Light Heavy-Duty Gasoline Vehicle
Evaporative Emissions Test Program
United States
Environmental Protection
tl	Agency

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Light Heavy-Duty Gasoline Vehicle
Evaporative Emissions Test Program
Assessment and Standards Division
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
Prepared for EPA by
SGS-Aurora, Eastern Research Group
EPA Contract No. EP-C-17-011
Work Assignment No. 1-22
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.
NOTICE
&EPA
United States
Environmental Protection
Agency
EPA-420-R-19-017
December 2019

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Table of Contents
1.0 Objectives and Background	1
2.0 Study Equipment and Preparation	2
2.1	Test Vehicles	2
2.2	Laboratory and Test Equipment Overview	3
2.3	Fuel Procurement and Preparation	5
2.4	Vehicle Preparation	6
3.0 Test Program	10
3.1	Testing Overview	10
3.2	Data Validation and Analysis	21
4.0	Final Results	22
5.0	Observations and Conclusions	29
6.0	Problems Encountered	30
7.0	References	32
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List of Tables
Table 2-1. Test Vehicle Summary	2
Table 2-2. Test Vehicle Details	3
Table 2-3. Fuel Properties	5
Table 4-1. Ford E-450 72-Hour VT SHED FTP Tailpipe Exhaust Emission Results	23
Table 4-2. Isuzu NPR 72-Hour VT SHED FTP Tailpipe Exhaust Emission Results	23
Table 4-3. Ford E-450 72-Hour VT SHED Running Loss Results	23
Table 4-4. Isuzu NPR 72-Hour VT SHED Running Loss Results	24
Table 4-5. Ford E-450 72-Hour VT SHED Results • 	24
Table 4-6. Isuzu NPR 72-Hour VT SHED Results'	25
Table 4-7. Ford E-450 ORVRFTP Exhaust Emissions Results	25
Table 4-8. Isuzu NPR ORVR FTP Exhaust Emissions Results	26
Table 4-9. Ford E-450 ORVR Results	26
Table 4-10. Isuzu NPR ORVR Results	26
Table 4-11. Static Test Results, Permeation Rates	26
Table 6-1. Voided Test Results	30
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List of Figures
Figure 3-1. FTP-75 Cycle	12
Figure 3-2. Hydrocarbon Sampling System	13
Figure 3-3. Urban Dynamometer Driving Schedule	14
Figure 3-4. New York City Cycle	15
Figure 3-5. 72 Hour VT SHED	18
Figure 3-6. 72 Hour VT SHED Procedure	18
Figure 3-7. ORVR Procedure	20
Figure 3-8. Static Test Procedure	21
Figure 4-1. Running Loss Tank Temperature Profiles	22
Figure 4-2. Ford E-450 72-Hour VT SHED Graphical Results	23
Figure 4-3. Isuzu NPR 72-Hour VT SHED Graphical Results	28
Figure 4-4. Isuzu NPR Static SHED Test Graphical Results	29
List of Images
Image 2-1. Sampling and Analytical Systems for Evaporative Emissions	4
Image 2-2. SHED which accommodates Light Heavy-Duty Trucks	5
Image 2-3 a-c. Isuzu NPR modified sending unit	7
Image 2-4. d-f Ford E-450 modified sending unit	8
Image 2-5. Snap-on Smart Smoke Evap Elite	9
Image 3-1. Sampling and Analytical Systems for Evaporative Emissions	13
Image 3-2. Ford E450 in SHED	16
Image 3-3. ORVR Prep	21
in

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Glossary of Terms and Acronyms
CFR
Code of Federal Regulations
CFV-CVS
Critical Flow Venturi—Constant Volume Sampler
ch4
Methane
CO
Carbon Monoxide
EPA
US Environmental Protection Agency
ERG
Eastern Research Group
FID
Flame Ionization Detector
FTP-72
Urban Dynamometer Driving Schedule of the Federal Test Procedure
FTP-75
City driving schedule of the Federal Test Procedure
GVWR
Gross Vehicle Weight Rating
HC
Hydrocarbon
LA-4
Urban Dynamometer Driving Schedule
NMHC
Non-Methane Hydrocarbons
NOx
Oxides of Nitrogen
OBD
Onboard Diagnostics
ORVR
Onboard Refueling Vapor Recovery
QAPP
Quality Assurance Project Plan
RVP
Reid Vapor Pressure
SGS-Aurora
SGS- Environmental Testing Center at Aurora Colorado
SHED
Sealed Housings for Evaporative Determination
UDDS
Urban Dynamometer Driving Schedule
VIN
Vehicle Identification Number
VI
Variable Temperature
iv

