Regulated and Air Toxic Exhaust Emissions from
Nonroad Diesel Engines and Equipment
Kent Helmer
U.S. EPA, Office of Transportation and Air Quality
2000 Traverwood Drive, Ann Arbor MI 48105
helmer.kent@epa. gov
Richard Cook
U.S. EPA, Office of Transportation and Air Quality
2000 Traverwood Drive, Ann Arbor MI 48105
cook.rich@epa. gov
John Volckens
U. S. EPA, HEASD,NERL
Research Triangle Park, NC 27711
volkens.i ohnf@epa. gov
Richard Baldauf
U. S. EPA Office of Transportation and Air Quality
Research Triangle Park, NC 27711
baldauf.richard@epa. gov
Mchael Starr
Southwest Research Institute
6220 Culebra Road
San Antonio, TX 78228
mstarr@swri.org
ABSTRACT
Exhaust emissions were measured from fifteen nonroad (NR) diesel engines and in-use pieces of NR
diesel equipment in three separate engine emission test programs. The test engines derived from construction,
utility and agricultural equipment applications, for the most part, and ranged from 7 horsepower (hp) up through
850 hp. The test fuels used varied by sulfur concentration: "2D" diesel at a nominal 350 ppmS; NR-grade
diesel at both 2500 and 3300 ppmS; and ultra-low sulfur diesel, nominally less than 10 ppmS. Test engines
were run over both steady-state and transient duty cycles, with some of the transient cycles being application-
specific, for example, rubber-tire loader, excavator, etc. Carbon monoxide, C02, NOx and PM were
quantified for each test engine, as well as, sulfate, ammonia, N20 and a range of C, - Cr2 compounds
(aldehydes, ketones, alcohols, etc.). Additional MSAT (mobile source air toxics) emissions were identified in
two of the three programs for seven of the fifteen engines. These emission species included, among others,
BTEX (benzene, toluene, ethylbenzene and xylene), PAHs, nitrated-PAHs and several metals. Emission results
were summarized in both grams/hour and grams/brake-horsepower-hour. With the emission data, EPA will
address differences between Tier 1 and unregulated NR diesel emissions, the impact of diesel fuel sulfur level
on engine emissions, whether any adjustments to default modeling TAFs (transient adjustment factors) used in

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the NONROAD emissions model are warranted by the new data, and the necessity of creating category- (by
source classification code) and power-specific NONROAD TAFs.
INTRODUCTION
In an effort to begin quantifying exhaust emissions from nonroad diesel engines, an emission testing plan
was created. The plan identified a matrix of engine types used in nonroad diesel equipment which EPA
targeted for emissions testing. The engine types themselves were created by pairing engine power classes, or
families, and engine management technology categories. The extent of that matrix of engine types and variables
may be seen in the columns below.
Rated Power Classes
Management/Technology Categories
¦	less than 50 hp
¦	50 hp, and greater
¦	150 hp, and greater
¦	300 hp, and greater
¦	500 hp, and greater
¦	750 hp, and greater
•	"Tier 0 "/ pre-regulation
•	Tier 1 / late 1990s
•	Tier 2 / early 2000s
(• Tiers 3 & 4 / 2006, and beyond)
Table 1 describes what is meant by a "typical engine" in each of the management/technology categories below.
Table 1. Engine Management and Technology Categories.
"Tier 0"
Tier 1
Tier 2
pre-control regulation
in phases, 1996-2000
in phases, 2000-2006
many 2-stroke engines
more 4-stroke engines
predominately 4-stroke engines
simpler, non-electronic controls
less simple, more electronics
predominately electronic controls
A key goal of testing was to identify trends in the transition from smaller to larger engines and from pre-emission
standards regulations engines to more technologically-advanced engine configurations. A path to that goal was
seen as creating engine profiles from each of these nonroad engine types from engine emission data.
One concern for the equipment/engines procured under this scheme was the actual "age", in terms of
hours of operation of the potential test engine. A older piece of nonroad diesel equipment would also carry
some engine emissions "deterioration factor" for its age and history of use. As such, any engine recruited for
the test program would need a low number of engine hours of usage, i.e., "newer" status. However, the newer
(and larger, for that matter) an engine was at recruitment, the more difficult to find and more expensive to obtain
that engine would be for the testing program.
Over time, using these nonroad engine types as test "targets", EPA staff have initiated and directed the
testing of various nonroad engines and in-use pieces of nonroad equipment for regulated and unregulated diesel
engine emissions. This has been done with an eye toward accumulating emission data for nonroad emission
inventories and to support regulatory initiatives in the nonroad equipment arena. Three programs in particular
have yielded sufficient data to warrant detailed analysis of the results of the various diesel engine emissions tests
and the effects of emission testing variables found in these programs. The first test program, identified in this

