.0137 0.0137 0.0137 0.0137

326 0.50 4.04 0.43 0.14 0.0010 0.0010 0.0010 0.0010

493 0.16 4.26 1.04 0.22 0.0014 0.0014 0.0014 0.0014

493 0.16 5.89 0.95 0.28 0.0004 0.0004 0.0004 0.0004

335 0.19 5.78 0.41 0.18 0.0002 0.0002 0.0002 0.0002

375 0.22 5.72 0.32 0.20 0.0038 0.0038 0.0038 0.0038

525 0.17 6.06 0.60 0.23 0.0002 0.0002 0.0002 0.0002

571 0.31 3.98 0.48 0.17 0.0022 0.0022 0.0022 0.0022
Table D5. 1999 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D31

475 0.28 4.09 0.46 0.15 0.0022 0.0022 0.0022 0.0022

327 0.22 6.39 0.46 0.14 0.0022 0.0022 0.0022 0.0022

327 0.24 6.11 0.48 0.13 0.0022 0.0022 0.0022 0.0022

330 0.07 5.07 0.44 0.10 0.0036 0.0036 0.0036 0.0036

330 0.04 5.64 0.40 0.16 0.0116 0.0116 0.0116 0.0116

313 0.27 6.26 0.31 0.06 0.0134 0.0134 0.0134 0.0134

381 0.21 6.55 0.61 0.08 0.0186 0.0186 0.0186 0.0186

496 0.13 6.12 0.28 0.07 0.0016 0.0016 0.0016 0.0016

Sales-wgt

EF 0.201521 6.049760 1.201752 0.192703 1.0000 1.0000 1.0000 1.0000

Sample

Size 55 55 55 55

Table D5. 1999 MY Certification Data (cont.)

600-750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

660 0.05 6.24 0.83 0.14 0.1765 0.1765 0.1765 0.1765

740 0.05 5.68 1.57 0.25 0.2857 0.2857 0.2857 0.2857

640 0.11 5.62 0.83 0.19 0.0071 0.0071 0.0071 0.0071

730 0.06 5.04 0.99 0.19 0.0903 0.0903 0.0903 0.0903

740 0.10 5.53 1.62 0.33 0.0429 0.0429 0.0429 0.0429

600 0.26 6.02 1.78 0.24 0.1618 0.1618 0.1618 0.1618

686 0.20 5.70 0.65 0.30 0.0139 0.0139 0.0139 0.0139

750 0.07 5.84 0.90 0.16 0.0113 0.0113 0.0113 0.0113

750 0.07 5.90 1.29 0.22 0.0588 0.0588 0.0588 0.0588

750 0.06 4.48 1.43 0.24 0.0597 0.0597 0.0597 0.0597

750 0.35 5.80 1.48 0.30 0.0828 0.0828 0.0828 0.0828

641 0.26 5.84 0.83 0.18 0.0046 0.0046 0.0046 0.0046

740 0.24 5.85 1.37 0.28 0.0046 0.0046 0.0046 0.0046

Sales-wgt

EF 0.118392 5.723896 1.361031 0.227162 1.0000 1.0000 1.0000 1.0000

Sample

Size 13 13 13 13
D32

Table D6. 2000 MY Certification Data

0-11 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

6 6.57 7.33 4.20 0.07 0.0000 0.1007 0.0289 0.0289 0.0289

6 5.28 7.78 3.16 0.12 0.0000 0.0280 0.0080 0.0080 0.0080

10 3.36 1.04 0.28 0.0000 0.0000 0.0088 0.0088 0.0088

7 3.82 2.11 0.35 0.0000 0.0000 0.0096 0.0096 0.0096

7 3.77 2.95 0.33 0.0000 0.0000 0.0225 0.0225 0.0225

11 5.45 4.10 0.24 0.0000 0.0000 0.0096 0.0096 0.0096

10 5.23 1.68 0.21 0.0000 0.0000 0.0193 0.0193 0.0193

7 6.54 3.81 0.43 0.0000 0.0000 0.0123 0.0123 0.0123

8 5.76 4.50 0.52 0.0000 0.0000 0.0006 0.0006 0.0006

10 5.03 4.21 0.42 0.0000 0.0000 0.0006 0.0006 0.0006

4 0.78 5.18 5.96 3.93 0.66 0.131414 0.1309 0.1141 0.0328 0.0328 0.0328

7 0.71 4.82 5.53 3.83 0.57 0.128205 0.6675 0.5817 0.1672 0.1672 0.1672

8 0.58 5.74 6.32 3.29 0.45 0.091981 0.1309 0.1141 0.0328 0.0328 0.0328

11 0.57 5.10 5.67 3.18 0.54 0.101183 0.0706 0.0615 0.0177 0.0177 0.0177

4 6.61 5.00 0.50 0.0000 0.0000 0.2089 0.2089 0.2089

7 6.25 5.03 0.49 0.0000 0.0000 0.1607 0.1607 0.1607

10 6.30 3.84 0.39 0.0000 0.0000 0.1832 0.1832 0.1832

7 6.57 3.61 0.48 0.0000 0.0000 0.0164 0.0164 0.0164

10 3.72 1.91 0.35 0.0000 0.0000 0.0501 0.0501 0.0501

9 3.88 3.84 0.33 0.0000 0.0000 0.0096 0.0096 0.0096

Sales-wgt

EF

0.6921

03

5.1703

37

5.96622

3

4.0513

66

0.4528

58 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 4 6 20 20 20 0.113196

Calc HC* 0.6753

51

Calc NOx* 5.2908

71

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D33

Table D6. 2000 MY Certification Data

11-25 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

19 5.02 1.36 0.45 0.0000 0.0000 0.0030 0.0032 0.0030

17 0.58 3.79 4.37 3.82 0.57 0.131868 0.0373 0.0289 0.0051 0.0053 0.0051

25 0.45 4.07 4.52 3.09 0.38 0.099558 0.1493 0.1156 0.0203 0.0211 0.0203

21 4.30 1.74 0.24 0.0000 0.0000 0.0005 0.0005 0.0005

17 5.26 1.69 0.39 0.0000 0.0000 0.0012 0.0012 0.0012

18 5.15 0.77 0.23 0.0000 0.0000 0.0013 0.0014 0.0013

23 3.98 1.08 0.26 0.0000 0.0000 0.0034 0.0035 0.0034

11 4.88 1.88 0.50 0.0000 0.0000 0.0026 0.0027 0.0026

17 4.38 2.36 0.52 0.0000 0.0000 0.0140 0.0146 0.0140

12 5.54 2.57 0.33 0.0000 0.0000 0.0081 0.0084 0.0081

18 1.10 4.96 0.56 0.0000 0.2254 0.0395 0.0000 0.0395

21 3.68 1.34 0.57 0.0000 0.0000 0.0130 0.0135 0.0130

24 3.54 1.06 0.30 0.0000 0.0000 0.0020 0.0021 0.0020

24 5.67 1.66 0.56 0.0000 0.0000 0.0022 0.0023 0.0022

25 6.45 1.20 0.41 0.0000 0.0000 0.0022 0.0023 0.0022

19 3.40 0.99 0.37 0.0000 0.0000 0.0028 0.0029 0.0028

18 0.17 5.59 5.76 0.97 0.54 0.028849 0.0033 0.0025 0.0004 0.0005 0.0004

17 0.10 3.48 3.58 0.56 0.33 0.027933 0.1866 0.1445 0.0253 0.0264 0.0253

25 0.11 3.38 3.49 0.56 0.30 0.030399 0.0974 0.0754 0.0132 0.0138 0.0132

12 5.53 2.77 0.22 0.0000 0.0000 0.3139 0.3268 0.3139

23 4.30 1.73 0.14 0.0000 0.0000 0.0810 0.0843 0.0810

22 4.66 1.50 0.12 0.0000 0.0000 0.0253 0.0264 0.0253

20 5.66 2.23 0.21 0.0000 0.0000 0.0041 0.0042 0.0041

16 4.02 3.13 0.19 0.0000 0.0000 0.0003 0.0003 0.0003

19 6.24 4.15 0.43 0.0000 0.0000 0.0223 0.0232 0.0223

21 4.30 1.74 0.24 0.0000 0.0000 0.0046 0.0047 0.0046

18 5.97 2.73 0.50 0.0000 0.0000 0.0152 0.0158 0.0152

21 4.10 2.24 0.35 0.0000 0.0000 0.0101 0.0105 0.0101

15 0.72 5.29 6.02 3.70 0.43 0.120198 0.0410 0.0318 0.0056 0.0058 0.0056

15 0.43 5.70 6.12 2.41 0.39 0.069428 0.0784 0.0607 0.0106 0.0111 0.0106

16 0.57 5.62 6.19 3.00 0.37 0.092771 0.0187 0.0145 0.0025 0.0026 0.0025

22 0.77 5.17 5.94 3.04 0.45 0.129397 0.3881 0.3006 0.0527 0.0548 0.0527

12 5.03 2.95 0.26 0.0000 0.0000 0.0010 0.0011 0.0010

16 4.46 2.98 0.35 0.0000 0.0000 0.0450 0.0468 0.0450

12 3.17 1.47 0.30 0.0000 0.0000 0.0505 0.0526 0.0505

19 4.29 1.28 0.08 0.0000 0.0000 0.0284 0.0295 0.0284

22 3.47 2.27 0.19 0.0000 0.0000 0.0374 0.0390 0.0374

24 5.63 0.90 0.25 0.0000 0.0000 0.0837 0.0872 0.0837

17 4.88 1.55 0.42 0.0000 0.0000 0.0398 0.0414 0.0398

18 3.24 1.91 0.32 0.0000 0.0000 0.0061 0.0063 0.0061

Sales-wgt

EF 0.489983 3.749647 4.948900 2.207041 0.289982 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 9 10 40 39 40 0.081156

Calc HC* 0.401631

Calc NOx* 4.547269
D34

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D35

Table D6. 2000 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

42 6.52 3.35 0.42 0.0000 0.0000 0.0025 0.0025 0.0025

25 5.31 1.49 0.50 0.0000 0.0000 0.0005 0.0005 0.0005

28 4.92 1.56 0.54 0.0000 0.0000 0.0022 0.0022 0.0022

34 5.21 1.44 0.38 0.0000 0.0000 0.0069 0.0069 0.0069

45 5.95 0.48 0.26 0.0000 0.0000 0.0007 0.0007 0.0007

36 3.12 1.31 0.39 0.0000 0.0000 0.0007 0.0007 0.0007

38 3.62 2.13 0.51 0.0000 0.0000 0.0033 0.0033 0.0033

30 2.79 3.06 0.46 0.0000 0.0000 0.0004 0.0004 0.0004

50 6.14 0.0000 0.1584 0.0000 0.0000 0.0000

30 6.94 1.64 0.27 0.0000 0.0000 0.0390 0.0390 0.0390

38 6.69 1.92 0.32 0.0000 0.0000 0.0133 0.0133 0.0133

46 6.65 2.29 0.35 0.0000 0.0000 0.0123 0.0123 0.0123

35 5.68 1.74 0.21 0.0000 0.0000 0.0036 0.0036 0.0036

39 6.58 1.84 0.11 0.0000 0.0000 0.0051 0.0051 0.0051

47 5.84 1.35 0.09 0.0000 0.0000 0.0044 0.0044 0.0044

25 4.35 0.64 0.13 0.0000 0.0000 0.0004 0.0004 0.0004

28 3.76 1.24 0.20 0.0000 0.0000 0.0022 0.0022 0.0022

30 3.86 0.83 0.17 0.0000 0.0000 0.0030 0.0030 0.0030

40 4.50 0.62 0.20 0.0000 0.0000 0.0013 0.0013 0.0013

47 3.38 0.87 0.27 0.0000 0.0000 0.0005 0.0005 0.0005

26 3.18 0.98 0.37 0.0000 0.0000 0.0004 0.0004 0.0004

27 5.66 1.62 0.56 0.0000 0.0000 0.0001 0.0001 0.0001

29 4.11 1.16 0.35 0.0000 0.0000 0.0160 0.0159 0.0159

40 2.78 1.62 0.42 0.0000 0.0000 0.0379 0.0379 0.0379

45 4.04 0.87 0.38 0.0000 0.0000 0.0147 0.0147 0.0147

28 3.57 2.65 0.43 0.0000 0.0000 0.0010 0.0010 0.0010

39 4.35 1.89 0.45 0.0000 0.0000 0.0004 0.0004 0.0004

28 0.13 4.23 4.36 1.33 0.54 0.029817 0.0267 0.0167 0.0019 0.0019 0.0019

37 0.16 3.56 3.72 2.30 0.58 0.041678 0.0595 0.0372 0.0043 0.0043 0.0043

37 0.67 6.00 6.67 3.55 0.42 0.10051 0.0017 0.0010 0.0001 0.0001 0.0001

27 0.11 4.52 4.63 0.57 0.31 0.023758 0.0017 0.0010 0.0001 0.0001 0.0001

27 0.09 3.95 4.04 0.82 0.46 0.021308 0.0278 0.0173 0.0020 0.0020 0.0020

37 0.85 4.85 5.56 2.55 0.38 0.149123 0.0076 0.0047 0.0005 0.0005 0.0005

35 0.08 4.56 4.64 0.90 0.40 0.017234 0.0216 0.0135 0.0016 0.0016 0.0016

40 0.69 6.19 6.88 1.62 0.25 0.100291 0.0056 0.0035 0.0004 0.0004 0.0004

35 0.56 4.54 5.10 1.52 0.48 0.109804 0.7065 0.4409 0.0509 0.0509 0.0509

46 0.04 3.75 3.79 0.68 0.33 0.010554 0.0014 0.0009 0.0001 0.0001 0.0001

34 0.14 3.66 3.80 0.98 0.50 0.036842 0.0734 0.0458 0.0053 0.0053 0.0053

47 0.12 6.71 6.83 0.74 0.30 0.01757 0.0050 0.0031 0.0004 0.0004 0.0004

48 0.64 6.36 7.00 1.46 0.31 0.091429 0.0151 0.0094 0.0011 0.0011 0.0011

38 6.16 1.66 0.41 0.0000 0.0000 0.0363 0.0363 0.0363

26 4.64 1.30 0.28 0.0000 0.0000 0.0076 0.0076 0.0076

31 3.80 1.16 0.36 0.0000 0.0000 0.0400 0.0400 0.0400

42 3.84 0.77 0.24 0.0000 0.0000 0.0073 0.0073 0.0073

26 4.46 0.96 0.35 0.0000 0.0000 0.0545 0.0545 0.0545

41 4.81 0.75 0.25 0.0000 0.0000 0.0009 0.0009 0.0009
Table D6. 2000 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

D36

31 5.27 0.74 0.19 0.0000 0.0000 0.0309 0.0309 0.0309

31 5.11 0.80 0.26 0.0000 0.0000 0.0582 0.0581 0.0581

37 4.47 0.80 0.29 0.0000 0.0000 0.2108 0.2107 0.2107

49 5.95 1.93 0.43 0.0000 0.0000 0.0018 0.0018 0.0018

38 5.99 1.58 0.36 0.0000 0.0000 0.0018 0.0018 0.0018

48 4.63 0.93 0.23 0.0000 0.0000 0.0031 0.0031 0.0031

40 0.18 4.99 5.17 0.94 0.48 0.034632 0.0465 0.0290 0.0033 0.0033 0.0033

30 2.79 3.06 0.46 0.0000 0.0000 0.0011 0.0011 0.0011

38 3.62 2.13 0.51 0.0000 0.0000 0.0003 0.0003 0.0003

26 2.62 1.83 0.25 0.0000 0.0000 0.0001 0.0001 0.0001

25 5.78 3.66 0.43 0.0000 0.0000 0.0029 0.0029 0.0029

33 2.37 1.58 0.53 0.0000 0.0000 0.0013 0.0013 0.0013

36 5.73 6.06 1.07 0.33 0.0000 0.0441 0.0051 0.0051 0.0051

30 5.29 1.50 0.33 0.0000 0.0000 0.0002 0.0002 0.0002

35 5.15 5.48 1.61 0.36 0.0000 0.0157 0.0018 0.0018 0.0018

40 4.62 5.53 2.57 0.22 0.0000 0.0236 0.0027 0.0027 0.0027

42 6.35 1.01 0.13 0.0000 0.0000 0.0001 0.0001 0.0001

44 4.82 5.56 1.69 0.34 0.0000 0.0157 0.0018 0.0018 0.0018

40 6.36 1.33 0.33 0.0000 0.0000 0.0015 0.0015 0.0015

38 6.00 1.25 0.36 0.0000 0.0000 0.0004 0.0004 0.0004

30 6.51 3.22 0.50 0.0000 0.0000 0.0038 0.0038 0.0038

42 6.07 0.70 0.31 0.0000 0.0000 0.0004 0.0004 0.0004

39 4.73 1.01 0.34 0.0000 0.0000 0.0138 0.0138 0.0138

45 5.62 1.30 0.38 0.0000 0.0000 0.0016 0.0016 0.0016

49 4.09 0.80 0.25 0.0000 0.0000 0.0038 0.0038 0.0038

44 6.19 1.09 0.53 0.0000 0.0000 0.0016 0.0016 0.0016

47 5.32 5.81 2.45 0.44 0.0000 0.0693 0.0080 0.0080 0.0080

43 6.35 2.33 0.26 0.0000 0.0000 0.0004 0.0004 0.0004

41 6.35 0.95 0.32 0.0000 0.0055 0.0000 0.0006 0.0006

48 6.25 1.59 0.28 0.0000 0.0000 0.0002 0.0002 0.0002

26 5.45 2.00 0.15 0.0000 0.0000 0.0236 0.0236 0.0236

28 5.78 3.61 0.40 0.0000 0.0000 0.0096 0.0096 0.0096

25 5.53 2.91 0.37 0.0000 0.0000 0.0129 0.0129 0.0129

30 5.82 2.93 0.35 0.0000 0.0000 0.0012 0.0012 0.0012

25 5.91 3.45 0.24 0.0000 0.0000 0.0006 0.0006 0.0006

33 5.76 2.74 0.28 0.0000 0.0000 0.0230 0.0230 0.0230

41 5.97 1.35 0.49 0.0000 0.0000 0.0009 0.0009 0.0009

29 5.82 2.82 0.25 0.0000 0.0000 0.0070 0.0070 0.0070

37 6.76 1.71 0.40 0.0000 0.0000 0.0007 0.0007 0.0007

25 6.01 3.03 0.32 0.0000 0.0000 0.0222 0.0222 0.0222

37 6.03 2.59 0.35 0.0000 0.0000 0.0181 0.0181 0.0181

25 6.09 3.03 0.20 0.0000 0.0000 0.0000 0.0000 0.0000

30 6.07 3.01 0.38 0.0000 0.0000 0.0117 0.0117 0.0117

45 5.85 3.21 0.45 0.0000 0.0000 0.0291 0.0291 0.0291

38 5.79 3.23 0.39 0.0000 0.0000 0.0027 0.0027 0.0027

48 6.00 1.56 0.44 0.0000 0.0000 0.0000 0.0000 0.0000
Table D6. 2000 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