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Executive Summary
This study, performed by Eastern Research Group (ERG) and subcontractor SGS-
Environmental Testing Center (SGS-Aurora), under contract to the US Environmental Protection
Agency (EPA), was designed and orchestrated by EPA characterize evaporative emissions
control on two light-heavy duty gasoline vehicles. This work builds on prior evaporative
emissions test programs performed to characterize evaporative emission rates in US
vehicles1'2'3'4'5'6.
The required laboratory testing for this program was done by a subcontractor, SGS-
Aurora at their Aurora test facility. All test procedures followed the Code of Federal Regulation
(CFR) 1066 Vehicle Test Procedures, Subpart J Evaporative Emissions. Two vehicles
participated in this study; both were supplied by EPA. Both vehicles were modified to
accommodate temperature sensors and fuel pressure measurement ports. Tests performed on
each vehicle consisted of a combined procedure including a complete variable temperature
SHED (Sealed Housing for Evaporative Determination) test, complete ORVR (On-Board
Refueling Vapor Recovery) test and static tests. Fuel tank temperatures and pressures,
evaporative housing temperatures and pressures, test cell temperatures, and continuous purge
data was recorded using the J1979 protocol.
The primary finding of this study was that the hydrocarbon evaporative emissions of both
the Ford E-450 and Isuzu NPR appeared to be controlled during the running loss, hot soak
SHED, Variable Temperature SHED, and static pressurization test sequences which are
presented in detail in Section 5. These vehicles are not regulated for on-board refueling vapor
recovery (ORVR) and therefore the tests resulted in as expected uncontrolled emissions.
1.0 Objectives and Background
EPA has been updating evaporative emissions modeling with data from several recent
studies1"6. Heavy duty gasoline emissions of recent technologies have been assumed based on the
light duty evaporative emissions test results.
The objective of this study was to evaluate the evaporative emissions from two in-use
light heavy-duty gasoline vehicles. The two vehicles were an Isuzu NPR and a Ford E-450
(further discussed in Section 2.1). Exhaust emissions were measured during the Federal Test
Procedure drive cycle for HC, CO, NOx, CH4 and NMHC, as well as canister purge volume, and
HC results from ORVR and 72-hour VT SHED testing with canister bleed.
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2.0	Study Equipment and Preparation
2.1	Test Vehicles
The EPA provided two vehicles to be tested in this study. The two vehicles provided for
the test program are listed in Table 2-1, and details regarding the selected vehicles and test
parameters are listed in Table 2-2. Road load coefficients for testing were provided to SGS-
Aurora by EPA. The same target road load coefficients were used for both vehicles and are
representative of a typical light heavy-duty truck. Test vehicle 1 is a 2015 Isuzu NPR, standard
cab, rear-wheel drive (RWD), with a 6.0L naturally aspirated V8 gasoline engine and dual
wheels in the rear. The engine is rated at 297 hp and 372 ft-lbs of torque. The transmission is a
6-speed automatic. The vehicle arrived with 51,711 miles on it and no discernible damage or
defects. Test vehicle 2 is a 2016 Ford E-450, standard cab, RWD, with a 6.8L naturally aspirated
V10 gasoline engine and dual wheels in the rear. The engine is rated at 305 hp and 420 ft-lbs of
torque. The transmission is a 5-speed overdrive automatic. The vehicle arrived with 33,667
miles on it and no discernible damage or defects. Vehicle volume was assumed as 50 cubic feet
per 40 CFR Part 86.143-96*.
Table 2-1. Test Vehicle Summary
Vehicle Make
and Model
Model
Year
Approx.
Odometer
Evaporative Emissions
Standard (grams/test)
2 Day 3 Day RL
Canister
Capacity (g)
Tank Volume
(gal)
2Canister/Tank
Ratio
Isuzu NPR
2015
51711
2.3
1.9
0.05
150
30
5
Ford E-450
2016
33667
2.3
1.9
0.05
265
55
4.82
1	Canister Capacity = canister working capacity, in grams
2	Canister working capacity (g) / Tank volume (gal)
*40 CFR Part 86.143-96 states that "Net enclosure volume, ft3, as determined by subtracting 50 ft3 (1.42 m3)
(assumed volume of vehicle with trunk and windows open) from the enclosure volume. A manufacturer may use the
measured volume of the vehicle (instead of the nominal 50 ft3) with advance approval by the Administrator:
Provided, the measured volume is determined and used for all vehicles tested by that manufacturer."
2

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Table 2-2. Test Vehicle Details


Inertia Weight
(lbs)

Dynamometer Coefficients


Vehicle
Model Year
Tank
Capacity* (gj
Road Load
A Target
(lbf)
Road Load
A Set (lbf)
Road Load
B Target
(lbf/mph)
Road Load
B Set
(lbf/mph)
Road Load
C Target
(lbf/(mph)2)
Road Load
C Set
(lbf/(mph)2)
Engine
Family
Evap
Family
Isuzu NPR
2015
14500
30
95.95
76.03
0.96917
0.30287
0.125125
0.128935
FGMXE0
6.0584
FSZXF01
76ME0
Ford E-450
2016
9320
55
95.95
73.8444
0.96917
0.03127
0.125125
0.130002
GFMXE0
6.8BWZ
HFMXF0
265NAT
*Throughout the testing procedure, there were fuel fills of 40%, 10%, and 95%. These fill amounts
were determined based off the manufacturer specified fuel tank capacity.
2.2 Laboratory and Test Equipment Overview
All testing was performed at SGS-Aurora's facility, which is equipped with one 40 CFR
Part 86.1234-96 compliant point-source running loss test cell and three specially equipped
variable temperature (VT) sealed housings for evaporative determination (SHEDs). The largest
of these SHEDS was employed for hot soak, diurnal, ORVR, and static pressurization tests.
SGS-Aurora provides emissions certification testing for new vehicles manufactured to meet US
EPA emissions standards.
SGS-Aurora has 3 SHEDs onsite, the largest of which was used for this project. This
SHED is 128 inches wide, 117 inches tall, and 330 inches deep (which makes for a volume of
2,860 cubic feet). This provided plenty of space for each vehicle to fit inside along with any
equipment needed during testing. (Image 2-2). This SHED employs three mixing fans.
SGS-Aurora provided all quality assurance and traceability requirements defined in CFR
Title 40 Part 86, Subpart B and other test procedures performed during this study.
Equipment used in the study consisted of laboratory-grade electronic thermometers with
thermocouples for measuring temperatures, pressure measurement devices and analytical
systems containing sample conditioning, process gas analyzers, and a data acquisition and
control system. This included the thermocouples for the fuel dispensing cart, vehicle fuel tank,
and SHED. The maintenance, calibration and verification of the measurement equipment used in
this study conformed to requirements defined in the work plan and quality assurance project plan
(QAPP) developed for this project.
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All measurement devices used in this study met the requirements of 40 CFR Part 86 and
were calibrated and verified for accuracy, precision and repeatability. Any changes to
measurement equipment were performed in accordance with 40 CFR regulations and the
standard operating procedures followed at SGS-Aurora.
Image 2-1. Sampling and Analytical Systems for Evaporative Emissions
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Image 2-2. SHED which accommodates Light Heavy-Duty Trucks
2.3 Fuel Procurement and Preparation
Real world regular unleaded gasoline, with 85 octane, that is commercially available in
the Denver Metro Area was used for this study. The test fuel was all purchased at the same time
from the same batch. This fuel was deemed acceptable because the engine knock index at
altitude accommodates a lower octane fuel than at sea level SGS-Aurora did not conduct an
independent octane test on the fuel provided. Reid Vapor Pressure (RVP) was determined at
SGS-Aurora and is presented in Table 2-3. Triplicate testing was conducted at three different
points during the testing program.
Table 2-3. Fuel Properties
Date
Test
Sampled By Tested By
RVP
Average

