Models \48\ incorporated into the Agency's MOVES model,\49\ that have
been thoroughly peer reviewed. The result is that for a typical E10
blend of gasoline, exhaust NMHC emissions have been found to decrease
by about 5%, and NOX emissions to increase by about 6%,
relative to E0.\50\
---------------------------------------------------------------------------

    \48\ A detailed description of the development of the EPA
Predictive Models is available in a Technical Support Document:
``Analysis of California's Request for Waiver of the Reformulated
Gasoline Oxygen Content Requirement for California Covered Areas'',
EPA420-R-01-016, June 2001.
    \49\ The Agency's MOVES model has undergone extensive peer
review and testing, and incorporates the EPA Predictive Models.
    \50\ These effects are based on the EPA Predictive Models and
are generally consistent with conclusions of CRC E-74b report (e.g.,
Figure ES-2). Fuels properties evaluated were based on market
averages and were as follows: E0 had aromatics content of 29.5 vol%,
a T50 of 215 [deg]F, a T90 of 325 [deg]F, and an RVP of 8.9 psi and
E10 had aromatics content of 24.9 vol%, a T50 of 202 [deg]F, T90 of
325 [deg]F, and an RVP of 8.9 psi. Other parameters not mentioned
here were assumed to be held constant between the blends.
---------------------------------------------------------------------------

    While the magnitude of impact may vary by a few percent depending
on the motor vehicle technology and how other fuel properties change
when ethanol is blended into gasoline, the relative magnitude and
direction of the impacts remains consistent for typical fuels.\51\
---------------------------------------------------------------------------

    \51\ Results based on data mostly from vehicle models that
predated the Tier 2 emission standards, so several recent test
programs have been focused on Tier 2 vehicles that will soon make up
the majority of the in-use fleet.
---------------------------------------------------------------------------

    While there is a great deal known about the immediate impacts of
gasoline-ethanol blends on emissions from the past studies and
modeling, it is all based on pre-Tier 2 motor vehicles and only ethanol
blends up to E10. The issue for the waiver is whether the impacts of
E15 would be significantly different in comparison to E0 and cause
motor vehicles to violate their emission standards over their full
useful life, and whether there is sufficient information to support
such a conclusion for Tier 2 motor vehicles as well as other motor
vehicles. While the information provided by Growth Energy was of
limited value, we believe that the additional information that is now
available can be used to assess the immediate emissions impacts on Tier
2 motor vehicles sufficiently to respond to the E15 waiver request.
    CRC recently completed a test program (E-74b) that evaluated the
emissions performance of E10 and E20 compared with E0 (``CRC Emissions
Study'').\52\ The study tested 15 MY1994-2006 motor vehicles on E0,
E10, and E20. The motor vehicles represented a cross-section of several
motor vehicle technologies and emissions compliance levels, and
included three Tier 1, five NLEV, and seven Tier 2 motor vehicles. The
test fuels were match-blended to yield appropriate test program
volatility

goals while attempting to maintain other desired property targets, such
as aromatics content and distillation behavior. The study's authors
attempted to evaluate increased oxygen levels through the blending of
ethanol in a variety of gasolines with fuel parameters representative
of those found in the real world. Emissions performance testing was
completed using the FTP at 75 [deg]F and 50 [deg]F. The study found a
statistically significant positive linear relationship between the
amount of ethanol blended into gasoline and NOX emissions
when controlling other fuel parameters. In other words, as the level of
ethanol blended into gasoline increased, the amount of NOX
emissions also increased, and this effect remained relatively
consistent across the motor vehicle technologies tested. Specifically,
the study found that NOX emissions increased with E10 by
about 9% relative to E0, consistent with the projection from the EPA
Predictive Models when the study's fuel properties are input.
NOX emissions for E20 increased by about 19% relative to E0.
The test program also found that HC emissions declined from 8% to 16%
over this same range. While not linear, a relationship of decreasing
emissions with increasing ethanol content was also observed for CO
emissions. Presumably the impacts of E15, had they tested it, would
have fallen somewhere between those of E10 and E20.
---------------------------------------------------------------------------

    \52\ CRC Report No. E-74b, ``Effects of Vapor Pressure, Oxygen
Content, and Temperature on CO Exhaust Emissions'', May 2009, EPA
Docket EPA-HQ-OAR-2009-0211-13980.
---------------------------------------------------------------------------

    The DOE Pilot Study cited by Growth Energy tested 16 different
MY1999-2007 light-duty motor vehicles on E0, E10, E15 and E20. These
motor vehicles included three Tier 1, six NLEV, and seven Tier 2 motor
vehicles of varying odometer mileage, generally proportional to age
(i.e., older motor vehicles had higher miles). Test fuels were splash
blended with the certification E0 fuel allowing the other fuel
properties (aromatic content, RVP, etc.) to change with ethanol
dilution. The motor vehicles were tested over the LA92 drive cycle
(also known as the Unified Cycle) which is considered to be
representative of real-world acceleration rates and speeds.\53\ The
study found small reductions in NOX and NMOG emissions
across the different fuels that were not statistically significant.
While these findings do not show the NOX emissions increase
and NMOG and CO emissions decrease that might be anticipated, this may
have been due to the limited scope of the program, the test cycle, and
other changes in the fuel properties known to directly impact
emissions. Nonetheless, the results do not show that the immediate
NOX emissions impacts of E15 to be of concern.
---------------------------------------------------------------------------

    \53\ The Alliance commented that only the FTP test cycle should
be used for emission impacts. While the LA92 cannot be used for
confirmation of vehicle emissions compliance, it is used regularly
in engineering and research work, including by manufacturers to
measure emission impacts and confirm OBD monitor operation and
therefore the Agency believes it remains a valid cycle for emissions
analysis.
---------------------------------------------------------------------------

    During the course of the DOE Catalyst Study (see Section IV.A.1.d),
some back-to-back tests of E15 and E0 fuels were performed. This
portion of the testing was not designed to be able to quantify the
immediate emission impacts with any degree of statistical confidence
unless the impacts turned out to be very large, and in fact it did not
show any statistically significant changes in NOX or NMOG
emissions for E15 compared to E0. At the same time, the data is useful
in supporting the conclusion that the immediate emission impacts of E15
compared to E0 are not large, and likely in the same range as other
studies have shown.
    Finally, as mentioned above, RIT performed additional testing
subsequent to the results Growth Energy submitted as part of its waiver
request application. These later results were presented at a meeting of
the Mid-Level Ethanol Blends Research Coordination Group on May 5,
2010.\54\ These results showed a 13.9% reduction in HC (NMOG was not
measured), 26.9% reduction in CO, and a 6.2% increase in NOX
for E20 in comparison to E0. Again, presuming E10 and E15 results would
lie within this range, these results are generally consistent with
earlier studies and models and continue to confirm that no large
increases in NOX emissions are expected.
---------------------------------------------------------------------------

    \54\ RIT-CIMS/USDOT E20 Test and Evaluation Program May 2010,
EPA Docket EPA-HQ-OAR-2009-0211-14003.8.
---------------------------------------------------------------------------

    When EPA assesses the more recent information and data available,
we believe it shows both: (1) That Tier 2 motor vehicles exhibit
similar immediate emission impact trends (small increases in
NOX and small decreases in NMHC and CO) as the data and
modeling show for older motor vehicles; and (2) that the immediate
emission impacts of E15 continue to show the same trends as E10 with
the effects being slightly exaggerated due to the higher ethanol
content. These four studies (CRC E74b, the DOE Pilot Study, the DOE
Catalyst Study, and the RIT Study) are all of limited size and scope
and thus show considerable variation in their results, for
NOX emissions in particular. However, taken together they
suggest that the immediate emission impacts of E10 are likely to be
comparable to those that would be projected using the EPA Predictive
Models and that a slightly larger NOX emission impact would
be expected with E15. Thus, the NOX emissions impact of E15
is likely to be in the range of 5% to 10% based on extrapolation from
E10 modeling using the Agency's Predictive Models, and this impact
would be expected to be roughly comparable for newer Tier 2 motor
vehicles as well as older motor vehicles. For example, a Tier 2 motor
vehicle that had NOX emissions levels of 0.030 grams per
mile (``g/mi'') on E0 would be expected to have NOX
emissions levels of 0.033 or less if the same motor vehicle was tested
on E15.
    Although the overall weight of the available data shows that E15
will cause an increase in NOX emissions, the issue is
whether such increases, by themselves or in combination with long-term
durability effects, would cause motor vehicles to exceed their
certified emissions standards. Given the relatively small magnitude of
the immediate NOX emissions increase in relation to the
large compliance margins that motor vehicle manufacturers have
traditionally built-in to the products they certify,\55\ and the lack
of any significant increase in NOX emissions deterioration
with E15 in comparison to E0 (as discussed in section IV.A.1.a.), it is
not anticipated that using E15 will cause or contribute to Tier 2
compliant motor vehicles exceeding their emissions standards.
---------------------------------------------------------------------------