D37

34 5.94 1.87 0.34 0.0000 0.0000 0.0715 0.0715 0.0715

50 4.85 0.0000 0.0435 0.0000 0.0000 0.0000

46 6.01 2.54 0.20 0.0000 0.0000 0.0064 0.0064 0.0064

41 5.76 2.79 0.33 0.0000 0.0000 0.0042 0.0042 0.0042

27 3.04 0.98 0.40 0.0000 0.0000 0.0023 0.0023 0.0023

39 5.53 1.96 0.26 0.0000 0.0000 0.0010 0.0010 0.0010

Sales-wgt

EF 0.452946 4.893606 5.083919 1.522782 0.331337 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 14 22 95 96 96 0.056039

Calc HC* 0.284899

Calc NOx* 4.799020

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D38

Table D6. 2000 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

67 6.40 0.0000 0.0035 0.0000 0.0000 0.0000

79 5.74 0.0000 0.0015 0.0000 0.0000 0.0000

96 5.81 0.0000 0.0005 0.0000 0.0000 0.0000

80 0.48 7.61 4.32 0.56 0.1534 0.0381 0.0000 0.1520 0.1572

67 0.75 6.35 1.96 0.34 0.0219 0.0054 0.0000 0.0217 0.0225

75 0.70 5.68 2.28 0.49 0.1315 0.0327 0.0000 0.1303 0.1348

85 0.48 6.14 1.03 0.35 0.0418 0.0104 0.0000 0.0415 0.0429

56 0.46 5.71 2.19 0.29 0.0418 0.0104 0.0000 0.0415 0.0429

75 0.70 5.68 2.28 0.49 0.0279 0.0069 0.0000 0.0276 0.0286

98 0.71 6.30 1.68 0.21 0.0005 0.0001 0.0000 0.0005 0.0005

62 6.23 0.0000 0.0010 0.0000 0.0000 0.0000

57 6.20 0.0000 0.0010 0.0000 0.0000 0.0000

55 5.80 0.0000 0.0010 0.0000 0.0000 0.0000

64 5.92 0.0000 0.0049 0.0000 0.0000 0.0000

82 5.23 0.0000 0.0802 0.0000 0.0000 0.0000

53 6.32 0.0000 0.0217 0.0000 0.0000 0.0000

83 6.47 0.0000 0.0029 0.0000 0.0000 0.0000

65 6.20 0.0000 0.0174 0.0000 0.0000 0.0000

84 6.79 0.0000 0.0000 0.0000 0.0000 0.0000

68 6.70 0.0000 0.0030 0.0000 0.0000 0.0000

51 5.38 0.0000 0.0015 0.0000 0.0000 0.0000

56 5.21 0.0000 0.0042 0.0000 0.0000 0.0000

78 6.22 0.0000 0.0001 0.0000 0.0000 0.0000

52 4.59 0.0000 0.0188 0.0000 0.0000 0.0000

50 3.43 0.0000 0.0079 0.0000 0.0000 0.0000

52 0.17 5.22 1.18 0.45 0.0094 0.0023 0.0000 0.0093 0.0096

51 1.44 5.79 3.90 0.38 0.0110 0.0027 0.0000 0.0109 0.0112

54 0.69 4.15 1.45 0.36 0.0240 0.0060 0.0000 0.0238 0.0246

51 0.60 6.68 3.04 0.63 0.0011 0.0003 0.0000 0.0011 0.0011

55 0.39 6.16 0.98 0.28 0.0163 0.0041 0.0000 0.0162 0.0167

64 0.43 5.62 2.17 0.60 0.0076 0.0019 0.0000 0.0075 0.0078

76 0.29 5.35 1.08 0.51 0.0149 0.0037 0.0000 0.0148 0.0153

51 0.41 5.34 2.22 0.64 0.0087 0.0022 0.0000 0.0086 0.0089

56 0.48 4.88 0.46 0.27 0.0014 0.0003 0.0000 0.0014 0.0014

83 0.49 4.80 0.76 0.34 0.0099 0.0025 0.0000 0.0098 0.0101

91 0.42 6.63 1.32 0.54 0.0378 0.0094 0.0000 0.0375 0.0388

79 0.55 5.25 2.47 0.55 0.0335 0.0083 0.0000 0.0332 0.0344

86 0.46 4.98 0.83 0.38 0.0013 0.0003 0.0000 0.0013 0.0013

86 0.35 5.09 0.67 0.21 0.0013 0.0003 0.0000 0.0013 0.0014

53 6.56 0.0000 0.0478 0.0000 0.0000 0.0000

51 0.05 3.56 0.75 0.20 0.0159 0.0040 0.0000 0.0158 0.0163

78 0.49 3.77 3.00 0.52 0.0159 0.0040 0.0000 0.0158 0.0163

74 0.76 4.70 2.06 0.32 0.0199 0.0050 0.0000 0.0197 0.0204

80 0.72 5.78 3.26 0.51 0.0060 0.0015 0.0000 0.0059 0.0061

98 0.71 6.30 1.68 0.21 0.0050 0.0012 0.0000 0.0049 0.0051

56 0.46 5.71 2.19 0.29 0.0002 0.0001 0.0000 0.0002 0.0002
Table D6. 2000 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

D39

85 0.48 6.14 1.03 0.35 0.0002 0.0001 0.0000 0.0002 0.0002

59 4.37 0.0000 0.0119 0.0000 0.0000 0.0000

51 5.12 0.0000 0.0005 0.0000 0.0000 0.0000

56 4.18 0.0000 0.0114 0.0000 0.0000 0.0000

89 3.57 0.0000 0.0178 0.0000 0.0000 0.0000

73 3.68 0.0000 0.0124 0.0000 0.0000 0.0000

86 5.42 0.0000 0.0104 0.0000 0.0000 0.0000

93 4.71 0.0000 0.0114 0.0000 0.0000 0.0000

72 4.31 0.0000 0.0054 0.0000 0.0000 0.0000

54 0.54 6.31 2.42 0.0157 0.0039 0.0000 0.0156 0.0000

65 0.05 4.18 4.24 0.90 0.0178 0.0044 1.0000 0.0177 0.0000

59 3.34 0.0000 0.0003 0.0000 0.0000 0.0000

53 4.60 0.0000 0.0015 0.0000 0.0000 0.0000

56 5.95 0.0000 0.0005 0.0000 0.0000 0.0000

54 2.62 0.0000 0.0048 0.0000 0.0000 0.0000

63 5.06 0.0000 0.0006 0.0000 0.0000 0.0000

57 4.46 0.0000 0.0052 0.0000 0.0000 0.0000

55 2.91 0.0000 0.0014 0.0000 0.0000 0.0000

51 5.35 0.0000 0.0154 0.0000 0.0000 0.0000

87 5.92 0.0000 0.0154 0.0000 0.0000 0.0000

52 6.32 0.0000 0.0050 0.0000 0.0000 0.0000

89 6.40 0.0000 0.0025 0.0000 0.0000 0.0000

67 0.22 5.71 1.01 0.54 0.1915 0.0476 0.0000 0.1898 0.1963

92 0.35 6.16 1.22 0.29 0.0992 0.0247 0.0000 0.0983 0.1017

55 2.62 0.0000 0.0012 0.0000 0.0000 0.0000

59 5.90 0.0000 0.0012 0.0000 0.0000 0.0000

85 2.18 0.0000 0.0013 0.0000 0.0000 0.0000

64 5.58 0.0000 0.0124 0.0000 0.0000 0.0000

79 6.16 0.0000 0.0067 0.0000 0.0000 0.0000

58 3.23 0.0000 0.0109 0.0000 0.0000 0.0000

52 6.62 0.0000 0.0097 0.0000 0.0000 0.0000

64 5.13 0.0000 0.0045 0.0000 0.0000 0.0000

60 6.06 0.0000 0.0258 0.0000 0.0000 0.0000

96 5.09 0.0000 0.1312 0.0000 0.0000 0.0000

68 5.85 0.0000 0.0669 0.0000 0.0000 0.0000

52 5.97 0.0000 0.0421 0.0000 0.0000 0.0000

68 6.11 0.0000 0.0099 0.0000 0.0000 0.0000

80 0.83 6.00 3.19 0.63 0.0060 0.0015 0.0000 0.0059 0.0061

80 0.86 5.40 4.00 0.64 0.0075 0.0019 0.0000 0.0074 0.0077

59 3.58 0.0000 0.0030 0.0000 0.0000 0.0000

84 6.14 0.0000 0.0010 0.0000 0.0000 0.0000

94 5.75 0.0000 0.0003 0.0000 0.0000 0.0000

50 5.80 1.78 0.38 0.0000 0.0008 0.0000 0.0034 0.0035

77 0.03 3.55 0.15 0.18 0.0021 0.0005 0.0000 0.0021 0.0021

59 5.59 0.96 0.45 0.0000 0.0010 0.0000 0.0040 0.0042

100 6.27 0.87 0.33 0.0000 0.0004 0.0000 0.0015 0.0015
Table D6. 2000 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx

wgt

HC+NOx

wgt

CO wgt PM wgt

D40

75 3.87 0.0000 0.0015 0.0000 0.0000 0.0000

58 3.91 0.0000 0.0020 0.0000 0.0000 0.0000

54 5.40 0.0000 0.0001 0.0000 0.0000 0.0000

67 4.89 0.0000 0.0163 0.0000 0.0000 0.0000

80 4.80 0.0000 0.0005 0.0000 0.0000 0.0000

56 5.23 0.0000 0.0016 0.0000 0.0000 0.0000

58 5.12 0.0000 0.0157 0.0000 0.0000 0.0000

60 4.12 0.0000 0.0025 0.0000 0.0000 0.0000

70 5.59 0.0000 0.0138 0.0000 0.0000 0.0000

58 5.72 0.0000 0.0002 0.0000 0.0000 0.0000

95 5.10 0.0000 0.0030 0.0000 0.0000 0.0000

100 5.73 0.0000 0.0114 0.0000 0.0000 0.0000

Sales-wgt

EF

0.46

289

5.4948

92

4.2355

76

2.047

06

0.460

43 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 35 104 1 38 36
D41

Table D6. 2000 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

173 0.33 6.37 0.78 0.11 0.0006 0.0004 0.0006 0.0006

108 6.47 0.0000 0.0007 0.0000 0.0000

143 6.09 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.2138 0.1425 0.2133 0.2164

125 0.23 6.21 0.47 0.16 0.0077 0.0051 0.0077 0.0078

118 0.25 4.53 0.54 0.22 0.0165 0.0110 0.0165 0.0167

155 0.38 4.23 0.75 0.35 0.1983 0.1322 0.1979 0.2008

110 6.06 0.0000 0.0019 0.0000 0.0000

165 6.24 0.0000 0.0495 0.0000 0.0000

166 4.95 0.0000 0.0040 0.0000 0.0000

125 0.23 6.21 0.47 0.16 0.1202 0.0801 0.1200 0.1217

118 0.25 4.53 0.54 0.22 0.0165 0.0110 0.0165 0.0167

144 4.97 0.0000 0.0026 0.0000 0.0000

109 6.41 0.0000 0.0026 0.0000 0.0000

133 6.50 0.0000 0.0026 0.0000 0.0000

168 0.11 6.17 0.63 0.13 0.0009 0.0006 0.0009 0.0009

155 6.39 0.0000 0.0170 0.0000 0.0000

109 6.32 0.53 0.13 0.0000 0.0000 0.0000 0.0000

157 6.65 0.0000 0.0116 0.0000 0.0000

121 0.49 4.30 1.23 0.28 0.0013 0.0009 0.0013 0.0013

134 0.34 4.30 1.00 0.24 0.0007 0.0004 0.0007 0.0007

103 0.57 6.26 1.58 0.39 0.0127 0.0085 0.0127 0.0129

153 0.51 5.65 0.49 0.26 0.0145 0.0097 0.0145 0.0147

164 0.47 4.67 1.06 0.23 0.0033 0.0022 0.0033 0.0033

139 0.52 4.30 1.25 0.19 0.0012 0.0008 0.0012 0.0012

144 6.61 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0881 0.0588 0.0880 0.0892

125 0.23 6.21 0.47 0.16 0.0220 0.0147 0.0220 0.0223

155 0.38 4.23 0.75 0.35 0.1102 0.0735 0.1100 0.1115

125 5.74 0.0000 0.0134 0.0000 0.0000

103 5.94 0.0000 0.0005 0.0000 0.0000

151 5.60 0.0000 0.0005 0.0000 0.0000

120 5.50 0.0000 0.0414 0.0000 0.0000

144 5.80 0.0000 0.0494 0.0000 0.0000

118 5.52 0.0000 0.0009 0.0000 0.0000

113 4.41 0.0000 0.0060 0.0000 0.0000

132 6.05 0.0000 0.0067 0.0000 0.0000

173 5.79 0.0000 0.0027 0.0000 0.0000

108 0.16 6.25 0.43 0.26 0.0759 0.0506 0.0757 0.0768

116 0.57 6.43 1.45 0.33 0.0150 0.0100 0.0150 0.0152

168 0.42 5.85 0.76 0.27 0.0382 0.0255 0.0381 0.0387

118 6.30 0.0000 0.0008 0.0000 0.0000

120 5.55 0.0000 0.0287 0.0000 0.0000

103 6.19 0.0000 0.0089 0.0000 0.0000

172 0.13 5.31 0.45 0.25 0.0180 0.0120 0.0180 0.0183

115 5.77 0.0000 0.0067 0.0000 0.0000

152 5.82 0.0000 0.0601 0.0000 0.0000
Table D6. 2000 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D42

103 0.53 5.30 1.24 0.51 0.0023 0.0015 0.0023 0.0023

135 0.45 6.68 0.92 0.24 0.0010 0.0007 0.0010 0.0010

130 0.63 6.61 1.21 0.36 0.0017 0.0011 0.0017 0.0017

100 0.57 5.50 1.35 0.47 0.0031 0.0021 0.0031 0.0031

114 6.39 0.0000 0.0040 0.0000 0.0000

127 5.38 0.0000 0.0013 0.0000 0.0000

117 6.23 0.0000 0.0013 0.0000 0.0000

172 6.23 0.0000 0.0040 0.0000 0.0000

173 0.54 6.57 1.83 0.42 0.0020 0.0013 0.0020 0.0020

142 5.92 1.33 0.23 0.0000 0.0013 0.0020 0.0020

138 6.68 0.0000 0.0014 0.0000 0.0000

161 0.23 5.96 0.83 0.0141 0.0094 0.0141 0.0000

130 5.05 0.0000 0.0002 0.0000 0.0000

116 5.82 0.0000 0.0003 0.0000 0.0000

Sales-wgt

EF 0.332460 5.593736 0.685810 0.282059 1.0000 1.0000 1.0000 1.0000

Sample

Size 27 61 29 28
D43

Table D6. 2000 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

257 0.43 6.43 0.76 0.20 0.0005 0.0005 0.0000 0.0005 0.0005

200 0.26 5.13 0.60 0.22 0.0678 0.0678 0.0000 0.0678 0.0678

240 0.10 5.06 0.38 0.15 0.0136 0.0136 0.0000 0.0136 0.0136

215 0.32 5.51 0.55 0.32 0.0329 0.0329 0.0000 0.0329 0.0329

260 0.44 5.82 0.70 0.27 0.0213 0.0213 0.0000 0.0213 0.0213

240 0.29 5.38 0.49 0.27 0.0213 0.0213 0.0000 0.0213 0.0213

280 0.47 5.47 0.52 0.23 0.0484 0.0484 0.0000 0.0484 0.0484

210 0.20 5.89 1.49 0.33 0.0362 0.0362 0.0000 0.0362 0.0362

275 0.11 4.56 1.26 0.26 0.0027 0.0027 0.0000 0.0027 0.0027

205 0.19 5.96 1.73 0.25 0.0096 0.0096 0.0000 0.0096 0.0096

255 0.08 6.20 0.96 0.29 0.0252 0.0252 0.0000 0.0252 0.0252

290 0.09 5.46 2.19 0.35 0.0097 0.0097 0.0000 0.0097 0.0097

260 0.36 5.73 1.30 0.39 0.0022 0.0022 0.0000 0.0022 0.0022

225 0.41 5.70 0.84 0.22 0.0588 0.0588 0.0000 0.0588 0.0588

240 0.10 5.06 0.38 0.15 0.0968 0.0968 0.0000 0.0968 0.0968

200 0.26 5.13 0.60 0.22 0.1355 0.1355 0.0000 0.1355 0.1355

189 0.33 3.95 0.54 0.20 0.0039 0.0039 0.0000 0.0039 0.0039

240 0.29 5.38 0.49 0.27 0.1936 0.1936 0.0000 0.1936 0.1936

200 0.25 5.43 1.23 0.35 0.0034 0.0034 0.0000 0.0034 0.0034

296 0.31 6.41 0.96 0.25 0.0034 0.0034 0.0000 0.0034 0.0034

261 0.47 6.06 0.89 0.27 0.0002 0.0002 0.0000 0.0002 0.0002

248 0.34 5.31 1.04 0.35 0.0002 0.0002 0.0000 0.0002 0.0002

275 0.14 5.38 0.48 0.14 0.0014 0.0014 0.0000 0.0014 0.0014

196 0.35 6.52 0.95 0.36 0.0037 0.0037 0.0000 0.0037 0.0037

184 0.24 5.84 0.69 0.15 0.0215 0.0215 0.0000 0.0215 0.0215

186 0.34 6.28 0.69 0.23 0.0017 0.0017 0.0000 0.0017 0.0017

249 0.48 6.37 1.08 0.24 0.0001 0.0001 0.0000 0.0001 0.0001

243 0.40 5.88 1.67 0.37 0.0002 0.0002 0.0000 0.0002 0.0002

185 0.54 4.19 4.73 0.93 0.20 0.0004 0.0004 0.5000 0.0004 0.0004

241 0.21 4.14 4.35 0.67 0.17 0.0004 0.0004 0.5000 0.0004 0.0004

241 0.41 6.44 1.11 0.34 0.0024 0.0024 0.0000 0.0024 0.0024

227 0.51 6.72 1.07 0.33 0.0055 0.0055 0.0000 0.0055 0.0055

193 0.60 6.69 0.85 0.21 0.0010 0.0010 0.0000 0.0010 0.0010

200 0.26 5.13 0.60 0.22 0.0194 0.0194 0.0000 0.0194 0.0194

189 0.33 3.95 0.54 0.20 0.0039 0.0039 0.0000 0.0039 0.0039

215 0.32 5.51 0.55 0.32 0.0194 0.0194 0.0000 0.0194 0.0194

240 0.29 5.38 0.49 0.27 0.0116 0.0116 0.0000 0.0116 0.0116

280 0.47 5.47 0.52 0.23 0.0020 0.0020 0.0000 0.0020 0.0020

189 0.31 5.40 0.92 0.21 0.0014 0.0014 0.0000 0.0014 0.0014

252 0.22 6.23 0.30 0.23 0.0092 0.0092 0.0000 0.0092 0.0092

238 0.21 5.95 0.51 0.19 0.0006 0.0006 0.0000 0.0006 0.0006

244 0.39 6.24 0.74 0.18 0.0011 0.0011 0.0000 0.0011 0.0011

285 0.06 5.93 0.60 0.09 0.0009 0.0009 0.0000 0.0009 0.0009

197 0.33 5.07 0.76 0.18 0.0044 0.0044 0.0000 0.0044 0.0044

251 0.23 5.59 0.42 0.11 0.0072 0.0072 0.0000 0.0072 0.0072

184 0.30 6.70 0.61 0.18 0.0023 0.0023 0.0000 0.0023 0.0023
Table D6. 2000 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D44