1


8.53
*
8/7/2018
2
DM
DM
8.5
*

3


8.57
LD
00
k

1


8.53
*
8/14/2018
2
DM
DM
8.56
*

3


8.5
LD
00
L

1


8.62
*
8/22/2018
2
DM
DM
8.56
*

3


8,56
<£>
00
k
5

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The RVP range of E10 certification gasoline is 8.7-9.2 psi, while high altitude (above
4,000 feet) E10 certification gasoline has a range of 7.6-8.0 psi (CFR §86.113-04: Fuel
specifications). The RVP of the test fuel was slightly above the standard for high altitude
certification fuel.
2.4 Vehicle Preparation
The following steps were performed for each test vehicle in preparation for the test
program.
1)	Test vehicles were checked to verify they were capable of safe operation on a
dynamometer.
2)	Test vehicles were examined for signs of potentially extraneous evaporative
emissions, such as indications of collision, recent painting, tampering, new tires,
interior vinyl treatments, and windshield replacement.
3)	Vehicle information such as VIN, year, make, model, engine and evaporative
families was documented.
4)	SGS-Aurora removed the cargo box from on top of the trailer from the Isuzu test
vehicle (the Ford test vehicle arrived with the box removed) in order to access the
fuel sending units. These units were modified on both vehicles to include two,
type-J fuel tank thermocouples and a fuel drain. One thermocouple was extended
into the liquid level and one thermocouple was kept in the vapor space at a 40%
fill. (Image 2-4 a-g). SGS-Aurora also replaced the line from the fuel tank to the
filler neck with a line that was modified with a tank pressure monitoring system.
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Image 2-3 a-c. Isuzu NPR modified sending unit
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Image 2-4. d-f Ford E-450 modified sending unit
Vapor space thermocouple
Liquid space thermocouple
8

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The vehicle's evaporative emissions control system was subjected to an initial static
pressure test using a Snap-on Smart Smoke Evap Elite leak detection unit (Image
2-5).
Image 2-5. Snap-on Smart Smoke Evap Elite
Pressure tests were performed after the modifications on each vehicle's fuel and
evaporative emissions control system using the Snap-On leak detection unit.
To minimize issues with crankcase oil impacting emissions, oil was not added
unless necessary, since new oil may impact evaporative testing results. No oil was
added to either vehicle during the testing.
The appropriate vehicle road load set coefficients for dynamometer testing were
derived based on the targets provided by EPA in accordance with SAE J2264-
201401: Chassis Dynamometer Simulation of Road Load Using Coastdown
Techniques.
The wiper fluid reservoir and system were drained and flushed with distilled water
to eliminate potential release of wiper fluid hydrocarbons into the SHED during
static tests.