    \55\ A compliance margin is the difference between the emission
standard and a vehicle or engine's actual certification emission
level. This certification level includes the manufacturer's
projected rate of deterioration over the useful life of the vehicle.
---------------------------------------------------------------------------

    A survey of official EPA Certification data showed that the average
compliance margins for the MY2007 light-duty motor vehicle fleet was
over 50% for NOX emissions.\56\ This margin is designed into
motor vehicles by the manufacturer to account for variations in
production vehicles and changes to the motor vehicle during actual
field usage. Additionally, data collected from EPA's In-use
Verification Program (IUVP) demonstrate large compliance margins for
motor vehicles operating in real-world conditions. IUVP is a
manufacturer run program in which manufacturers test motor vehicles for
emissions levels and submit the results to EPA. IUVP was designed to
ensure that light-duty motor vehicles are meeting emissions standards
in-use

versus only through the certification process. According to the data
submitted to EPA, the in-use compliance margins are similar to
compliance margins experienced during certification. For IUVP testing
for MY2007 as of August 2010, the average compliance margin for light-
duty motor vehicles certified to the Tier 2 Bin 5 standard was over
60%.\57\
---------------------------------------------------------------------------

    \56\ See 2007 Progress Report: Vehicle and Engine Compliance
Activities. These compliance margin values are consistent with the
general trend EPA has seen for Tier 2 vehicles.
    \57\ Tier 2 Bin 5 is the certification standard for a large
majority of vehicles certified in MY2007 (approximately 80%). See
2007 Progress Report: Vehicles and Engine Compliance Activities.
---------------------------------------------------------------------------

    In addition, the results of the recently completed DOE Catalyst
Study also supports this conclusion for Tier 2 motor vehicles. While
the Catalyst Durability Test Program was carried out to assess long-
term exhaust emissions (durability) impacts, the immediate emission
impacts of ethanol are also captured in the testing. All but two of the
Tier 2 motor vehicles tested continued to comply with their exhaust
emission standards at FUL despite both the immediate and durability
impacts of E15 on emissions. One motor vehicle appeared to exceed the
standard not due to E15, but other problems, as it also exceeded the
standard on E0. The other motor vehicle model experienced catastrophic
issues with the comparable E0 and E20 motor vehicles which were unable
to complete the testing. Those motor vehicles that complied with the
standard on E15 continued to comply as is typical in IUVP data.\58\
---------------------------------------------------------------------------

    \58\ EPA, in collaboration with DOE and CRC has recently
completed the testing part of the largest fuels emission research
program conducted in the past two decades to assess the impacts of
gasoline fuel properties on emissions, including the relationship
between ethanol content and higher NOX emissions. E-89
``Comprehensive Gasoline Light-duty Exhaust Fuel Effects Test
Program.'' The test program evaluated emission changes on a motor
vehicle test fleet consisting of 15 Tier 2 vehicles (including three
FFVs) that was specifically selected to be representative of the
makes and models in the national light-duty motor vehicle fleet. The
focus was on Tier 2 vehicles to fill a data gap, since existing
emission models are based on testing conducted on older technology
vehicles. The program used 27 fuels of varying volatility (RVP),
aromatic content, distillation range (T50 and T90) and ethanol
concentrations (E0, E10, E15 and E20), which were blended specially
to allow emission impacts to be attributed to one fuel parameter or
another. Each vehicle in the test program had multiple emissions
tests conducted on each fuel resulting in nearly 1000 emissions
tests. While testing has been completed, the Agency is still in the
process of working with DOE and CRC to evaluate the test data and
develop emission models based on it to allow an understanding of the
impacts of fuel changes on emissions. However, since the evaluations
of the data have not been completed and the data is not publicly
available, EPA is not relying on the data for purposes of evaluating
the waiver request. EPA has reviewed the data preliminarily solely
to determine whether it would be appropriate to delay making a
decision until the evaluation is complete and the test program
results could be incorporated into a decision on the waiver. EPA's
view based on its preliminary review of the data is that it is
appropriate to go forward at this time with the waiver decision, as
it is anticipated that the test program will reinforce the results
found in the earlier studies and in the EPA Predictive Models.
---------------------------------------------------------------------------

d. Conclusion
    While data is limited on Tier 2 motor vehicles, and particularly
with E15, there is a long history of test programs that have been
carried out on light-duty motor vehicles and trucks that have
quantified the immediate emissions impacts of blending ethanol into
gasoline. The common theme across these various test programs is that,
consistent with combustion theory, the enleanment of the A/F ratio
caused by the oxygen in ethanol leads to an immediate reduction in HC
and CO emissions and a corresponding increase in NOX
emissions. While other factors influence this, such as the combustion
characteristics of the ethanol itself, other changes that occur in the
gasoline when ethanol is added, and the test conditions under which the
emissions are measured, cause some variations in study results, the
bottom line is that the emissions changes are fairly well known.
Several more recent studies have been performed looking at the impacts
of gasoline-ethanol blends on more recent Tier 2 compliant motor
vehicles, as well as some older model year motor vehicles. The size,
scope, and design of these studies limit the ability to draw any firm
conclusion to quantify the precise magnitude of the immediate emissions
impacts. However, analysis of this more recent data in the context of
historical data and modeling leads to the conclusion that Tier 2 motor
vehicles likely respond similarly to older technology motor vehicles
with respect to immediate emissions impacts, and that the magnitude of
the immediate emissions impacts of E15 are relatively small, with
decreases in NMHC and CO emissions and increases in NOX
emissions in the range of 5 to 10% depending on how other fuel
properties change. For Tier 2 motor vehicles, there is generally a
significant margin in both motor vehicle certification and in-use to
emit within the emission standards even if the motor vehicle
experiences the predicted immediate NOX increases from E15
when compared to E0.
    The Agency believes that the data above, coupled with the average
compliance margins, are sufficient to show that the immediate exhaust
emissions effects by themselves would not cause motor vehicles to
exceed their exhaust standards over their useful lives. As discussed
earlier, however, whether the fuel or fuel additive will cause motor
vehicles to exceed their exhaust emission standards requires
consideration of the combined impact of immediate emissions increases
and the long-term exhaust emissions (durability) effects.\59\
---------------------------------------------------------------------------

    \59\ Separately, the Agency has been performing analysis needed
to support the anti-backsliding analysis required under the Energy
Independence and Security Act. We are now in the process of
assessing possible control measures to offset the potential
increases in ozone and particulate matter that are expected to
result from the increased use of renewable fuels required by EISA
and in response to the May 21, 2010 presidential memorandum
directive. (NOX emissions contribute to the formation of
both pollutants.) We will incorporate the results of our analysis
under this assessment in a proposal on new motor vehicle and fuel
control measures.
---------------------------------------------------------------------------

3. Evaporative Emissions on MY2007 and Newer Light-Duty Motor Vehicles
a. Introduction
    EPA has set evaporative emission standards for motor vehicles since
1971. During the ensuing years, these evaporative standards have
continued to evolve, resulting in additional evaporative emissions
reductions. Thus, consideration of the impact of E15 on evaporative
emissions compliance requires consideration of the applicable
evaporative emissions standards to which the particular motor vehicles
were certified. There are now five main components to motor vehicle
evaporative emissions that are important for our standards: (1) Diurnal
(evaporative emissions that come off the fuel system as a motor vehicle
heats up during the course of the day); (2) hot soak (evaporative
emissions that come off a hot motor vehicle as it cools down after the
engine is shut off); (3) running loss (evaporative emissions that come
off the fuel system during motor vehicle operation); (4) permeation
(evaporative emissions that come through the walls of elastomers in the
fuel system and are measured as part of the diurnal test); and (5)
unintended leaks due to deterioration/damage that is now largely
monitored through onboard diagnostic standards.
    Prior to MY1999, the evaporative emissions standards addressed
diurnal and hot soak emissions, but the test procedure did not require
control of running loss and permeation emissions. The Enhanced
Evaporative Emissions requirements were fully phased in for Light-duty
motor vehicles and light-duty trucks by MY1999. These new requirements
included both new standards and new test procedures: The two-day and
three-day diurnal tests with new canister loading procedures, and a
running loss test. In addition to the new procedures, the useful life
was

extended from 5 years/50,000 miles to 10 years/100,000 miles for light-
duty motor vehicles.
    Along with the Enhanced Evaporative Emissions requirements, EPA
introduced the On Board Diagnostic (OBD) requirements for evaporative
leak detection monitors. This required motor vehicles to detect a leak
equivalent to .040 inch in the fuel or evaporative emissions system.
Beginning in MY2001, EPA allowed manufacturers to comply with
California OBD regulations which required motor vehicles to detect a
leak equivalent to a .020 inch. While not required Federally, many
manufacturers developed one leak detection system for sale in all 50
States which complied with the more stringent California requirement.
    The Federal Tier 2 evaporative emissions standards \60\ were phased
in beginning in 2004 with the exhaust standards and were fully phased
in by 2007 for light-duty motor vehicles (2009 for HLDT and MDPV).
These standards were significantly lower (over a 50% reduction for LDVs
and LLDTs--as seen in Table 1 below) and used the same test procedures,
which were introduced with the Enhanced Evaporative Emissions
requirements. However, one important change was made in that a
demonstration of evaporative system durability on E10 was required to
address concerns with respect to permeation of hydrocarbons through
elastomers in the fuel and evaporative emission systems. This prompted
manufacturers to change materials to those with improved permeation
barriers with ethanol. Once again in 2009 the evaporative emission
standards for LDVs were cut nearly in half with the introduction of the
Federal LEV II requirements, a harmonization of Federal and California
evaporative standards. See Table IV.A-4 below. This section discusses
the evaporative emissions impacts on MY2007 and newer light-duty motor
vehicles. Discussion of evaporative emission impacts on older motor
vehicles is addressed in sections IV.B. and IV.C. However, since the
information we received through Growth Energy's waiver request
application, information supplied by commenters, and other available
information regarding evaporative emission impacts of ethanol blends
were not specific to the model year of the motor vehicles, this section
also contains some of the information covering older motor vehicles as
well.
---------------------------------------------------------------------------