280 0.19 5.68 0.51 0.18 0.0039 0.0039 0.0000 0.0039 0.0039

298 0.37 6.32 1.16 0.30 0.0029 0.0029 0.0000 0.0029 0.0029

212 0.29 6.41 0.40 0.14 0.0035 0.0035 0.0000 0.0035 0.0035

210 0.09 5.16 0.90 0.18 0.0070 0.0070 0.0000 0.0070 0.0070

225 0.09 6.78 0.40 0.16 0.0058 0.0058 0.0000 0.0058 0.0058

286 0.22 5.35 1.24 0.38 0.0304 0.0304 0.0000 0.0304 0.0304

181 0.15 5.69 0.44 0.27 0.0127 0.0127 0.0000 0.0127 0.0127

202 0.38 8.06 1.42 0.42 0.0009 0.0009 0.0000 0.0009 0.0009

190 0.66 6.08 1.56 0.40 0.0007 0.0007 0.0000 0.0007 0.0007

177 0.34 6.20 0.89 0.28 0.0026 0.0026 0.0000 0.0026 0.0026

182 0.42 6.43 0.87 0.30 0.0009 0.0009 0.0000 0.0009 0.0009

207 0.44 6.59 1.15 0.37 0.0009 0.0009 0.0000 0.0009 0.0009

217 0.36 5.49 1.00 0.22 0.0018 0.0018 0.0000 0.0018 0.0018

183 0.54 6.63 0.81 0.34 0.0009 0.0009 0.0000 0.0009 0.0009

227 0.35 6.34 0.51 0.27 0.0009 0.0009 0.0000 0.0009 0.0009

244 0.19 6.30 1.66 0.36 0.0035 0.0035 0.0000 0.0035 0.0035

272 0.35 6.44 1.09 0.23 0.0035 0.0035 0.0000 0.0035 0.0035

255 0.25 5.89 0.40 0.13 0.0087 0.0087 0.0000 0.0087 0.0087

Sales-wgt

EF

0.2663

10

5.4417

29 4.540000 0.666725

0.2406

85 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 64 64 2 64 64
D45

Table D6. 2000 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

310 0.34 5.48 0.79 0.13 0.0016 0.0029 0.0016 0.0015 0.0000

415 0.10 4.65 0.40 0.08 0.0053 0.0030 0.0053 0.0042 0.0000

496 0.13 6.12 0.28 0.07 0.0011 0.0008 0.0011 0.0011 0.0000

340 0.12 3.91 0.56 0.17 0.0395 0.0253 0.0395 0.0267 0.0000

300 0.08 5.78 0.43 0.13 0.0053 0.0023 0.0053 0.0053 0.0000

395 0.51 6.48 2.14 0.16 0.0759 0.2081 0.0759 0.0852 0.0000

300 0.28 6.13 0.81 0.36 0.0071 0.0107 0.0071 0.0075 0.0000

330 0.33 5.28 1.07 0.36 0.0087 0.0154 0.0087 0.0079 0.0000

397 0.19 4.65 1.35 0.19 0.0039 0.0040 0.0039 0.0032 0.0000

362 0.16 5.49 1.57 0.21 0.2706 0.2327 0.2706 0.2574 0.0000

322 0.15 3.98 0.75 0.19 0.0379 0.0306 0.0379 0.0261 0.0000

455 0.12 5.48 0.82 0.17 0.0053 0.0034 0.0053 0.0050 0.0000

599 0.04 6.59 2.67 0.33 0.1111 0.0239 0.1111 0.1268 0.0000

535 0.08 5.79 2.10 0.34 0.0087 0.0037 0.0087 0.0087 0.0000

350 0.22 6.52 1.17 0.20 0.0869 0.1010 0.0869 0.0982 0.0000

430 0.14 6.29 0.34 0.13 0.0290 0.0221 0.0290 0.0316 0.0000

525 0.16 6.52 0.65 0.16 0.0158 0.0139 0.0158 0.0179 0.0000

440 0.11 6.38 0.35 0.13 0.0200 0.0117 0.0200 0.0221 0.0000

336 0.14 5.48 0.45 0.15 0.0103 0.0077 0.0103 0.0097 0.0000

422 0.15 4.97 0.40 0.11 0.0003 0.0002 0.0003 0.0002 0.0000

449 0.14 5.10 5.24 0.50 0.15 0.0005 0.0004 0.0005 0.0005 1.0000

308 0.28 5.68 0.45 0.20 0.0021 0.0031 0.0021 0.0021 0.0000

335 0.27 5.51 0.74 0.28 0.0006 0.0009 0.0006 0.0006 0.0000

563 0.14 5.11 0.40 0.11 0.0016 0.0012 0.0016 0.0014 0.0000

543 0.22 5.66 0.54 0.25 0.0116 0.0139 0.0116 0.0114 0.0000

305 0.09 6.00 0.99 0.13 0.0104 0.0052 0.0104 0.0108 0.0000

325 0.10 6.51 0.51 0.13 0.0235 0.0130 0.0235 0.0265 0.0000

315 0.28 5.20 0.70 0.17 0.0358 0.0545 0.0358 0.0322 0.0000

329 0.24 6.60 0.84 0.17 0.0037 0.0048 0.0037 0.0042 0.0000

590 0.34 6.40 0.72 0.23 0.0001 0.0002 0.0001 0.0001 0.0000

335 0.26 6.17 1.05 0.32 0.0003 0.0004 0.0003 0.0003 0.0000

306 0.24 6.29 0.72 0.37 0.0145 0.0187 0.0145 0.0158 0.0000

326 0.50 4.04 0.43 0.14 0.0048 0.0130 0.0048 0.0034 0.0000

493 0.16 4.26 1.04 0.22 0.0029 0.0025 0.0029 0.0021 0.0000

493 0.16 5.89 0.95 0.28 0.0006 0.0005 0.0006 0.0006 0.0000

334 0.25 5.58 0.31 0.18 0.0284 0.0387 0.0284 0.0275 0.0000

322 0.23 3.99 0.41 0.20 0.0009 0.0011 0.0009 0.0006 0.0000

375 0.22 5.72 0.32 0.20 0.0055 0.0066 0.0055 0.0055 0.0000

525 0.17 6.06 0.60 0.23 0.0047 0.0044 0.0047 0.0050 0.0000

330 0.21 6.39 0.44 0.20 0.0003 0.0004 0.0003 0.0004 0.0000

571 0.31 3.98 0.48 0.17 0.0032 0.0052 0.0032 0.0022 0.0000

475 0.28 4.09 0.46 0.15 0.0032 0.0048 0.0032 0.0022 0.0000

542 0.32 3.80 0.56 0.19 0.0032 0.0054 0.0032 0.0021 0.0000

327 0.22 6.39 0.46 0.14 0.0032 0.0038 0.0032 0.0035 0.0000

327 0.24 6.11 0.48 0.13 0.0032 0.0041 0.0032 0.0033 0.0000

460 0.19 3.35 0.33 0.05 0.0003 0.0003 0.0003 0.0002 0.0000
Table D6. 2000 MY Certification Data (cont.)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D46

335 0.43 4.29 0.81 0.12 0.0013 0.0029 0.0013 0.0009 0.0000

330 0.05 5.33 0.43 0.21 0.0405 0.0115 0.0405 0.0374 0.0000

313 0.27 6.26 0.31 0.06 0.0148 0.0214 0.0148 0.0161 0.0000

381 0.21 6.55 0.61 0.08 0.0289 0.0324 0.0289 0.0328 0.0000

496 0.13 6.12 0.28 0.07 0.0016 0.0011 0.0016 0.0017 0.0000

Sales-wgt

EF

0.1860

24

5.7702

60

5.24000

0

1.2545

46

0.2031

48 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 51 51 1 51 51

Table D6. 2000 MY Certification Data (cont.)

600-750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

660 0.05 6.24 0.83 0.14 0.1743 0.1743 0.1743 0.1743

740 0.05 5.68 1.57 0.25 0.2823 0.2823 0.2823 0.2823

730 0.06 5.04 0.99 0.19 0.0892 0.0892 0.0892 0.0892

740 0.10 5.53 1.62 0.33 0.0423 0.0423 0.0423 0.0423

600 0.26 6.02 1.78 0.24 0.1598 0.1598 0.1598 0.1598

630 0.16 4.46 0.66 0.18 0.0249 0.0249 0.0249 0.0249

641 0.19 5.98 1.05 0.23 0.0137 0.0137 0.0137 0.0137

740 0.24 5.85 1.37 0.28 0.0066 0.0066 0.0066 0.0066

740 0.24 5.85 1.37 0.28 0.0066 0.0066 0.0066 0.0066

750 0.07 5.84 0.90 0.16 0.0112 0.0112 0.0112 0.0112

750 0.08 6.01 1.92 0.30 0.0589 0.0589 0.0589 0.0589

750 0.35 5.80 1.48 0.30 0.0818 0.0818 0.0818 0.0818

750 0.13 5.89 1.06 0.13 0.0357 0.0357 0.0357 0.0357

684 0.19 5.98 0.68 0.22 0.0062 0.0062 0.0062 0.0062

671 0.48 6.63 0.52 0.16 0.0062 0.0062 0.0062 0.0062

Sales-wgt EF 0.126821 5.790567 1.368105 0.225632 1.0000 1.0000 1.0000 1.0000

Sample Size 15 15 15 15
D47

Table D6. 2000 MY Certification Data (cont.)

>750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

800 0.03 6.19 0.36 0.10 0.0321 0.0321 0.0321 0.0321

758 0.07 5.26 1.07 0.16 0.0067 0.0067 0.0067 0.0067

1082 0.04 5.96 0.70 0.15 0.0555 0.0555 0.0555 0.0555

1850 0.16 5.89 1.10 0.31 0.0658 0.0658 0.0658 0.0658

2750 0.14 6.18 1.31 0.17 0.0515 0.0515 0.0515 0.0515

1200 0.17 5.17 0.34 0.16 0.0044 0.0044 0.0044 0.0044

2000 0.31 5.91 1.49 0.25 0.0297 0.0297 0.0297 0.0297

1250 0.20 6.51 0.51 0.13 0.4683 0.4683 0.4683 0.4683

1500 0.54 6.24 0.87 0.27 0.2120 0.2120 0.2120 0.2120

1200 0.17 5.17 0.34 0.16 0.0297 0.0297 0.0297 0.0297

899 0.21 6.02 0.53 0.15 0.0044 0.0044 0.0044 0.0044

1230 0.12 6.03 0.67 0.26 0.0024 0.0024 0.0024 0.0024

1874 0.38 6.15 1.36 0.15 0.0059 0.0059 0.0059 0.0059

1207 0.23 5.45 1.26 0.24 0.0059 0.0059 0.0059 0.0059

1026 0.26 5.07 0.70 0.18 0.0059 0.0059 0.0059 0.0059

2346 0.40 6.04 1.39 0.26 0.0198 0.0198 0.0198 0.0198

Sales-wgt

EF 0.259060 6.252638 0.727419 0.183308 1.0000 1.0000 1.0000 1.0000

Sample

Size 16 16 16 16
D48

Table D7. 2001 MY Certification Data

0-11 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

9 6.70 4.70 0.57 0.0000 0.0000 0.0426 0.0426 0.0426

10 3.36 1.04 0.28 0.0000 0.0000 0.0059 0.0059 0.0059

7 3.82 2.11 0.35 0.0000 0.0000 0.0106 0.0106 0.0106

7 3.77 2.95 0.33 0.0000 0.0000 0.0355 0.0355 0.0355

11 5.45 4.10 0.24 0.0000 0.0000 0.0284 0.0284 0.0284

10 5.23 1.68 0.21 0.0000 0.0000 0.0248 0.0248 0.0248

7 1.59 4.67 6.26 3.81 0.44 0.253454 0.2013 0.2013 0.0106 0.0106 0.0106

8 4.09 1.09 0.44 0.0000 0.0000 0.0004 0.0004 0.0004

4 0.78 5.18 5.96 3.93 0.66 0.131414 0.1409 0.1409 0.0075 0.0075 0.0075

7 0.71 4.82 5.53 3.83 0.57 0.128205 0.1477 0.1477 0.0078 0.0078 0.0078

8 0.58 5.74 6.32 3.29 0.45 0.091981 0.1409 0.1409 0.0075 0.0075 0.0075

10 5.49 3.86 0.51 0.0000 0.0000 0.0075 0.0075 0.0075

11 0.57 5.10 5.67 3.18 0.54 0.101183 0.3691 0.3691 0.0195 0.0195 0.0195

4 6.61 5.00 0.50 0.0000 0.0000 0.2768 0.2768 0.2768

7 6.25 5.03 0.49 0.0000 0.0000 0.1821 0.1821 0.1821

10 6.30 3.84 0.39 0.0000 0.0000 0.2425 0.2425 0.2425

7 6.57 3.61 0.48 0.0000 0.0000 0.0234 0.0234 0.0234

10 3.72 1.91 0.35 0.0000 0.0000 0.0554 0.0554 0.0554

9 3.88 3.84 0.33 0.0000 0.0000 0.0114 0.0114 0.0114

Saleswgt EF

0.8283

78

5.0737

63

6.0188

91

4.1740

66

0.4420

10 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 5 5 19 19 19 0.141247

Calc HC* 0.8501

53

Calc

NOx*

5.1687

38

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D49

Table D7. 2001 MY Certification Data (cont.)

11-25 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

19 5.02 1.36 0.45 0.0000 0.0000 0.0029 0.0029 0.0029

17 0.58 3.79 4.37 3.82 0.57 0.131868 0.0312 0.0312 0.0036 0.0036 0.0036

25 0.45 4.07 4.52 3.09 0.38 0.099558 0.1248 0.1248 0.0143 0.0143 0.0143

16 0.60 3.61 4.21 2.31 0.10 0.141844 0.0062 0.0062 0.0007 0.0007 0.0007

21 0.30 3.77 4.07 1.72 0.20 0.073394 0.0312 0.0312 0.0036 0.0036 0.0036

17 5.26 1.69 0.39 0.0000 0.0000 0.0004 0.0004 0.0004

18 5.15 0.77 0.23 0.0000 0.0000 0.0005 0.0005 0.0005

23 3.98 1.08 0.26 0.0000 0.0000 0.0024 0.0024 0.0024

11 4.88 1.88 0.50 0.0000 0.0000 0.0027 0.0027 0.0027

17 4.38 2.36 0.52 0.0000 0.0000 0.0037 0.0037 0.0037

12 5.54 2.57 0.33 0.0000 0.0000 0.0021 0.0021 0.0021

18 4.96 1.10 0.56 0.0000 0.0000 0.0301 0.0301 0.0301

21 3.68 1.34 0.57 0.0000 0.0000 0.0064 0.0064 0.0064

24 3.54 1.06 0.30 0.0000 0.0000 0.0014 0.0014 0.0014

24 5.67 1.66 0.56 0.0000 0.0000 0.0020 0.0020 0.0020

19 3.40 0.99 0.37 0.0000 0.0000 0.0031 0.0031 0.0031

18 0.17 5.59 5.76 0.97 0.54 0.028849 0.0027 0.0027 0.0003 0.0003 0.0003

17 0.10 3.48 3.58 0.56 0.33 0.027933 0.2702 0.2702 0.0309 0.0309 0.0309

25 0.11 3.38 3.49 0.56 0.30 0.030399 0.1179 0.1179 0.0135 0.0135 0.0135

12 5.53 2.77 0.22 0.0000 0.0000 0.3563 0.3563 0.3563

20 5.66 2.23 0.21 0.0000 0.0000 0.0107 0.0107 0.0107

23 4.30 1.73 0.14 0.0000 0.0000 0.2138 0.2138 0.2138

22 4.66 1.50 0.12 0.0000 0.0000 0.0356 0.0356 0.0356

16 0.60 3.61 4.21 2.31 0.10 0.142113 0.0031 0.0031 0.0004 0.0004 0.0004

19 0.98 4.38 5.36 3.78 0.25 0.182132 0.1373 0.1373 0.0157 0.0157 0.0157

18 1.03 5.04 6.05 3.50 0.41 0.169964 0.0811 0.0811 0.0093 0.0093 0.0093

21 0.30 3.77 4.07 1.72 0.20 0.073154 0.0343 0.0343 0.0039 0.0039 0.0039

21 4.10 2.24 0.35 0.0000 0.0000 0.0071 0.0071 0.0071

17 3.62 1.57 0.30 0.0000 0.0000 0.0170 0.0170 0.0170

23 5.34 0.68 0.22 0.0000 0.0000 0.0020 0.0020 0.0020

15 0.72 5.29 6.02 3.70 0.43 0.120198 0.0137 0.0137 0.0016 0.0016 0.0016

15 0.43 5.70 6.12 2.41 0.39 0.069428 0.0137 0.0137 0.0016 0.0016 0.0016

16 0.57 5.62 6.19 3.00 0.37 0.092771 0.0069 0.0069 0.0008 0.0008 0.0008

22 0.77 5.17 5.94 3.04 0.45 0.129397 0.0630 0.0630 0.0072 0.0072 0.0072

22 0.37 5.17 5.53 1.58 0.32 0.066038 0.0624 0.0624 0.0071 0.0071 0.0071

12 5.03 2.95 0.26 0.0000 0.0000 0.0011 0.0011 0.0011

16 4.46 2.98 0.35 0.0000 0.0000 0.0323 0.0323 0.0323

12 3.17 1.47 0.30 0.0000 0.0000 0.0355 0.0355 0.0355

19 4.29 1.28 0.08 0.0000 0.0000 0.0217 0.0217 0.0217

22 3.47 2.27 0.19 0.0000 0.0000 0.0276 0.0276 0.0276

24 5.63 0.90 0.25 0.0000 0.0000 0.0351 0.0351 0.0351

17 4.88 1.55 0.42 0.0000 0.0000 0.0280 0.0280 0.0280

18 3.24 1.91 0.32 0.0000 0.0000 0.0043 0.0043 0.0043

Saleswgt EF

0.4478

31

4.1095

21

4.8069

20

2.1148

84

0.2429

92 1.0000 1.0000 1.0000 1.0000 1.0000
Table D7. 2001 MY Certification Data (cont.)