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3.0	Test Program
3.1	Testing Overview
Tailpipe vehicle emissions were recorded during the FTP portion of the testing.
Hydrocarbon emissions from engine exhaust and evaporative sources emitted during the running
loss, hot soak SHED, VT SHED, ORVR, and static pressurization test sequence were collected
and sampled per 40 CFR Part 86, Subpart B. The emissions collected in the sample bags were
analyzed within 20 minutes of their respective sample collection phases, as described in
§86.137—94(b)(15), "Dynamometer test run, gaseous and particulate emissions". The results of
the analysis were used per §86.143 "Calculations: evaporative emissions", to calculate the mass
of hydrocarbons emitted. Canister purge volume was recorded on both the running loss and FTP
portions of the test. Other data collected during this study consisted of vehicle and test setup
information, temperature and pressure measurements from the fuel tank, test cell, and
evaporative housing, and associated date and time for each of the measurements.
No special procedures were performed to initially flush the fuel system while changing
fuel from what arrived in the vehicle to the test fuel used in the study. The standard procedure of
drain and fill, preconditioning drive cycle, drain and fill, and canister load was deemed suitable
for clearing the system of the previous test fuel.
The following steps detail the test sequence performed.
Step 1) Vehicle Prep, Modify / Restore & Documentation: SGS-Aurora prepared the
vehicle for the test process (Section 2.4), scanned the OBD system for diagnostic trouble codes
and readiness status, and established a data repository.
Step 2) Drain and Refuel 1: To drain existing fuel and refuel the vehicle, an external pump
was connected to the fuel tank drain quick connect located on the fuel tank, and the pump was run
until vapors were observed in the clear Teflon tube coming from the tank. The pump system was
turned off and adsorbent towels were placed under the quick connect. The pump system was
disconnected at the quick connect and any liquid spills were contained on the adsorbent towel
ensuring that no fuel spilled on the vehicle. The vehicle was then fueled to 40% of tank capacity
with the fuel specified in the sequence and placed into soak.
Step 3) 6 to 24 Hour Soak: The vehicle was then placed in a temperature-controlled room
where the temperature was maintained at 68 °F to 86 °F for a time exceeding 6 hours but less than
24 hours.
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Step 4) Vehicle Derivation (Road-Load Model): The vehicle was run on the dyno in
order to obtain the coefficients needed to test according to SAE J2264. This is accomplished by
performing a double highway cycle followed by a set of vehicle coast-downs.
Step 5) Preconditioning LA-4 cycle: The standard LA-4 drive cycle was used in this step
to prepare the vehicle for subsequent procedures. Note: The LA-4 cycle is also called the U.S.
FTP-72 (Federal Test Procedure) cycle or the Urban Dynamometer Driving Schedule (UDDS)
(Figure 3-3).
Step 6) Drain and Refuel 2: This procedure is identical to the "Drain and Refuel 1"
procedure described in Step 2 (again, to 40% fill).
Step 7) Canister Load with Butane/Nitrogen mixture: Within one hour of the fueling
event, the evaporative emissions carbon canister on the vehicle was loaded with a 50/50 mixture
by volume of butane and Nitrogen, at a rate of 40 grams per hour, until a 2 gram breakthrough
occurred, or to 1,5x working capacity of the canister, depending on the test sequence (ORVR tests
used a 2g breakthrough while 72 hour VT SHED tests used 1.5x working capacity). This step was
done in parallel to Step 8 below.
Step 8) 12 to 36 Hour Soak: The vehicle was placed in a temperature-controlled room
where the temperature was maintained at 68 °F to 86 °F for a time exceeding 12 hours but less
than 36 hours.
Step 9) FTP-75 three phase cycle: The vehicle was then operated on the chassis
dynamometer over the FTP-75 cycle, the driving cycle that is part of the certification process and
graphically shown in Figure 3-1. Each phase fills an emissions bag which is analyzed after the
conclusion of that phase. Canister purge volume was measured during this portion of the test with
the Alicat purge meter (Image 3-1).
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Figure 3-1. FTP-75 Cycle
a*
EPA Federal Test Procedure
Dumber! 1B74 &r»cgiK]& - Di&ianctf - 11 04 niMi; - A-rtifAQA «poAd - 21 2 mpfi - MibumutH (.(.wJ - Sft 7 -vipTi
Cold S*sn Phase
505 secottds

Tronjitnt Phase
B64 sscomts
Hot SlJrt Phjjp
505 seconds
§ss?sig§gff3sf§
Test Time (seconds)

§ I
Step 10) Running Loss Test: A running loss test was then performed employing the
following steps and procedures:
If performing the Running Loss procedure for a VT SHED:
1)	For the three-day VT SHED, immediately after the hot transient exhaust emission
test (FTP-75), the vehicle was soaked in a temperature-controlled area at 95 °F for
a maximum of 6 hours until the fuel temperature stabilized. The fuel was allowed
to be heated or cooled to stabilize fuel temperatures, but the fuel heating rate was
not allowed to exceed 5 °F in any 1-hour interval during the soak period.
2)	Fuel temperatures were held at 95 ±3 °F for at least one hour before beginning the
running loss test.
3)	Running Loss Test. The running loss test was conducted using the point-source
method described in §86.134-96(g)(2). Measurements were taken at point sources:
canister vent and gas cap, as shown in Figure 3-2. Canister purge volume was also
measured during this portion of the test with the Alicat purge meter (Image 3-1).
12

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Image 3-1. Image 2-1. Sampling and Analytical Systems for Evaporative
Emissions
4)	Fans were positioned as described in §86.135—90(b) "Dynamometer Procedure"
and §86.107-96(d) "Sampling and Analytical Systems; Evaporative Emissions".
5)	The running loss vapor vent collection system was properly positioned at the fuel
vapor vents and in the vehicle's fuel and evaporative emission systems. This is
standard practice for all 3-day running loss tests. The sampling system
configuration is shown in Figure 3-2.
Figure 3-2. Hydrocarbon Sampling System
Continuous
Analysis
System
Modal
Analysis
System
I *•—1W
a
CVS
Fan
Airflow

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6)	The running loss vapor vent collection system was connected to a CFV-CVS bag
collection system and to a continuous FID analyzer.
7)	The vehicle air conditioning system (if so equipped) was set to the "normal" air
conditioning mode and adjusted to the minimum discharge air temperature and high
fan speed. Vehicles equipped with automatic temperature-controlled air
conditioning systems were set to operate in "automatic" temperature and fan modes
with the system set at 72 °F. Both vehicles were equipped with automatic air
conditioning.
8)	The temperature of the liquid fuel was monitored and recorded at least every 1
second with the temperature recording system specified in §86.107-96(e). The
vapor temperature was monitored for reference only and was not used as a process
variable for controlling tank temperature.
9)	When the ambient temperature was 95±5 °F (35±3 °C) and the fuel tank
temperature was 95±3 °F, the running loss test began.
10)	The running loss test was conducted by operating the test vehicle through one
Urban Dynamometer Driving Schedule (UDDS), a 2-minute idle, two New York
City Cycles (NYCC), another 2-minute idle, another UDDS, and then a final 2-
minute idle (see §86.115). These are shown graphically in Figure 3-3 and Figure
3-4. Phase one of the Running Loss cycle is the first UDDS cycle, phase two is both
of the NYCCs, and phase three is the final UDDS cycle.
Figure 3-3. Urban Dynamometer Driving Schedule
EPA Urban Dynamometer Driving Schedule
Length 1369 seconds - Distance = 7.45 miles - Average Speed = 19.59 mph
6G
50 --
* 40 --
*30 --
,9 20 --
O N t ^ DO O
in O ID O M) —
Test Time, sees
14