    \60\ This Decision refers to several vehicle types as commonly
used acronyms: Light-duty motor vehicles (LDV), light-duty trucks
(LDT), light light-duty trucks (LLDT), heavy light-duty trucks
(HLDT), and medium-duty passenger vehicles (MDPV). See ``Vehicle
Weight Classifications'' found at: http://www.epa.gov/otaq/
standards/weights.htm.
---------------------------------------------------------------------------

BILLING CODE 6560-50-P

[GRAPHIC] [TIFF OMITTED] TN04NO10.001

BILLING CODE 6560-50-C
b. Growth Energy's Submission
    Growth Energy primarily argued that based on the similar volatility
and permeation characteristics of E15 to E10, the evaporative emissions
for motor vehicles using E15 should be no

worse than those from motor vehicles using E10. Growth Energy pointed
to two studies to support this conclusion. The first study cited was
the E-65-3 study on permeation conducted by the CRC.\61\ The E-65-3
study measured the impact of E6, E10, E20, and E85 gasoline-ethanol
blends on permeation and diurnal canister breakthrough emissions in
comparison to E0 on test rigs taken from five MY2000-2005 California
motor vehicles. The testing was performed on California fuels using
California test procedures.
---------------------------------------------------------------------------

    \61\ CRC Report No. E-65-3, Fuel Permeation from Automotive
Systems: E0, E6, E10, E20 and E85 Final Report, December, 2006. EPA
Docket EPA-HQ-OAR-0211-14012.
---------------------------------------------------------------------------

    The second study cited was completed by the University of Stockholm
for the government of Sweden to investigate the potential effects that
increased ethanol levels blended into gasoline may have if approved for
use in Sweden (``Stockholm Study'').\62\ The Stockholm Study is
primarily a literature review that includes studies and experiences
with gasoline-ethanol blends in several countries (e.g., Brazil, the
Netherlands, and Australia). As part of the Stockholm Study, a small
test program compared vapor generation rates from two summer-time
gasoline fuels blended with ethanol at contents of zero, five, 10, and
15 vol%. The Stockholm Study found that the impact of ethanol on the
RVP of gasoline blends peaked somewhere between E5 and E10, consistent
with past studies.
---------------------------------------------------------------------------

    \62\ Growth Energy Request Letter--Tab 4, 1st half, EPA Docket
EPA-HQ-OAR-2009-0211-0002.12.
---------------------------------------------------------------------------

    Other than cross-referencing materials compatibility testing,
Growth Energy did not address the potential impacts of E15 on
evaporative emissions durability, hot soak and running loss emissions,
or fuel system integrity (leaks as monitored by the OBD system) to
assess noncompliance with the evaporative emissions standards. Growth
Energy simply used these two studies to argue that the evaporative
emissions of E15 will be lower or no worse than E10 or E6. They argued
that since the CRC Permeation Study and the Stockholm Study show no
increases in evaporative emissions between E10 and E15, that materials
compatibility testing showed no problem, and that if EPA can place a
condition requiring finished fuels to meet ASTM volatility
specifications, evaporative emissions criteria for a waiver are
satisfied.
c. Public Comment Summary
    Several commenters point to design flaws and limitations with both
the Stockholm Study and CRC Study which underscore the need for more
investigation into E15's impact on vehicles' evaporative emissions. API
and others argue that the fuels used in the Stockholm Study's
evaporative emissions test program do not resemble fuels produced and
used in the United States. API argues that RVP of the base fuels tested
in the program are relatively high in comparison to summertime non-
ethanol fuels used in the US (9.14 and 10.15 psi). API also argues that
since the test program did not complete the evaporative emissions
testing in the VT-SHED with actual vehicles and did not utilize the EPA
approved Federal Test Procedure, it would be difficult to determine
what the actual emissions results for E15 would have been under real
world conditions.
    Similarly, many commenters noted limitations and concerns with the
CRC E-65-3 permeation study cited by Growth Energy. The study did not
evaluate evaporative emissions from entire motor vehicles, but rather
from test rigs set up specifically to study permeation rates with
various gasoline-ethanol blends. While the study also measured diurnal
emissions by measuring breakthrough of the canister, it did so only
using very low RVP fuels that met California's reformulated gasoline
standards. Further, the test rigs were uniquely configured for precise
permeation measurement and not for a quantitative assessment of vapors
from canister breakthrough.
    Several commenters allude to the fact that Growth Energy provided
no analysis of how evaporative emissions control systems will behave
over the full useful lives of motor vehicles. The New York Department
of Environmental Conservation (``NYDEC'') expressed in particular their
concern that full useful life testing is needed since E15 could cause
increased water absorption which in turn may lead to decreased canister
capacity and evaporative emissions breakthrough of the canister.
    Several comments noted that Growth Energy often compares
performance results of E15 to E10 rather than E15 to certification fuel
(E0) to satisfy waiver criteria. AllSAFE and the Alliance both suggest
that EPA has a legal obligation to only consider comparisons of E15 to
certification fuel. AllSAFE argues that EPA has required that CAA
section 211(f)(4) waiver requests compare the test fuel with
certification fuel over the past 30 years, and that comparing E15 to
E10 would be making a comparison between two fuels that are not
``substantially similar'' to certification fuel. AllSAFE continues by
arguing that allowing comparisons to fuels that have been granted
waivers rather than a comparison to fuels that are substantially
similar to certification fuels may allow for ``incremental creep'' that
might mask emissions effects of new fuels or fuel additives.
d. EPA Analysis
    Growth Energy's conclusions with respect to evaporative emission
impacts are not adequately supported by the evidence they submitted.
They did not provide any test data of in-use motor vehicles showing
that they continued to meet their evaporative emission standards over
their full useful life, but rather provided only limited information to
address these concerns. The Stockholm Study they cited cannot be used
to assess actual motor vehicle emission performance in comparison to
their standards, but rather simply quantifies the potential increase in
vapor generation rates (fuel volatility) for various gasoline-ethanol
blends. Increased vapor generation may result in increased motor
vehicle emissions, but one needs to evaluate this in the context of
evaporative emissions control systems on actual motor vehicles.
    The CRC E-65-3 permeation study cited by Growth Energy did not
evaluate evaporative emissions from entire motor vehicles, but rather
from test rigs set up specifically to study permeation rates with
various gasoline-ethanol blends. This study measured diurnal using only
very low RVP fuels that met California's reformulated gasoline
standards. As a result, it cannot be used to assess the impact on
diurnal emissions of higher volatility fuels. However, perhaps the most
important limitation of this study is simply that it was a predecessor
to much more comprehensive studies not addressed by Growth Energy (E-
77, E-77-2, E-77-2b, E-77-2c) \63\ into the permeation and evaporative
emission impacts of various gasoline-ethanol blends that grew out of
the original E-65-3 study.
---------------------------------------------------------------------------

    \63\ These studies are available at http://www.crcao.org.
---------------------------------------------------------------------------