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paper as EPA's Ten Engine Emissions Program, is th eresult of a nonroad engine testing program at Southwest
Research Institute (SwRI). The program was jointly administered through the California-Air Resources Board
(CARB) and EPA and its full title was "Transient and Steady-State Emissions Testing of Ten Different
Nonroad Diesel Engines Using Four Fuels", SwRI # 08.03316. The second program is EPA's "Three Engine
Program", identified as EPA Contract #68-C-98-169, and includes work assignments #03-05 and #02-03. It
is entitled "Nonroad Duty Cycle Testing for Toxic Emissions." The third program is the "Four In-Use Engines
Program" and is identified as EPA Contract #68-C-98-158, work assignment #03-04 and is entitled " Air
Toxic Emissions from In-Use Nonroad Diesel Equipment."
The purpose of this paper is to describe these three test programs, including engines, fuels and duty
cycles, and to show early results of data summary efforts. Test engine procurement is described, as well as, the
level of effort necessary to secure a variety of nonroad engines for laboratory-based engine dynamometer
testing. Engine emission test species are listed for each program and descriptions of sampling equipment and
methods are outlined in this presentation. The paper will further describe efforts to make test program results
available to EPA's constituents in the air quality arena and to the public, at large. Both summary emission
results and database-ready formats for the data are being prepared for release.
We do not address gasoline engines in this discussion of nonroad engine emissions because
spark-ignition nonroad equipment comprises a much smaller percentage of the nonroad equipment population
than compression-ignition, or diesel (for the most part), engines. Presumably, nonroad spark-ignition engine
emissions have also benefitted from technology changes required of their more and earlier regulated passenger
and on-highway, heavy-duty gasoline engine counterparts.
METHODS
Ten Engine Emissions Program
Engine emission data were generated for the ten engines in this study over various transient and steady-
state duty cycles using at least two different diesel fuels per engine. Steady-state engine duty testing included
40 operating conditions, including a typical eight-mode steady-state cycle. Transient testing included running up
to six different cycles per engine, each in triplicate. Brake-specific emissions for total hydrocarbons (HC),
carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter (PM) and selected unregulated emissions
were quantified using full-flow exhaust dilution.
Test Engines and Fuels
In this study, emission testing was performed to characterize regulated and select unregulated emissions
using ten different diesel engines representing a cross-section of nonroad equipment and applications and was
jointly administered by California-EPA Air Resources Board (CARB) and the EPA.1 The ten engines tested in
this program were all four-stroke, diesel engines ranging in power from 7 to 850 horsepower (hp). Nine of the
ten engines were obtained in cooperation with the Engine Manufacturers Association (EMA) and its member
companies and one engine, the Deere 6101, was obtained from an in-use excavator. The engine was returned
to its original owner and restored to its former usefulness at the close of emission testing.
The five lower-powered engines and five higher-powered engines were obtained from various sources,
and each was mounted in a transient-capable emissions test cell to run the desired testing. They are described in
Table 2 below.

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TABLE 2. Descriptions of Ten Nonroad Diesel Test Engines.
Intended
Application
Engine
Mfr and Model
Model
Year
Engine
Control
Disp.,
liters
Rated Condition
hp
rpm
utility
Yanmar 2TNE68
1998
Mechanical
0.5
14
3600
utility
Yanmar
L100AE-DE
1998
Mechanical
0.2
9
3600
forklift truck
Kubota V2203B
1999
Mechanical
2.2
49
2800
generator/pump
Lombardini
LDW903-FOCS
1999
Mechanical
0.92
20
3600
utility/pump
Hatz B130
1999
Mechanical
0.35
7
3600
tractor/trailer
Navistar B250-F
1998
Electronic
7.4
250
2600
construction
equipment
Cummins QSL-9
1999
Electronic
8.3
330
2000
excavator
John Deere 6101
1997
Mechanical
10.0
320
2000
construction/
agriculture use
DDC Series 60
1999
Electronic
12.7
400
2100
mining truck
Caterpillar 3508
1999
Electronic
34.5
850
1750
A total of four diesel fuels were used in this program, ranging from a high sulfur nonroad-grade diesel to
an ultra low sulfur diesel fuel. The fuels used in this study were a Certification-grade Type-2D diesel fuel, a
high-sulfur Nonroad-2D diesel fuel, a California 2D fuel, and a clean emissions control diesel obtained from
ARCO®, deemed "ECD" fuel. The regular 2D and nonroad-2D fuels had similar distillation curves and similar
hydrogen-to-carbon ratios. However, the 2D fuel had a sulfur level of 390 ppm and an API gravity of 36.1
and the nonroad diesel had 2,570 ppm sulfur and 34.8 API gravity. Apart from sulfur content, the California
and ARCO® diesels differed from the other diesel fuels in this study primarily in having a lower aromatics and
higher saturates composition, which lead to a higher cetane number, as well.. The California-grade 2D fuel had
a sulfur level of 50 ppm and an API gravity of 39.1 and the ARCO® ECD-type ultra-low sulfur fuel had a
nominal sulfur level of 2 ppm and an API gravity of 42.7. A fifth fuel, nonroad grade 3300 ppm sulfur diesel,
was introduced for limited emission testing on the in-use Deere 6101 engine because previous EPA work had
generated emission data on such fuel with that same engine. Results are presented for tests using three fuels for
the Deere excavator engine rather than just two different fuels.
Engine emission test cycles
Steady-state emission measurement procedures adhered to CFR 40 Part 89 and generally satisfied
ISO 8178-1 and 8178-4 requirements. An ordered sequence of over forty steady-state operating modes was
used for conducting steady-state emission tests, with additional subsets of those modes conducted on most
engines. The additional steady-state testing consisted of the eight operating modes specified in CFR 40, Part
89 (also referred to as an ISO (International Standards Organization) eight mode, CI-weighted steady-state

