United States Air and Radiation EPA420-R-99-025
Environmental Protection April 1999
Agency
vxEPA Phase II RFG
Report on
Performance Testing
> Printed on Recycled Paper
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EPA420-R-99-025
April 1999
II RFG
on
Fuels and Energy Division
Office of Air Transportation and Air Quality
U.S. Environmental Protection Agency
NOTICE
This technical report does not necessarily represent final EPA decisions or positions.
It is intended to present technical analysis of issues using data which are currently available.
The purpose in the release of such reports is to facilitate the exchange of
technical information and to inform the public of technical developments which
may form the basis for a final EPA decision, position, or regulatory action.
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CONTENTS
I. Executive Summary
II. Background
A. RFC Program
B. Implementation Workgroup
III. Vehicle Performance Test Program
A. Design
B. Fuel
C. Fleets
D. Vehicle Performance
IV Fuel Economy
A. Southwest Research Institute Study
B. Fleet Average Fuel Economy
V. Nonroad Test Program
A. Utility, Lawn, and Garden Equipment
B. Marine Engines
VI. Motorcycle Test Program
VII. Conclusion
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TABLES
1. Test Fuel Properties
2. Boston Police Department Fleet
3. Elk Grove Village Fleet
4. Houston Lighting & Power Fleet
5. Arlington County Nonroad Engines
6. Harley-Davidson Motorcycles Tested in Laboratory
7. Harley-Davidson Motorcycles Tested On-road
APPENDICES
A. Phase II RFC Implementation Workgroup
B. Testing Team
C. Technical Steering Committee
D. Test Plan: Evaluation of On-Highway Motor Vehicles Operated on Federal
Phase II Reformulated Gasoline
E. Comparison of Fuel Parameters in California Cleaning Burning Gasoline and
Federal Phase II RFC
F. Statement of Work
G. Certificates of Analysis
H. NVFEL Fuel Analyses
I. Daily Minimum and Maximum Temperatures in Test Cities
J. Ford Analysis
K. General Motors Analyses
L. Letter from Elk Grove Village Fleet Manager
M. Southwest Research Institute Fuel Economy Study
N. Temperatures at Milwaukee Mitchell Airport: October - November 1998
Acknowledgment
This report was peer reviewed by the Phase IIRFG Implementation Workgroup's
technical steering committee. Members of the technical steering committee are listed in
Appendix C.
This report was also reviewed by John Hornback, director of the Kentucky
Department for Environmental Protection's Division for Air Quality and co-chair of the
workgroup, and by Marlin Gottschalk, manager of the Georgia Department of Natural
Resources's Mobile Sources and Area Sources Program.
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I. Executive Summary
The federal reformulated gasoline (RFC) program was introduced in January
1995. RFC is a specially blended gasoline that burns cleaner, reducing vehicle
emissions of air pollutants that cause smog. Congress requires the RFC program in
those cities with the worst smog problems. Other areas may choose to participate in the
program. Seventeen states and the District of Columbia currently use RFC. About 30
percent of the U.S. gasoline supply is reformulated.
The second phase of the RFC program will begin in January 2000. Phase II RFC
will achieve even greater vehicle emission reductions than Phase I, although the
gasoline blend will be similar in many ways. To ensure that any vehicle performance
problems with Phase II RFC would be identified before the fuel is introduced to the
public, the U.S. Environmental Protection Agency (EPA) conducted a fleet testing
program in 1998.
EPA tested 374 in use vehicles in three cities over a period of three to five
months. Conditions during testing included subfreezing temperatures in the north and
record heat in the south. The combined test fleets drove over one million miles with
Phase II RFC. No performance problems with Phase II RFC were reported.
Fleets that participated in the testing program include the Boston Police
Department, Elk Grove Village in suburban Chicago, and the Houston Lighting & Power
Company. Vehicles in these fleets were generally well maintained.
Well maintained vehicles should experience no unusual performance problems
with Phase II RFC. Of course, as vehicles age, parts wear out, so maintenance is the
key to good performance with any fuel.
In a separate study by Southwest Research Institute, fuel economy with Phase II
RFC was compared to Phase I RFC with 12 vehicles of various makes, ages, and
mileage under normal driving conditions. The results indicate no statistically significant
difference between the fuels. The results are consistent with other fuel economy studies
which show that fuels of equivalent energy content will produce equivalent fuel
economy.
Testing was also conducted with small engines, including 177 pieces of utility,
lawn, and garden equipment, and with marine and motorcycle engines. No
performance problems were reported.
In summary, no difference in vehicle performance or fuel economy is expected
when Phase II RFC replaces Phase I RFC. In addition, no difference in performance is
expected with small engines, marine engines, or motorcycles.
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II. Background
A. RFG Program
Section 211(k) of the Clean Air Act (CAA) directs EPA to issue regulations
establishing a reformulated gasoline program that will significantly reduce vehicle
emissions that contribute to smog. On February 16, 1994, EPA published a final rule
establishing various content and emission reduction standards for RFG, including
provisions for enforcement of RFG standards (59 FR 7716). The purpose of the RFG
program is to improve air quality by requiring that gasoline sold in certain areas of the
U.S. be reformulated to reduce emissions of toxics and smog-forming compounds from
motor vehicles.