    In addition to these study limitations, perhaps the most important
concern is that Growth Energy failed to use the available information
to perform the correct comparison. To grant a waiver for a fuel or fuel
additive under CAA section 211(f)(4), it must be shown that motor
vehicles will continue to meet their evaporative emission standards
over their full useful life. Short of actual test data on motor
vehicles demonstrating this, the evaluation of the potential emissions
impacts must compare motor vehicles using the new fuel or fuel additive
to their emissions performance on the fuel they were

certified on, in this case E0. Instead, when considering the potential
permeation and diurnal emission impacts, Growth Energy only drew their
conclusion for E15 relative to E10 and E6, which themselves have been
demonstrated in the CRC studies to cause elevated permeation and
diurnal emissions.
    Growth Energy also failed to address potential long-term
evaporative emission durability concerns in any meaningful way,
referencing only the materials compatibility work discussed in section
IV.A.4.
    Despite the limitations of the Growth Energy petition with respect
to vehicle evaporative emissions, the Agency believes that sufficient
information is available through other studies to support the
conclusion that as long as E15 meets a summertime gasoline volatility
level of no higher than 9.0 psi, Tier 2 compliant motor vehicles--which
includes all MY2007 and newer gasoline-fueled light-duty motor vehicles
and trucks, and medium-duty passenger vehicles--are expected to
continue to comply with their evaporative emissions standards on E15.
    By virtue of testing of motor vehicles with gasoline-ethanol blends
for more than three decades, it is known that gasoline-ethanol blends
can have negative impacts on evaporative emissions when compared to E0
on which the motor vehicles are certified. Ethanol impacts diurnal
emissions primarily through its impact on the volatility of the
gasoline-ethanol blend, boosting the RVP of the final gasoline-ethanol
blend by approximately 1 psi unless the gasoline blendstock is produced
to offset the increase. Permeation emissions through elastomers in fuel
tanks, lines, valves, and connectors have been shown to be strongly
influenced by the presence of ethanol in the fuel, though the Tier 2
standards have minimized this impact for Tier 2 compliant motor
vehicles. Hot soak and running loss emissions will change in chemical
composition with gasoline-ethanol blends and could be impacted over the
long term by impacts of ethanol on motor vehicle component materials.
Ethanol is also known to cause degradation of certain materials that
have been used in motor vehicle gasoline and evaporative emission
control systems that could lead to increased evaporative emissions over
time. As a result of the changing emission standards and motor vehicle
designs over the years, these impacts of ethanol on evaporative
emissions will vary depending on the age of the motor vehicle. The
discussion which follows is focused on the impact on Tier 2 motor
vehicles.
    For hot soak and running loss emissions, E15 should not impact
compliance with the evaporative emissions standards (see Figures 1 and
2). Data from the CRC E-77 test programs suggest that there may be some
correlation between hot soak and running loss \64\ emissions and
ethanol content, but the impact is small, of questionable statistical
significance, and may be related to permeation that occurs during the
testing (see Figures IV.A-1 and 2).
---------------------------------------------------------------------------

    \64\ Running loss emissions measured in the E-77 programs did
not use the certification cycle. The study was focused on the worst
case for permeation emissions and therefore used back-to-back LA92
cycles to increase the tank temperature with more aggressive
driving. The certification cycle uses the NYCC which has many stops
and starts, making it more difficult to purge the canister. There
was no canister breakthrough measured during running loss tests in
the study, therefore the chart in Figure 2 shows the effects of
ethanol and RVP on running loss permeation.
[GRAPHIC] [TIFF OMITTED] TN04NO10.002

[GRAPHIC] [TIFF OMITTED] TN04NO10.003

    The CRC E-77 test programs also support the conclusion that diurnal
evaporative emissions with E15 are likely to be comparable to those
with E0 at the same RVP. Testing performed on E0, E10, and E20 shows
that diurnal emissions are a function of the volatility of the fuel,
not the ethanol content. As the volatility of the fuel was increased,
the number of motor vehicles which experienced canister emissions
breakthrough also increased, with seven of eight Tier 2 motor vehicles
experiencing canister breakthrough at 10.0 psi RVP. These elevated
diurnal emissions are not unexpected since the increased volatility of
10.0 psi versus 9.0 psi fuel results in roughly a 25% increase in
evaporative vapor generation that must be captured by the canister
beyond what has been required of manufacturers in motor vehicle
certification. Almost any canister breakthrough would be enough to
cause Tier 2 motor vehicles to exceed their evaporative emissions
standard. However, since these tests were done on a more severe diurnal
cycle of 65 [deg]F-105 [deg]F (California cycle), as opposed to the
Federal requirement of 72 [deg]F-96 [deg]F, these test results only
serve to highlight the concern that fuel with a higher volatility than
9.0 psi RVP during the summer will lead to motor vehicles exceeding
their evaporative emissions standard in-use, but do not demonstrate it.
At the same time, the Agency is also not aware of any data that would
show that E15 with an RVP greater than 9.0 psi would in fact allow
motor vehicles to continue to meet their evaporative emissions
standards. Given this lack of data and the significant potential for
increased evaporative emissions at higher gasoline volatility levels,
the E15 waiver can only be considered in the context of E15 that
maintains the same volatility as required of E0 certification fuel. As
long as the volatility of the fuel does not exceed 9.0 psi during the
summer, diurnal emissions from E15 are not anticipated to cause the
motor vehicles to exceed their evaporative emissions standards. In
addition to the increased evaporative emissions impacts that would
result from allowing E15 to have a higher RVP than E0, as discussed in
section X, EPA interprets CAA section 211(h)(4) as limiting the 1.0 psi
waiver to gasoline-ethanol blends that contain 10 vol% ethanol,
including limiting the provision concerning ``deemed to be in full
compliance'' to the same 10 vol% blends. This interpretation is also
consistent with how EPA has historically implemented CAA section
211(h)(4) through 40 CFR 80.27(d), which provides that gasoline-ethanol
blends that contain at least 9 vol% ethanol and not more than 10 vol%
ethanol qualify for the 1.0 psi waiver of the applicable RVP standard.
    While the CRC E-77 test programs were extremely valuable in
assessing diurnal emissions, their primary purpose was to allow the
quantification and modeling of evaporative permeation emissions
separate and apart from other evaporative emissions for E0, E10, and
E20. Some key findings of the test programs were that gasoline-ethanol
blends can significantly increase permeation emissions compared to pure
gasoline. However, consistent with the results from the E-65-3 test
program, it appears that the magnitude of the impact is relatively
constant across E6, E10, and E20 blends, i.e., no statistically
significant difference. In other words, permeation emissions are a
strong function of the presence of ethanol in the gasoline, not a
strong function of the concentration within the range tested.
Consequently, results for E15 would be anticipated to be comparable to
those

for E10 and E20. The results of the test program also demonstrate the
effectiveness of the Tier 2 evaporative emissions standards at reducing
permeation emissions. Based on the test results shown in Figure IV.A-3,
the additional permeation emissions caused by the ethanol in E15
relative to results with E0 would appear to add little if anything,
given the confidence intervals, to the evaporative emissions
measurements of a Tier 2 motor vehicle operating over the Federal test
cycle. Given the magnitude of manufacturer's evaporative emissions
compliance margins for Tier 2 motor vehicles, as shown in Figure IV.A-
4, any increase in permeation due to E15 should not be sufficient to
cause Tier 2 motor vehicles to exceed their evaporative emission
standards.
---------------------------------------------------------------------------

    \65\ Permeation here will include some background motor vehicle
emissions, such as off-gassing from plastic components. The test
procedure excluded canister breakthrough emissions and any
refrigerant and methanol windshield washer solvent emissions.
[GRAPHIC] [TIFF OMITTED] TN04NO10.004

[GRAPHIC] [TIFF OMITTED] TN04NO10.005

    In addition to immediate evaporative emission impacts, Tier 2 motor
vehicles' evaporative emissions controls systems were designed for
regular E10 use, and they should be compatible and durable with E15 use
over the full useful life of the motor vehicle. While they are tested
for compliance with their applicable evaporative emissions standards on
E0, these motor vehicles are required to demonstrate durability of the
evaporative emissions control systems by performing aging with E10;
therefore, these motor vehicles must demonstrate that they meet their
evaporative emissions standards over their full useful lives after
essentially operating exclusively on E10 prior to the certification
testing. In other words, the seals, connections and other evaporative
and fuel system hardware must be designed to meet evaporative emissions
standards over their full useful lives after aging exclusively on E10.
In addition to designing them for sustained E10 exposure, these designs
must have sufficient design robustness to encompass production
variability in materials and tolerances. Robustness in the design of
these components should provide the safety margin manufacturers target
for volume production. That same robustness is what we believe should
allow for durability on E15, and the available test data supports this
conclusion.
---------------------------------------------------------------------------

    \66\ The two-day evaporative in-use data includes light-duty
motor vehicles, light-duty trucks, and MDPVs, with the appropriate
standards for each type of motor vehicle given in Table IV.A-4.
---------------------------------------------------------------------------

    Testing conducted as part of the DOE Catalyst Study supports the
conclusion that Tier 2 motor vehicle evaporative emissions systems
should be durable in-use when operating on E15. The program, described
above in section IV.A.1, did not show any evidence of evaporative
emissions related problems. The onboard diagnostic monitors on the
motor vehicles did not set any fault codes for evaporative emission
system leaks. Furthermore, no physical differences were found between
the impacts of E15 and E0 on motor vehicle components exposed to fuel
or fuel vapor during the teardowns of the 12 Tier 2 motor vehicles
analyzed (six aged on E0 and six aged on E15).\67\ In the same study,
one of DOE's contractors performed evaporative emission testing on
eight of the Tier 2 motor vehicles (four aged on E0 and four aged on
E15) on which they were performing motor vehicle aging and exhaust
emission deterioration testing. They performed evaporative emission
tests at the same mileage intervals where they measured exhaust
emission performance. While this was only a limited sample size, and
not directly applicable to Federal certification testing due to the
lower RVP of the test fuels, they did not show any greater
deterioration in evaporative emission performance over time on E15
compared to E0 (See Figure IV.A-5). While EPA is aware of another
ongoing study, AVFL-15, which is looking at the durability of fuel
system components, our understanding is that it is performing the
testing on E20 using an atypical, ``aggressive'' ethanol. Consequently,
while it may provide useful information for the manufacturers in
designing their motor vehicles for the worst case conditions, it would
not appear that it would have any bearing on the E15 partial waiver
decision being made today.
---------------------------------------------------------------------------

    \67\ Technical Summary of DOE Study on E15 Impacts on Tier 2
Vehicles and Southwest Research Teardown Report. See EPA-HQ-OAR-
2009-0211.