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test), and the eleven-mode ISO-8178 Type-C2 points in combination with three partial-load modes to
complete an ISO-8178 "E3" 14-mode steady-state test2.
After steady-state testing was complete, each of the ten engines was individually mounted in a transient-
capable emission test cell. The test cells were each equipped with a DC electric dynamometer and a control
system capable of motoring and absorbing loads during transient operation. Dynamometers and associated
control hardware were calibrated prior to performing emission tests, in accordance with procedures outlined in
the Code of Federal Regulations (CFR), Title 40, Part 86. For each engine, suitable dynamometer and throttle
control strategies were developed to achieve "passing" regression values for cycle performance criteria over the
FTP cycle. For most engines, subsequent operation over different transient cycles employed the strategy
developed over the FTP. In contrast, the strategy for the Deere 6101 engine was to tune the operation of the
engine for a crawler-dozer application cycle, as it had been in a prior emissions testing program.
The list of transient regulatory and application duty cycles3 used in this study is as follows:
•	U.S. On-Highway Heavy-Duty Federal Test Procedure (FTP) cycle
•	European On-Highway Transient Duty Cycle (ETC)4
•	Agricultural tractor nonroad duty cycle (AGT)
•	Backhoe loader nonroad duty cycle (BHL)
•	Crawler-dozer nonroad duty cycle (CRT)
•	Composite excavator nonroad duty cycle (CEX)
•	Arc welder typical (AWT) nonroad duty cycle
•	Arc welder high transient torque (AWQ) nonroad duty cycle
•	Rubber-tired loader typical (RTL) nonroad duty cycle
•	Rubber-tired loader high transient torque (RTQ) nonroad duty cycle
•	Skid steer loader typical (SST) nonroad duty cycle
•	Skid steer loader high transient torque (SSQ) nonroad duty cycle
Because the ten engines differed significantly in horsepower and are found normally in various pieces of
nonroad equipment, a transient duty cycle was assigned to a particular test engine if that cycle was considered
representative of actual or potentially applicable nonroad applications for that engine.
All engines, with exception of the Hatz engine, were tested over the FTP and the BHL transient duty
cycles and only one engine, the Yanmar 2TNE68, was not tested on the ETC. Additionally, most engines were
tested over the AGT and CRT cycles. All the rest of the cycles were tested on either two or three engines,
with the exception of the SSQ (one engine only).
Engine Emissions Sampled
Information on regulated exhaust emissions, total hydrocarbons (HC), carbon monoxide (CO), oxides
of nitrogen (NOx) and particulate matter (PM), was generated for each engine at numerous steady-state
conditions and over six transient cycles using two fuels per engine. Each emission test cell was fitted with a
constant volume sampling (CVS) system and related hardware, with dedicated gaseous emissions analyzers and
systems for sampling dilute exhaust by various methodologies from the full-flow exhaust emission tunnel. This
study included measuring regulated and a limited number of unregulated emissions. Gaseous samples for HC
and NOx were quantified using dedicated analyzers at each test cell. Bagged samples of proportionally
gathered dilute exhaust were analyzed to quantify CO and C02 concentrations. Total PM was measured using
a double dilution system to draw a portion of the dilute CVS exhaust flow through a series of 90 millimeter

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diameter Pallflex T60A20 filter media. All filter media was baked in a vacuum oven prior to its use in testing.
Sampling methods for measuring emissions over transient cycles and steady-state tests adhered to calibration
requirements and procedures outlined in CFR 40, Parts 86 and 89, respectively.
Unregulated emissions were quantified only over duplicate BHL cycles and the eight ISO Type-Cl
operating modes using one fuel per engine, generally the fuel with the lowest sulfur content of the two used for
testing that engine. For these selected tests, additional samples were obtained to quantify the specific
unregulated emissions. Namely, an array of impingers, or "bubblers", in a DNPH solution was used during
emission tests to capture gaseous samples of dilute exhaust for later quantifying aldehyde and ammonia levels.
Ammonia emissions were measured using a Dionex® ion chromatograph and calibrated to analyze NH3
samples. In addition, a 40 percent segment or "pie slice" was cut from the same 90 mm PM filter pairs that
were used to express total PM levels and was shaken in a mixture of 60:40 isopropanol and water. The
solution was then injected into the same Dionex® instrument setup equipped with a conductivity detector to
measure sulfate levels. Finally, bagged samples of proportionally-gathered dilute exhaust were used to measure
nitrous oxide (N20) levels.
Three Engine and Four Engine In-Use Test Programs
Regulated emissions testing in these two programs used full-flow CVS dilution techniques to quantify
brake-specific levels of regulated emissions. However, the primary focus of data collection from these seven
engines in these two programs was to gather and analyze additional nonroad engine emission samples to
quantify selected unregulated diesel exhaust emissions. Numerous samples were gathered and analyzed using
special sampling techniques and related hardware to quantify levels for specific unregulated emissions, or
"toxics." These are the same Mobile Source Air Toxics (MSATs) described in EPA's March 29th, 2001
Federal Register notice (66 FR, 17235).
Three Engine Test Program
The three engines tested under this program were run using two different diesel fuels under limited
steady-state and transient test cycle operations to quantify both regulated and numerous unregulated emissions.5
The engines tested in this program were a 50 hp Kubota V2203E, a 330 hp Cummins QSL9, and a 480 hp
Caterpillar 3408 engine. Each engine had accumulated between 125 and 250 hours of operation. The Kubota
and Cummins engines originally had been obtained from their respective manufacturers for use in the separate
CARB-EPA ten engine study, described above. As such, one set of regulated and limited unregulated engine
emission results already existed for these two engines from the earlier study. The third engine was mounted in
the engine test cell specifically for use in this study. The three test engines are described briefly in Table 3
below.
TABLE 3. Three Different Nonroad Test Engines.
Intended
Application
Engine
Mfr and
Model
Model
Year
Engine
Control
Number of
Cylinders
Disp.,
liters
Rated
Condition
hp
rpm
forklift truck
Kubota
V2203E
1999
Mechanical
Inline-4
2.2
50
2800