Section 211(k) mandates that RFG be sold in the nine specific metropolitan areas
with the most severe summertime ozone levels as measured during the period 1987
through 1989; RFG must also be sold in any ozone nonattainment area subsequently
reclassified as a severe area. Other ozone nonattainment areas may choose to
participate or "opt in" to the program. Ground level or tropospheric ozone is the primary
ingredient of smog. Ground level ozone results from a reaction between such gases as
volatile organic compounds (VOCs) and oxides of nitrogen (NOx) that are emitted from
vehicles and other sources.
The Act mandates certain requirements for the RFG program. Section 211 (k)(1)
directs EPA to issue regulations that:
require the greatest reduction in emissions of ozone forming volatile organic
compounds (during the high ozone season) and emissions of toxic air pollutants
(during the entire year) achievable through the reformulation of conventional
gasoline, taking into consideration the cost of achieving such emission
reductions, any nonair-quality and other air-quality related health and
environmental impacts and energy requirements.
Section 211 (k) specifies the minimum requirement for reduction of VOCs and toxics for
1995 through 1999, or Phase I of the RFG program; the section specifies that EPA must
require the more stringent of a specified fuel formula or an emission reduction
performance standard, measured on a mass basis, equal to 15 percent of baseline
emissions. Baseline emissions are the emissions of 1990 model year technology
vehicles operated on a specified baseline gasoline. Section 211(k) compositional
specifications for RFG include a 2.0 weight percent oxygen minimum standard and a 1.0
volume percent benzene maximum standard. Section 211(k) also specifies that
emissions of NOx may not increase in RFG over baseline emissions.
For the year 2000 and beyond, or Phase II of the RFG program, the Act specifies
that the VOC and toxic performance standards must be no less than either a specified
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fuel formula or a 25 percent reduction from baseline emissions, whichever is more
stringent. EPA can adjust these standards upward or downward taking into account
such factors as technological feasibility and cost, but in no case can the standards be
less than 20 percent.
Shortly after passage of the CAA Amendments in 1990, EPA entered into a
regulatory negotiation with interested parties to develop specific proposals for
implementing the RFC program. In August 1991, the negotiating committee reached
consensus on a program outline that would form the basis for a notice of proposed
rulemaking, addressing emission content standards for Phase I (1995-1999), emission
models, certification, enforcement, and other important program elements.
The regulatory negotiation conducted by EPA did not address the Phase II VOC
and toxic standards for RFC, nor did it address a reduction in NOx emissions beyond
the statutory cap imposed under section 211(k)(2)(A). The final rule promulgated by
EPA closely followed the consensus outline agreed to by various parties in the
negotiated rulemaking process. The final rule also adopted a NOx emission reduction
performance standard for Phase II RFC, relying on authority under section 211(c)(1)(A).
Reformulated Gasoline Average Emission Reduction Requirements*
Phase I** Phase II**
Volatile Organic Compounds 17% 27%
Nitrogen Oxides 2% 7%
Toxics 17% 22%
*Reductions are from 1990 nationwide baseline.
**Complex model averaged standards for VOC-control Region 2 (i.e., northern areas).
The Phase I RFC program is designed to reduce the air pollution that causes
smog by 36,000 tons per year in the areas that use RFC, compared to conventional
gasoline - the equivalent of eliminating the emissions from over eight million vehicles.
When Phase II RFC replaces Phase I, the program is designed to reduce smog
pollutants by an additional 45,000 tons per year in RFC areas, for a combined
equivalent of eliminating the emissions from over 16 million vehicles.
Analysis of fuel data submitted to EPA by industry for compliance purposes
indicates that in each year since the RFC program's introduction in 1995, VOC and toxic
reductions from the RFC program have exceeded program requirements. Preliminary
data analysis for 1998 indicates that, on average, all Phase I emission reduction
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standards are being met and exceeded. In 1998, most RFC already exceeded the
Phase II RFC average performance standard for toxics, and some RFC in the Northeast
exceeded Phase II RFC emission reduction standards for NOx in the ozone control
season (i.e., the summer months). At this time, refiners are still making incremental
investments to produce adequate volumes of compliant Phase II RFC.
Air quality monitoring data for 1995, the first year of the RFC program, shows a 43
percent reduction in benzene in the ambient air in RFC areas, according to EPA's
National Air Quality and Emission Trends Report, 1995. A greater percentage of
monitoring sites in RFC areas showed statistically significant decreases in average
benzene than did sites in non-RFG areas. The RFC program limits benzene. Still, to
overcome the difficulties inherent in linking changes in the ambient air to particular
pollution reduction programs like RFC, an independent analysis of the data was
conducted by Sonoma Technology, Inc. The analysis of the 1995 ambient air
monitoring data indicates that there is a strong case that the ambient reductions in
benzene resulted from RFC.