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Figure 3-4. New York City Cycle
New Vork City Cycle Driving Schedule
Length 598 seconds - Distance =1.18 miles - Average Speed = 7.1 mph
30 -i—
25
> 20 --
W
4>
!£ 10
j=
>
15 --
5 --
K" '¦£' "J-. "N in CG ^ Tl- r- O KI '¦£> U> C--I in CO - Tj- > o Ki '¦£" cr. C--J If) CO
IM Ti- ..£1 cr. ¦*- hO -il' ffl O W ID h (J^ |"J	'¦£« (J*. ^ hO '¦£' CO O iN Ifi T- 'T'-
Test Time, sees
11)	The ambient temperature was maintained at 95±5 °F (95±2 °F on average) during
the running loss test.
12)	Fuel temperatures were controlled according to the specifications of the
temperature profile provided. See Figure 4-1.
13)	Proceed to step 1 la to continue the VT SHED procedure.
If performing the Running Loss procedure for an ORVR:
1)	For the ORVR test, the temperature remains at ambient conditions and there is no
soak period after the FTP finishes.
2)	Fuel temperature is not monitored or controlled.
3)	The running loss test is conducted with no emissions sampling equipment.
4)	Fans were positioned as described in §86.135-90(b) "Dynamometer Procedure" and
§86.107-96(d) "Sampling and Analytical Systems; Evaporative Emissions".
5)	The vehicle air conditioning system is set to off.
6)	The running loss test was conducted by operating the test vehicle through one Urban
Dynamometer Driving Schedule (UDDS), a 2-minute idle, two New York City
15

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Cycles (NYCC), another 2-minute idle, another UDDS, and then a final 2-minute idle
(see §86.115). These are shown graphically in Figure 3-3 and Figure 3-4. Phase one
of the Running Loss cycle is the first UDDS cycle, phase two is both of the NYCCs,
and phase three is the final UDDS cycle.
7)	The ambient temperature was maintained at 68 °F to 86 °F during the running loss
test.
8)	Proceed to step 1 lb to continue the QRVR procedure.
Step It a) Hot Soak Test/SHED Cool down: For the VT SHED test, following
completion of the running loss test, the vehicle was administered a one-hour hot soak test in a
SPIED that was maintained and preheated to 95 (±2) °F in accordance with 40 CFR 86.138-96,
"Hot soak test". The SHED is then cooled to 72 °F to prepare for the VT SITED test. See Image
3-1. VT SHED procedure resumes at Step 12a).
Image 3-2. Ford E450 in SHED
Step 11 b) QRVR Drain and Refuel/SHED Soak: For the ORVR test, following the
completion of the running loss test, the vehicle was drained and filled to 10% of the total tank
capacity, and then the vehicle was soaked at 80 (±2) °F for a time exceeding 6 hours but less than
24 hours. ORVR procedure resumes at Step 12 b).
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Step 12 a) 72 Hour VT SHED: The three-day VT SHED is performed in accordance with
40 CFR 1066.910, "SHED enclosure specifications", using the temperature profile shown in
Figure 3-5. Canister bleed emissions were also recorded during this test. (See Figure 3-6 for test
procedure flow chart. See Image 3-2 for VT-SHED).
Step 12 b) ORVR: The ORVR test is performed. Fuel is dispensed inside the SHED and
HC mass is measured in accordance with 40 CFR 86.150-98, "Refueling test procedure". (See
Figure 3-7 for test procedure flow chart. See Image 3-3 for ORVR prep). Temperature
measurement devices used in this test sequence have been verified.
Step 13) Static Test: Once the ORVR or VT SHED sequence is completed, the static
testing will be performed on the vehicle. See Figure 3-8. This is performed by:
1)	The vehicle is prepared for the test by installing a pressure line in the fuel tank of
the vehicle.
2)	The fuel pump is modified so that it can be actuated remotely.
3)	The vehicle is leak-checked with the Snap-on leak check device to confirm that
there are no static leaks on the vehicle.
4)	The vehicle is placed in the SHED and the pressure and temperature lines are
hooked up.
5)	The SHED sniffs the background to establish a baseline. The vehicle then soaks
in the SHED for one hour.
6)	Once the vehicle has soaked for an hour, the SHED begins measurement to
determine the permeation rate of the vehicle over one hour.
7)	The vapor space in the fuel tank is pressurized for 30 minutes while the SHED
measures the HC concentration.
8)	For the next 30 minutes, the fuel pump on the vehicle is activated, while the HC
concentration is measured.
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Figure 3-5. 72 Hour VT SHED
72 Hour VT SHED
Time (s)
Figure 3-6. 72 Hour VT SHED Procedure
Vehicle Setup
LA4 Preconditioning
Drain and Refill 1 (a), 40%
Road Load
Derivation*
Drain and Refill 2
40%
FTP Emissions Test
Heat Build to 95° F
Canister Load (During Soak)
Vehicle Soak (>12 hours, <36 hours)
18

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*Road Load Derivation is only completed once per vehicle. It is not performed as a part of each
72 Hour VT
SHED
1 Hour SHED
Soak (a> 95° F
Running Loss
Emissions Test
SHED Soak Cool
Down 72° F
individual test sequence.
19

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Figure 3-7. ORVR Procedure

Vehicle Setup



r

Drain and Refill 1 @ 40%

ORVR
FTP Emissions Test
LA4 Preconditioning
Canister Load (During Soak)
SHED Drain and
Refill (ca 10%
Drain and Refill 2
40%
Running Loss
Preconditioning
Vehicle Soak (>12 hours, <36 hours)
ORVR Soak @ 80° F
(>6 hours, <24 hours
20

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Image 3-3. ORVR Prep
Figure 3-8. Static Test Procedure
'/2 Hour Tank Pressure Test
1 Hour Permeation Rate Test
% Hour Fuel System
Pressure Test
Data Validation and Analysis
A quality check was performed on each test in order to verify the following:
•	Proper progression of preparatory activities
•	Trace conformance during running loss test
•	Fuel temperature during running loss test for VT SHED
•	Start of hot soak test within all otted time after completion of running loss test for
VT SHED
•	Correct amount of fuel dispensed for ORVR
21