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construction
equipment
Cummins
QSL9
1999
Electronic
Inline-6
8.8
330
2000
rubber-tired
loader
Caterpillar
3408
1999
Electronic
V-8
18
480
1800
NOTE: Kubota and Cummins engines carried over from Ten Engine Emission test program to capture air toxic emissions data.
The diesel fuels used in testing were an emissions certification test grade Type-2D and a Nonroad-2D
diesel. The 2D fuel had a sulfur level of 390 ppm and an API gravity of 36.1, and the nonroad diesel had
2,570 ppm sulfur and an API gravity of 34.8. In each case, a thorough fuel change procedure was completed,
with new fuel filters and sufficient engine operation to purge the system of any previous fuel prior to emissions
testing on the next fuel. Each engine's torque map was measured using both fuels for use in applicable emissions
testing, but engine power output did not differ significantly from fuel-to-fuel.
Four Engine Tn-TIse Test Program
In this program, four diesel engines were obtained from different pieces of "in-use" nonroad
equipment.6 A particular piece of nonroad equipment and its engine, once identified, were selected based on
the engine power class and management technology categories defined earlier under EPA's test plan. Each
engine was removed from its host piece of equipment and mounted in a dynamometer test cell. Test engines
were run over a variety of steady-state operating conditions, and over several transient duty cycles, to generate
samples for quantifying regulated and selected unregulated engine emissions using two different diesel fuels.
The four different engines tested represent a cross-section of engines found in nonroad equipment
applications. Each engine was an in-line, six-cylinder diesel engine equipped with charge air cooling. Table 4
below identifies the in-use equipment and briefly describes the engines selected for this test program.
TABLE 4. Description of four in-use test engines/equipment.
NR Application
Model
Year
Hour
Meter
Engine Model
Engine
Control
Disp.,
liters
Rated Condition
hp
rpm
motor grader
1996
2,289
Deere 6068T
Mechanical
6.8
160
2200
excavator
1997
4,107
Cummins
Ml 1C
Mechanical
10.7
270
1700
agricultural tractor
2001
416
Caterpillar
3196
Electronic
10.0
420
2100
telescoping boom
excavator
2001
868
Cummins
ISB 190
Electronic
5.9
194
2300
NOTE: the Cummins ISB190 engine is emissions-certified for on-highway operation so that piece of nonroad equipment can
travel on city streets to move between work sites.
The two fuels used in this program were an emissions certification grade Type-2D diesel fuel, and a
high-sulfur Nonroad-2D diesel fuel. These two fuels had similar distillation curves, and similar hydrogen to
carbon ratios. However, the 2D fuel had a sulfur level of 390 ppm and an API gravity of 36.1, and the
nonroad diesel had 2,570 ppm sulfur and 34.8 API gravity.

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Engine Emission Test Cycles Used in the Three Engine and Four Engine In-Use Test Programs
Testing for each engine included sampling for regulated and unregulated emissions at all modes of an
eight mode ISO-type CI emissions test and over two different transient test cycles, the on-highway FTP for
heavy-duty diesel engines and the EPA backhoe loader (BHL) cycle.
Emissions testing under steady-state engine operation was accomplished using an eight-mode, Cl-
weighting test cycle, running eight individual modes, to establish regulated and selected unregulated emission
levels on both low- and high-sulfur diesel fuels. Sampling systems were prepared for running the eight-mode
CI test to collect emission samples for use in quantifying the various emissions. Calibration and sampling
methods adhered to test procedures in the Code of Federal Regulations (CFR) Part 89 and, generally, satisfied
International Standards Organization ISO-8178-1 guidelines. In addition, the Kubota engine was tested over
the eight mode CI test using a "stacked PM' approach, where PM emissions are accumulated from all
operating modes into a single time-weighted PM emission sample for each set of analyses. This involves using
one set of particulate filters over the eight different modes, while running each mode for a time proportional to
the applicable CI weighting factor. There was no "stacked" steady-state testing performed on the Cummins or
Caterpillar engines from the three engine work.
The transient duty cycles used in testing each of these seven engines were the on-highway FTP cycle
and the BHL cycle. Prior to running the core test program, duplicate FTP transient cycle tests were performed
on each engine using Type-2D fuel to quantify transient regulated emission levels of HC, CO, NOx, and total
PM. Engine emissions were then sampled under transient operating conditions for each engine using a test cell
control strategy developed for commanding dynamometer and throttle control for each engine over the on-
highway FTP cycle. Minimal tuning subsequently improved transient control and cycle performance for testing
over the BHL and/or SAT nonroad cycles. Prior to emissions testing, engines were run over a preparatory
test cycle, followed by a 20-minute engine-off soak period. After engin soak, each transient emission test was
run from a hot-start utilizing procedures and sampling processes given in CFR 40, Part 86, Subpart N.
Another 20-minute engine-off soak period separated any duplicate runs of a test cycle. In addition, duplicate
runs of the recently-developed nonroad transient composite duty cycle, or SAT cycle, was used to provide
further baseline information for regulated emissions on each engine using only 2D fuel.
Engine Emissions Sampled in the Three Engine and Four Engine In-Use Test Programs
Testing for regulated engine emissions used full-flow dilution techniques to quantify brake-specific levels
of HC, CO and NOx. Total PM was quantified using a double dilution technique. Measurements of
unregulated emissions consisted of carbonyls (generally, aldehyde and ketone species), ammonia, N20 and
sulfate. Several hydrocarbon species from C, through C12 were quantified for each test. Proportional bag
samples of dilute exhaust were analyzed via gas chromatography to speciate hydrocarbons from C, through C12
using a method similar to the Phase II Auto-Oil method.7 Selected hydrocarbon species, benzene, 1,3-
butadiene, ethylbenzene, n-hexane, styrene, toluene and xylene, were all of particular interest in these studies.
These seven hydrocarbon compounds constitute a short list of important mobile source air toxics (MSATs).
Specifically, MSATs are toxic pollutants emitted by on-highway vehicles and off-highway, or nonroad,
equipment. In a rulemaking published in 2001,8 EPA identified 21 MSATs, of which six are of major public
health concern - acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde, and diesel particulate matter.
Sample collection and procedures to determine carbonyls, ammonia, nitrous oxide, and sulfate were the
same throughout the three emission test programs. To quantify sulfate levels, a 40 percent segment or "pie
slice" was cut from the 90 millimeter diameter T60A20 Pallflex® filter pair used to quantify total PM, and