B. Implementation Workgroup
In April 1997, EPA formed a stakeholder workgroup under the Federal Advisory
Committee Act to focus on Phase II RFC implementation issues. The Phase II RFC
Implementation Workgroup was established by the Clean Air Act Advisory Committee's
Mobile Source Technical Review Subcommittee. The workgroup includes
representatives of the automobile and oil industries, environmental and public health
groups, and state agencies and associations. The goal of the workgroup is to provide
factual information to the public by working together to identify, gather, and analyze data
on Phase II RFC. Members of the workgroup are listed in Appendix A. The workgroup
formed teams to focus on testing and education activities.
III. Vehicle Performance Test Program
To ensure that any vehicle performance problems with Phase II RFC would be
identified before the fuel is introduced to the public, the testing team recommended a
fleet testing program with Phase II RFC, compared to Phase I RFC. The fleet testing
recommendation was adopted by the workgroup, and the Mobile Source Technical
Review Subcommittee. Members of the testing team are listed in Appendix B.
The testing team also recommended formation of a technical steering committee
to guide development of the fleet testing program. Members of the technical steering
committee are listed in Appendix C.
A. Design
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The purpose of the test program was to identify any performance problems that
might be associated with Phase II RFC before the fuel is introduced to the public in
January 2000 by conducting performance testing in several cities representative of RFC
areas. Boston, Chicago, and Houston were selected by the workgroup as test program
sites.
The technical steering committee worked with EPA to develop a test plan,
"Evaluation of On-Highway Motor Vehicles Operated on Federal Phase II Reformulated
Gasoline," included as Appendix D. The plan is similar to the test program conducted
by the California Air Resources Board for the introduction of its cleaner burning gasoline
program in June 1996, but smaller in scale.
From February to August 1995, the California Air Resources Board conducted a
performance and compatibility test program with its cleaner burning gasoline (CaRFG).
With a fleet of 1466 vehicles, 829 test vehicles were driven over five million miles with
CaRFG. The workgroup believes that the California data is applicable to Phase II RFC
since the testing was conducted on a wide mix of vehicle types and ages with a fuel
more severely reformulated and designed to burn cleaner than is expected for Phase II
RFC. A comparison of the properties of Phase II RFC and CaRFG is included in
Appendix E.
California's test results indicate that CaRFG performed as well as conventional
fuel in terms of driveability, starting, idling, acceleration, power, and safety. There was
no significant difference between the frequency of problems in the test and control
fleets. Newer vehicles did not experience problems. Historical maintenance and repair
data indicate an increasing rate of failures in fuel system components associated with
aging irrespective of the fuel used.
The workgroup determined that the California testing results are relevant for
Phase II RFC. However, several data gaps were identified, particularly vehicle
performance with ethanol-oxygenated fuels and vehicle performance in cold
temperatures and the shoulder season (i.e., the period of time in late spring and early
autumn when unseasonably cold temperatures may occur). Therefore, EPA's test
program was designed to fill gaps in existing data.
Funding for the test fuel for Boston and Chicago was provided by the American
Petroleum Institute, Oxygenated Fuels Association, and American Methanol Institute.
Management of fuel distribution for the Boston and Chicago fleets was handled by the
Lake Michigan Air Directors Consortium. EPA provided test fuel for Houston. EPA
entered into a contract with each participating fleet that covered identification of the test
fleet, vehicle inspection, incident reporting, and fuel provisions. An example of a
statement of work for these contracts is included in Appendix F.
To carry out the test plan, EPA technicians from the National Vehicle and Fuel
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Emissions Laboratory inspected the fuel systems of each test and control vehicle
included in the test program. Fuel system inspections were conducted three times over
five months in Boston and Chicago, and twice over three months in Houston. For each
test and control vehicle inspected, relevant information such as mileage and vehicle
description was noted on fuel system inspection forms. Examples of these forms are
included with the test plan in Appendix D.
The test plan also includes driveability incident logs that were designed to
capture information on vehicle performance measures such as starting, running, and
idling. EPA provided copies of the driveability incident log to participating fleets. The
driveability incident log is included in Appendix D.
B.
Fuel
The technical steering committee developed four formulations of test fuel for the
fleet testing program that meet the standards for Phase II RFC: winter fuel oxygenated
with MTBE, winter fuel oxygenated with ethanol, summer fuel oxygenated with MTBE,
and summer fuel oxygenated with a mixture of MTBE and TAME. The test fuel
formulations are equivalent to the average or 50th percentile fuel expected for Phase II
RFC. The test fuel property specifications developed by the technical steering
committee are shown in the test plan in Appendix D. The technical steering committee
also developed allowable ranges of parameters and maximum blending fractions for
each test fuel to assure that the test fuels would be representative of actual refinery
blends. The fractions and ranges are included in the test plan in Appendix D. The
properties of the test fuels used in the fleet testing program are shown in Table 1.