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Issues that were discovered during the test program or during the data validation and
analysis stage were documented and addressed as described in Section 6. More details are found
in the Quality Assurance Project Plan (QAPP).
4.0 Final Results
The following tables and figures characterize the total emissions measured through each
vehicle's series of tests. Figure 4-1 shows the temperature profiles that were used during the 72-
hour SHED running loss driving trace (provided by the EPA). The Ford E-450's 72-hour SHED
results for Test 1 and 2 were voided due to (1) a power outage, and (2) a SHED auto start error.
Those results are presented in Section 6.0. The VT SHED re-test results from Test 3 and 4 on
the Ford were valid and are reported below.
Figure 4-1. Running Loss Tank Temperature Profiles
Target Fuel Tank Temperature Profiles
^^—Vehcile Speed (mph)	Ford E-450Temp	Isuzu NPR Temp
0 250 500 750 1000125015001750 2000 2250250027503000 3250 3500 37504000 4250 4500
Time (s)
22

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Table 4-1. Ford E-450 72-Hour VT SHED FTP Tailpipe Exhaust Emission Results

72 hour VT SHED FTP Weighted Results (g/mi)

HC
CO
C02
NOx
CH4
n-CH4
mpg
Ford Test 3
0.3787
2.62
942.93
0.4038
0.0602
0.3227
9.1
Ford Test 4
0.3717
3.73
960.60
0.3585
0.0616
0.3142
8.9

72-hour VT SHED FTP Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Ford Test 3
98.74
567.27
248.00
914.01
Ford Test 4
103.41
579.54
197.07
880.01
Table 4-2. Isuzu NPR 72-Hour VT SHED FTP Tailpipe Exhaust Emission Results

72-hour VT SHED FTP Weighted Results (g/mi)

HC
CO
C02
NOx
CH4
n-CH4
mpg
Isuzu Test 1
0.1928
4.45
1135.27
0.4824
0.0581
0.1387
7.5
Isuzu Test 2
0.1841
3.69
1128.00
0.4318
0.0569
0.1311
7.6

72-hour VT SHED FTP Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Isuzu Test 1*
N/A
N/A
N/A
N/A
Isuzu Test 2
43.68
321.92
165.74
531.34
¥Purge meter did not record purge volume correct
y on test 1
Table 4-3. Ford E-450 72-Hour VT SHED Running Loss Results

72-hour VT SHED Running Loss Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Ford Test 3
866.87
963.72
975.17
2805.77
Ford Test 4
751.85
839.55
894.36
2485.76

72-hour VT SHED Running Loss Weighted HC (g/mi)

Phase 1
Phase 2
Phase 3
Total
Ford Test 3
0.0007
0.0002
0.0001
0.0010
Ford Test 4
0.0006
0.0003
0.0002
0.0011
23

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Table 4-4. Isuzu NPR 72-Hour VT SHED Running Loss Results

72-hour VT SHED Running Loss Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Isuzu Test 1
N/A
N/A
N/A
N/A
Isuzu Test 2
462.40
398.92
400.18
1261.51

72-hour VT SHED Running Loss Weighted HC (g/mi)

Phase 1
Phase 2
Phase 3
Total
Isuzu Test 1
0.0004
0.0001
0.0000
0.0002
Isuzu Test 2
0.0002
0.0001
0.0000
0.0003
Table 4-5. Ford E-450 72-Hour VT SHED Results 1.1

72-hour VT SHED HC Mass (g)

Day 1
Day 2
Day 3
Total
Ford Test 3
0.303
0.270
0.301
0.874
Ford Test 4
0.302
0.240
0.295
0.836

72-hour VT SHED Canister Bleed (g)

Day 1
Day 2
Day 3
Total
Ford Test 3
0.0231
0.0261
0.0383
0.0875
Ford Test 4
0.0194
0.0158
0.0207
0.0559
t 40 CFRPart 86.1813-17 states that "In the case of rig, diurnal, hot soak, and running loss testing withElO test
fuel, multiply measured (unspeciated) FID values by 1.08 to account for the FID's reduced response to ethanol."
However, the test fuel was market gasoline and therefore no certificate of analysis (COA) was available, the results
are reported uncorrected.
* This testing was conducted for inventory purposes only, and do not reflect evaporative emissions compliance as
described in 40 CFR Part 1813-17. As such, these results should not be used to determine compliance.
24

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Table 4-6. Isuzu NPR 72-Hour VT SHED Results§**

72-hour VT SHED HC Mass (g)

Day 1
Day 2
Day 3
Total
Isuzu Test 1
0.609
0.682
0.672
1.962
Isuzu Test 2
0.530
0.717
0.581
1.828

72-hour VT SHED Canister Bleed (g)

Day 1
Day 2
Day 3
Total
Isuzu Test 1
0.0550
0.0330
0.0245
0.1125
Isuzu Test 2^
0.0007
0.0192
0.0460
0.0659
Table 4-7. Ford E-450 ORVR FTP Exhaust Emissions Results

ORVR FTP Weighted Results (g/mi}


HC
CO
C02
NOx
CH4
n-CH4
mpg
Ford Test 1
0.3982
2.63
972.58
0.4274
0.0551
0.3469
8.8
Ford Test 2
0.3544
2.25
965.01
0.3948
0.0533
0.3049
8.9