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shaken in a mixture of 60:40 isopropanol and water. The solution was then injected into a Dionex® ion
chromatograph equipped with a conductivity detector to measure sulfate levels. Ammonia levels were
quantified using the same Dionex® instrument setup and calibrated to analyze ammonia samples. For ammonia
and carbonyls, an array of impingers was used during each emission test to capture gaseous samples of dilute
exhaust for later analyses. Formaldehyde and acetaldehyde were measured using a DNPH technique, as
outlined in CFR Title 40, Part 86. A liquid chromatograph was used to quantify aldehydes and ketones
captured by the impingers in a 2,4-dinitrophenyl hydrazine (DNPH) solution. Finally, bagged samples of
proportionally-gathered dilute exhaust were analyzed for N20 levels using a gas chromatograph equipped with
an electron capture detector.
Mass emission rates for lead, manganese, nickel, arsenic, and chromium were determined in the solid
phase. Trace levels of elemental inorganic metals were quantified for particulate captured on 47 millimeter
diameter Fluoropore® filters using an inductively-coupled plasma - mass spectrometry (ICP-MS) technique to
detect the selected elements. ICP-MS is useful for a quantitative determination of multi-elements and isotopes
in a wide variety of sample types at trace and ultra-trace concentration levels. The detection limits of the
procedure, under ideal conditions, range from 0.01 to 50 ng/L, depending on the element(s) under investigation.
The ICP-MS method used in this study digested PM-laden filters in a mixture of nitric and perchloric acid,
followed by aqua regia.
In addition, mercury was sought in the gas phase using an impinger containing a solution of potassium
permanganate (K2Mn04). Resulting solutions were analyzed by ICP for selected inorganic elements. The
instrument was standardized using NIST traceable standard reference materials. Immediately after the standard
check sample was run, a blank sample was run to verify the zero setting of standardization. Check samples are
required to be within the control limits of 90-110% recovery of the certified value. Absolute value of the check
blank was required to be below the reporting limit for the samples. If either condition had not been met, the
analysis would be terminated and the instrument re-standardized and re-checked.
Additional PM and gas phase particulate samples were collected to quantify selected polynuclear
aromatic hydrocarbons (PAH) and nitrated-PAH (n-PAH) compounds. The solid particulate emission phase
was sampled using a single 20-inch by 20-inch square sheet of Pallflex® T60A20 filter media. Semi-volatile,
gaseous phase PAH and n-PAH compounds were sampled separately using a pair of emission-trapping
polyurethane foam (PUF) canisters mounted in parallel and located downstream of the particulate phase
collection filter. Each PUF trap consisted of two pieces of 4-inch diameter by 1.5-inch thick polyurethane
foam disks separated by a thin layer of XAD resin. In the interest of economy, the extract of solid phase and
extract of gaseous phase particulate samples for a given test were combined into one set for analysis, with the
combined extract used to quantify both PAH and n-PAH compounds. Both sampling media were extracted,
then combined prior to concentrating the samples, and finally, analyzed using a gas chromatograph-mass
spectrometer (GC/MS), operated in the selective ion monitoring (SIM) mode.
Listed below are the sixteen PAH compounds chosen for speciation in these two programs. They are
the same compounds identified and measured in EPA Method 6109 and tracked in EPA's National Emissions
Inventory (NEI) and National Air Toxics Assessment (NATA).
•	Benzo(a)anthracene	• Acenaphthylene
•	Benzo(a)pyrene	• Anthracene
•	Benzo(b)fluoranthene • Benzo(ghi)perylene
•	Benzo(k)fluoranthene • Fluoranthene
•	Chrysene	• Fluorene

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•	Dibenz(a,h)anthracene • Naphthalene
•	Indeno(l,2,3-cd)pyrene • Phenanthrene
•	Acenapthene	• Pyrene
The seven compounds, in the following list, are those n-PAHs targeted for speciation and measurement by
these two programs.
•	2-Nitro Fluorene	• 9-Nitro Anthracene
•	3-Nitro Fluoranthene • 1-Nitro Pyrene
•	6-Nitro Chrysene	• Dinitro Pyrenes
•	6-Nitro Benzo(a)pyrene
RESULTS AND ANALYSIS
Emission results for the ten engine program were presented in three subsections. The first gives results
of regulated emission levels measured at steady-state conditions; the second lists regulated emission levels over
transient cycles; and the third subsection presents unregulated emission levels. Unregulated emissions were only
quantified using one fuel per engine. Testing for the two Yanmar engines did not include quantifying unregulated
emissions.
Problems with several of the test engines required involvement by representatives of the respective
engine manufacturers. Minor problems were handled by telephone, and more invasive procedures involved
their on-site support. All but one engine completed the planned testing. There were no problems with the
Yanmar 2TNE68 engine but the first Yanmar L100AE-DE engine was scrapped at 35 hours into testing
(broken engine output shaft) and a second engine of the same type procured. The second L100AE-DE
successfully completed the planned testing. The engine throttle lever broke on the four cylinder Kubota
V2203B engine prior to emission testing, was repaired and the engine successfully completed the planned
testing. During emissions testin g, the Lombardini showed intermittent unstable performance and erratic HC
emission levels were observed. Fuel system adjustments were made, a new fuel injector installed and the
engine successfully completed the planned testing. After all planned steady-state testing was completed on the
Hatz B130, and during preparatory activities prior to conducting transient duty emission testing, lubricating oil
and combustion gases were observed escaping from the engine's single cylinder. No timely remedy was
available and the Hatz engine was removed from the study without generating emissions data over transient
cycles.
No problems were encountered with either the Cummins or the Navistar engines. However, the
Navistar engine is certified to on-highway, heavy-duty emission standards (for the tractor/trailer market) and
was procured because of its similarity to equally powerful nonroad engines and for its availability. All other
engines in this study were directly applicable to nonroad equipment and generally had higher emissions. The
Deere 6101 was the only engine in this group which was obtained from the field for use in testing; it was
removed from a John Deere 992-E excavator. Limited emissions testing was conducted on the engine in "as
received" condition prior to effecting two minor gasket repairs. The JD6101 then completed all planned testing
without further incident. Detroit Diesel (DDC) Series 60 was unique in that it had an electronic variable speed
governor (VSG) but was tested, nonetheless, in its "as received" configuration. This engine was programmed
to operate within a somewhat narrow window of speed and load points but after some dynamometer and
throttle tuning efforts, the engine was passing the established on-highway FTP duty cycle performance and
statistical regression values. The Caterpillar 3508, being a larger engine, presented some installation difficulties