11-25 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D50

Sample

Size 16 16 43 43 43 0.09869

Calc HC* 0.4743

95

Calc

NOx*

4.3325

25

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D51

Table D7. 2001 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

42 6.52 3.35 0.42 0.0000 0.0000 0.0016 0.0016 0.0016

25 5.31 1.49 0.50 0.0000 0.0000 0.0013 0.0013 0.0013

28 4.92 1.56 0.54 0.0000 0.0000 0.0016 0.0016 0.0016

49 4.93 0.92 0.34 0.0000 0.0000 0.0011 0.0011 0.0011

34 5.21 1.44 0.38 0.0000 0.0000 0.0041 0.0041 0.0041

33 0.11 4.65 4.77 0.98 0.25 0.023474 0.0149 0.0116 0.0016 0.0016 0.0016

38 0.26 3.59 3.85 0.92 0.19 0.067829 0.0030 0.0023 0.0003 0.0003 0.0003

30 0.16 4.00 4.17 1.17 0.26 0.039356 0.0030 0.0023 0.0003 0.0003 0.0003

26 0.29 3.02 3.31 1.33 0.15 0.087838 0.0030 0.0023 0.0003 0.0003 0.0003

28 0.00 7.02 1.48 0.24 0.0000 0.0000 0.0350 0.0349 0.0349

43 0.00 6.89 2.10 0.34 0.0000 0.0000 0.0119 0.0119 0.0119

48 0.00 6.82 1.99 0.44 0.0000 0.0000 0.0110 0.0110 0.0110

35 5.68 1.74 0.21 0.0000 0.0000 0.0013 0.0013 0.0013

39 6.39 1.87 0.16 0.0000 0.0000 0.0024 0.0024 0.0024

47 6.37 1.24 0.12 0.0000 0.0000 0.0024 0.0024 0.0024

25 4.35 0.64 0.13 0.0000 0.0000 0.0001 0.0001 0.0001

28 3.76 1.24 0.20 0.0000 0.0000 0.0047 0.0047 0.0047

30 3.86 0.83 0.17 0.0000 0.0000 0.0033 0.0033 0.0033

40 4.50 0.62 0.20 0.0000 0.0000 0.0025 0.0025 0.0025

47 3.38 0.87 0.27 0.0000 0.0000 0.0006 0.0006 0.0006

29 4.11 1.54 0.50 0.0000 0.0000 0.0008 0.0008 0.0008

29 4.11 1.16 0.35 0.0000 0.0000 0.0156 0.0156 0.0156

33 3.13 1.00 0.34 0.0000 0.0000 0.0495 0.0495 0.0495

35 4.21 0.85 0.37 0.0000 0.0000 0.0204 0.0204 0.0204

28 3.57 2.65 0.43 0.0000 0.0000 0.0029 0.0029 0.0029

39 4.35 1.89 0.45 0.0000 0.0000 0.0009 0.0009 0.0009

28 0.13 4.23 4.36 1.33 0.54 0.029817 0.0417 0.0324 0.0046 0.0046 0.0046

33 0.55 4.81 5.36 2.62 0.47 0.102612 0.1204 0.0935 0.0132 0.0131 0.0131

37 0.16 3.56 3.72 2.30 0.58 0.041678 0.0459 0.0356 0.0050 0.0050 0.0050

37 0.67 6.00 6.67 3.55 0.42 0.10051 0.0361 0.0280 0.0039 0.0039 0.0039

27 0.11 4.52 4.63 0.57 0.31 0.023758 0.0002 0.0001 0.0000 0.0000 0.0000

37 0.82 4.27 5.09 3.10 0.37 0.1611 0.0387 0.0301 0.0042 0.0042 0.0042

27 0.09 3.95 4.04 0.82 0.46 0.021308 0.0051 0.0039 0.0006 0.0006 0.0006

49 0.51 4.59 5.10 2.85 0.50 0.1 0.0605 0.0470 0.0066 0.0066 0.0066

35 0.08 4.56 4.64 0.90 0.40 0.017234 0.0566 0.0440 0.0062 0.0062 0.0062

45 0.75 5.33 6.08 2.40 0.29 0.123355 0.0548 0.0426 0.0060 0.0060 0.0060

35 0.56 4.54 5.10 1.52 0.48 0.109804 0.4172 0.3240 0.0456 0.0456 0.0456

46 0.04 3.75 3.79 0.68 0.33 0.010554 0.0038 0.0029 0.0004 0.0004 0.0004

34 0.14 3.66 3.80 0.98 0.50 0.036842 0.0459 0.0356 0.0050 0.0050 0.0050

47 0.12 6.71 6.83 0.74 0.30 0.01757 0.0015 0.0012 0.0002 0.0002 0.0002

48 0.64 6.36 7.00 1.46 0.31 0.091429 0.0042 0.0032 0.0005 0.0005 0.0005

30 1.41 0.62 0.26 0.0000 0.0000 0.0326 0.0325 0.0325

26 4.64 1.30 0.28 0.0000 0.0000 0.0065 0.0065 0.0065

31 3.80 1.16 0.36 0.0000 0.0000 0.0195 0.0195 0.0195

42 3.84 0.78 0.24 0.0000 0.0000 0.0163 0.0163 0.0163

26 4.46 0.95 0.35 0.0000 0.0000 0.0651 0.0651 0.0651

44 5.37 1.10 0.38 0.0000 0.0000 0.0000 0.0000 0.0000
Table D7. 2001 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D52

33 5.52 1.71 0.36 0.0000 0.0000 0.0000 0.0000 0.0000

41 4.81 0.75 0.25 0.0000 0.0000 0.0003 0.0003 0.0003

31 5.27 0.74 0.19 0.0000 0.0000 0.0326 0.0325 0.0325

31 5.11 0.80 0.26 0.0000 0.0000 0.0391 0.0390 0.0390

38 6.16 1.66 0.41 0.0000 0.0000 0.0260 0.0260 0.0260

37 4.47 0.80 0.29 0.0000 0.0000 0.1628 0.1627 0.1627

49 5.95 1.93 0.43 0.0000 0.0000 0.0003 0.0003 0.0003

38 5.99 1.58 0.36 0.0000 0.0000 0.0003 0.0003 0.0003

48 4.63 0.93 0.23 0.0000 0.0000 0.0020 0.0020 0.0020

35 3.69 3.83 1.40 0.29 0.0000 0.0231 0.0033 0.0033 0.0033

40 3.36 3.54 0.95 0.21 0.0000 0.0231 0.0033 0.0033 0.0033

40 0.18 4.99 5.17 0.94 0.48 0.034632 0.0136 0.0105 0.0015 0.0015 0.0015

38 0.26 3.59 3.85 0.93 0.19 0.068327 0.0006 0.0005 0.0001 0.0001 0.0001

26 0.29 3.02 3.31 1.33 0.15 0.088659 0.0012 0.0009 0.0001 0.0001 0.0001

25 0.59 4.87 5.47 1.88 0.29 0.108272 0.0143 0.0111 0.0016 0.0016 0.0016

33 0.23 4.10 4.33 0.74 0.23 0.054045 0.0104 0.0081 0.0011 0.0011 0.0011

36 5.26 5.58 1.87 0.28 0.0000 0.0116 0.0016 0.0016 0.0016

35 6.03 2.07 0.21 0.0000 0.0000 0.0015 0.0015 0.0015

31 4.68 1.10 0.16 0.0000 0.0000 0.0015 0.0015 0.0015

41 5.65 2.45 0.24 0.0000 0.0000 0.0024 0.0024 0.0024

42 6.35 1.01 0.13 0.0000 0.0000 0.0020 0.0020 0.0020

30 5.12 1.98 0.43 0.0000 0.0000 0.0035 0.0035 0.0035

42 3.24 0.94 0.33 0.0000 0.0000 0.0003 0.0003 0.0003

39 4.73 1.01 0.34 0.0000 0.0000 0.0026 0.0026 0.0026

45 5.62 1.30 0.38 0.0000 0.0000 0.0009 0.0009 0.0009

49 4.00 0.64 0.24 0.0000 0.0000 0.0001 0.0001 0.0001

43 5.12 1.98 0.43 0.0000 0.0000 0.0001 0.0001 0.0001

35 6.27 2.35 0.48 0.0000 0.0000 0.0033 0.0033 0.0033

44 6.19 1.09 0.45 0.0000 0.0000 0.0015 0.0015 0.0015

34 3.53 3.55 1.22 0.53 0.0000 0.0127 0.0018 0.0018 0.0018

49 3.20 3.31 1.29 0.40 0.0000 0.0694 0.0098 0.0098 0.0098

47 5.44 5.83 1.86 0.44 0.0000 0.0509 0.0072 0.0072 0.0072

43 6.35 2.33 0.34 0.0000 0.0000 0.0006 0.0006 0.0006

30 6.09 1.99 0.46 0.0000 0.0000 0.0003 0.0003 0.0003

26 5.45 2.00 0.15 0.0000 0.0000 0.0280 0.0280 0.0280

28 5.78 3.61 0.40 0.0000 0.0000 0.0097 0.0097 0.0097

25 5.53 2.91 0.37 0.0000 0.0000 0.0137 0.0137 0.0137

30 5.82 2.93 0.35 0.0000 0.0000 0.0009 0.0009 0.0009

25 5.91 3.45 0.24 0.0000 0.0000 0.0018 0.0018 0.0018

33 5.76 2.74 0.28 0.0000 0.0000 0.0476 0.0476 0.0476

41 5.97 1.35 0.49 0.0000 0.0000 0.0009 0.0009 0.0009

29 5.82 2.82 0.25 0.0000 0.0000 0.0030 0.0030 0.0030

37 5.40 1.73 0.50 0.0000 0.0000 0.0009 0.0009 0.0009

25 6.01 3.03 0.32 0.0000 0.0000 0.0004 0.0004 0.0004

37 6.03 2.59 0.35 0.0000 0.0000 0.0272 0.0272 0.0272

25 6.09 3.03 0.20 0.0000 0.0000 0.0000 0.0000 0.0000
Table D7. 2001 MY Certification Data (cont.)

25-50 hp Emission Factors (g/hp-hr) Sales Weightings

Rated

HP

HC NOx HC+NOx CO PM HC frac of

HC+NOx*

HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D53

30 6.07 3.01 0.38 0.0000 0.0000 0.0110 0.0110 0.0110

45 5.85 3.21 0.45 0.0000 0.0000 0.0367 0.0367 0.0367

38 5.79 3.23 0.39 0.0000 0.0000 0.0017 0.0017 0.0017

48 6.00 1.56 0.44 0.0000 0.0000 0.0000 0.0000 0.0000

34 5.94 1.87 0.34 0.0000 0.0000 0.0689 0.0689 0.0689

46 6.01 2.54 0.20 0.0000 0.0000 0.0063 0.0062 0.0062

41 5.76 2.79 0.33 0.0000 0.0000 0.0030 0.0030 0.0030

48 6.25 1.59 0.28 0.0000 0.0000 0.0002 0.0002 0.0002

27 3.04 0.98 0.40 0.0000 0.0000 0.0021 0.0021 0.0021

39 5.53 1.96 0.26 0.0000 0.0000 0.0010 0.0010 0.0010

30 0.17 4.01 1.17 0.26 0.040139 0.0036 0.0028 0.0000 0.0004 0.0004

50 4.85 0.0000 0.0325 0.0000 0.0000 0.0000

Saleswgt EF

0.4729

17

4.4696

47

4.9529

01

1.5320

28

0.3292

22 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 25 35 103 104 104 0.064006

Calc HC* 0.3170

14

Calc

NOx*

4.6358

87

* HC fraction of HC+NOx = HC ÷ (HC+NOx). The average HC fraction is not a sales-weighted average.

Calculated HC = ( avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).

Calculated NOx = (1- avg HC fraction of HC+NOx) * (sales-wgt avg HC+NOx).
D54

Table D7. 2001 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

67 6.40 0.0000 0.0016 0.0000 0.0000

79 5.74 0.0000 0.0004 0.0000 0.0000

96 5.81 0.0000 0.0002 0.0000 0.0000

80 0.48 7.61 4.32 0.56 0.0621 0.0157 0.0591 0.0608

67 0.75 6.35 1.96 0.34 0.0036 0.0009 0.0034 0.0035

75 0.70 5.68 2.28 0.46 0.0888 0.0224 0.0844 0.0869

80 0.72 5.78 3.26 0.51 0.0855 0.0216 0.0813 0.0837

56 0.62 5.83 1.63 0.41 0.0339 0.0086 0.0322 0.0332

75 0.70 5.68 2.28 0.49 0.0586 0.0148 0.0557 0.0573

98 0.71 6.30 1.68 0.21 0.0004 0.0001 0.0004 0.0004

62 6.23 0.0000 0.0008 0.0000 0.0000

57 6.20 0.0000 0.0008 0.0000 0.0000

55 5.80 0.0000 0.0008 0.0000 0.0000

59 6.56 0.0000 0.0045 0.0000 0.0000

84 5.74 0.0000 0.0478 0.0000 0.0000

59 0.89 8.82 3.55 0.84 0.1563 0.0395 0.1486 0.1530

78 0.48 5.36 1.92 0.35 0.0858 0.0217 0.0816 0.0840

81 0.33 6.35 2.33 0.38 0.0154 0.0039 0.0147 0.0151

74 5.90 0.0000 0.0040 0.0000 0.0000

59 5.90 0.0000 0.0205 0.0000 0.0000

82 5.44 0.0000 0.0661 0.0000 0.0000

65 5.80 0.0000 0.0179 0.0000 0.0000

58 6.39 0.0000 0.0002 0.0000 0.0000

87 6.39 0.0000 0.0002 0.0000 0.0000

83 6.56 0.0000 0.0024 0.0000 0.0000

65 6.20 0.0000 0.0143 0.0000 0.0000

84 6.79 0.0000 0.0000 0.0000 0.0000

79 6.32 0.0000 0.0025 0.0000 0.0000

94 6.09 0.0000 0.0004 0.0000 0.0000

94 6.09 0.0000 0.0004 0.0000 0.0000

94 6.09 0.0000 0.0004 0.0000 0.0000

51 5.38 0.0000 0.0024 0.0000 0.0000

56 4.98 0.0000 0.0011 0.0000 0.0000

78 6.22 0.0000 0.0000 0.0000 0.0000

51 4.86 1.51 0.0000 0.0022 0.0084 0.0000

60 4.06 1.73 0.0000 0.0022 0.0084 0.0000

52 4.59 0.0000 0.0163 0.0000 0.0000

50 3.43 0.0000 0.0094 0.0000 0.0000

52 0.17 5.22 1.18 0.45 0.0107 0.0027 0.0101 0.0104

51 1.44 5.79 3.90 0.38 0.0179 0.0045 0.0170 0.0175

54 0.69 4.15 1.45 0.36 0.0100 0.0025 0.0095 0.0098

51 0.60 6.68 3.04 0.63 0.0008 0.0002 0.0008 0.0008

55 0.39 6.16 0.98 0.28 0.0134 0.0034 0.0127 0.0131

64 0.43 5.62 2.17 0.60 0.0042 0.0011 0.0040 0.0041

76 0.29 5.35 1.08 0.51 0.0092 0.0023 0.0087 0.0090

51 0.41 5.34 2.22 0.64 0.0386 0.0098 0.0367 0.0378
Table D7. 2001 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D55

56 0.48 4.88 0.46 0.27 0.0048 0.0012 0.0046 0.0047

83 0.49 4.80 0.76 0.34 0.0065 0.0016 0.0061 0.0063

91 0.42 6.63 1.32 0.54 0.0172 0.0043 0.0163 0.0168

79 0.55 5.25 2.47 0.55 0.0248 0.0063 0.0236 0.0243

86 0.46 4.98 0.83 0.38 0.0012 0.0003 0.0011 0.0012

86 0.35 5.09 0.67 0.21 0.0002 0.0001 0.0002 0.0002

59 6.65 0.0000 0.0333 0.0000 0.0000

51 0.05 3.56 0.75 0.20 0.0097 0.0024 0.0092 0.0095

74 0.49 3.77 3.00 0.52 0.0008 0.0002 0.0008 0.0008

74 0.76 4.70 2.06 0.32 0.0161 0.0041 0.0153 0.0158

80 0.72 5.78 3.26 0.51 0.0018 0.0004 0.0017 0.0017

99 0.28 4.15 0.76 0.25 0.0133 0.0034 0.0127 0.0130

98 0.71 6.30 1.68 0.21 0.0040 0.0010 0.0038 0.0039

56 0.62 5.83 1.63 0.41 0.0019 0.0005 0.0018 0.0018

59 4.37 0.0000 0.0367 0.0000 0.0000

51 5.12 0.0000 0.0004 0.0000 0.0000

51 4.72 0.0000 0.0004 0.0000 0.0000

56 4.18 0.0000 0.0245 0.0000 0.0000

89 4.79 0.0000 0.0020 0.0000 0.0000

73 4.93 0.0000 0.0020 0.0000 0.0000

86 5.42 0.0000 0.0082 0.0000 0.0000

93 4.71 0.0000 0.0082 0.0000 0.0000

72 4.31 0.0000 0.0151 0.0000 0.0000

54 0.54 6.31 2.42 0.0085 0.0021 0.0081 0.0000

59 3.34 0.0000 0.0002 0.0000 0.0000

51 4.78 0.0000 0.0029 0.0000 0.0000

56 5.95 0.0000 0.0029 0.0000 0.0000

51 3.91 0.0000 0.0031 0.0000 0.0000

54 2.62 0.0000 0.0039 0.0000 0.0000

63 5.06 0.0000 0.0006 0.0000 0.0000

95 5.58 0.0000 0.0002 0.0000 0.0000

57 4.46 0.0000 0.0046 0.0000 0.0000

51 5.35 0.0000 0.0042 0.0000 0.0000

87 5.92 0.0000 0.0056 0.0000 0.0000

55 2.91 0.0000 0.0013 0.0000 0.0000

81 5.87 0.0000 0.0001 0.0000 0.0000

92 5.10 0.0000 0.0002 0.0000 0.0000

52 6.32 0.0000 0.0041 0.0000 0.0000

72 5.14 0.0000 0.0008 0.0000 0.0000

89 6.40 0.0000 0.0020 0.0000 0.0000

67 0.22 5.71 1.01 0.54 0.0934 0.0236 0.0888 0.0914

92 0.35 6.16 1.22 0.29 0.0638 0.0161 0.0606 0.0624

55 2.62 0.0000 0.0010 0.0000 0.0000

85 2.18 0.0000 0.0011 0.0000 0.0000

59 5.90 0.0000 0.0002 0.0000 0.0000

64 5.58 0.0000 0.0102 0.0000 0.0000
Table D7. 2001 MY Certification Data (cont.)