Table 1 - Test Fuel Properties
Oxygenate, vol%
RVP, psi
Sulfur, ppm
Aromatics, vol%
Olefins, vol%
Benzene, vol%
T10, F
T50, F
T90, F
Summer MTBE
11.2
6.8
155
24.5
12
1.0
139.7
205.7
312.5
Summer MTBE +
TAME
10.81 MTBE
3.288 TAME
6.75
169
23.5
13
1.0
138.5
192.7
308.2
Winter MTBE
11.7
12.8
298
23.85
10.5
0.98
106.5
190.3
331.3
Winter Ethanol
9.74
13.1
309
25.2
11
0.999
110.4
182.7
335.3
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Test fuel was manufactured by Phillips Chemical Company. Certificates of analysis for
the four fuel formulations used in the testing program are included in Appendix G. Fuel
property analyses were also performed for verification by EPA's National Vehicle and
Fuel Emissions Laboratory (NVFEL) in Ann Arbor. NVFEL analyses confirmed that the
fuels fell within acceptable ranges for Phase II RFC, or within test method precision
range, which specifies an acceptable range of variability. NVFEL analyses are included
in Appendix H.
During the testing program, Boston received five test fuel deliveries totaling
39,914 gallons. Of the total, 23,947 gallons were the winter fuel oxygenated with MTBE,
8,073 gallons were the summer fuel oxygenated with MTBE, and 7,894 gallons were
the summer fuel oxygenated with MTBE and TAME.
Elk Grove Village in suburban Chicago received three fuel deliveries totaling
24,432 gallons. Of the total, 16,272 gallons were the winter fuel oxygenated with
ethanol, and 8,160 gallons were the summer fuel oxygenated with MTBE.
Houston received three test fuel deliveries totaling 23,448 gallons. All test fuel
used in Houston was the summer fuel oxygenated with MTBE.
C. Fleets
Three vehicle fleets in three cities participated in the program. Boston, Chicago,
and Houston were selected by the testing team and approved by the workgroup as
representative of geographic areas participating in the RFC program. The National
Association of Fleet Administrators provided assistance in locating participating fleets.
Testing in Boston and suburban Chicago's Elk Grove Village was conducted
from March through July. In Houston, the test period was June through August. Daily
minimum and maximum temperatures for the test period for Boston, Chicago, and
Houston are listed in Appendix I.
In Boston, the Police Department agreed to participate in the fleet testing
program. The fleet was composed of two police precincts; one precinct provided a test
fleet and another precinct provided a control fleet. Due to the preexisting sizes of the
fleet at each precinct, it was not possible to find a closer match between the number of
vehicles in the test and control fleets.
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Table 2 - Boston Police Department Test Fleet
Test Fuel
Control Fuel
Year
99
98
97
96
95
94
93
92
91
90
89
88
Total
1
4
35
9
20
2
10
1
9
2
2
2
97
Cars
0
3
35
9
17
2
8
1
9
0
2
1
87
Trucks
1
1
0
0
3
0
2
0
0
2
0
1
10
Cars
0
0
23
8
8
0
5
1
6
0
1
1
53
Trucks
0
1
0
0
2
0
1
0
0
1
0
1
6
Cars
0
3
12
1
9
2
3
0
3
0
1
0
34
Trucks
1
0
0
0
1
0
1
0
0
1
0
0
4
In suburban Chicago, Elk Grove Village agreed to participate in the program.
The fleet is composed of vehicles used in the full range of municipal activities, including
fire and police protection, and parks and sewer maintenance.
Two motorcycles belonging to Elk Grove Village also used Phase II RFC during
the test program. The motorcycles are not included in the table or in the results
because of their small number and because there were no control motorcycles. No
performance problems were reported with the two motorcycles using Phase II RFC. For
further information on motorcycle performance with Phase II RFC, see section VI for a
description of the motorcycle testing program conducted by Harley-Davidson.
1 1
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Table 3 - Elk Grove Village Test Fleet
Test Fuel
Control Fuel
Year
97
96
95
94
93
92
91
90
89
88
87
86
83
82
81
79
73
Total
4
14
11
13
14
14
8
3
1
8
1
2
1
1
1
1
1
98
Cars
0
13
10
11
13
13
7
3
1
3
1
0
0
0
0
0
0
75
Trucks
4
1
1
2
1
1
1
0
0
5
0
2
1
1
1
1
1
23
Cars
0
6
5
6
6
7
3
2
0
2
0
0
0
0
0
0
0
37
Trucks
2
1
0
1
0
0
1
0
0
3
0
1
1
0
1
0
1
12
Cars
0
7
5
5
7
6
4
1
1
1
1
0
0
0
0
0
0
38
Trucks
2
0
1
1
1
1
0
0
0
2
0
1
0
1
0
1
0
11
In Houston, the Lighting & Power Company agreed to participate in the test
program. Unlike the Boston and Chicago fleets, most of the vehicles in the Houston
fleet are trucks.
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Table 4 - Houston Lighting & Power Test Fleet
Test Fuel
Control Fuel
Year
97
96
95
94
93
92
91
Total
53
12
59
15
10
0
30
179
Cars
15
5
1
0
1
0
23
45
Trucks
38
7
58
15
9
0
7
134
Cars
11
3
1
0
0
0
12
27
Trucks
21
6
30
4
4
0
2
67
Cars
4
2
0
0
1
0
11
18
Trucks
17
1
28
11
5
0
5
67
The fleets involved in the testing program were composed primarily of General
Motors and Ford cars and trucks, with model years ranging from 1973 to 1999. Trucks
include sport utility vehicles, vans, pickups, and step vans. The practicalities of finding
fleets of an appropriate size, in the geographic locations desired, at the time needed,
necessarily limited potential options in terms of representing all automobile
manufacturers. The vehicle technologies tested are generally representative of vehicle
technologies employed over the same time period.