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and showed only a minor starting problem, which was soon cleared. Testing of the engine proceeded without
incident.
The original test plan for the Deere 6101 was to conduct testing using nonroad-grade diesel fuel at
3300 ppp sulfur (HS fuel ), but unscheduled maintenance interrupted testing to repair coolant leaks in th
eengine. The supply of HS fuel was diminished, and CARB and EPA opted to start over using NR fuel.
Emission tests performed using HS fuel prior to the unscheduled maintenance included select transient cycles
and an 8-mode steady-state test. Another 8-mode test was conducted after the maintenance using HS fuel to
bracket unscheduled procedures. At that point, work on the Deere 6101 switched to begin using NR fuel, and
planned testing again started from the beginning for that engine.
Composite eight mode, C-l weighted steady-state emission levels for the ten engine program are
shown in Table 5 below:
TABLE 5. Composite Eight Mode, C-l Weighted Steady-State Emission Levels for Ten Different
Nonroad Engines Using Low and High Sulfur Diesel Fuels.


Fuel
TYPE-C1 WEIGHTED EMISSION LEVELS, g/hp-hr

Engine Model
ID
HC
CO
NOx
PM
co2
1
Yanmar
2D
0.328
2.878
4.320
0.460
843

2TNE68
NR
0.534
5.648
4.167
0.929
825
2
Yanmar
2D
1.512
8.305
6.407
1.263
719

L100AE-DE
NR
1.556
9.344
6.159
1.587
706
3
Lombardini
CA
0.242
2.766
3.004
0.609
767

LDW903
NR
0.619
3.072
3.355
0.636
798
4
Kubota
2D
0.075
1.053
4.253
0.600
668

V2203B
NR
0.090
1.234
4.272
0.615
671
5
Hatz
2D
0.633
4.025
5.347
0.510
783

1B30
NR
0.628
4.220
5.126
0.523
758
6
Navistar
2D
0.086
0.439
4.358
0.077
582

B250
NR
0.097
0.408
4.668
0.102
572
7
Cummins
EC
0.038
1.196
4.093
0.098
478

QSL9
2D
0.054
1.176
4.209
0.124
493
8
Deere
CA
0.489
0.800
5.308
0.124
502

6101
NR
0.486
0.949
5.704
0.192
503
9
DDC
EC
0.032
0.782
5.847
0.074
462

Series 60
CA
0.040
0.787
6.077
0.082
461
10
Caterpillar
2D
0.233
1.189
11.703
0.159
501

3508
NR
0.363
1.240
12.042
0.215
506

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Notes: 2D - Emissions grade Type-2D (390 ppm sulfur) diesel fuel
NR - High sulfur (-2,500 ppm) nonroad 2D diesel fuel
CA - California low-sulfur (50 ppm sulfur) diesel fuel
EC - Arco® "ECD" ultra-low sulfur (~2 ppm) diesel fuel
Nine of the ten engines completed the planned transient cycle emissions testing. Each engine was tested
over six different transient cycles. Most engines were tested in triplicate over the selected cycles using two
fuels. The two Yanmar engines were tested in duplicate using 2D fuel, and single tests using NR fuel. The
Yanmar 2TNE68 engine was not tested over the European transient cycle (ETC). Otherwise, the on-highway
FTP and ETC cycles were run for each engine and four nonroad transient application cycles were chosen
specifically for testing a given engine. Eight of the ten engines included testing to quantify select unregulated
emissions. The two Yanmar engines did not include these measurements, and the Hatz engine did not complete
transient testing.
The ten-engine study measured emission levels over the various transient cycles that differ significantly
for different size and technology engines. Engines were tested over many of the same transient cycles. Several
of the smaller engines included measuring emissions during activities typical of skid steer loader and arc welder
duty cycles, whereas several of the larger engines included running cycles based on excavators and a rubber
tired loader. Most engines were tested using a low sulfur fuel and a high sulfur fuel. Levels for PM were
generally elevated using high sulfur fuels, with negligible performance differences. The Cummins and DDC
engines were tested using EC fuel. This ultra low sulfur and higher cetane fuel affected emissions by consistently
lowering both NOX and PM levels over all operations.
As expected, all engines from the three engine and four engine in-use test programs generally had
elevated PM levels when using the higher sulfur fuel. Composite eight mode, Cl-weighted test emission levels
were computed for each engine using results obtained on the two diesel test fuels. Duplicate "stacked" tests for
the Kubota on each fuel showed good test-to-test emissions repeatability, and compared reasonably well to
composite eight mode, CI PM levels (see Table 6 below).
TABLE 6. Composite Eight Mode Type C-l Weighted Steady-State Emission Levels for Seven
Different Nonroad Engines Using Low and High Sulfur Diesel Fuels.
Test Engine
Fuel
ID
Weighted Transient Emissions, g/hp-hr
BSFC,
lb/hp-hr
HC
CO
NOx
n2o
PM
Kubota V2203E
(3-engine study)
2D
0.04
0.97
4.13
0.009
0.472
0.447
0.03
1.07
4.20
0.008
0.438
0.447
0.04
0.88
3.98
0.009
0.431
0.433
NR
0.07
1.05
4.05
0.012
0.525
0.438
0.07
0.99
3.95
0.010
0.548
0.423
0.07
1.00
4.08
0.020
0.530
0.440
Cummins QSL9
(3-engine study)
2D
0.08
1.19
4.43
0.007
0.118
0.365
NR
0.08
1.32
4.38
0.026
0.162
0.377
Caterpillar 3408
2D
0.02
0.95
4.03
0.004
0.134
0.376
(3-engine study)