50-100 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D56

79 6.16 0.0000 0.0055 0.0000 0.0000

55 3.22 0.0000 0.0090 0.0000 0.0000

52 6.62 0.0000 0.0080 0.0000 0.0000

64 5.13 0.0000 0.0037 0.0000 0.0000

60 6.06 0.0000 0.0212 0.0000 0.0000

96 5.09 0.0000 0.1081 0.0000 0.0000

68 5.85 0.0000 0.0551 0.0000 0.0000

52 5.97 0.0000 0.0347 0.0000 0.0000

68 6.34 0.0000 0.0347 0.0000 0.0000

80 0.83 6.00 3.19 0.63 0.0043 0.0011 0.0041 0.0042

80 0.86 5.40 4.00 0.64 0.0051 0.0013 0.0048 0.0050

59 3.58 0.0000 0.0025 0.0000 0.0000

89 5.10 0.0000 0.0008 0.0000 0.0000

94 5.75 0.0000 0.0002 0.0000 0.0000

50 5.80 1.78 0.46 0.0000 0.0002 0.0008 0.0009

74 0.05 4.00 0.25 0.20 0.0002 0.0000 0.0002 0.0002

82 0.07 4.84 1.22 0.44 0.0113 0.0029 0.0107 0.0111

60 5.87 3.96 0.31 0.0000 0.0004 0.0015 0.0016

58 6.27 1.32 0.27 0.0000 0.0015 0.0058 0.0059

59 5.59 0.96 0.45 0.0000 0.0003 0.0013 0.0013

75 3.87 0.0000 0.0013 0.0000 0.0000

58 3.91 0.0000 0.0017 0.0000 0.0000

54 5.40 0.0000 0.0001 0.0000 0.0000

67 4.89 0.0000 0.0135 0.0000 0.0000

80 4.80 0.0000 0.0004 0.0000 0.0000

56 5.23 0.0000 0.0015 0.0000 0.0000

58 5.12 0.0000 0.0037 0.0000 0.0000

60 4.12 0.0000 0.0032 0.0000 0.0000

70 5.59 0.0000 0.0117 0.0000 0.0000

57 5.72 0.0000 0.0002 0.0000 0.0000

95 5.10 0.0000 0.0032 0.0000 0.0000

100 5.73 0.0000 0.0144 0.0000 0.0000

50 0.52 4.77 5.28 1.94 0.33 0.0121 0.0031 0.3000 0.0115 0.0118

65 0.05 4.18 4.24 0.90 0.0040 0.0010 0.1000 0.0038 0.0000

79 5.98 6.61 1.71 0.37 0.0000 0.0061 0.6000 0.0230 0.0237

Sales-wgt

EF

0.5758

67

5.6045

15

5.9769

57

2.3143

72

0.5068

24 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 40 127 3 47 43
D57

Table D7. 2001 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

173 0.33 6.37 0.78 0.11 0.0003 0.0002 0.0003 0.0003

108 6.47 0.0000 0.0002 0.0000 0.0000

143 6.09 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0857 0.0682 0.0856 0.0863

125 0.23 6.21 0.47 0.16 0.0057 0.0045 0.0057 0.0058

118 0.25 4.53 0.54 0.22 0.0021 0.0017 0.0021 0.0021

155 0.38 4.23 0.75 0.35 0.1029 0.0819 0.1027 0.1035

110 6.06 0.0000 0.0039 0.0000 0.0000

165 6.24 0.0000 0.0303 0.0000 0.0000

166 4.95 0.0000 0.0003 0.0000 0.0000

155 0.15 4.25 1.91 0.22 0.0072 0.0057 0.0072 0.0072

100 0.35 6.08 0.70 0.28 0.1247 0.0992 0.1244 0.1255

125 0.23 6.21 0.47 0.16 0.0623 0.0496 0.0622 0.0627

118 0.25 4.53 0.54 0.22 0.0023 0.0018 0.0023 0.0023

155 0.38 4.23 0.75 0.35 0.0935 0.0744 0.0933 0.0941

158 6.53 0.0000 0.0016 0.0000 0.0000

109 6.41 0.0000 0.0016 0.0000 0.0000

144 4.97 0.0000 0.0016 0.0000 0.0000

168 0.11 6.17 0.63 0.13 0.0007 0.0006 0.0007 0.0007

135 0.40 5.70 1.75 0.29 0.2824 0.2248 0.2819 0.2842

168 6.26 0.0000 0.0105 0.0000 0.0000

109 6.32 0.53 0.13 0.0000 0.0001 0.0001 0.0001

158 6.70 0.0000 0.0072 0.0000 0.0000

119 0.58 6.20 0.63 0.17 0.0010 0.0008 0.0010 0.0010

121 0.49 4.30 1.23 0.28 0.0011 0.0009 0.0011 0.0011

134 0.34 4.30 1.00 0.24 0.0050 0.0040 0.0050 0.0050

103 0.57 6.26 1.58 0.39 0.0059 0.0047 0.0059 0.0059

153 0.51 5.65 0.49 0.26 0.0078 0.0062 0.0078 0.0079

164 0.47 4.67 1.06 0.23 0.0017 0.0014 0.0017 0.0017

139 0.52 4.30 1.25 0.19 0.0006 0.0005 0.0006 0.0006

106 6.01 0.0000 0.0426 0.0000 0.0000

144 6.61 0.0000 0.0001 0.0000 0.0000

100 0.35 6.08 0.70 0.28 0.0457 0.0364 0.0456 0.0460

125 0.23 6.21 0.47 0.16 0.0114 0.0091 0.0114 0.0115

155 0.38 4.23 0.75 0.35 0.0571 0.0455 0.0570 0.0575

125 5.74 0.0000 0.0041 0.0000 0.0000

114 5.42 0.0000 0.0002 0.0000 0.0000

151 5.60 0.0000 0.0000 0.0000 0.0000

120 5.50 0.0000 0.0009 0.0000 0.0000

144 5.80 0.0000 0.0001 0.0000 0.0000

114 6.35 0.0000 0.0113 0.0000 0.0000

113 4.41 0.0000 0.0060 0.0000 0.0000

132 6.05 0.0000 0.0041 0.0000 0.0000

173 5.79 0.0000 0.0017 0.0000 0.0000

108 0.16 6.25 0.43 0.26 0.0407 0.0324 0.0406 0.0410

116 0.57 6.43 1.45 0.33 0.0050 0.0040 0.0050 0.0051

168 0.42 5.85 0.76 0.27 0.0199 0.0159 0.0199 0.0200
Table D7. 2001 MY Certification Data (cont.)

100-175 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

D58

118 6.30 0.0000 0.0005 0.0000 0.0000

120 5.55 0.0000 0.0178 0.0000 0.0000

103 6.19 0.0000 0.0055 0.0000 0.0000

172 0.13 5.31 0.45 0.17 0.0094 0.0074 0.0093 0.0094

115 5.77 0.0000 0.0041 0.0000 0.0000

152 5.82 0.0000 0.0372 0.0000 0.0000

103 0.53 5.30 1.24 0.51 0.0010 0.0008 0.0010 0.0010

135 0.45 6.68 0.92 0.24 0.0004 0.0003 0.0004 0.0004

130 0.63 6.61 1.21 0.36 0.0007 0.0006 0.0007 0.0007

100 0.57 5.50 1.35 0.47 0.0015 0.0012 0.0015 0.0015

114 6.39 0.0000 0.0025 0.0000 0.0000

127 5.38 0.0000 0.0008 0.0000 0.0000

117 6.23 0.0000 0.0008 0.0000 0.0000

172 6.23 0.0000 0.0025 0.0000 0.0000

173 0.54 6.57 1.83 0.42 0.0010 0.0008 0.0010 0.0010

122 0.07 3.93 0.42 0.14 0.0001 0.0001 0.0001 0.0001

122 0.07 5.75 1.06 0.34 0.0049 0.0039 0.0049 0.0050

100 6.27 0.87 0.33 0.0000 0.0005 0.0006 0.0006

142 5.92 1.33 0.23 0.0000 0.0008 0.0010 0.0010

138 6.68 0.0000 0.0019 0.0000 0.0000

161 0.23 5.96 0.83 0.0082 0.0065 0.0082 0.0000

116 5.82 0.0000 0.0005 0.0000 0.0000

Sales-wgt

EF 0.355107 5.574714 1.003922 0.289340 1.0000 1.0000 1.0000 1.0000

Sample Size 34 69 37 36
D59

Table D7. 2001 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

272 0.32 6.24 0.62 0.10 0.0003 0.0003 0.0000 0.0003 0.0003

257 0.43 6.43 0.76 0.20 0.0002 0.0002 0.0000 0.0002 0.0002

200 0.26 5.13 0.60 0.22 0.0045 0.0045 0.0000 0.0045 0.0045

240 0.10 5.06 0.38 0.15 0.0023 0.0023 0.0000 0.0022 0.0022

240 0.07 4.06 0.50 0.16 0.0023 0.0023 0.0000 0.0022 0.0022

215 0.32 5.51 0.55 0.32 0.0038 0.0038 0.0000 0.0037 0.0037

260 0.44 5.82 0.70 0.27 0.0015 0.0015 0.0000 0.0015 0.0015

240 0.29 5.38 0.49 0.27 0.0064 0.0064 0.0000 0.0063 0.0063

280 0.47 5.47 0.52 0.23 0.0151 0.0151 0.0000 0.0149 0.0149

210 0.20 5.89 1.49 0.33 0.0092 0.0092 0.0000 0.0091 0.0091

275 0.11 4.56 1.26 0.26 0.0002 0.0002 0.0000 0.0002 0.0002

205 0.19 5.96 1.73 0.25 0.0024 0.0024 0.0000 0.0024 0.0024

255 0.08 6.20 0.96 0.29 0.0143 0.0143 0.0000 0.0141 0.0141

290 0.09 5.46 2.19 0.35 0.0016 0.0016 0.0000 0.0016 0.0016

205 0.39 5.95 1.19 0.31 0.0008 0.0008 0.0000 0.0007 0.0007

190 0.55 5.64 1.44 0.32 0.0227 0.0227 0.0000 0.0225 0.0225

240 0.10 5.06 0.38 0.15 0.0038 0.0038 0.0000 0.0037 0.0037

200 0.26 5.13 0.60 0.22 0.0753 0.0753 0.0000 0.0745 0.0745

189 0.33 3.95 0.54 0.20 0.0015 0.0015 0.0000 0.0015 0.0015

215 0.32 5.51 0.55 0.32 0.0376 0.0376 0.0000 0.0372 0.0372

260 0.44 5.82 0.70 0.27 0.0205 0.0205 0.0000 0.0203 0.0203

240 0.29 5.38 0.49 0.27 0.0753 0.0753 0.0000 0.0745 0.0745

280 0.47 5.47 0.52 0.23 0.0075 0.0075 0.0000 0.0074 0.0074

240 0.07 4.06 0.50 0.16 0.0038 0.0038 0.0000 0.0037 0.0037

200 0.25 5.43 1.23 0.35 0.0013 0.0013 0.0000 0.0013 0.0013

296 0.31 6.41 0.96 0.25 0.0013 0.0013 0.0000 0.0013 0.0013

255 0.36 6.45 0.72 0.24 0.0000 0.0000 0.0000 0.0000 0.0000

261 0.47 6.06 0.89 0.27 0.0000 0.0000 0.0000 0.0000 0.0000

248 0.34 5.31 1.04 0.35 0.0001 0.0001 0.0000 0.0001 0.0001

275 0.14 5.38 0.48 0.14 0.0008 0.0008 0.0000 0.0008 0.0008

220 0.20 5.87 0.72 0.27 0.0042 0.0042 0.0000 0.0041 0.0041

234 0.19 5.45 0.62 0.25 0.0097 0.0097 0.0000 0.0096 0.0096

196 0.28 5.44 0.65 0.28 0.4205 0.4205 0.0000 0.4161 0.4161

199 0.27 5.70 1.05 0.32 0.0147 0.0147 0.0000 0.0146 0.0146

294 0.38 5.99 0.95 0.23 0.0640 0.0640 0.0000 0.0633 0.0633

285 0.46 6.51 1.19 0.22 0.0164 0.0164 0.0000 0.0163 0.0163

216 0.59 6.20 1.55 0.28 0.0458 0.0458 0.0000 0.0453 0.0453

285 0.47 4.59 0.73 0.26 0.0287 0.0287 0.0000 0.0284 0.0284

237 0.78 6.32 1.30 0.38 0.0000 0.0000 0.0000 0.0000 0.0000

189 0.43 6.65 1.04 0.34 0.0014 0.0014 0.0000 0.0014 0.0014

194 0.31 6.28 0.81 0.17 0.0083 0.0083 0.0000 0.0083 0.0083

288 0.62 6.62 1.69 0.36 0.0005 0.0005 0.0000 0.0005 0.0005

186 0.34 6.28 0.69 0.23 0.0004 0.0004 0.0000 0.0004 0.0004

249 0.48 6.37 1.08 0.24 0.0001 0.0001 0.0000 0.0001 0.0001

243 0.40 5.88 1.67 0.37 0.0000 0.0000 0.0000 0.0000 0.0000

210 0.09 5.16 0.90 0.11 0.0021 0.0021 0.0000 0.0020 0.0020
Table D7. 2001 MY Certification Data (cont.)

175-300 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

D60

250 0.09 5.29 0.44 0.05 0.0001 0.0001 0.0000 0.0001 0.0001

215 0.10 6.30 0.50 0.07 0.0005 0.0005 0.0000 0.0005 0.0005

197 0.33 4.42 0.71 0.20 0.0002 0.0002 0.0000 0.0001 0.0001

241 0.21 4.14 0.67 0.17 0.0002 0.0002 0.0000 0.0001 0.0001

241 0.41 6.44 1.11 0.34 0.0006 0.0006 0.0000 0.0006 0.0006

227 0.51 6.72 1.07 0.33 0.0009 0.0009 0.0000 0.0009 0.0009

193 0.60 6.69 0.85 0.28 0.0004 0.0004 0.0000 0.0004 0.0004

200 0.26 5.13 0.60 0.22 0.0075 0.0075 0.0000 0.0074 0.0074

189 0.33 3.95 0.54 0.20 0.0015 0.0015 0.0000 0.0015 0.0015

215 0.32 5.51 0.55 0.32 0.0075 0.0075 0.0000 0.0074 0.0074

240 0.29 5.38 0.49 0.27 0.0045 0.0045 0.0000 0.0045 0.0045

280 0.47 5.47 0.52 0.23 0.0008 0.0008 0.0000 0.0008 0.0008

189 0.31 5.40 0.92 0.21 0.0001 0.0001 0.0000 0.0001 0.0001

252 0.22 6.23 0.30 0.23 0.0030 0.0030 0.0000 0.0029 0.0029

283 0.14 4.25 0.43 0.17 0.0011 0.0011 0.0000 0.0011 0.0011

262 0.17 5.84 0.57 0.21 0.0002 0.0002 0.0000 0.0002 0.0002

244 0.39 6.24 0.74 0.18 0.0004 0.0004 0.0000 0.0004 0.0004

285 0.06 5.93 0.60 0.09 0.0003 0.0003 0.0000 0.0003 0.0003

215 0.04 4.10 0.51 0.16 0.0034 0.0034 0.0000 0.0034 0.0034

197 0.33 5.07 0.76 0.18 0.0021 0.0021 0.0000 0.0021 0.0021

251 0.23 5.59 0.42 0.11 0.0039 0.0039 0.0000 0.0039 0.0039

184 0.30 6.70 0.61 0.18 0.0010 0.0010 0.0000 0.0010 0.0010

280 0.19 5.68 0.51 0.18 0.0020 0.0020 0.0000 0.0019 0.0019

298 0.37 6.32 1.16 0.30 0.0011 0.0011 0.0000 0.0011 0.0011

212 0.29 6.41 0.40 0.14 0.0014 0.0014 0.0000 0.0014 0.0014

286 0.22 5.35 1.24 0.37 0.0083 0.0083 0.0000 0.0082 0.0082

208 0.15 4.28 0.52 0.26 0.0051 0.0051 0.0000 0.0050 0.0050

202 0.28 6.00 1.05 0.33 0.0003 0.0003 0.0000 0.0003 0.0003

190 0.66 6.08 1.56 0.40 0.0002 0.0002 0.0000 0.0002 0.0002

177 0.34 6.20 0.89 0.28 0.0010 0.0010 0.0000 0.0010 0.0010

182 0.42 6.43 0.87 0.29 0.0003 0.0003 0.0000 0.0003 0.0003

207 0.44 6.59 1.15 0.36 0.0003 0.0003 0.0000 0.0003 0.0003

217 0.36 5.49 1.00 0.22 0.0007 0.0007 0.0000 0.0007 0.0007

244 0.19 6.30 1.66 0.37 0.0014 0.0014 0.0000 0.0014 0.0014

272 0.35 6.44 1.09 0.22 0.0014 0.0014 0.0000 0.0014 0.0014

255 0.25 5.89 0.40 0.13 0.0026 0.0026 0.0000 0.0026 0.0026

279 4.18 0.73 0.20 0.0000 0.0000 0.8977 0.0102 0.0102

275 0.11 4.02 4.13 0.80 0.16 0.0002 0.0002 0.0209 0.0002 0.0002

185 0.54 4.19 4.73 0.93 0.20 0.0002 0.0002 0.0132 0.0001 0.0001

245 4.55 0.45 0.15 0.0000 0.0000 0.0359 0.0004 0.0004

295 0.22 4.08 4.29 0.60 0.13 0.0003 0.0003 0.0299 0.0003 0.0003

268 0.30 4.00 4.47 0.66 0.19 0.0000 0.0000 0.0024 0.0000 0.0000

Sales-wgt

EF

0.3147

65

5.5065

45

4.2032

95

0.7446

33

0.2666

22 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 86 86 6 88 88
D61

Table D7. 2001 MY Certification Data (cont.) (Tier 2 for this hp category)

300-600 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

325 4.56 1.52 0.17 0.0000 0.0000 0.0516 0.0516 0.0516

439 3.75 1.19 0.16 0.0000 0.0000 0.0589 0.0589 0.0589

515 3.58 1.14 0.17 0.0000 0.0000 0.0521 0.0521 0.0521

593 4.08 0.58 0.10 0.0000 0.0000 0.2080 0.2080 0.2080

475 4.14 0.99 0.14 0.0000 0.0000 0.0460 0.0460 0.0460

325 4.56 1.52 0.17 0.0000 0.0000 0.0516 0.0516 0.0516

449 0.10 3.80 3.91 0.37 0.10 0.0036 0.0036 0.0011 0.0011 0.0011

422 0.14 4.09 4.24 0.35 0.10 0.0279 0.0279 0.0082 0.0082 0.0082

322 0.13 4.37 4.50 0.44 0.11 0.0110 0.0110 0.0032 0.0032 0.0032

333 0.15 4.38 4.53 0.53 0.14 0.6951 0.6951 0.2042 0.2042 0.2042

300 4.53 0.82 0.14 0.0000 0.0000 0.0038 0.0038 0.0038

350 4.71 0.77 0.11 0.0000 0.0000 0.0038 0.0038 0.0038

500 4.75 1.30 0.12 0.0000 0.0000 0.1467 0.1467 0.1467

500 4.61 0.48 0.12 0.0000 0.0000 0.0258 0.0258 0.0258

300 0.06 4.02 4.08 0.59 0.13 0.0239 0.0239 0.0070 0.0070 0.0070

317 0.39 4.19 4.58 0.80 0.15 0.0150 0.0150 0.0044 0.0044 0.0044

321 0.17 4.22 4.39 0.52 0.14 0.0389 0.0389 0.0114 0.0114 0.0114

483 0.16 4.23 4.39 0.46 0.13 0.0235 0.0235 0.0069 0.0069 0.0069

360 0.12 4.47 4.59 0.63 0.09 0.0030 0.0030 0.0009 0.0009 0.0009

326 0.50 4.04 4.54 0.43 0.14 0.0022 0.0022 0.0006 0.0006 0.0006

456 0.15 4.37 4.52 0.57 0.10 0.0070 0.0070 0.0021 0.0021 0.0021

481 0.10 4.44 4.53 0.43 0.08 0.0036 0.0036 0.0011 0.0011 0.0011

322 4.34 0.65 0.15 0.0000 0.0000 0.0066 0.0066 0.0066

410 4.40 0.30 0.11 0.0000 0.0000 0.0264 0.0264 0.0264

508 4.20 0.30 0.12 0.0000 0.0000 0.0016 0.0016 0.0016

572 4.53 0.86 0.19 0.0000 0.0000 0.0019 0.0019 0.0019

503 4.50 0.93 0.15 0.0000 0.0000 0.0064 0.0064 0.0064

571 4.29 0.48 0.14 0.0000 0.0000 0.0035 0.0035 0.0035

475 4.38 0.46 0.11 0.0000 0.0000 0.0035 0.0035 0.0035

595 4.20 0.63 0.16 0.0000 0.0000 0.0035 0.0035 0.0035

367 4.55 0.45 0.15 0.0000 0.0000 0.0035 0.0035 0.0035

493 4.49 0.71 0.13 0.0000 0.0000 0.0006 0.0006 0.0006

493 4.49 0.71 0.13 0.0000 0.0000 0.0006 0.0006 0.0006

324 0.22 4.30 4.53 0.47 0.08 0.0100 0.0100 0.0029 0.0029 0.0029

375 0.25 4.29 4.54 0.48 0.08 0.1354 0.1354 0.0398 0.0398 0.0398

Sales-wgt

EF

0.1669

24

4.3351

13

4.34534

8

0.8424

60

0.1315

81 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 14 14 35 35 35
D62

Table D7. 2001 MY Certification Data (cont.)