---------------------------------------------------------------------------

[GRAPHIC] [TIFF OMITTED] TN04NO10.006

     \68\
e. Conclusion
---------------------------------------------------------------------------

    \68\ The vehicles in this study were not aged over standard
evaporative emissions systems aging protocol but rather underwent
rapid mileage accumulation. Three vehicles are presented here as the
fourth vehicle developed a leak and the data was not comparable for
fuel effects.
---------------------------------------------------------------------------

    In assessing the potential impacts of E15 on evaporative emissions
in their waiver application, Growth Energy did not draw their
conclusions by comparing E15 to certification fuel (E0), but rather
compared E15 to other gasoline-ethanol blends. In addition, Growth
Energy provided only limited information on whether E15 would cause
motor vehicles to violate their evaporative emission standards over
their full useful lives. In fact, they made only a passing reference to
potential evaporative emissions durability impacts of E15. As a result,
they did not adequately support their waiver application with respect
to evaporative emissions, either immediate emission impacts or long-
term durability impacts. However, both evaporative emission testing
performed in the CRC E-77 test programs (E-77, E-77-2, E-77-2b, E-77-
2c) and limited evaporative emission testing as part of the DOE
Catalyst Study support the conclusion that as long as E15 meets a
summertime gasoline volatility level of no higher than 9.0 psi, Tier 2
motor vehicles are expected to continue to comply with their
evaporative emission standards over their full useful lives when using
E15.
4. Materials Compatibility for MY2007 and Newer Light-Duty Motor
Vehicles
a. Introduction
    Materials compatibility is a key factor in considering a waiver
request since poor materials compatibility can lead to serious exhaust
and evaporative emissions compliance problems not only immediately upon
using the new fuel or fuel additive, but especially over time. In most
cases one would expect any materials incompatibility to show up in the
emissions tests, but there may be impacts that do not show up due to
the way the testing is performed or because the tests simply do not
capture the effect. As a result, along with emissions testing,
materials compatibility is a key factor in assessing the emissions
durability of a fuel or fuel additive. This section discusses materials
compatibility issues for MY2007 and newer light-duty motor vehicles.
However, since Growth Energy's submission and information supplied by
commenters regarding immediate emissions impacts of E15 were not
specific to the model year of the motor vehicles, this section also
contains much of the information and discussion on emission impacts on
older motor vehicles that is further discussed in section IV.C.
b. Growth Energy's Submission
    Growth Energy submitted a series of studies completed by the State
of Minnesota and the Renewable Fuels Association (RFA) \69\ that
investigated materials compatibility of motor vehicle engines and
engine components using three test fuels: E0, E10, and E20 (``Minnesota
Compatibility Study''). The Minnesota Compatibility Study looked at 19
metals (``Metals Study''),\70\ eight elastomers (rubber materials)
(``Elastomers Study''),\71\ eight plastics

(``Plastics Study''),\72\ and 24 common fuel sending unit and fuel pump
combinations (``Fuel Pumps Study'' and ``Fuel Pump Endurance
Study''),73 74 currently used in automotive, marine, small
engine, and fuel system dispensing equipment for physical or chemical
effects due to ethanol.\75\ The Compatibility Study concluded that
``the effects of 20 percent ethanol blended fuels would not present
problems for current automotive or fuel dispensing equipment.'' While
much of the data cited by Growth Energy was on E20, they argued that
because E20 showed comparable performance to E10 or E0, E15 should also
be comparable by interpolation. In addition, Growth Energy stated that
materials used to construct motor vehicle fuel systems have been
certified to industry standards (SAE J1681) that are qualified using
fuels containing 15% methanol, which is much more aggressive than
ethanol. Since these standards have been used by the automotive
industry for the last 15 years, Growth Energy concluded that most motor
vehicles in use today should have fuel and evaporative systems
compatible with up to 15% ethanol.
---------------------------------------------------------------------------

    \69\ State of Minnesota and Renewable Fuels Association. The
Feasibility of 20 Percent Ethanol Blends by Volume as a Motor Fuel,
EPA Docket EPA-HQ-OAR-2009-0211-0337.
    \70\ ``The Effects of E20 on Metals Used in Automotive Fuel
System Components;'' Bruce Jones, Gary Mead, Paul Steevens, and Mike
Timanus; Minnesota Center for Automotive Research at Minnesota State
University, Mankato; February 22, 2008. EPA Docket EPA-HQ-
OAR-2009-0211-0338.
    \71\ ``The Effects of E20 on Elastomers Used in Automotive Fuel
System Components;'' Bruce Jones, Gary Mead, Paul Steevens, and
Chris Connors; Minnesota Center for Automotive Research at Minnesota
State University, Mankato; February 22, 2008. EPA Docket
EPA-HQ-OAR-2009-0211-0002.5.
    \72\ ``The Effects of E20 on Plastic Automotive System
Components;'' Bruce Jones, Gary Mead, and Paul Steevens; Minnesota
Center for Automotive Research at Minnesota State University,
Mankato; February 21, 2008. EPA Docket EPA-HQ-OAR-2009-
0211-0002.8.
    \73\ ``The Effects of E20 on Automotive Fuel Pumps and Sending
Units;'' Nathan Hanson, Thomas Devens, Colin Rohde, Adam Larson,
Gary Mead, Paul Steevens, and Bruce Jones; Minnesota State
University, Mankato; February 21, 2008. EPA Docket EPA-HQ-
OAR-2009-0211-0002.28.
    \74\ ``An Examination of Fuel Pumps and Sending Units During a
4000 Hour Endurance Test in E20;'' Gary Mead, Bruce Jones, Paul
Steevens, Nathan Hanson, and Joe Harrenstein, Minnesota Center for
Automotive Research at Minnesota State University, Mankota, March
25, 2009. EPA Docket EPA-HQ-OAR-2009-0211-2721. Also
available at http://www.mda.state.mn.us/news/publications/renewable/
ethanol/e20endurance.pdf.
    \75\ Effects assessed in the studies include: Pitting, surface
texture change, discoloration, or loss of mass for metals;
appearance, volume, weight, tensile strength, elongation, and
hardness for elastomers; mass loss or gain, volume loss or gain,
tensile elongation, impact resistance, and tensile strength for
plastics; and corrosion and longevity as measured by flow and
pressure tests for pumps and sending units.
---------------------------------------------------------------------------

c. Public Comment Summary
    Commenters responded to Growth Energy's claims by arguing that
E15's effect on fuel system materials has not been properly studied.
Many commenters noted that Growth Energy may have selectively excluded
important findings from the Minnesota Compatibility Study.
    Regarding the Metals Study, some comments noted that 14 out of the
19 metal samples that were tested exhibited greater than 50% measurable
mass changes when tested with E20 compared to E10, and if those metals
had been compared to E0 instead of E10, some mass changes would have
exceeded 200%. The Alliance stated that such mass changes in metals
``can be a very noteworthy indication of heavily accelerated corrosive
effects'' since unprotected metals often accelerate in a non-linear
fashion.\76\ With respect to specific materials, commenters stated that
E15 will increase corrosion of terne plate gas tanks which were used in
light-duty motor vehicles prior to the mid-1990s.
---------------------------------------------------------------------------

    \76\ ``Alliance of Automobile Manufacturers Comments on Clean
Air Act Waiver Application to Increase the Allowable Ethanol Content
of Gasoline to 15 Percent, A-22. EPA Docket EPA-HQ-OAR-
2009-0211-2551.1.
---------------------------------------------------------------------------