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NR
0.02
0.95
4.03
0.008
0.162
0.359
Deere 6068T
2D
0.37
0.96
10.35
0.006
0.229
0.361
NR
0.34
1.00
10.51
0.022
0.303
0.359
Cummins M11C
2D
0.27
0.57
6.07
0.004
0.134
0.343
NR
0.29
0.75
5.99
0.011
0.165
0.342
Caterpillar 3196
2D
0.07
0.83
6.04
0.004
0.076
0.325
NR
0.06
0.84
5.98
0.012
0.122
0.324
Caterpillar 3408
2D
0.05
0.49
3.85
0.004
0.072
0.375
NR
0.04
0.48
3.42
0.006
0.112
0.373
Notes: Shaded results are "stacked"; time-weighted sampling of 8 steady-state modes
CI - ISO Type-Cl weighted emissions computed from individual runs of each mode
2D - Emissions grade Type-2D (-500 ppm sulfur) diesel fuel
NR - High sulfur (-2,500 ppm) nonroad 2D diesel fuel
Emission data and cycle performance repeatability were generally good for duplicate transient cycle
testing performed on each engine using both fuels. Engines generally ran the different cycles without problems
and each was able to pass the cycle control criteria for the FTP cycle. The Kubota V2203E passed the cycle
performance criteria over the FTP and BHL transient cycles. In contrast, the Cummins QSL-9 and Caterpillar
3408 had mixed performance over the different cycles, as they passed the FTP on some runs, but sometimes
failed to do so in duplicate testing. Table 7 compares emission levels across transient and steady-state tests for
these two engines. Cycle control of the Cummins engine passed some runs of the BHL cycle and not others,
while cycle control of the Caterpillar engine did not pass the BHL cycle. It should be noted that minimal
additional tuning was done after a given engine passed the FTP cycle, so subsequent testing over nonroad
cycles used the same engine and dynamometer cycle control strategy established in FTP tuning efforts.
TABLE 7. Comparison of Averaged Regulated Emission Levels for Two Nonroad Engines Over
Selected Cycles Using Type-2D Diesel Fuel.
Engine
Cummins QSL9
Caterpillar 3408
Cycle
CI
FTP
SAT
BHL
CI
FTP
SAT
BHL
HC, g/hp-hr
0.08
0.13
0.08
0.19
0.02
0.02
0.02
0.04
CO, g/hp-hr
1.2
2.5
1.6
2.8
1.0
2.4
1.8
3.3
NOx, g/hp-hr
4.43
4.51
4.00
4.26
4.03
4.06
3.85
5.02
PM, g/hp-hr
0.12
0.17
0.16
0.18
0.14
0.28
0.30
0.45
BSFC, g/hp-hr
0.365
0.365
0.357
0.370
0.376
0.421
0.411
0.435
Ref. Work, hp-hr
na
25.04
44.97
21.17
na
33.80
61.26
25.83
FTP U.S. on-highway transient duty cycle hot-start levels
CI Steady-state composite weighted ISO Type-Cl values
SAT EPA composite nonroad transient duty cycle hot-start levels
BHL Backhoe loader nonroad transient duty cycle hot-start levels

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Unregulated Emission Results
Data summaries give results on both a mass and brake-specific basis. In all cases, the resulting
emission levels are shown after correcting for background and diesel exhaust sampling tunnel blank
contributions. When an emission result was not quantifiable, or its concentration was quantifiable at a level
below the minimum detection limit, null values and/or "nd" were reported as with much of the metals emission
results. "Trace" results were reported when an emission level was quantifiable at less than twice the detection
limit. Nitrous oxide, sulfate, ammonia and carbonyl emission results are expressed in units of milligrams per
brake horsepower hour. Test-to-test variability was good for most compounds, and general trends can be
seen in the results for each engine. Sulfate emissions tend to track the sulfur level in the diesel fuel used in
testing. Nitrous oxide levels were typically very low, and often approached ambient background levels. PAH
and n-PAH emission results were reported on both a concentration and a brake-specific (brake horsepower-
hour) basis in micrograms and nanograms, respectively.
DISCUSSION
The emission data from these three nonroad diesel engine emission studies are expected to answer
many questions for EPA and its many constituents, but the data appear to carry with them several unanswered
questions, as well. The data will help elucidate differences between pre- and post-Tier 1 engines in these test
groups and begin to gauge the impacts of fuel composition and sulfur level on nonroad diesel engine emissions.
In the arena of air toxic emissions, this group of engines represents one of the larger data sets and the emissions
data will be used to better characterize levels of PAHs and n-PAHs, metals, like mercury and lead, and
carbonyl compounds in nonroad diesel engines. We will look at the effect of engine duty cycle on engine
emissions, as well, with respect to engine displacement and management technologies.
To successfully operate an engine transiently on a dynamometer depends largely on how well that
engine responds to changes in fuel flow and keeps up with the demands of the transient duty cycle, which it is
following.. This performance over a transient cycle, in statistical regression terms, can then be refined over
many practice runs of the same cycle, the refinement process being called a control strategy. In these three test
programs, it was decided to run all transient duty cycles using a dynamometer control strategy and engine
settings similar to those used for the running of an FTP cycle, except the Deere excavator engine, as noted. In
general, engine performance over all transient cycles largely met, or "passed," the established cycle
performance criteria from CFR 40 Part 86, Subpart N for testing over the on-highway heavy-duty FTP cycle.
However, few of these engines achieved "passing" values over cycle-specific performance criteria for more
than one or two of the transient cycles over which they were tested. While engines were not individually
"tuned" to run each cycle, the repeatability of engine emissions from multiple FTP, SAT and nonroad transient
application duty cycle runs was generally considered good for these nonroad engines.
Preliminary analyses of the nonroad emission dataset from these engines are still in progress, but some
trends are emerging from the data. Brake-specific PM emissions seem to track falling sulfur levels for each
engine's respective test fuel(s), but as engine displacement and power falls, regardless of fuel, total PM may be
rising. Likewise with falling engine displacement and power, there may be a rise in ammonia and N20 exhaust
emissions in these engines, though these are generally a small percent of overall diesel engine emissions. On a
concentration basis, formaldehyde emission levels seemed to stay "fairly stable," but other aldehyde emissions
appeared to increase as engine displacement and power dropped.. The overall effect of different transient
cycles on emissions from the same engine was quite varied, suggesting a need for engine work- or cycle-
specific emission profiles. Emissions "profiles" for these engines will include VOC emissions ratioed to total