600-750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx HC+NOx CO PM HC wgt NOx wgt HC+NOx

wgt

CO wgt PM wgt

660 0.05 6.24 0.83 0.14 0.0276 0.0276 0.0000 0.0192 0.0192

742 0.04 6.27 0.52 0.10 0.0408 0.0408 0.0000 0.0284 0.0284

654 0.04 6.21 1.58 0.25 0.1192 0.1192 0.0000 0.0829 0.0829

730 0.06 5.04 0.99 0.19 0.1159 0.1159 0.0000 0.0806 0.0806

740 0.10 5.53 1.62 0.33 0.0850 0.0850 0.0000 0.0591 0.0591

670 0.25 6.53 1.27 0.36 0.0795 0.0795 0.0000 0.0553 0.0553

710 0.27 6.63 2.31 0.30 0.0552 0.0552 0.0000 0.0384 0.0384

641 0.19 5.98 1.05 0.23 0.0353 0.0353 0.0000 0.0246 0.0246

740 0.24 5.85 1.37 0.28 0.0839 0.0839 0.0000 0.0583 0.0583

684 0.19 5.98 0.68 0.22 0.0055 0.0055 0.0000 0.0038 0.0038

671 0.48 6.63 0.52 0.16 0.0221 0.0221 0.0000 0.0153 0.0153

747 0.22 4.50 0.76 0.09 0.0055 0.0055 0.0000 0.0038 0.0038

680 3.89 0.33 0.12 0.0000 0.0000 0.7192 0.3047 0.3047

601 0.13 4.19 4.32 0.22 0.12 0.1049 0.1049 0.1721 0.0729 0.0729

750 0.07 5.84 0.90 0.16 0.0121 0.0121 0.0000 0.0084 0.0084

750 0.13 5.89 1.06 0.13 0.1413 0.1413 0.0000 0.0982 0.0982

630 0.12 3.87 3.99 0.87 0.18 0.0662 0.0662 0.1087 0.0460 0.0460

Sales-wgt

EF

0.13806

5

5.61241

8 3.975047 0.88330

5

0.18377

3 1.0000 1.0000 1.0000 1.0000 1.0000

Sample

Size 16 16 3 17 17
D63

Table D7. 2001 MY Certification Data (cont.)

>750 hp Emission Factors (g/hp-hr) Sales Weightings

Rated HP HC NOx CO PM HC wgt NOx wgt CO wgt PM wgt

758 0.07 5.26 1.07 0.16 0.0052 0.0052 0.0052 0.0052

891 0.05 6.22 0.73 0.14 0.0152 0.0152 0.0152 0.0152

1850 0.16 5.89 1.09 0.30 0.0654 0.0654 0.0654 0.0654

2250 0.16 6.43 1.28 0.20 0.0395 0.0395 0.0395 0.0395

755 0.35 5.80 1.48 0.30 0.0599 0.0599 0.0599 0.0599

1200 0.17 5.17 0.34 0.16 0.0033 0.0033 0.0033 0.0033

2000 0.31 5.91 1.49 0.25 0.0228 0.0228 0.0228 0.0228

1110 0.23 6.03 0.55 0.14 0.4402 0.4402 0.4402 0.4402

1500 0.54 6.24 0.87 0.27 0.2677 0.2677 0.2677 0.2677

1200 0.17 5.17 0.34 0.16 0.0228 0.0228 0.0228 0.0228

899 0.21 6.02 0.53 0.15 0.0088 0.0088 0.0088 0.0088

1230 0.12 6.03 0.67 0.26 0.0046 0.0046 0.0046 0.0046

811 0.27 6.24 1.05 0.21 0.0152 0.0152 0.0152 0.0152

1874 0.38 6.15 1.36 0.15 0.0024 0.0024 0.0024 0.0024

878 0.34 5.96 0.89 0.14 0.0152 0.0152 0.0152 0.0152

1207 0.23 5.45 1.26 0.24 0.0030 0.0030 0.0030 0.0030

1026 0.26 5.07 0.70 0.18 0.0009 0.0009 0.0009 0.0009

2346 0.40 6.04 1.39 0.26 0.0076 0.0076 0.0076 0.0076

Sales-wgt

EF 0.313093 6.052394 0.800887 0.203589 1.0000 1.0000 1.0000 1.0000

Sample

Size 18 18 18 18
E1

HCCM 

HS AHC

HS i j

ij ij

i,j

,

, ,

= −

Appendix E

Derivation of Highway-Certification Compliance Margins and 

Application to Nonroad Compression Ignition Engines

Here below, we describe the derivation of the highway-certification compliance

margins (HCCMs) in greater detail. The highway certification results used for this

purpose in derivation of Tier 2/3 emission factors (option 4) are summarized in a report

updating emission levels for heavy-duty highway diesel engines for use in MOBILE6 (1). 

The report presents results for light, medium, and heavy vehicle classes in model years

1988-1989 and 1991-1994. For this analysis, we supplemented these certification data

with more recent highway certification data from model years 1997-2001.

We used the highway certification results to calculate compliance margins

(HCCM) for some highway engines for MY 1988-2001. The procedure followed several

steps ( refer to Table E1):

(1) We assigned highway model-year groups, (e.g., 1991-93) to each nonroad

horsepower category (e.g., 50-100 hp). These assignments vary for each

pollutant and individual horsepower category. The assignments attempt to

associate similar highway and nonroad engine technologies. We averaged results

for multiple years within a model-year group.

(2) We assigned nonroad engines less than 50 horsepower to the light heavy-duty

diesel vehicle weight class (LHDD), engines in the range of 50-250 hp to the

medium heavy-duty diesel vehicle weight class (MHDD), and engines greater

than 250 hp to the heavy heavy-duty diesel vehicle weight class (HHDD). Within

a model-year group, these assignments identified subsets of certification data to

represent specific nonroad horsepower categories. Correspondence between

highway weight class (light-duty, medium-duty, heavy-duty) and nonroad

horsepower categories follows relationships established by the California Air

Resources Board (CARB 2000).

(3) We used the highway certification data described above and assigned to the

appropriate nonroad horsepower categories to calculate compliance margins for

highway engines at certification:

where HCCMi,j, HSi,j and AHCi,j are the highway-certification compliance margin,

highway standard and average certification emissions level, respectively, for

pollutant i, and horsepower category j (e.g., NOx, 50-100 hp).
E2

While we calculated the highway-certification compliance margins for all

pollutants and horsepower categories, note that Table E1 presents results only for NOx

and PM. We do not present compliance margins for HC and CO because the margins

were higher than 80 percent. As a result, we did not use them to estimate HC and CO

Tier 2/3 emission factors.

References

(1) EPA, “Update of Heavy-Duty Emission Levels (Model Years 1988-2004+) for Use in

MOBILE6,” EPA420-R-99-010, April 1999.
E3

Table E1. Highway-Certification Compliance Margins by Horsepower Category

Nonroad Engine

Power Categories

(hp)

Highway ModelYear Group

(MYG)

Corresponding Heavy-Duty Highway Vehicle Weight Class

(VWC), Emission Standards (HS), Certification Test Results

(AHC) and Compliance Margins (HCCM)

NOx

VWC1 HS

(g/hp-hr)

AHC 2

(g/hp-hr)

HCCM

(% HS)

< 11 1991-93 LHDD 5.0 4.28 14

11-25 1991-93 LHDD 5.0 4.28 14

25-50 1991-93 LHDD 5.0 4.28 14

50-100 1991-93 MHDD 5.0 4.54 9.0

100-175 1998-2003 MHDD 4.0 3.78 5.5

175-300 1998-2003 MHDD 4.0 3.58 10.5

300-600 1998-2003 HHDD 4.0 3.92 2.0

600-750 1998-2003 HHDD 4.0 3.84 4.0

>750 1998-2003 HHDD 4.0 3.84 4.0

PM

< 11 1988-89 LHDD 0.6 0.44 27

11-25 1988-89 LHDD 0.6 0.44 27

25-50 1988-89 LHDD 0.6 0.44 27

50-100 1991-93 MHDD 0.25 0.20 20

100-175 1991-93 MHDD 0.25 0.20 20

175-300 1994-97 MHDD 0.10 0.08 20

300-600 1994-97 HHDD 0.10 0.08 20

600-750 1994-97 HHDD 0.10 0.08 20

>750 1994-97 HHDD 0.10 0.08 20

1

 LHDD = “light heavy-duty diesel,” MHDD = “medium heavy-duty diesel,” and HHDD = “heavy heavy-duty

diesel.”

2

 Source: USEPA (1999), for NOx, Table 10 or MY 1997-2001 highway certification data; for PM, Table 11 or MY

1997-2001highway certification data.
F1

Appendix F

Derivation of Transient Adjustment Factors (TAFs) for

Nonroad Compression Ignition Engines

Nonroad engines often operate under conditions unlike that of the steady-state

ISO-C1 testing procedure typically used in emissions testing. This alternate operation

can cause a change in the emission characteristics of nonroad compression ignition (CI)

engines. As in NEVES, the NONROAD model accounts for in-use (transient) operation

in CI engines by applying an adjustment to emission factors generated using the ISO-C1

(8-mode) steady-state tests. Unlike NEVES, the NONROAD model uses transient

adjustment factors derived from emission testing designed to represent operational

behavior of nonroad equipment. Note that the transient adjustments are not applied by

the NONROAD model, but are applied by EPA during the creation of the NONROAD

emission factor input files.

TAFs are applied to the Base, Tier 0, Tier 1, Tier 2, and Tier 3 emission factors. 

Since transient emission control is expected to be an integral part of all Tier 4 engine

design considerations, TAFs are not applied to the emission factors for Tier 4 engines

(i.e., the model applies a TAF of 1.0).

Development of Transient Adjustment Factors

In NEVES, EPA adjusted the ISO-C1-derived emission factor data available at

the time to account for in-use operation by applying a set of multipliers. These factors

were derived from a comparison of only a few engines tested with both the ISO-C1 test

procedure and the highway Federal Test Procedure (FTP). (1) These factors shown in

Table F1 were applied in NEVES only to engines used in applications judged to be

sufficiently transient in nature.

Table F1. NEVES Test Cycle Adjustment from ISO-C1 Emission Factors

NEVES

Adjustment

HC CO NOx PM

1.4 2.0 1 1.6

NONROAD’s steady-state emission factors for pre-1988 CI engines of greater

than 50 hp are based on the emission factors used in the NEVES. As a result, the

NEVES in-use adjustments were removed to determine pre-1988 average steady-state

emissions for these engines. The TAFs described below are then applied consistently to

all the steady-state emission factors in NONROAD, including the NEVES-derived

steady-state emission factors.

Since it was recognized that the highway test procedure may not simulate engine
F2

TAF

EF

EF trans

ss

=

behavior when used in nonroad applications, a joint EMA\EPA project was initiated to

develop more realistic test cycles for nonroad engine emissions characterization. The

project developed cycles to represent typical operation of an agricultural tractor, a

crawler dozer, and a backhoe\loader. The cycles were developed from data acquired

from instrumenting one piece of each type of equipment. This data was used to construct

appropriate test cycles from statistical criteria developed by EMA and EPA. Southwest

Research Institute (SwRI) then tested nine late-model nonroad engines using the steadystate ISO-C1 certification procedure and the three nonroad test cycles. (2) Later testing

at SwRI involved three additional engines and four additional cycles (rubber-tire loader,

skid-steer loader, arc welder, and excavator cycles). (3) A summary of the cycle specific

emission results for each engine is given in Table F2.

For each pollutant and test cycle, we calculate the TAF as the ratio of the transient

emission factor (EFtrans) to the corresponding steady-state (ISO-C1) emission factor

(EFss):

Transient adjustment factors may be greater than or less than 1.0.

Using the emission data in Table F2, TAFs were calculated for each engine,

pollutant, and test cycle. The resulting TAFs for each engine are provided in Table F3. 

The TAFs for each engine were then averaged to obtain composite TAFs for each of the

seven test cycles. These are also shown in Table F3 along with the standard deviations. 

TAFs for Tier 0 and Tier 1 engines were combined, since they were not statistically

different, based on P values obtained from performing the Student’s t-Test.

For this version of NONROAD, the seven average cycle TAFs were further

binned into two categories, Hi LF and Lo LF, based on the cycle load factors. We

thought this approach would be more defensible, given the limited data available. This

approach is also consistent with that used to develop the new load factors in the model. 

Table F4 shows how the cycle TAFs were binned. When reviewing the cycle load

factors, two bins emerged. A high load factor bin consisted of the following cycles:

agricultural tractor (LF=0.78), crawler dozer (LF=0.58), rubber-tire loader (LF=0.48),

and excavator (LF=0.53). A low load factor bin consisted of the remaining cycles:

backhoe/loader (LF=0.21), skid-steer loader (LF=0.23), and arc welder (LF=0.19). The

TAFs for the high load factor cycles were averaged to obtain a composite Hi LF TAF. 

Similarly, the TAFs for the low load factor cycles were averaged to obtain a composite

Lo LF TAF. As a result, the cycle TAFs were replaced by either a Hi LF TAF or a Lo LF

TAF, depending on the cycle assignment.

Table F5 presents the CI TAFs used in draft NONROAD2004. The TAFs are
F3

carried over from Table F4 with the exception of the Tier 3 TAFs for NOx and PM. The

rationale for the NOx and PM Tier 3 TAFs is described in detail below.

Transient Emission Control and Implications for Tier 3 NOx and PM TAFs

The nonroad engine test cycle (for pre-Tier 4 engines) is a weighted 8 mode

steady-state emission cycle without a transient test element. This is in contrast to onhighway diesel regulations which are set based on average emissions over a 20 minute

transient test and a separate steady-state test. The absence of a transient test allows some

additional control flexibilities for nonroad engines not available, or available at a

diminished level, for on-highway diesel engines. The nonroad engine standards are

therefore inherently less restrictive than otherwise equivalent on-highway emission

standards, as explained in the following paragraphs.

Transient PM emission control is realized for on-highway diesel engines by

limiting fuel injection quantities dependent upon the oxygen content available (the air to

fuel ratio, A/F) to burn the fuel. When an on-highway diesel engine transitions from a

low load steady-state condition to a higher load it does so by increasing the fuel injection

rate and the air induction rate through increases in the intake manifold pressure (i.e.

higher boost from the turbocharger) in order to maintain an A/F ratio with acceptable PM

emissions. While the fueling rate can be changed almost instantaneously on a diesel

engine, it takes a longer amount of time for the turbocharger to increase the air flow due

to the inertial lag of the turbocharger and the mass of air. During the transient period

when the turbocharger is gradually increasing the air flow, the engine control system

limits the addition of fuel in order to prevent excess PM emissions. It is only after the air

flow has increased to the proper amount, that the engine control system allows the

fueling rate to rise to the level needed to deliver the desired engine torque. This control

approach limits transient PM emissions so that the engine will pass the highway transient

test. Absent a transient PM emissions test, the engine controller could immediately

increase the fueling rate, providing rapid attainment of the desired torque level, but this

would also dramatically increase PM emissions. The increase in PM emissions under

transient conditions due to the lack of oxygen (low A/F) is exacerbated by the use of

exhaust gas recirculation (EGR) to limit NOx emissions. This is because the recirculated

gases have a lower oxygen content (the very reason they help to lower NOx emissions). 

In order to maintain effective PM emission control with EGR, turbocharger boost levels

are increased (more low oxygen content air is forced in to the engine in order to give a

total oxygen content similar to without EGR). Because of the higher boost pressure

required, transient PM control might be expected to be worse for EGR equipped engines. 

For highway diesel engines which must meet a transient PM emission standard, these

issues are addressed with sophisticated control systems and with the use of advanced

turbocharger systems (i.e., variable geometry turbochargers). Absent a transient test

procedure, these advanced systems would not necessarily be used.

Similarly, NOx control for on-highway diesel engines equipped with EGR
F4

systems are significantly constrained by the transient emission test procedure. When

undergoing a transient event as described in the previous example, an EGR emission

control system for on-highway engines would briefly turn off EGR in order to increase

the fresh air flow to the system in order to limit PM emissions and increase engine torque

response. The control system must, however, restore the EGR relatively quickly in order

to control NOx emissions under the highway transient test procedure. Failure to do so

would lead to higher NOx emissions. Absent a transient NOx standard, the EGR system

could be turned off for a long period under transient operation, leading to substantially

higher NOx emissions than what would be expected based upon a steady state emission

test level alone. The extent of this increase in NOx emissions is dependent upon the

degree of transient operation (the relative change in engine load). To the extent that load

transient are less severe or not extended, the differences in the resulting NOx emissions

would be less evident.

The lack of a transient emission test procedure for pre-Tier 4 nonroad engines is a

concern to the Agency, because we know that PM emissions realized in use can be

significantly higher than the steady-state emission level set by the PM standards. 

Similarly, we have concerns that NOx emissions under transient conditions may be higher

than indicated by the steady state emissions test and the associated standards. We are

therefore working to develop a more comprehensive set of emission test requirements for

nonroad engines to include a transient test element. In the absence of such a test

procedure for Tier 3 engines, we believe that it is prudent to try to characterize these inuse emissions by increasing the TAFs applied for NOx and PM emissions for Tier 3

engines from the level estimated for Tier 2 engines. Since Tier 3 engines are not

available to provide test data to establish the level of adjustment required, we have

applied engineering judgement to estimate the level of increase in emissions. For PM we

have estimated that the TAF will increase by 20 percent due to the lack of a transient test

and the inherent reduction in average A/F ratio values due to the use of EGR. Given the

highly transient nature of some nonroad diesel engine applications the actual level of

increase could be even higher. In the absence of more definitive data we believe that a

20 percent increase in the TAF is appropriate. We intend to investigate this issue further

when Tier 3 engines become available for testing. We also believe that the NOx TAF

should be adjusted in a similar manner. For NOx we believe that a 10 percent increase in

the TAF is appropriate given the characteristics of EGR systems as we understand them

today. We believe that nonroad engine manufacturers will choose to modulate EGR rates

during high load change transient operation in order to limit PM emissions increases. 