    The Alliance criticized the Elastomers Study for testing raw
materials instead of actual fuel system components (such as hoses,
seals, and diaphragms), and argued that the impacts of mid-level
gasoline-ethanol blends on raw materials would differ substantially
from manufactured parts because manufacturers vary the compounds used
in the construction of fuel system parts. The Alliance commented
further that most of the materials tested were neither being used nor
expected to be used in the future. The Alliance also commented that the
study failed to justify how a 500 hour exposure test period provides
the ability to predict compatibility of materials. The Alliance added
that while studies have shown generally acceptable materials
compatibility with ethanol up to 10 vol% ethanol, higher dosages have
degraded certain metals, elastomers, plastics, and motor vehicle
finishes.\77\ The Alliance also commented that many researchers have
found that the effects of gasoline-ethanol blends on elastomers may be
non-linear with increasing ethanol content and that a blend containing
10-25% ethanol may be more harmful to elastomers than E85 or E100.\78\
Moreover, the Alliance noted in their comments that over 30 years of
research has led to the conclusion that concentrations between 15 and
50% ethanol provide the most challenging environment for elastomers
compared to other ethanol levels. Regarding specific elastomers,
commenters stated that E15 will damage fuel system components made of
nitrile rubber while fluorocarbon elastomers have shown the best
resistance to swell, tensile strength, and elongation for ethanol
gasoline blends at 10 vol%.79 80 81
---------------------------------------------------------------------------

    \77\ SAE J1297, revised July 2007, Surface Vehicle Information
Report, Alternative Fuels.
    \78\ SAE 800786, ``Effects of Mixtures of Gasoline With Methanol
and With Ethanol on Automotive Elastomers,'' Ismat A. Abu-Isa,
General Motors Research Laboratory. SAE 2007-01-2738.
    \79\ SAE 800786, ``Effects of Mixtures of Gasoline With Methanol
and With Ethanol on Automotive Elastomers,'' Ismat A. Abu-Isa,
General Motors Research Laboratory.
    \80\ SAE 800789, ``The Volume Increase of Fuel Handling Rubbers
in Gasoline/Alcohol Blends,'' Nersasian, A., Passenger Car Meeting,
June 9-13, 1980.
    \81\ SAE 912413 ``An Overview of the Technical Implications of
Methanol and Ethanol as Highway Motor Vehicle Fuels,'' Frank Black,
U.S. Environmental Protection Agency, Research Triangle Park, NC.
---------------------------------------------------------------------------

    Some commenters also expressed concerns with a particular material,
polybutlyene terephthalate (PBT), tested in the Plastics Study. The
Alliance noted that PBT experienced a slight elevation in tensile
elongation as the percentage of ethanol was increased, and that the
study was performed at temperatures lower than would be experienced
under real-world driving conditions. Since materials like PBT undergo a
chemical transformation when exposed to ethanol, the Alliance argued
that the elongation effect on PBT would be greater at the elevated
temperatures found in real-world driving conditions. The Alliance
concluded that E15 will damage fuel system components made of PBT and
noted that at least one fuel system supplier used PBT in fuel pump
modules between model years 1993 and 2004.
    Several comments noted that the sample size for the Fuel Pumps
Study was too small to draw conclusions about the effects of E20 and
that the duration of the test program included only a short-term,
static soak test of 720 hours as opposed to testing periods of at least
2,000 hours and up to 10,000 hours usually used to validate fuel pump
designs and materials. Several commenters referred to the materials
compatibility work in the Orbital Study 82 83 which evaluated the
effects of E20 on fuel system components for several older model
Australian passenger vehicles.\84\
---------------------------------------------------------------------------

    \82\ ``Market Barriers to the Uptake of Biofuels Study, A
Testing Based Assessment to Determine Impacts of a 20% Ethanol
Gasoline Fuel Blend on the Australian Passenger Vehicle Fleet,
Report to Environment Australia;'' Orbital Engine Company; March
2003.
    \83\ ``Market Barriers to the Uptake of Biofuels Study Testing
Gasoline Containing 20% Ethanol (E20), Phase 2B Final Report to the
Department of the Environment and Heritage;'' Orbital Engine
Company; May 2004.
    \84\ Components were selected from three vehicles, the Holden
1990 VN and 1985 VK Commodore and a 1985 Ford XE Falcon to encompass
most component types within the Australian passenger car fleet.

---------------------------------------------------------------------------

d. EPA Analysis
    The Agency is concerned, based on its review of the literature and
automotive industry comments, that most pre-Tier 2 motor vehicles,
including Tier 0 vehicles (from the 1980s to 1995) and Tier 1 vehicles
(from 1996 to 2001), may have been designed for only limited exposure
to E10 and consequently may have the potential for increased materials
degradation with the use of E15. This potential for materials
degradation may make the emissions control and fuel systems more
susceptible to corrosion and chemical reactions from E15 when compared
to the certification fuels for these motor vehicles which did not
contain any ethanol, and therefore may increase motor vehicle
emissions. For MY2000 and older motor vehicles especially, E15 use may
result in degradation of metallic and non-metallic components in the
fuel and evaporative emissions control systems that can lead to highly
elevated HC emissions from both vapor and liquid leaks. Potential
problems such as fuel pump corrosion or fuel hose swelling will likely
be worse with E15 than historically with E10, especially if motor
vehicles operate exclusively on E15. Since ethanol historically
comprised a much smaller portion of the fuel supply, in-use experience
with E10 was often discontinuous or temporary, while material effects
are time and exposure dependent. Thus, issues may surface with E15 that
may not have surfaced historically in-use with E10.
    Newer motor vehicles, such as Tier 2 and NLEV vehicles (MY2001 and
newer), on the other hand, were designed to encounter more regular
ethanol exposure compared to earlier model year motor vehicles. IUVP,
introduced under CAP2000, requires manufacturers to perform exhaust and
evaporative emissions tests on in-use motor vehicles. This emphasis on
real-world motor vehicle testing prompted manufacturers to consider
different available fuels when developing and testing their emissions
systems. Additionally, beginning with Tier 2, the durability
demonstration procedures required the demonstration of evaporative
emission system durability on E10. As a result, the materials in Tier 2
motor vehicles have been able to mitigate the permeation effects of
ethanol in the fuel, as discussed in section IV.A.2. As a result, our
engineering analysis would suggest that Tier 2 compliant motor vehicles
are more likely to be compatible with E15 than older motor vehicles.
    While Growth Energy asserted that 15% methanol was a worst-case
fuel for E15 materials compatibility purposes, the Agency is not aware
of any analysis or industry standard practice that confirms that motor
vehicle materials tested on 15% methanol test fuels will cover
gasoline-ethanol blends up to 15% for materials compatibility and
evaporative emissions purposes. SAE J1681 provides specifications and
formulations for evaluating oxygenates in gasoline, including ethanol,
on automotive fuel system components.\85\ EPA's evaluation of SAE J1681
does not reveal that 15% methanol would be the surrogate worst case
test fuel in evaluating all oxygenates. To the contrary, the fuel
formulations for aggressive methanol and aggressive ethanol are
different, as described in Appendix E of SAE J1681. EPA believes this
difference is to account for contaminants that may be present in these
two different products during production and/or transportation of each
product. To properly evaluate the potential worse case impacts of a
mid-level gasoline-ethanol blend, such as E15, on motor vehicle fuel
systems components, the Agency believes it would be prudent to use the
aggressive ethanol fuel formulation provided in Appendix E of SAE
J1681, to the extent that it reflects E15 according to ethanol content,
as well as any contaminant, that may be associated with the production
or transportation of an E15 gasoline product. The Agency notes that SAE
J1681 includes language describing potential impacts of oxygenates on
metals (from by-products derived from oxygenates and especially when
water is present), polymers (including elastomers and plastics), and
polymer systems (including laminates and multi-layered components).\86\
---------------------------------------------------------------------------

    \85\ SAE J1681, ``Surface Vehicle Recommended Practice, for
Gasoline, Alcohol and Diesel Fuel Surrogates for Materials
Testing,'' Issued 1992-09, Revised 2000-01.
    \86\ Ibid.
---------------------------------------------------------------------------

e. Conclusions
    The Agency has reviewed the studies and information submitted by
Growth Energy, commenters, and other publicly available information to
further assess the potential materials compatibility performance of
E15, including the Minnesota Compatibility Studies.\87\ The Minnesota
studies were on component parts using laboratory bench tests rather
than durability studies of whole motor vehicle fuel systems simulating
``real world'' motor vehicle use. Such tests are typically used to
provide a first level screening of potential materials prior to more
real-world testing to demonstrate materials compatibility of actual
vehicle and engine components. In addition, the study admittedly
assessed only a subset of materials used in motor vehicles and nonroad
products over the years, and provided no information with which to
correlate the materials tested with those in use in either the MY2007
and newer motor vehicles or older motor vehicles and nonroad products.
Manufacturers have continually modified engine, fuel system, and
emissions control system materials over the years in response to
technology needs, in-use fuel quality changes (including E10), and
emission standards. In many cases, they have incorporated special
coatings and barriers in existing materials to address problems
discovered in the field or in emissions testing. Furthermore, as
commenters point out, there were differences found in the testing for
some of the materials, which would suggest further testing was
necessary. Finally, conclusions Growth Energy reached comparing the
results of some of the materials on E20 to E10 are not helpful in
assessing the impacts of E15 relative to E0. Consequently, while the
Minnesota studies are informative, they cannot by themselves be used to
draw any definitive conclusions. Rather, the conclusion is that actual
vehicle durability testing is warranted.
---------------------------------------------------------------------------