D.
Vehicle Performance
For the purposes of this fleet testing program, the term "incident" means that a
fuel system component was adjusted, repaired, or replaced other than through regular
scheduled maintenance. There were six incidents during the course of the testing
program involving vehicles using Phase II RFC test fuel.
Boston
During the test program, one fuel pump from a 1988 truck in the Boston Police
fleet using Phase II RFC was sent to the vehicle manufacturer for analysis. The pump
symptom was a leak at the pump outlet port. The manufacturer determined that the
pump's performance was still within specifications. The manufacturer's examination
indicated that the cause of the leak was mechanical and not fuel related. It was most
likely to have resulted from damage to the fitting that screws into the pump outlet port.
The manufacturer's analysis is included in Appendix J. The incident occurred during
the use of summer test fuel oxygenated with MTBE and TAME.
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Elk Grove Village
Four incidents were reported on vehicles using Phase II RFC test fuel during the
course of testing in suburban Chicago's Elk Grove Village. All four incidents occurred
with the winter test fuel oxygenated with ethanol.
In three cases, electric fuel pumps failed on police vehicles that ranged in age
from 1992 to 1996 with between 56,000 and 85,000 miles. Fuel pumps from the 1995
and 1996 vehicles were sent to the vehicle manufacturer for analysis. The
manufacturer determined that the two pumps failed because of severe corrosion of the
positive brush shunt wire. According to the manufacturer, the corrosion is typical of
previously observed field results during long-term exposure to gasoline containing
reactive sulfur compounds that did not meet ASTM specifications. The manufacturer
concluded that a high level of corrosion probably was present in both pumps at the start
of the testing program, and the failures were unrelated to the use of Phase II RFC. The
analysis submitted by the manufacturer is included as Appendix K. The third electric
fuel pump, from the 1992 vehicle, was inadvertently disposed of by a fleet mechanic
before it could be shipped to the manufacturer for analysis. While it seems likely that
the third fuel pump suffered from the same corrosion as the other two, there is
insufficient information to determine the cause of the failure.
In response to the findings in the manufacturer's analysis, samples of the winter
test and control fuels were analyzed to assess relative corrosivity. Some sulfur
compounds that remain in gasoline after refining can have a corroding action on
various metals. Copper strip corrosion tests were performed and the results showed
both fuels to be non-corrosive. The results of the corrosivity tests support the
manufacturer's view that the electric pump failures were unrelated to the use of Phase II
RFC.
The fourth fuel pump from the Elk Grove Village fleet was removed from a 1981
step van with 66,000 miles. The manufacturer's analysis indicates that the mechanical
pump is an after market part of unknown manufacture and showed no obvious signs of
failure except an oil leak and extruded seal. The oil leak was not caused by fuel
composition, but the extruded seal could be the result of excessive swell caused by
oxygenates or a high aromatic content or a combination, or by an assembly problem.
The manufacturer speculated that if the seal extruded because of excessive swell, that
could have happened in the short duration of the test program; however, the
manufacturer concluded it is more likely that the pump failure was unrelated to Phase II
RFC use.
According to the Elk Grove Village fleet manager, the number of fuel pump
failures during the test program is normal for the fleet's size; in his experience, fuel
pump replacement is expected on vehicles that have accumulated more than 60,000
miles. The fleet manager's comments are included in Appendix L.
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Houston
One fuel pump using test fuel in Houston failed during the course of the test
program. That pump and three pumps from fleet vehicles not participating in the test
program were sent to the manufacturer for analysis. All four pumps were from 1993
pickups with mileage ranging from 72,771 to 86,589. Heavy commutator wear coupled
with normal brush wear led the manufacturer to believe that all four pumps failed due to
operation on peroxidized fuel, also known as sour fuel. Since the failure occurred with
both the test and control fuels, the manufacturer theorized that the failures are more
likely related to the fuel dispensing system or to vehicle usage and operating factors
rather than the composition of either fuel. The manufacturer's analysis is included in
Appendix K.
The three pickups using Phase I RFC control fuel that had pump failures,
described above, were not assigned to the control fleet. However, fleet personnel
alerted EPA to the incidents. Although not assigned to the control fleet, the three
pickups were using the same fuel as the control fleet. The incidents are reported here
due to their close occurrence in time and similarity to the single test fleet fuel pump
failure.
Fuel samples from both the test and control fuel dispensers in Houston were
analyzed to determine their levels of peroxide, gum, and acidity, properties related to
storage and handling degradation. Both fuel analyses indicated the fuel properties
were within acceptable ranges. These analyses suggest that individual vehicle usage
and operating factors are more likely related to the incidents than the fuel dispensing
system, since peroxidation occurred in individual fuel tanks, not in the fleet's fuel
dispensing system. The summer testing in Houston included an extended period of
extremely hot weather, a condition conducive to oxidation of gasoline in individual
vehicle fuel tanks.