ORVR FTP Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Ford Test 1
90.20
585.38
274.89
950.48
Ford Test 2
N/A
N/A
N/A
N/A
? 40 CFRPart 86.1813-17 states that "In the case of rig, diurnal, hot soak, and running loss testing withElO test
fuel, multiply measured (unspeciated) FID values by 1.08 to account for the FID's reduced response to ethanol."
However, the test fuel was market gasoline and therefore no certificate of analysis (COA) was available, the results
are reported uncorrected.
This testing was conducted for inventory purposes only, and do not reflect evaporative emissions compliance as
described in 40 CFR Part 1813-17. As such, these results should not be used to determine compliance.
^ Canister bleed emissions did not report correctly for Isuzu Test 2
25

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Table 4-8. Isuzu NPR ORVR FTP Exhaust Emissions Results

ORVR FTP Weighted Results (g/mi


HC
CO
C02
NOx
CH4
n-CH4
mpg
Isuzu Test 1
0.1791
3.58
1127.95
0.3509
0.0461
0.1363
7.6
Isuzu Test 2
0.1841
3.69
1128.00
0.4318
0.0569
0.1311
7.6

ORVR FTP Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Isuzu Test 1
N/A
N/A
N/A
N/A
Isuzu Test 2
34.91
295.90
161.81
492.61
Table 4-9. Ford E-450 ORVR Results

ORVR Results

Average g/gal
SHED grams
Ford Test 1
2.261
113.611
Ford Test 2
2.145
107.631
Table 4-10. Isuzu NPR ORVR Results

ORVR Results

Average g/gal
SHED grams
Isuzu Test 1
2.163
55.252
Isuzu Test 2
2.833
72.390
Isuzu Test 3**
2.775
71.215
Table 4-11. Static Test Results, Permeation Rates

Static Test Results SHED Mass (g)
Static Test Results SHED Mass (g/hr)

Phase 1
Phase 2
Phase 3
Total
Phase 1
Phase 2
Phase 3
Total
Isuzu Test 1
0.032
0.017
0.028
0.078
0.032
0.034
0.056
0.039
Ford Test 1
0.013
0.008
0.010
0.031
0.013
0.016
0.020
0.0155
S This ORVR result was the refueling event only. It did not include the initial prep, canister load, FTP, or Running
Loss. The vehicle canister was purged, then the vehicle was drained and filled per the ORVR procedure, underwent
the ORVR soak, and then underwent the ORVR refueling event. This was done as a check due to the discrepancy in
the initial ORVR results.
26

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Figure 4-2. Ford E-450 72-Hour VT SHED Graphical Results
100
90
80
70
« 60
BQ
01
Q
.a so
E
£ 40
30
20
10
0
_r~	x.
Ford Test #3
72 Hour VT SHED


/
Y
2.5
-Can Bleed ppm -Corr
-SHEDT
'Can Bleed Gms * 10'	j 5 §
Total SHED Gms (uncorrected)
A
J
VJ_
0.5
256 511 766 1021 1276 1531 1786 2041 2296 2551 2806 3061 3316 3571 3826 4081
Time (mins)
00
100
90
80
70
60
6
o3 50
E
£ 40
30
20
10
0
Ford Test #4
72 Hour VT SHED
-Can Bleed ppm - Corr
-SHEDT
'Can Bleed Gms * 10'
Total SHED Gms (uncorrected)

\
2.5
1.5
0.5
256 511 766 1021 1276 1531 1786 2041 2296 2551 2806 3061 3316 3571 3826 4081
Time (mins)
27

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Figure 4-3. Isuzu NPR 72-Hour VT SHED Graphical Results
Isuzu Test #1
72 Hour VT SHED
o3
E
100
90
80
70
60
50
40
30
20
10
0
—Can Bleed ppm - Corr
-SHED T
'Can Bleed Gms * 10'
Total SHED Gms (uncorrected)
r	^

2.5
1.5
0.5
256 511 766 1021 1276 1531 1786 2041 2296 2551 2806 3061 3316 3571 3826 4081
Time (mins)
00
100
90
80
70
60
6
tfj 50
E
£ 40
30
20
10
0
Isuzu Test #2
72 Hour VT SHED
-Can Bleed ppm - Corr
-SHED T
'Can Bleed Gms * 10'
Total SHED Gms (uncorrected)
256
511
766 1021 1276 1531 1786 2041 2296 2551
Time (mins)
2806 3061 3316 3571 3826 4081
2.5
1.5
28

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Static Test Permeation Results
CD
s
!-h
(L)
fin
u
0.06
0.05
0.04
0.03
0.02
0.01
0
Time (hours)
Figure 4-4. Isuzu NPR Static SHED Test Graphical Results
5.0 Observations and Conclusions
Comparing the performance of the two vehicles throughout the testing procedures show
that the purge strategy of both vehicles is very similar, with the Ford purging approximately 8%
of total canister weight between the end of canister loading and the end of the SHED hot soaks,
while the Isuzu purged approximately 8.5% of its canister weight.
The ORVR testing showed both vehicles performed similarly in terms of the grams
emitted per gallon of fuel recorded during the fueling procedure. The total SHED grams were
significantly higher on the Ford when compared to the Isuzu, but the amount of fuel dispensed is
also significantly higher due to the Ford's larger fuel tank (55 gallons compared to 30 for the
Isuzu). When results are compared on a basis of grams per gallons of fuel dispensed, both
vehicles performed similarly. The larger fuel tank in the Ford is also the reason its ORVR test is
slightly longer than that of the Isuzu (5 minutes vs. 3 minutes).
The static emissions test was conducted to obtain the permeation rate of HC on the
vehicles. The HC concentration was measured in the SHED for each phase of the Static Test:
The vehicle sat in the SHED for the first hour, then the vapor space was pressurized for next
29