    \87\ SAE J1297, revised July 2007, Surface Vehicle Information
Report, Alternative Fuels.
---------------------------------------------------------------------------

    In the case of MY2007 and newer motor vehicles, the Agency believes
that the DOE Catalyst Study has provided the additional information
needed. Along with (1) our engineering analysis of the types of changes
manufacturers have made in response to the Tier 2 motor vehicle
standards and the rapid rise of E10 use across the nation; (2) the
limited information available from the Minnesota studies; and (3) the
lack of any information from commenters showing definitive problems on
Tier 2 compliant motor vehicles, we believe that the durability testing
performed by DOE as discussed in section IV.A.1. above is sufficient to
provide assurance that MY2007 and newer motor vehicles will not exhibit
any serious materials incompatibility problems with E15. Not only did
the DOE Catalyst Study not uncover any emissions deterioration problems
with E15 in comparison to E0, it also did not uncover any material
differences upon tear-down and inspection of six of the motor vehicle
pairs tested out to FUL.\88\ Therefore, the Agency does not expect that
there will

be materials compatibility issues with E15 that would cause MY2007 and
newer light-duty motor vehicles to exceed their exhaust or evaporative
emission standards over their full useful lives.
---------------------------------------------------------------------------

    \88\ Only a difference in intake valve deposits was seen.
---------------------------------------------------------------------------

5. Driveability and Operability for MY2007 and Newer Light-Duty Motor
Vehicles
a. Introduction
    In past waiver applications before the Agency, driveability and
general operability of the motor vehicle have not necessarily been
impacted by the fuel or fuel additive and therefore not significant to
the decision making process. However, a change in the driveability of a
motor vehicle that results in significant deviation from normal
operation (i.e., stalling, hesitation, etc.) can conceivably result in
unexpected emission increases and should be considered when evaluating
a fuel or fuel additive. These increases may not be demonstrated in the
emissions certification test cycles but instead be present during in-
use operation. A motor vehicle stall and subsequent restart can result
in a significant emissions increase because HC and CO emissions rates
are typically highest during cold starts. Further, a consumer or
operator might tamper with the motor vehicle in an attempt to correct
the driveability by modifying the vehicle from its original certified
configuration.
b. Growth Energy's Submission
    Growth Energy relies on the Minnesota Driveability Study, the RIT
Study, the MCAR Study, and the DOE Pilot Study to support their claim
that ``E-15 will cause no driveability issues'' and will not lead to
the removal of or the rendering inoperative of emissions control
devices or systems based on negative performance impacts. Growth Energy
claims that the RIT Study supports the Minnesota Driveability Study's
findings by driving 10 motor vehicles with significant mileage (between
30,000 and 120,000 miles) for over 75,000 miles on E20 under ``real
world conditions.'' They argue that the RIT Study's drivers did not
detect any performance degradation and there were no engine or fuel
part failures that required abnormal maintenance.\89\ Growth Energy
argues that the MCAR Study, which tested 15 in-use cars and light-duty
trucks operating on E10 and E30 for a year, showed ``no driveability
complaints, no reports of cold starting, vapor lock, or hard starting
conditions, and no reports of hesitation with the E-30 blend of fuel.''
\90\ Growth Energy contends that the DOE Pilot Study showed that ``none
of the vehicles tested displayed a malfunction indicator light as a
result of the ethanol content, no fuel filter plugging symptoms were
observed, no cool start problems were observed in 75 [deg]F and 50
[deg]F laboratory conditions, and no fuel leaks or conspicuous
degradation of the fuel systems were observed.'' \91\
---------------------------------------------------------------------------

    \89\ In Growth Energy's comments submitted during the E15 public
notice and comment period, Growth Energy submitted an updated
summary for the RIT Study. See below for more details.
    \90\ Application For A Waiver Pursuant to Section 211(f)(4) of
The Clean Air Act For E-15 submitted by Growth Energy on behalf of
52 United States Ethanol Manufacturers see EPA-HQ-OAR-2009-0211, 33.
    \91\ Application For A Waiver Pursuant to Section 211(f)(4) of
The Clean Air Act For E-15 submitted by Growth Energy on behalf of
52 United States Ethanol Manufacturers see EPA-HQ-OAR-2009-0211, 34.
---------------------------------------------------------------------------

    In their application, Growth Energy asserts that the Minnesota
Driveability Study, the MCAR Study, and the RIT Study demonstrate that
higher gasoline-ethanol blends do not result in driveability or
performance problems.
c. Public Comment Summary
    Several commenters mention specific methodological issues with the
driveability studies included in Growth Energy's waiver request. The
Alliance pointed out what they believe to be several flaws with the
Minnesota Driveability Study. First, they noted low response rates for
the drivers rating operability concerns. Second, the trained drivers
did not drive motor vehicles back-to-back on E0 and E20, which made
direct comparison of driveability on E0 to E20 impossible. Third, the
Alliance argues that many of the batch fuel analyses were suspect,
casting doubt on the actual fuel properties used in the study. The
Alliance and others had similar critiques with the MCAR Study and also
noted that neither the Minnesota Driveability Study nor the MCAR Study
were peer-reviewed. With regard to the RIT Study, as mentioned
previously, many commenters point out that the study summary provided
with Growth Energy's public comments does not provide enough detail to
conduct a thorough independent analysis, making it difficult to verify
Growth Energy's claims. The Alliance argues that more testing needs to
be conducted evaluating how ethanol affects T50 and TV/L in the
gasoline-ethanol blends containing greater than 10 vol% ethanol.
    Growth Energy responded to these driveability issues in their
comments by reiterating the arguments made in their E15 waiver
application and noting that the updated summary of the RIT Study that
they submitted as part of their comments showed no driveability or
mechanical problems with approximately 400 motor vehicles driven on E20
for over 1.5 million miles.
    Commenters also raised questions regarding the sensitivity of the
OBD system to increased gasoline-ethanol blends and some ongoing
studies to quantify potential impacts. Honda submitted some limited
data regarding potential motor vehicle sensitivity to higher gasoline-
ethanol blends. Additionally, at the Mid-Level Ethanol Blends Research
Coordination Group meeting on May 5, 2010, a presentation was made to
members regarding possible implications of increased levels of ethanol
on the vehicle OBD systems \92\. The presentation described the
findings of the first phase of CRC project E-90 which is intended to
study the impact of ethanol on OBD systems. Phase 1 of the study was
designed to investigate differences in the status of vehicle OBD
monitors and other emissions control information in E10 versus E0 areas
of the country in an attempt to isolate potential ethanol impacts to
OBD. Since E15 and E20 are not currently legal fuels for conventional
motor vehicles (i.e., non-flex fuel vehicles), the study used the
differences between E0 and E10 to project potential impacts of E15 and
E20 on the OBD system but did not actually perform any testing on E15
or E20. Similarly, Honda did not perform any actual testing using E15
or E20 but instead used the E0 to E10 information, combined with
potential component tolerance stack-up, to assess risk of having the
OBD system set a fault and illuminate the malfunction indicator lamp
(MIL).
---------------------------------------------------------------------------

    \92\ ``E15/E20 Tolerance of In-Use Vehicle OBD-II Systems.''
Presentation available at http://www.crcao.com/.
---------------------------------------------------------------------------

d. EPA Analysis
    The Agency understands the concern for driveability and other
operational issues that could potentially occur with an increase in
ethanol content. During the initial introduction of ethanol over 30
years ago, problems with hot fuel handling were encountered due to the
ethanol boiling in the fuel system, resulting in operational issues
like stalls, engine hesitations, misfires and vapor lock preventing hot
restarts. Since the introduction of ethanol, motor vehicles have
evolved to alleviate these early issues, mainly through fuel system
design. These changes included the switch to fuel injection with an
associated increase in the system fuel

pressure, all of which have worked to reduce the potential for hot fuel
issues when operating on gasoline-ethanol blends. In fact, E85 capable
FFVs sold today typically operate at similar or the same fuel pressure
as their non-FFV counterparts with no reported issues. Due to the
stringent emission standards requiring precise fuel control, Tier 2
vehicles have been engineered with the highest fuel pressure systems in
vehicle history which make them also highly robust at managing
ethanol's low boiling point. The Agency does not believe that properly
functioning fuel injected vehicles, particularly Tier 2 vehicles, will
encounter any new heat related operational issues with an increase in
ethanol content of the fuel to 15 vol%.
    Driveability issues could also occur from incompatibility between
E15 and manufacturers' approaches at calibrating a motor vehicle for
fuels it is expected to encounter in-use. If the error in fuel
quantity, caused by the fuel properties of E15 (i.e., oxygen content),
is beyond what the system is designed to compensate for, driveability
issues (cold start roughness, hesitations) can arise. However, due to
the large variability found in fuels in the market today which can
result in similar driveability behaviors, from experience with in-use
fuels, manufacturers have employed methods to counter or compensate for
fuel differences and try to prevent these driveability issues. Because
of the stringent Tier 2 emission standards, Tier 2 vehicles required
focused attention to cold start fueling to ensure emission compliance
while tolerating the different fuel blends that the vehicle could
encounter in-use. This resulted in modification of calibration and
control strategies by manufacturers to balance the need for precise
cold start fuel that meet both emission requirements and operate
properly when fuel properties vary in-use. Because manufacturers
already calibrate motor vehicles based on their experience with in-use
fuels, combined with lack of any reported driveability issues in any of
the E15 and E20 test programs during both laboratory and road testing,
the Agency believes that properly functioning and maintained motor
vehicles will not experience an increase in driveability issues when
operating on a properly blended E15 fuel. Collectively, the RIT Study,
Minnesota Driveability Study, MCAR Study and a CRC cold start study
\93\ did not report any fuel related driveability issues demonstrated
across different E15 and E20 seasonally blended fuels and verified
during winter, summer and shoulder seasons, supporting the Agency's
findings.
---------------------------------------------------------------------------