Summary
There were six incidents during the course of the testing program in vehicles
using test fuel. Five of the six incidents were deemed unrelated to the use of Phase II
RFC by the relevant automobile manufacturer. In the sixth incident, the part in question
was lost and the cause of its failure could not be determined.
No problems with starting, running, idling, acceleration, or power were reported
by any fleet. One fleet manager described his fleet's use of Phase II RFC as
transparent; fleet users and the mechanical staff saw no change or effect (see Appendix
L).
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IV. Fuel Economy
Another aspect of the testing program recommended by the workgroup involves
measuring fuel economy with Phase II RFC compared to Phase I RFC. Two data sets
are presented here.
A. Southwest Research Institute Study
EPA hired Southwest Research Institute (SWRI) to conduct a fuel economy study
comparing Phase II RFC with Phase I RFC. Fuel economy was measured for 12
vehicles of various makes, ages, mileage, and fuel delivery systems. The vehicles were
driven over fixed 50 mile urban and suburban routes. Fuel usage was determined by
using a flow meter to precisely measure the total volume of fuel consumed during the 50
mile route. The Phase II RFC summer fuel oxygenated with MTBE was used. The
results of this study do not indicate any statistically significant fuel economy difference
between the fuels.
The fleet average fuel economy was 21.71 miles per gallon with Phase I RFC
and 21.36 miles per gallon with Phase II RFC. The difference in fleet fuel economies
was 0.343. Statistical tests indicate that the small difference in fleet fuel economies
cannot be attributed to the fuel, and that the difference would have to be almost twice as
large to be significant. The difference in fleet fuel economies may be due to variability
in the test method. Sources of such test-to-test variability that could not be entirely
controlled in the study include differences in driver inputs, traffic patterns, and weather
effects.
The outcome of the SWRI study is consistent with other fuel economy studies,
and with EPA's analysis of test fleet fuel economy (discussed below). Fuel economy is
generally proportional to the energy content of the fuel. During the past few years,
studies of the fuel economy effects of reformulated gasolines with oxygenates, including
laboratory and on-road studies, have shown that the addition of two percent oxygen, by
weight, to gasoline results in a one to three percent fuel economy loss. In this study,
both gasolines have essentially the same oxygen content and the same energy content.
Since the energy content difference between Phase I RFC and Phase II RFC is
expected to be minimal, the absence of an impact on the fuel economy measured in this
study was expected.
The SWRI study was designed to minimize the effects of the fuel economy
variables that are normally present in driving. The key variables include differences in
personal driving habits, weather (temperature, wind effects, and precipitation), traffic
patterns (rush hour versus weekend, highway versus city driving), number of
passengers, vehicle condition, and changes in tire pressure. The relative effect of many
of these variables can be expected to exceed any reduction due to the use of RFC. The
SWRI report is included as Appendix M. The report was reviewed by the technical
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steering committee and presented to the workgroup.
B. Fleet Average Fuel Economy
Data on fleet average fuel economy for this analysis is limited. The Boston fleet
provided no data on fuel economy because the records of fuel usage were not
sufficient. Data from the Houston fleet contained gaps and inconsistencies that
prevented useful analysis. The Elk Grove Village fleet maintained sufficient fueling
records to determine fuel economy for a portion of the fleet, and is included here.
Data obtained from the Elk Grove Village fleet for the test period in 1997 and
1998 indicate that there is no meaningful difference in fuel economy between Phase I
RFC and Phase II RFC. For the Elk Grove Village fleet, vehicles using Phase I RFC as
control fuel were different than those using Phase II RFC as test fuel, unlike the study
performed by SWRI. Also, the routes and driving styles of each individual vehicle
differed within each fuel group. Nevertheless, the makes and types of vehicles were
essentially the same between each fuel group. The test fleet included seven Caprices
and one E250. The control fleet included 12 Caprices, one Mustang, and one Tempo.
For the test period, March through July in 1998, the composite averages in miles
per gallon (i.e., total fleet miles driven divided by total fleet gallons used) for the test and
control fleets were 9.59 and 9.47 respectively, representing a 1.2 percent difference
between the two fuels. The value of 1.2 percent does not represent a meaningful
difference in miles per gallon between the two fuels, given the other measures of
variability between the two data sets, noted above.
By comparison, during March through July in 1997, when both fleets were using
Phase I RFC, the composite averages in miles per gallon for the test and control fleets
were 9.48 and 9.47 respectively, representing a 0.1 percent difference between the two
fuels. The 95 percent confidence interval for the 1997 control fleet was 9.32 to 11.29
miles per gallon. The mean miles per gallon for the individual vehicles in the test fuel
fleet (as opposed to a composite average) was 9.33 miles per gallon, which lies within
the confidence interval for the control fleet.
V. Nonroad Test Program
In addition to vehicle testing, the workgroup recommended a testing program to
evaluate the performance of Phase II RFC with nonroad engines. The test fuel used for
nonroad engine testing was the same as the test fuel used with vehicle fleets. The
nonroad test program included 177 pieces of gasoline-powered equipment that
encompassed 11 types of utility, lawn, and garden equipment, and included both two-
cycle and four-cycle engine designs. In addition, two-cycle and four-cycle marine
engines were tested by Mercury Marine at six sites.