This will lead to an increase in NOx emission for the period that the EGR rate is

modulated below the steady-state level. For example, a 10 percent increase in NOx

emissions could correspond to an EGR rate of zero for 10 percent of the time (a duty

cycle of 90 percent moderate transient and steady-state operation and 10 percent highly

transient operation) assuming that NOx emissions double when the EGR flow is zero. 

For some applications with extreme transient operations it is conceivable that the increase

in emission could be even higher. As with PM, we intend to investigate the actual level

of NOx emissions when Tier 3 engines become available.
F5

Applying In-use Adjustment Factors

To apply the in-use adjustment factors listed in Table F5 to the entire CI

equipment population, EPA matched nonroad applications with the test cycle that most

closely represents the nonroad activity for the application. Table F6 lists the nonroad

applications used in the NONROAD model and the in-use adjustment most representative

of that application. If steady-state operation is typical of an application no adjustment

was made, and the cycle adjustment is listed as ‘none’.

Table A3 presents the resulting TAFs assigned to each equipment application. 

The steady-state emission factors given in Table A2 were then multiplied by the

appropriate in-use adjustment factor to create NONROAD’s emission factor inputs for CI

engines.

Comparison with Previous Draft Versions of NONROAD

Table F7 presents a comparison of TAF methodologies used in the various draft

versions of NONROAD.

References

(1) EPA, “Nonroad Engine and Vehicle Emission Study” (NEVES), U.S. EPA, Office

of Air and Radiation, 21A-2001. November, 1991

(2) Fritz, S. G. and M.E. Starr, “Emission Factors for Compression Ignition Nonroad

Engines Operated on Number 2 Highway and Nonroad Diesel Fuel,” Southwest Research

Institute. EPA contract # 68-C5-0077, SwRI 08-7601-822, March 1998.

(3) Starr, M.E., “Nonroad Engine Emissions Testing,” Southwest Research Institute. 

EPA contract # 68-C5-0076 and 68-C-98-169, September 1999.
F6

Table F2. CI Engine Emissions Data Used to Calculate Transient Adjustment Factors

Engine

(reference) Tier Test Cycle HC 

(g/hp-hr)

CO 

(g/hp-hr)

NOx

(g/hp-hr)

PM

(g/hp-hr)

BSFC

(lb/hp-hr)

Caterpillar 3116 (2) 0 ISO-C1 8-mode 0.07 2.51 9.38 0.406 0.352

Agricultural Tractor 0.04 0.75 9.4 0.28 0.357

Backhoe Loader 0.36 7.47 9.46 0.652 0.411

Crawler Dozer 0.09 7.3 8.7 0.713 0.362

Caterpillar 3054 (2) 0 ISO-C1 8-mode 0.66 1 7.53 0.387 0.393

Agricultural Tractor 0.46 0.47 9.46 0.263 0.377

Backhoe Loader 1.22 3.34 5.45 0.759 0.446

Crawler Dozer 0.51 1.06 8.28 0.384 0.372

John Deere 4039 (2) 0 ISO-C1 8-mode 0.41 2.17 11.22 0.384 0.389

Agricultural Tractor 0.2 0.56 11.7 0.173 0.361

Backhoe Loader 1 2.62 9.57 0.447 0.471

Crawler Dozer 0.33 1.42 11.7 0.254 0.372

John Deere 7076 (2) 0 ISO-C1 8-mode 0.53 2.05 10.22 0.25 0.385

Agricultural Tractor 0.54 0.57 9.45 0.168 0.366

Backhoe Loader 1.13 4.82 14.35 0.522 0.493

Crawler Dozer 0.52 2.22 10.14 0.303 0.37

Consolidated Diesel 

6TA-830 (2)

0 ISO-C1 8-mode 0.86 1.5 6.53 0.397 0.365

Agricultural Tractor 0.9 1.07 5.62 0.304 0.377

Backhoe Loader 2.08 9.86 6.69 1.698 0.438

Crawler Dozer 0.83 3.76 6.06 0.805 0.37

John Deere 6619 (2) 0 ISO-C1 8-mode 0.82 4.69 7.29 0.662 0.397

Agricultural Tractor 0.87 1.16 6.77 0.283 0.4

Backhoe Loader 1.99 6.89 8.29 1.102 0.466

Crawler Dozer 0.8 3.31 7.01 0.698 0.398

Consolidated Diesel 

4039 (2)

0 ISO-C1 8-mode 1.32 3.37 7.57 0.581 0.389

Agricultural Tractor 0.86 2.5 7.28 0.43 0.367

Backhoe Loader 2.89 3.31 6.52 0.725 0.436

Crawler Dozer 1.22 2.1 7.4 0.413 0.364

Caterpillar 3306 (2) 0 ISO-C1 8-mode 1.27 1.46 6.52 0.248 0.373

Agricultural Tractor 1.33 0.82 6.46 0.201 0.372

Backhoe Loader 2.3 5.14 7.22 0.813 0.415

Crawler Dozer 1.16 2.7 6.54 0.436 0.37

John Deere 6101 (2) 1

ISO-C1 8-mode 0.47 0.86 5.55 0.186 0.350

Agricultural Tractor 0.50 0.32 4.93 0.125 0.362

Backhoe Loader 1.07 1.92 6.36 0.430 0.434

Crawler Dozer 0.51 1.17 5.25 0.246 0.362

John Deere 6101(same

engine) retested (3)

1 ISO-C1 8-mode 0.50 1.17 5.73 0.219 0.363

Agricultural Tractor 0.46 0.44 5.16 0.130 0.355

Backhoe Loader 0.93 1.90 6.04 0.430 0.419

Crawler Tractor 0.47 1.14 5.50 0.250 0.357
Table F2. CI Engine Emissions Data Used to Calculate Transient Adjustment Factors

Engine

(reference) Tier Test Cycle HC 

(g/hp-hr)

CO 

(g/hp-hr)

NOx

(g/hp-hr)

PM

(g/hp-hr)

BSFC

(lb/hp-hr)

F7

John Deere 6101 (same

engine) retested

1 ISO-C1 8-mode 0.46 0.95 5.75 0.19

Agricultural Tractor 0.39 0.39 5.24 0.11

Backhoe Loader 0.68 1.58 6.09 0.33

Crawler Dozer 0.37 1.33 5.61 0.24

Excavator 0.67 0.40 4.92 0.171

John Deere 6101

(average of three tests)

1 ISO-C1 8-mode 0.48 0.99 5.68 0.20 0.36

Agricultural Tractor 0.45 0.38 5.11 0.12 0.36

Backhoe Loader 0.89 1.80 6.16 0.40 0.43

Crawler Dozer 0.45 1.21 5.45 0.24 0.36

Excavator 0.67 0.40 4.92 0.171

Caterpillar 3176 (3) 1 ISO-C1 8-mode 0.08 1.78 5.51 0.183 0.333

Agricultural Tractor 0.08 1.47 5.39 0.180 0.330

Backhoe Loader 0.12 4.12 7.20 0.290 0.367

Crawler Dozer 0.06 2.67 5.61 0.230 0.334

MX270 (3) 1 ISO-C1 8-mode 0.11 0.40 4.51 0.096 0.340

Agricultural Tractor 0.06 0.30 4.33 0.090 0.332

Backhoe Loader 0.09 1.30 4.49 0.200 0.382

Crawler Tractor 0.04 0.78 4.11 0.140 0.341

Typ Rubber-Tire 0.07 1.32 4.33 0.180 0.350

Typ Skid-Steer 0.09 0.68 4.15 0.160 0.374

Typ Arc Welder 0.20 1.28 5.39 0.190 0.442

MX240 (3) 1 ISO-C1 8-mode 0.06 0.51 4.32 0.116 0.351

Agricultural Tractor 0.05 0.26 4.02 0.090 0.340

Backhoe Loader 0.12 1.06 4.63 0.200 0.380

Crawler Tractor 0.05 1.04 3.99 0.160 0.342

Typ Rubber-Tire 0.09 2.07 4.18 0.250 0.368

Typ Skid-Steer 0.13 1.00 4.25 0.210 0.379

Typ Arc Welder 0.27 1.65 6.15 0.260 0.451
F8

Table F3. CI Transient Adjustment Factors for Various Nonroad Test Cycles

Engine Tier Test Cycle HC CO NOx PM BSFC

Caterpillar 3116 0 Agricultural Tractor 0.57 0.30 1.00 0.69 1.01

Backhoe Loader 5.14 2.98 1.01 1.61 1.17

Crawler Dozer 1.29 2.91 0.93 1.76 1.03

Caterpillar 3054 0 Agricultural Tractor 0.70 0.47 1.26 0.68 0.96

Backhoe Loader 1.85 3.34 0.72 1.96 1.13

Crawler Dozer 0.77 1.06 1.10 0.99 0.95

John Deere 4039 0 Agricultural Tractor 0.49 0.26 1.04 0.45 0.93

Backhoe Loader 2.44 1.21 0.85 1.16 1.21

Crawler Dozer 0.80 0.65 1.04 0.66 0.96

John Deere 7076 0 Agricultural Tractor 1.02 0.28 0.92 0.67 0.95

Backhoe Loader 2.13 2.35 1.40 2.09 1.28

Crawler Dozer 0.98 1.08 0.99 1.21 0.96

Consolidated Diesel 

6TA-830

0 Agricultural Tractor 1.05 0.71 0.86 0.77 1.03

Backhoe Loader 2.42 6.57 1.02 4.28 1.20

Crawler Dozer 0.97 2.51 0.93 2.03 1.01

John Deere 6619 0 Agricultural Tractor 1.06 0.25 0.93 0.43 1.01

Backhoe Loader 2.43 1.47 1.14 1.66 1.17

Crawler Dozer 0.98 0.71 0.96 1.05 1.00

Consolidated Diesel 

4039

0 Agricultural Tractor 0.65 0.74 0.96 0.74 0.94

Backhoe Loader 2.19 0.98 0.86 1.25 1.12

Crawler Dozer 0.92 0.62 0.98 0.71 0.94

Caterpillar 3306 0 Agricultural Tractor 1.05 0.56 0.99 0.81 1.00

Backhoe Loader 1.81 3.52 1.11 3.28 1.11

Crawler Dozer 0.91 1.85 1.00 1.76 0.99

John Deere 6101

(average of three tests)

1 Agricultural Tractor 0.99 0.37 0.89 0.63 1.01

Backhoe Loader 2.06 1.88 1.10 2.12 1.20

Crawler Dozer 1.01 1.14 0.95 1.22 1.01

Excavator 1.40 0.44 0.87 0.89 1.03

Caterpillar 3176 1 Agricultural Tractor 1.00 0.83 0.98 0.98 0.99

Backhoe Loader 1.50 2.31 1.31 1.58 1.10

Crawler Dozer 0.75 1.50 1.02 1.26 1.00

MX270 1 Agricultural Tractor 0.55 0.75 0.96 0.94 0.98

Backhoe Loader 0.82 3.25 1.00 2.08 1.12

Crawler Dozer 0.36 1.95 0.91 1.46 1.00

Typ Rubber-Tire 0.64 3.30 0.96 1.88 1.03

Typ Skid-Steer 0.82 1.70 0.92 1.67 1.10

Typ Arc Welder 1.82 3.20 1.20 1.98 1.30

MX240 1 Agricultural Tractor 0.83 0.51 0.93 0.78 0.97

Backhoe Loader 2.00 2.08 1.07 1.72 1.08

Crawler Dozer 0.83 2.04 0.92 1.38 0.97
Table F3. CI Transient Adjustment Factors for Various Nonroad Test Cycles

Engine Tier Test Cycle HC CO NOx PM BSFC

F9

Typ Rubber-Tire 1.50 4.06 0.97 2.16 1.05

Typ Skid-Steer 2.17 1.96 0.98 1.81 1.08

Typ Arc Welder 4.50 3.24 1.42 2.24 1.28

Average of

Individual TAFs

Agricultural Tractor 0.83 0.50 0.98 0.71 0.98

Backhoe Loader 2.23 2.66 1.05 2.07 1.16

Crawler Dozer 0.88 1.50 0.98 1.29 0.99

Typ Rubber-Tire 1.07 3.68 0.96 2.02 1.04

Typ Skid-Steer 1.49 1.83 0.95 1.74 1.09

Typ Arc Welder 3.16 3.22 1.31 2.11 1.29

Excavator 1.40 0.44 0.87 0.89 1.03

Standard Deviation

of TAFs

Agricultural Tractor 0.22 0.21 0.10 0.17 0.03

Backhoe Loader 1.02 1.49 0.19 0.88 0.06

Crawler Dozer 0.22 0.75 0.06 0.42 0.03

Typ Rubber-Tire 0.61 0.54 0.01 0.20 0.01

Typ Skid-Steer 0.95 0.18 0.04 0.10 0.01

Typ Arc Welder 1.90 0.02 0.16 0.19 0.01

Student’s t-test: 

P value*

T0 vs T1

Agricultural Tractor 0.90 0.21 0.40 0.08 0.77

Backhoe Loader 0.13 0.67 0.40 0.63 0.17

Crawler Dozer 0.11 0.64 0.26 0.83 0.36

* P value > 0.05 indicates that the difference between the Tier 0 and Tier 1 values is not statistically

significant.
F10

Table F4. CI Cycle Transient Adjustment Factors Binned by Load Factor Category

Cycle Cycle

Load

Factors*

Assignment HC CO NOx

Cycle

TAFs

New

TAFs

Cycle

TAFs

New

TAFs

Cycle

TAFs

New

TAFs

None (steady-state) N/A None 1.00 1.00 1.00 1.00 1.00 1.00

Agricultural Tractor 0.78 Hi LF 0.83 1.05 0.50 1.53 0.98 0.95

Backhoe/Loader 0.21 Lo LF 2.23 2.29 2.66 2.57 1.05 1.10

Crawler Dozer 0.58 Hi LF 0.88 1.05 1.50 1.53 0.98 0.95

Rubber-Tire Loader 0.48 Hi LF 1.07 1.05 3.68 1.53 0.96 0.95

Skid-Steer Loader 0.23 Lo LF 1.49 2.29 1.83 2.57 0.95 1.10

Arc Welder 0.19 Lo LF 3.16 2.29 3.22 2.57 1.31 1.10

Excavator 0.53 Hi LF 1.40 1.05 0.44 1.53 0.87 0.95

avg Hi LF 1.05 1.53 0.95

avg Lo LF 2.29 2.57 1.10

Cycle Cycle

Load

Factors*

Assignment PM BSFC

Cycle TAFs New TAFs Cycle TAFs New TAFs

None (steady-state) N/A None 1.00 1.00 1.00 1.00

Agricultural Tractor 0.78 Hi LF 0.71 1.23 0.98 1.01

Backhoe/Loader 0.21 Lo LF 2.07 1.97 1.16 1.18

Crawler Dozer 0.58 Hi LF 1.29 1.23 0.99 1.01

Rubber-Tire Loader 0.48 Hi LF 2.02 1.23 1.04 1.01

Skid-Steer Loader 0.23 Lo LF 1.74 1.97 1.09 1.18

Arc Welder 0.19 Lo LF 2.11 1.97 1.29 1.18

Excavator 0.53 Hi LF 0.89 1.23 1.03 1.01

avg Hi LF 1.23 1.01

avg Lo LF 1.97 1.18

* The load factors shown were obtained from engine test data and are not used directly in

NONROAD.

Table F5. CI Transient Adjustment Factors in Draft NONROAD2004

Assignment HC CO NOx PM BSFC

BaseTier 3BaseTier 3Base,

Tiers 0-2

Tier 3* Base,

Tiers 0-2

Tier 3* BaseTier 3

avg Hi LF 1.05 1.53 0.95 1.04 1.23 1.47 1.01

avg Lo LF 2.29 2.57 1.10 1.21 1.97 2.37 1.18

None 1.00 1.00 1.00 1.10 1.00 1.20 1.00

* NOx Tier 3 TAF = 1.1*(NOx Base, Tiers 0-2 TAF). PM Tier 3 TAF = 1.2*(PM Base, Tiers 0-2 TAF). 