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thirty minutes, and for the final thirty minutes the fuel pump was activated. This testing yielded
very little HC mass for both vehicles. The rate at which the Ford E-450 permeates stayed
consistent throughout the test. The rate at which the Isuzu NPR permeates did increase when the
fuel pump is activated (as shown in Figure 4-4), indicating a small liquid leak somewhere in the
system.
Results for the 72-hour VT SHED show the Isuzu having a higher HC mass than the
Ford. The Ford showed canister bleed emission spikes during both 72 hour VT SHED tests
(Figure 4-2, day 3 for the third test, day 1 for the fourth). This could indicate the canister
breaking through, or just releasing a brief burst of HC.
Repeatability for purge volume and emissions was consistent for both vehicles
throughout testing.
6.0 Problems Encountered
During the testing process, the problems encountered included two of the 72-hour VT
SHEDS being voided on the Ford E-450. Test 1 was due to a power outage, and Test 2 was due
to an error with the test auto-start on the SHED.
During the FTP and running loss portions of testing, there were instances of the canister
purge data not recording. The data from the voided tests is presented below.
Table 6-1. Voided Test Results

72 hour VT SB
ED FTP Weighted Exhuast Emissions Results (g/mi)

HC
CO
C02
NOx
CH4
n-CH4
mpg
Ford 1 (SHED
Void)
0.3434
3.01
954.01
0.3878
0.0526
0.2944
9.0
Ford 2 (SHED
Void)
0.3285
3.13
1029.10
0.4565
0.0613
0.2715
8.3

72-hour VT SHED FTP Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Ford 1 (SHED
Void)
77.81
562.91
232.12
872.85
Ford 2 (SHED
Void)
84.25
583.55
276.85
944.65
30

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72-hour VT SHED Running Loss HC (g/mi)

Phase 1
Phase 2
Phase 3
Total
Ford 1 (SHED
Void)
0.0004
0.0002
0.0001
0.0006
Ford 2 (SHED
Void)
0.0011
0.0027
0.5145
0.5184


72-hour VT SHED Running Loss Purge Volume (L)

Phase 1
Phase 2
Phase 3
Total
Ford 1
(SHED Void)
805.76
1064.78
964.60
2835.14
Ford 2
(SHED Void)
N/A
N/A
N/A
N/A
31

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7.0 References
1	Haskew, H., Liberty, T. (2008), Vehicle Evaporative Emission Mechanisms: A Pilot study.
(Coordinating Research Council E-77)
2	Haskew, H., Liberty, T. (2010), Enhanced Evaporative Emission Vehicles. (Coordinating
Research Council E-77-2)
3	Haskew, H., Liberty, T. (2010), Evaporative Emissions from In-Use Vehicles: Test Fleet
Expansion. (Coordinating Research Council E-77-2b)
4	Haskew, H., Liberty, T. (2010), Study to Determine Evaporative Emission Breakdown,
Including Permeation Effects and Diurnal Emissions Using E20 Fuels on Aging Enhanced
Evaporative Emissions Certified Vehicles. (Coordinating Research Council E-77-2c)
5	DeFries, T., Lindner, J., Kishan, S., Palacios, C. (2011), Investigation of Techniques for High
Evaporative Emissions Vehicle Detection: Denver Summer 2008 Pilot Study at Lipan Street
Station.
6	DeFries, T., Palacios, C., Weatherby, M., Stanard, A., Kishan, S. (2013), Estimated Summer
Hot-Soak Distributions for Denver's Ken Caryl I/M Station Fleet.
32

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Appendix A
List of Electronic Files Provided to OTAQ

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Excel Files
•	04162600.csv-IsuzuNPR FTP 8/5/18
•	04162601.csv - Isuzu NPR Running Loss (Prep) 8/4/18
•	04162714.csv-Isuzu NPR FTP 8/8/18
•	04162717.csv - Isuzu NPR Running Loss 8/8/18
•	04162952.csv-Isuzu NPR FTP 8/15/18
•	04162962.csv - Isuzu NPR Running Loss (Prep) 8/15/18
•	04163104.csv-Isuzu NPR FTP 8/17/18
•	04163116.csv - Isuzu NPR Running Loss 8/17/18
•	04163314.csv-Ford E450 FTP 8/21/18
•	04163318.csv - Ford E450 Running Loss (Prep) 8/21/18
•	04163501.csv- Ford E450 FTP 8/24/18
•	04163508.csv - Ford E450 Running Loss 8/24/18
•	04163655.csv- Ford E450 FTP 8/28/18
•	04163656.csv - Ford E450 Running Loss (Prep) 8/28/18
•	04163822.csv-Ford E450 FTP 8/30/18
•	04163825.csv - Ford E450 Running Loss 8/30/18
•	04163909.csv - Ford E450 FTP 9/1/18
•	04163910.csv - Ford E40 Running Loss 9/1/18
•	04164117.csv-Ford E450 FTP 9/6/18
•	04164119.csv - Ford E450 Running Loss 9/6/18
HTML Files
•	7500162716.htm
•	7500162754.htm
•	7500163001.htm
•	7500163122.htm
•	7500163382.htm
•	7500163543.htm
•	7500163666.htm
•	7500163687.htm
•	7500162642 htm
•	7500163745.htm
•	7500163857.htm
•	7500163912.htm
•	7500164132.htm
-	Test No. 162716, Isuzu NPR, Hot Soak
-	Test No. 162754, Isuzu NPR, VT SHED
-	Test No. 163001, Isuzu NPR, ORVR
-	Test No. 163122, Isuzu NPR, VT SHED
-	Test No. 163382, Ford E-450, ORVR
-	Test No. 163543, Ford E-450, VT SHED
-	Test No. 163666, Isuzu NPR, VT SHED
-	Test No. 163687, Ford E-450, ORVR
-	Test No. 162642, Isuzu NPR, ORVR
-	Test No. 163745, Ford E-450, VT SHED
-	Test No. 163857, Ford E-450, VT SHED
-	Test No. 163912, Ford E-450, VT SHED
-	Test No. 164132, Ford E-450, VT SHED

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