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A. Utility, Lawn, and Garden Equipment
The Arlington County, Virginia Department of Parks and Natural Resources
provided the equipment and resources to evaluate utility, lawn, and garden equipment.
Their equipment fleet consisted of 177 units ranging from three horsepower handheld
trimmers to 17 horsepower tractors, with both two-cycle and four-cycle engine designs.
The engines listed in the following table were used for in use testing of Phase II
RFC. Most of the engines are used in brush cutters, mowers, gas-powered hedge
trimmers, chainsaws, backpack leaf blowers, generators, rototillers, edgers, vacuum
blowers, and pruners, and had horsepower ratings between three and eight. Four units
are small tractors with horsepower ratings between 12 and 17. Eighteen of the 177
units meet EPA's emission regulations for small handheld engines (40 CFR 90); all 18
units were manufactured by Stihl.
Table 5 - Arlington County Nonroad Engines
Number of Units
60
35
30
25
15
4
4
4*
Engine Make
Stihl
Kawasaki
Briggs and Stratton
Tecumseh
Honda
Tanaka
Yamaha
Kohler
Engine Type
two-cycle
two-cycle
four-cycle
four-cycle
four-cycle
two-cycle
two-cycle
four-cycle
* Tractors
The test fuel for this equipment was the summer fuel oxygenated with MTBE. The
fuel was delivered on August 28, 1998 to a storage tank at the County water treatment
plant. To aid equipment refueling, a pickup truck was used as a mobile fueling station.
A 100 gallon fuel tank in the back of the truck was used to fuel two-cycle engines, and
six five-gallon cans were used to fuel four-cycle engines. The truck tank and cans were
refilled at the main storage tank as necessary. Each refill of the 100 gallon tank
included the addition of two-cycle engine oil at a gasoline/oil ratio of 40 to one. During
the test period, Quaker State Itasca two-cycle engine oil was used.
The performance testing consisted of fueling the engines with Phase II RFC and
operating them normally. The fuel was replenished as needed. Any performance
problems encountered were to be reported. The testing period began on September 1
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and continued until the test fuel was expended during the third week in November. The
amount of use for each piece of equipment was not recorded. The primary activities
during the testing period consisted of lawn maintenance, leaf removal, and ball field
maintenance.
During the testing period, 185 gallons of Phase II RFC were consumed.
Assuming a maximum fuel consumption rate of about one-half gallon per hour, testing
consisted of more than 370 hours of operation.
No performance-related incidents occurred during the test period. The
equipment supervisor reported that there were no perceptible changes in engine
performance and no indications of leaks.
B. Marine Engines
Approximately 3,800 gallons of summer fuel oxygenated with MTBE were
provided to four Mercury Marine testing facilities in Wisconsin, Florida, and Oklahoma,
and two materials testing locations in Illinois and North Carolina. The engines tested
ranged from small two-cycle, 25 horsepower outboard engines to large four-cycle, 500
horsepower inboard and stern drive engines.
Small two-cycle outboard engines were tested for startability and running quality,
with storage at cool temperatures. Cool temperatures were those lower than are typical
for summer fuel. The field testing in November 1998 in Wisconsin with summer fuel
captured the temperature conditions that are characterized as the fall shoulder season.
Testing consisted of start-up, warm-up, idle quality, and running quality phases. The
engines were mounted on a dock for the four-phase test and then moved to an outdoor
storage rack for 40 hours to stabilize at ambient conditions, in a temperature range of 35
to 55 degrees. The engines were then returned to the dock and startability testing was
conducted. No performance problems with Phase II RFC were reported.
In addition to field testing, engine dynamometer testing was conducted with two-
cycle outboard engines. A dynamometer is a device that simulates the resistance the
engine would experience under normal operating conditions. The dynamometer tests
measured the maximum power produced using the summer test fuel and a baseline fuel
known as indolene. No noticeable difference in operating performance was found.
Large four-cycle engines were also tested using both test and baseline fuels.
The tests measured power output using an engine dynamometer and found no
significant difference between the fuels.
Testing of fuel system materials was done by Airtex and Magnetti Morelli.
Gaskets and other fuel system materials were tested. No detrimental effects were
reported.
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VI. Motorcycle Test Program
Over 1,700 gallons of summer fuel oxygenated with MTBE were provided to
Harley-Davidson for laboratory testing of six current model motorcycles, on-road
performance testing of six privately-owned motorcycles, and materials compatibility
testing. The Harley-Davidson motorcycles listed in the following table were used for
laboratory testing of Phase II RFC.