TAFs are not applied to the emission factors for Tier 4 engines (i.e., the model applies a TAF of 1.0).
F11

Table F6. CI Transient Adjustment Factor Assignments by Equipment Type

SCC Equipment Type Representative

Cycle

TAF

Assignment

2270001000 Recreational Vehicles All Backhoe Lo LF

2270001020 Recreational Vehicles Snowmobiles None None

2270001030 Recreational Vehicles All Terrain Vehicles None None

2270001040 Recreational Vehicles Minibikes None None

2270001050 Recreational Vehicles Golf Carts None None

2270001060 Recreational Vehicles Speciality Vehicle Carts Backhoe Lo LF

2270002003 Construction Equipment Pavers Crawler Hi LF

2270002006 Construction Equipment Tampers/Rammers None None

2270002009 Construction Equipment Plate Compactors None None

2270002015 Construction Equipment Rollers Crawler Hi LF

2270002018 Construction Equipment Scrapers Crawler Hi LF

2270002021 Construction Equipment Paving Equipment Crawler Hi LF

2270002024 Construction Equipment Surfacing Equipment Crawler Hi LF

2270002027 Construction Equipment Signal Boards None None

2270002030 Construction Equipment Trenchers Crawler Hi LF

2270002033 Construction Equipment Bore/Drill Rigs None None

2270002036 Construction Equipment Excavators Excavator Hi LF

2270002039 Construction Equipment Concrete/Industrial Saws Crawler Hi LF

2270002042 Construction Equipment Cement & Mortar Mixers None None

2270002045 Construction Equipment Cranes None None

2270002048 Construction Equipment Graders Crawler Hi LF

2270002051 Construction Equipment Off-highway Trucks Crawler Hi LF

2270002054 Construction Equipment Crushing/Proc. Equipment None None

2270002057 Construction Equipment Rough Terrain Forklifts RTLoader Hi LF

2270002060 Construction Equipment Rubber Tire Loaders RTLoader Hi LF

2270002063 Construction Equipment Rubber Tire Dozers Crawler Hi LF

2270002066 Construction Equipment Tractors/Loaders/Backhoes Backhoe Lo LF

2270002069 Construction Equipment Crawler Dozer Crawler Hi LF

2270002072 Construction Equipment Skid Steer Loaders SSLoader Lo LF

2270002075 Construction Equipment Off-Highway Tractors Crawler Hi LF

2270002078 Construction Equipment Dumpers/Tenders Backhoe Lo LF

2270002081 Construction Equipment Other Construction Equipment Crawler Hi LF

2270003010 Industrial Equipment Aerial Lifts Backhoe Lo LF

2270003020 Industrial Equipment Forklifts RTLoader Hi LF

2270003030 Industrial Equipment Sweepers/Scrubbers None None

2270003040 Industrial Equipment Other General Industrial Equipment None None

2270003050 Industrial Equipment Other Material Handling Equipment Backhoe Lo LF

2270003060 Industrial Equipment AC\Refrigeration None None

2270003070 Terminal Tractors Crawler Hi LF

2270004000 Lawn & Garden Equipment ALL None None

2270004010 Lawn & Garden Equipment Lawn mowers (Residential) None None

2270004011 Lawn & Garden Equipment Lawn mowers (Commercial) None None

2270004015 Lawn & Garden Equipment Rotary Tillers < 6 HP None None

2270004016 Lawn & Garden Equipment Rotary Tillers < 6 HP

(Commercial)

None None

2270004020 Lawn & Garden Equipment Chain Saws < 6 HP None None

2270004021 Lawn & Garden Equipment Chain Saws < 6 HP

(Commercial)

None None
Table F6. CI Transient Adjustment Factor Assignments by Equipment Type

SCC Equipment Type Representative

Cycle

TAF

Assignment

F12

2270004025 Lawn & Garden Equipment Trimmers/Edgers/Brush

Cutters

None None

2270004026 Lawn & Garden Equipment Trimmers/Edgers/Brush

Cutters (Commercial)

None None

2270004030 Lawn & Garden Equipment Leafblowers/Vacuums None None

2270004031 Lawn & Garden Equipment Leafblowers/Vacuums

(Commercial)

None None

2270004035 Lawn & Garden Equipment Snowblowers None None

2270004036 Lawn & Garden Equipment Snowblowers (Commercial) None None

2270004040 Lawn & Garden Equipment Rear Engine Riding Mowers None None

2270004041 Lawn & Garden Equipment Rear Engine Riding Mowers

(Commercial)

None None

2270004045 Lawn & Garden Equipment Front Mowers None None

2270004046 Lawn & Garden Equipment Front Mowers (Commercial) None None

2270004050 Lawn & Garden Equipment Shredders < 6 HP None None

2270004051 Lawn & Garden Equipment Shredders < 6 HP

(Commercial)

None None

2270004055 Lawn & Garden Equipment Lawn & Garden Tractors None None

2270004056 Lawn & Garden Equipment Lawn & Garden Tractors

(Commercial)

None None

2270004060 Lawn & Garden Equipment Wood Splitters None None

2270004061 Lawn & Garden Equipment Wood Splitters (Commercial) None None

2270004065 Lawn & Garden Equipment Chippers/Stump Grinders None None

2270004066 Lawn & Garden Equipment Chippers/Stump Grinders

(Commercial)

None None

2270004071 Lawn & Garden Equipment Commercial Turf Equipment

(Commercial)

None None

2270004075 Lawn & Garden Equipment Other Lawn & Garden

Equipment

None None

2270004076 Lawn & Garden Equipment Other Lawn & Garden

Equipment (Commercial)

None None

2270005010 Farm Equipment 2-Wheel Tractors AgTractor Hi LF

2270005015 Farm Equipment Agricultural Tractors AgTractor Hi LF

2270005020 Farm Equipment Combines AgTractor Hi LF

2270005025 Farm Equipment Balers AgTractor Hi LF

2270005030 Farm Equipment Agricultural Mowers AgTractor Hi LF

2270005035 Farm Equipment Sprayers AgTractor Hi LF

2270005040 Farm Equipment Tillers > 6 HP AgTractor Hi LF

2270005045 Farm Equipment Swathers AgTractor Hi LF

2270005050 Farm Equipment Hydro Power Units None None

2270005055 Farm Equipment Other Agricultural Equipment AgTractor Hi LF

2270005060 Farm Equipment Irrigation Sets None None

2270006000 Light Commercial ALL None None

2270006005 Light Commercial Generator Sets None None

2270006010 Light Commercial Pumps None None

2270006015 Light Commercial Air Compressors None None

2270006020 Light Commercial Gas Compressors None None

2270006025 Light Commercial Welders ArcWelder Lo LF

2270006030 Light Commercial Pressure Washers None None

2270007005 Logging Equipment Chain Saws > 6 HP RTLoader Hi LF

2270007010 Logging Equipment Shredders > 6 HP RTLoader Hi LF

2270007015 Logging Equipment Forest Equipment RTLoader Hi LF
Table F6. CI Transient Adjustment Factor Assignments by Equipment Type

SCC Equipment Type Representative

Cycle

TAF

Assignment

F13

2270008005 Airport Service Equipment Airport Support Equipment RTLoader Hi LF

2270009010 Other Underground Mining Equipment Backhoe Lo LF

2270010010 Other Oil Field Equipment None None

2282020005 Recreational Pleasure Craft, Inboards None None

2282020010 Recreational Pleasure Craft, Outboards None None

2282020015 Recreational Pleasure Craft, Personal Water Craft None None

2282020025 Recreational Pleasure Craft, Sailboat Aux. Outboard None None

2285002015 Railway Maintenance Backhoe Lo LF

Table F7. Comparison of TAF Methodology Used in Draft Versions of NONROAD

Model Date Model

Version

Name

Data as Basis

(# of engines)

Cycles Used Treatment

of Tier 0 vs

Tier 1 Data

Ratio of

Averages

or Average

of Ratios?

TAFs Used

and

Assignments

June 1998 “Original” 9 engines

(8 Tier 0 and 1

Tier 1 engines)

Ag tractor

Backhoe Loader

Crawler Dozer

Tier 0 and

Tier 1 data 

combined

Ratio of

averages

3 cycle TAFs.

One assigned

to each

equipment type

April 1999 “Tier 2" No TAF-related changes

June 2000 “2007 HD

Rule”

12 engines

(8 Tier 0 and 4

Tier 1 engines)

Ag tractor

Backhoe Loader

Crawler Dozer

RT Loader

SS Loader

Arc Welder

Tier 0 and

Tier 1 data

separated;

separate

TAFs for

each

Ratio of

averages

Revised to

accomodate

separate T0

and T1 TAFs

and 3

additional

cycles

Nov 2000 “Final

Finding /

ANPRM”

No TAF related changes relative to June 2000 version

Oct 2001 “Pentathalon

NPRM”

12 engines

(8 Tier 0 and 4

Tier 1 engines)

Ag tractor

Backhoe Loader

Crawler Dozer

RT Loader

SS Loader

Arc Welder

Tier 0 and

Tier 1 data

re-combined

Average of

ratios

6 cycle TAFs. 

One assigned

to each

equipment type

March 2002

April 2004

“NONROAD

2002" and

“NONROAD

2004"

12 engines

(8 Tier 0 and 4

Tier 1 engines)

Ag tractor

Backhoe Loader

Crawler Dozer

RT Loader

SS Loader

Arc Welder

Excavator

Tier 0 and

Tier 1 data

combined

Average of

ratios

7 cycle TAFs

binned in two

categories: Hi

LF and Lo LF. 

One assigned

to each

equipment

type.
G0
G1

Appendix G

Derivation of Deterioration Factors for

Nonroad Compression Ignition Engines

Deterioration factors used in emissions models are intended to account for

increases in emissions above a new engine or vehicle’s base emissions level with time. 

Emissions can increase with time for a number of reasons including, engine wear, poor

maintenance practices, and willful or unwitting tampering with emission control systems. 

Emissions from diesel engines increase with time (deteriorate) at a very slow rate when

the engine is properly maintained and operated. In fact for a number of pollutants

(primarily NOx), emission levels can actually drop slightly as the engine ages. However,

anecdotal and emission test experience suggests that many diesel engines emit at a much

higher level in-use (especially PM) than would be anticipated for a well maintained

diesel engine.

Diesel engines are extremely robust and can continue to provide adequate

performance for a user, even when they have been poorly maintained. Unlike speed and

load characterized performance, however, their emissions performance can decrease quite

rapidly when the engine receives poor maintenance. Analysis and testing conducted by

contractors to EPA and to the California Air Resources Board (CARB) have shown that

these maintenance and tampering issues comprise the bulk of the observed increase in

PM emissions from diesel engines in-use. (1) When CARB updated the large CI

component of its OFFROAD model in 2000, they accounted for this increase in

emissions by using deterioration factors developed from real world observations of in-use

PM emissions correlated to particular engine technologies. (2) We believe that this is the

appropriate approach for PM emission modeling in order to account for all of the possible

mechanisms of PM deterioration. We have therefore adopted the PM deterioration

factors from CARB’s OFFROAD model in this version of NONROAD. We averaged the

highway-based LDDT, MHDT, and HHDT PM deterioration factors used in CARB’s

OFFROAD model (0.31, 0.44, and 0.67, respectively) and applied the average (0.473) to

all tiers.

For HC, CO, and NOx, we have continued our practice of using deterioration

factors developed by manufacturers based upon well maintained engines. We have done

so because we believe that maintenance and tampering issues do not effect the emission

rates of these pollutants as dramatically. As a result, we base the HC, CO, and NOx

deterioration factors adopted for nonroad engines on highway certification data (zeromile levels and lifetime deterioration) (3). We used the same data to derive highway

compliance margins for the steady-state emission factor analysis. Correspondence

between highway weight class (light, medium, heavy), highway model-year group, and

nonroad horsepower categories is identical to that used for the steady-state emission

factor analysis.
G2

DF

EF

EF rel

DT

zm

L

L

DT

zm

=





 



⋅





 



⋅

=

100

100

DF

EF EF

abs y

x

zm DT zm

L

DT

L = = + −

− = ∆∆

( )

0

We converted the highway engine deterioration estimates into a format applicable

to nonroad engines, following these steps:

(1) We calculated absolute deterioration rates DFabs using the zero-mile emission

factors and lifetime deterioration estimates presented in reference (3).

(2) We converted the absolute deterioration rates DFabs (g/hp-hr2) to relative

deterioration rates DFrel (% emissions increase/% useful life expended).

(3) We calculated a separate DFrel for each combination of pollutant, Tier, and

horsepower category. Then to derive a single value for each Tier and pollutant,

we simply averaged the DFrel.

We discuss these calculations in greater detail below.

To adapt highway-certification deterioration rates for application to nonroad

engines, it was necessary to convert them from an absolute basis (emissions increase over

engine’s useful life (g/hp-hr)) to a relative basis (% emissions increase/% useful life

expended). This conversion involves relating the emissions increase over the engine’s

useful life to the zero-hour emission factor, in proportional terms.

We achieved this conversion as follows. To begin, if we assume linear

deterioration with the intercept at the zero-mile emission factor, (0 deterioration increase

at 0 miles (0 hours useful life)), it is possible to calculate the absolute slope of the line,

i.e., the absolute deterioration rate DFabs (g/hp-hr2) (Figure 1 on next page). The required

data are the absolute emissions increase DT (g/hp-hr) over engine’s useful life L (years)

and the zero-mile emission factor EFzm (g/hp-hr):

Dividing the numerator and denominator by EFzm and L, respectively, and

multiplying each by 100 expresses the deterioration factor in percentage terms with

respect to emissions increase and useful life, giving a relative deterioration rate DFrel (%

emissions increase/% useful life):

Thus, the relative deterioration rate is the quotient of the absolute emissions

increase and the zero-mile emission factor. Tables G1-G3 present estimates of DFrel for

each combination of pollutant, Tier and horsepower category. To derive individual

values of DFrel for each pollutant and Tier, we calculated simple unweighted averages.
G3

Figure 1. Conceptual representation of absolute linear em issions 

deterioration over the useful life of a diesel en g ine.

X

Y

tim e (years)

brake specific emissions (g/hp-hr)

L E F zm

D T

D F abs

The resulting DFrel for each pollutant and Tier are presented in Table G4.

We intend to continue to monitor in-use PM emissions levels, and as the body of

data increases (especially for newer engine technologies), we intend to further update the

deterioration factors used here. Similarly, if we learn that deterioration rates for other

pollutants also increase significantly in-use, we will update those factors as well.

References

(1) Engine, Fuel and Emissions Engineering, Inc., “Modeling Deterioration in HeavyDuty Diesel Particulate Emissions,” report prepared for U.S. Environmental Protection

Agency, 1998.

(2) ARB, “Public Meeting to Consider Approval of the Emissions Inventory of Off-Road

Large Compression-Ignited (CI) Engines (>25HP),” January 2000.

(3) EPA, “Update of Heavy-Duty Emission Levels (Model Years 1988-2004+) for Use in

MOBILE6,” EPA420-R-99-010, April 1999.
G4

Table G1. Hydrocarbon (HC) Deterioration Factors by Tier and

Horsepower Category

Nonroad

Engine

Power

Categories

(hp)

Corresponding

Highway

Vehicle Weight

Class1

Corresponding

Highway

Model-Year

Group

Corresponding Highway Certification Test Results

and Deterioration Factors

EFZM

2

(g/hp-hr)

DT

3

(g/hp-hr)

DFrel

4

(%increase/%

useful life)

Tier 0

< 11 LHDD 1988-89 0.64 0.02 0.031

11-25 LHDD 1988-89 0.64 0.02 0.031

25-50 LHDD 1988-89 0.64 0.02 0.031

50-100 MHDD 1988-89 0.66 0.05 0.068

100-175 MHDD 1988-89 0.66 0.05 0.068

175-300 MHDD 1988-89 0.66 0.05 0.068

300-600 HHDD 1988-89 0.47 0.02 0.043

600-750 HHDD 1988-89 0.47 0.02 0.043

>750 HHDD 1988-89 0.47 0.02 0.043

Tiers 1-3

< 11 LHDD 1994-97 0.26 0.01 0.038

11-25 LHDD 1994-97 0.26 0.01 0.038

25-50 LHDD 1994-97 0.26 0.01 0.038

50-100 MHDD 1994-97 0.31 0.00 0.000

100-175 MHDD 1994-97 0.31 0.00 0.000

175-300 MHDD 1994-97 0.31 0.00 0.000

300-600 HHDD 1994-97 0.22 0.02 0.068

600-750 HHDD 1994-97 0.22 0.02 0.068

>750 HHDD 1994-97 0.22 0.02 0.068

1

 LHDD = “light heavy-duty diesel,” MHDD = “medium heavy-duty diesel,” and HHDD = “heavy heavy-duty diesel.” 2

 Zero-mile emission factor, Source: USEPA 1999, Table 8.

3

 Lifetime Deterioration (cumulative deterioration over vehicle useful life), Source USEPA 1999, Table 8. 4

 Relative Deterioration Factor, calculated as DT/EFzm. For discussion, see text.
G5

Table G2. CO Deterioration Factors by Tier and Horsepower Category1

Nonroad

Engine

Power

Categories

(hp)

Corresponding

Highway

Vehicle Weight

Class1

Corresponding

Highway

Model-Year

Group

Corresponding Highway Certification Test Results

and Deterioration Factors

EFZM

2

(g/hp-hr)

DT

3

(g/hp-hr)

DFrel

4

(%increase/%

useful life)

Tier 0

< 11 LHDD 1988-89 1.22 0.24 0.198

11-25 LHDD 1988-89 1.22 0.24 0.198

25-50 LHDD 1988-89 1.22 0.24 0.198

50-100 MHDD 1988-89 1.70 0.33 0.195

100-175 MHDD 1988-89 1.70 0.33 0.195

175-300 MHDD 1988-89 1.70 0.33 0.195

300-600 HHDD 1988-89 1.36 0.22 0.162

600-750 HHDD 1988-89 1.36 0.22 0.162

>750 HHDD 1988-89 1.36 0.22 0.162

Tiers 1-3

< 11 LHDD 1994-97 1.20 0.03 0.021

11-25 LHDD 1994-97 1.20 0.03 0.021

25-50 LHDD 1994-97 1.20 0.03 0.021

50-100 MHDD 1994-97 0.88 0.17 0.189

100-175 MHDD 1994-97 0.88 0.17 0.189

175-300 MHDD 1994-97 0.88 0.17 0.189

300-600 HHDD 1994-97 1.07 0.10 0.093

600-750 HHDD 1994-97 1.07 0.10 0.093

> 750 HHDD 1994-97 1.07 0.10 0.093

1

 LHDD = “light heavy-duty diesel,” MHDD = “medium heavy-duty diesel,” and HHDD = “heavy heavy-duty diesel.” 2

 Zero-mile emission factor, Source: USEPA 1999, Table 9.

3

 Lifetime Deterioration (cumulative deterioration over vehicle useful life), Source USEPA 1999, Table 9. 4

 Relative Deterioration Factor, calculated as DT/EFzm. For discussion, see text.
G6

Table G3. NOx Deterioration Factors by Pollutant and Horsepower Category1

Nonroad

Engine Power

Categories

(hp)

Corresponding

Highway Vehicle

Weight Class1

Corresponding

Highway ModelYear GroupCorresponding Highway Certification Test Results and

Deterioration Factors

EFZM

2

(g/hp-hr)

DT

3

(g/hp-hr)

DFrel

4

(%increase/%

useful life)

Tier 0-1

< 11 LHDD 1988-89 4.34 0.02 0.005

11-25 LHDD 1988-89 4.34 0.02 0.005

25-50 LHDD 1988-89 4.34 0.02 0.005

50-100 MHDD 1988-89 6.43 0.16 0.025

100-175 MHDD 1988-89 6.43 0.16 0.025

175-300 MHDD 1988-89 6.43 0.16 0.025

300-600 HHDD 1988-89 6.28 0.28 0.044

600-750 HHDD 1988-89 6.28 0.28 0.044

>750 HHDD 1988-89 6.28 0.28 0.044

Tier 2

< 11 LHDD 1991-93 4.28 0.01 0.003

11-25 LHDD 1991-93 4.28 0.01 0.003

25-50 LHDD 1991-93 4.28 0.01 0.003

50-100 MHDD 1998-2003 4.67 0.03 0.006

100-175 MHDD 1998-2003 4.67 0.03 0.006

175-300 MHDD 1998-2003 4.67 0.03 0.006

300-600 HHDD 1998-2003 4.70 0.05 0.011

600-750 HHDD 1998-2003 4.70 0.05 0.011

>750 HHDD 1998-2003 4.70 0.05 0.011

Tier 3

50-100 MHDD 1998-2003 4.67 0.03 0.006

100-175 MHDD 1998-2003 4.67 0.03 0.006

175-300 MHDD 1998-2003 4.67 0.03 0.006

300-600 HHDD 1998-2003 4.70 0.05 0.011

600-750 HHDD 1998-2003 4.70 0.05 0.011

1

 LHDD = “light heavy-duty diesel,” MHDD = “medium heavy-duty diesel,” and HHDD = “heavy heavy-duty diesel.” 2

 Zero-mile emission factor, Source: USEPA 1999, Table 10.

3

 Lifetime Deterioration (cumulative deterioration over vehicle useful life), Source USEPA 1999, Table 10.
G7

Table G4. Deterioration Factors for Nonroad Diesel Engines

Pollutant Relative Deterioration Factor (DFrel) (% increase/%useful life)1

Base/Tier 0 Tier 1 Tier 2 Tier 3

HC 0.047 0.036 0.034 0.027

CO 0.185 0.101 0.101 0.151

NOx 0.024 0.024 0.009 0.008

PM 0.473 0.473 0.473 0.473

1

DFrel = A in the equation: DF =1+A*(fraction of useful life expended)B