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HC and semi-volatile organics ratioed to total PM.
Uses for new nonroad diesel emission dataset are many. Supporting technical analyses for EPA's
upcoming Mobile Source Air Toxics Rule will benefit from the data set for nonroad emissions. Improvements
can be made in national, nonroad emissions inventories and the models which track those emissions for the air
quality community. EPA's National Emission Inventory (NEI) for HAPs can benefit from this new data, as
well. In addition, engine profiles can be created using engine duty cycle-specific emission data, for each engine
running over a specific duty cycle typical for that engine. Thes profiles could then be integrated into EPA's
Nonroad Mobile Inventory Model (NMDVI) and the output of the model then used to update future versions of
the NEI.
Finally, nonroad diesel emission data will be converted into database, FoxPro® or MS-Access®, as
useful, or spreadsheet formats for ease of use by modelers and to facilitate entering data into OTAQ's Mobile
Source Observations Database (MSOD).10 When loaded into EPA's MSOD database, nonroad engine
emission data can be made generally available to the public for querying. Hardcopy and electronic forms on
CD-ROM disks of nonroad diesel engine emission data will also be made available for distribution to State,
Regional and Local air quality managers, as requested. Air managers could use any new nonroad data, in
conjunction with the natioal inventories, to tailor state models and inventories to their own situations.
ACKNOWLEDGMENTS
The authors would like to thank Cleophas Jackson (EPA-Ann Arbor) and Marion Hoyer (EPA-Ann
Arbor) for early administrative and technical support in formulating and refining test plans. We would also like
to thank Kathryn Sargeant (EPA-Ann Arbor) for logistical and strategic support in setting the scope of EPA's
NR diesel emissions test program. Thanks, as well, to George Hoffman (Computer Science Corporation) for
his efforts to summarize and organize our nonroad engine emission results.
REFERENCES
1.	Starr, M.E. "Transient and Steady-State Emissions Testing of Ten Different Nonroad Diesel Engines
Using Four Fuels"; SwRI 08.03316, Prepared for California Air Resources Board, El Monte, CA and
U.S. Environmental Protection Agency, Ann Arbor, MI, 2003.
2.	Stein, J.H., Herdan, T. Worldwide Harmonization of Exhaust Emission Test Procedures for
Nonroad Engines Based on the International Standard ISO 8178", SAE Technical Paper Series
1998, #982043, 1-12.
3.	Electronic files of speed (rpm) and load (lbs-ft) points from EPA's nonroad application duty cycle
schedules, including a draft of EPA's Nonroad Composite Duty Cycle (or SAT cycle), may be found
at http://www.epa.gov/oms/regs/nonroad/equip-hd/cvcles/nrcvcles.htm . Additional information on
these cycles may be found at EPA's proposed Program for Low Emission Nonroad Diesel Engines and
Fuel webpage at http ://epa. gov/otaq/nonroad/.
4.	This web address/URL describes the European Transient Cycle (ETC) test cycle and lists the time-
speed-load data points of the cycle: www.dieselnet.com/standards/cycles/etc.html.
5. Starr, M.E. "Nonroad Duty Cycle Testing for Toxic Emissions"; SwRI 08.05004.05, Prepared for
U.S. Environmental Protection Agency, Ann Arbor, MI, 2004.

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6.Starr, M.E. "Air Toxic Emissions from In-Use Nonroad Diesel Equipment"; SwRI 08.05004.04,
Prepared for U.S. Environmental Protection Agency, Ann Arbor, MI, 2004.
7.	This is the web address/URL for the Auto Oil II web site created by the European Commission
Directorate-General for the Environment, http://europa.eu.int/comm/environment/autooil/.
8.	The Federal Register text describing EPA's MSATs can be found at 66 FR 17235, 3-29-2001.
The web address for EPA's air toxics website is http://www.epa.gov/otaq/toxics.htm.
9.	EPA. 1988. Second Supplement to Compendium of Methods for Determination of Toxic Organic
Compounds in Ambient Air. Atmospheric Research and Exposure Assessment Laboratory. Research
Triangle Park, NC. EPA 600/4-89/018. Pp TO-13 to TO-97.
10.	The Mobile Source Observation Database (MSOD) is a relational database developed by the
Assessment and Standards Division (ASD) of the U.S. EPA, Office of Transportation and Air Quality
(formerly the Office of Mobile Sources). Information on this resource may be found at
http://www.epa.gov/otaq/models/msod/msodannc.htm.
KEY WORDS
exhaust
emissions
nonroad
diesel
PM
air toxics
MSATs

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