Table 6 - Harley-Davidson Motorcycles Tested in Laboratory
Number
2
2
2
Year
1997
1998
1998
Model
Sportster
FLT/HT
FLT/HT
Engine (cc)
1200
1450
1450
Fuel System
Carburetor
Carburetor
Fuel Injection
The laboratory testing consisted of performance tests on six motorcycles using
the test fuel and a baseline fuel known as indolene. Testing was conducted using a
chassis dynamometer, a device that allows the motorcycle to remain stationary while
the rear wheel turns a drum that provides resistance to simulate the resistance of the
motorcycle and rider on the highway. The rider operates the motorcycle as though it
were on the highway by shifting gears and adjusting the throttle to follow a graph on a
video screen. Acceleration, driveability, and startability were evaluated during these
tests. No significant difference in performance was observed between the baseline fuel
and Phase II RFC.
On-road testing was conducted by Harley-Davidson employees on their own
Harley-Davidson motorcycles. The Harley-Davidson motorcycles listed in the following
table were used for on-road testing of Phase II RFC.
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Table 7 - Harley-Davidson Motorcycles Tested On-road
Year
1998
1998
1998
1998
1998
1999
Model ID
FLHT
FLHTC
FLHTCUi
FLTR
FLTRI
FLTR
Model Name
Electra Glide
Electra Glide
Classic
Ultra Classic
Road Glide
Road Glide
Road Glide
Type
Touring
Touring
Touring
Touring
Touring
Touring
Engine (cc)
1450
1450
1450
1450
1450
1450
Starting
Odometer
675
12500
1300
9000
2000
150
Accumulated
Miles
1575
1200
500
2500
700
500
The test period with the summer test fuel was from mid-October until the end of
November in the Milwaukee, Wisconsin area, although summer fuel is not provided to
retail stations after September 15. The daily temperatures for the on-road testing period
are listed in Appendix N. Performance was evaluated using both the test fuel and a
commercially available fuel. No performance problems with Phase II RFC were
reported.
Materials compatibility tests were done on three sets of fuel system elastomer
components. An independent laboratory tested the components by soaking them in
both the test fuel and a baseline gasoline and then measuring size changes. Paint
finish and decal compatibility tests were also performed using the test fuel and a
baseline fuel. Finished fuel tanks were placed in an outdoor rack and each fuel was
periodically spilled over a tank during a period of three weeks to determine the effect.
No detrimental effects were identified.
VII. Conclusion
All available data indicate that consumers should experience no difference in
performance or fuel economy when Phase II RFC replaces Phase I RFC.
EPA tested in use vehicles in three cities over a period of three to five months.
The combined test fleet drove over one million miles with Phase II RFC. Out of a
combined fleet of 374 vehicles, six component-related incidents occurred during the
course of the testing program. Five of the six incidents were deemed unrelated to the
use of Phase II RFC by the relevant automobile manufacturer. In the sixth incident, the
part in question was lost and the cause of its failure could not be determined.
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No problems with starting, running, idling, acceleration, or power were reported by
any fleet. One fleet manager described his fleet's use of Phase II RFC as transparent;
fleet users and the mechanical staff saw no change or effect (see Appendix L).
Studies have shown that incident rates increase with vehicle mileage, irrespective
of the fuel used. Vehicle maintenance is the key to good performance with any fuel.
In a separate study, SWRI compared fuel economy with Phase II RFC to Phase I
RFC. Fuel economy was measured for 12 vehicles of various makes, ages, mileage, and
fuel delivery systems. The vehicles were driven over fixed 50 mile urban and suburban
routes. Fuel usage was determined by using a flow meter to precisely measure the total
volume of fuel consumed during the 50 mile route. The results of this study do not
indicate any statistically significant fuel economy difference between the fuels.
The outcome of the SWRI study is consistent with other fuel economy studies, and
with EPA's analysis of test fleet fuel economy. Fuel economy is generally proportional to
the energy content of the fuel. During the past few years, studies of the fuel economy
effects of reformulated gasolines with oxygenates, including laboratory and on-road
studies, have shown that the addition of two percent oxygen, by weight, to gasoline
results in a one to three percent fuel economy loss. In this study, both gasolines have
essentially the same oxygen content and the same energy content. Since the energy
content difference between Phase I RFC and Phase II RFC is expected to be minimal, the
absence of an impact on the fuel economy measured in this study was expected.
The Arlington County, Virginia Department of Parks and Natural Resources
provided the equipment and resources to evaluate utility, lawn, and garden equipment.
Their equipment fleet consisted of 177 units ranging from three-horsepower handheld
trimmers to 17-horsepower tractors with both two-cycle and four-cycle engine designs.
Testing began September 1 and concluded the third week in November. During the
testing period, 185 gallons of Phase II RFC were consumed. Assuming a maximum fuel
consumption rate of about one-half gallon per hour, testing consisted of more than 370
hours of operation. No performance-related incidents occurred during the test period.
The equipment supervisor reported that there were no perceptible changes in engine
performance and no indications of leaks.
Performance and materials testing was conducted with motorcycles by Harley-
Davidson and with marine engines by Mercury Marine. In both cases, outdoor testing in
Wisconsin occurred in the autumn with summer test fuel, capturing shoulder season
effects. The results indicate no performance problems with Phase II RFC.
In summary, no difference in vehicle performance or fuel economy is expected
when Phase II RFC replaces Phase I RFC. In addition, no difference in performance is
expected with small engines, marine engines, or motorcycles.
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