    \93\ CRC Report No. 652, ``2008 CRC Cold-Start and Warm-up E85
and E15/E20 Driveability Program,'' October 2008.
---------------------------------------------------------------------------

    Motor vehicles produced since approximately 1995 have been equipped
with OBD systems that monitor all aspects of the exhaust and
evaporative emissions control system. The Agency recognizes that the
additional oxygen content in E15 will be identified by the OBD system
as a shift in the fueling requirements. In some motor vehicles, a shift
in the fuel requirements beyond predetermined thresholds, based on the
manufacturer's research, can result in a MIL illumination. However,
across the many different test programs with different motor vehicles
and duty cycles, including lab testing, mileage accumulation and in-use
operation, there were no reported incidences of MIL illumination from
the use of increased ethanol for both E15 and E20. Based on this, the
Agency believes that properly functioning (i.e., within component
tolerances) and maintained motor vehicles will not experience an
increase in MIL illumination due to the use of E15. However, for a
vehicle that has a component issue or failure (i.e., intake vacuum
leak, exhaust leak, etc.) which indirectly effects the same OBD
monitors as ethanol content, it is possible that the increase in
ethanol may push the OBD system monitor over the calibrated thresholds
and cause a MIL illumination.
e. Conclusion
    The Agency has reviewed the studies and information submitted by
Growth Energy, commenters, as well as other information from the
emissions and durability test programs to assess the potential for
driveability and diagnostic issues on Tier 2 motor vehicles (i.e.,
MY2007 and newer). With the exception of ethanol content, fuel
properties were largely allowed to vary across the different studies
and test programs (i.e., gasoline blend stocks varied between programs
and season). This included ethanol blends as high as E30 in the MCAR
Study and the program with the largest amount of vehicles, the RIT
study, operating on E20 throughout the year which included summer,
winter, spring, and fall operation. In these two studies where the
ethanol levels exceeded E15 and the vehicles were operated in a
relatively uncontrolled manner (i.e., not driven on a specific duty-
cycle), there were no reported driveability issues or OBD related
problems on the vehicles.
    The DOE test programs, both the DOE Pilot Study and the DOE
Catalyst Study, did not report any occurrence of driveability or
diagnostics issues throughout the testing. For the durability program,
mileage accumulation on the Tier 2 vehicles occurred at three locations
including one location at altitude (Denver Colorado). For the mileage
accumulation, fuels where made by splash blending locally available
commercial fuels. Vehicle mileage accumulation was performed both on
mileage accumulation dynamometers and on a track with actual drivers.
There were no reported driveability issues or OBD related problems
during the mileage accumulation period on the Tier 2 vehicles at the
various testing locations.
    The Agency's review of the data and information from the different
test programs finds no specific reports of driveability, operability or
OBD issues across many different vehicles and duty cycles including lab
testing and in-use operation. Thus, while the potential exists for some
vehicles more sensitive to ethanol to experience driveability or
operability issues, the frequency is likely not more than what is
currently experienced in-use today. Therefore, the Agency does not
anticipate that there will be driveability, operability or OBD issues
with E15 on properly operating and maintained MY2007 and newer light-
duty motor vehicles.
6. Overall Immediate and Long-Term Emissions Conclusions
    As described in the preceding sections, EPA evaluated Growth
Energy's submission based on five factors: Long-term exhaust emissions
impact over time, immediate exhaust emissions impact; immediate and
long-term evaporative system impacts; the impact of materials
compatibility on emissions; and the impact of drivability and
operability on emissions. Based on results from the DOE Catalyst Study
in particular coupled with our engineering judgment, EPA believes there
is strong evidence that MY2007 and newer light-duty motor vehicles will
not exceed their emission standards over their useful life when
operated on E15. Therefore, EPA is granting the waiver for MY2007 and
newer light-duty motor vehicles.

B. MY 2001-2006 Light-Duty Motor Vehicles

    EPA is deferring its decision on MY2001-2006 light-duty motor
vehicles. DOE is in the process of conducting additional catalyst
durability testing that will provide data regarding MY2001-2006 motor
vehicles. The DOE testing is scheduled to be completed by November
2010. The data will be made available to the public.

EPA will then consider these data and other data and information
available to make a further determination on the use of E15 in those MY
motor vehicles.

C. MY2000 and Older Light-Duty Motor Vehicles

    Due to differences in vehicle standards and technology over time
and in light of the data and information available, the Agency has
chosen to split consideration of the E15 waiver request into model year
groupings. This section concerns MY2000 and older light-duty motor
vehicles.

                    Table IV.C-1--Tier 0 and Tier 1 Emission Standards Phase-in by Model Year
----------------------------------------------------------------------------------------------------------------
                                                                                Tier 1 Phase-in percentage
                                                        Tier 0            --------------------------------------
                                                                              MY1994       MY1995       MY1996
----------------------------------------------------------------------------------------------------------------
Passenger car.............................  MY1981 and newer*............           40           80          100
Light duty truck <6000 GVW................  MY1988 and newer.............           40           80          100
Light duty truck >6000 GVW................  MY1990 and newer.............  ...........           50          100
----------------------------------------------------------------------------------------------------------------
* Final diesel particulate standard required came in 1987.

    MY2000 and older light-duty motor vehicles have much less
sophisticated emissions control systems compared to today's vehicles
and, as described below, may experience conditions that lead to
immediate emission increases and may exceed their emission standards if
operated on E15. Vehicles produced prior to the mid-1980s were equipped
primarily with carbureted engines. The A/F ratio of the carburetor is
preset at the factory based on the expected operating conditions of the
engine such as ambient temperature, atmospheric pressure, speed, and
load. As a result, carburetors have ``open loop'' fuel control which
means that the air and fuel are provided at a specified, predetermined
ratio that is not automatically adjusted during vehicle operation. As
fuel composition can vary, an engine with a carburetor and open loop
fuel control would never know if it achieved the desired A/F ratio or
not. Since the vehicles at this time operated ``open loop'' all of the
time with no ability to react to changes in the A/F ratio, the addition
of ethanol to the fuel tended to make the A/F ratio leaner, typically
resulting in an immediate emission impact of reducing HC and CO
emissions, but increasing NOX emissions. However, some of
these older open loop systems already operate at the lean edge of
combustion on current commercial fuels so an increase in ethanol may
cause them to begin to misfire resulting in HC and CO increases.
    As a result of the Clean Air Act of 1970, EPA established standards
and measurement procedures for exhaust, evaporative, and refueling
emissions of criteria pollutants. From 1975 into the 1980s, vehicles
became equipped with catalytic converters, first with catalysts capable
of oxidizing HC and CO, and then, in response to EPA's `Tier 0'
standards, with three-way catalysts that also reduced NOX.
With the `Tier 0' standards, closed loop fuel control was required to
maintain proper fuel air ratio control necessary to achieve high
conversion efficiency in the three way catalyst. In most vehicles this
was accomplished through the use of feedback carburetors. Vehicles
produced from the late 1980s and even more so into the 1990s, as a
result of more stringent California and Federal standards, evolved to
incorporate more sophisticated and durable emission control systems.
These systems generally included an onboard computer, oxygen sensor,
and early electronic fuel injection with more precise closed loop fuel
compensation and therefore A/F ratio control during more of the
engine's operating range. However, even with the use of closed loop
systems through the late 1990s, the emission control system and
controls remained fairly simple with a limited range of authority and
were primarily designed to adjust for component variability (i.e., fuel
pressure, injectors, etc.) and not for changes in the fuel composition.
During this period, ethanol was only available in very limited areas of
the U.S. so the manufacturers' designs of the emission controls and the
durability of emission control hardware generally did not account for
the increased oxygen content of ethanol. As a result, this generation
of vehicles certified to Tier 0 and early Tier 1 emission standards
experienced immediate emission impacts of ethanol and likely also
deteriorated at different rates when exposed to ethanol. These designs
continued to evolve during the early period of the Tier 1 emission
standards as manufacturers and component suppliers gained experience
with vehicles in-use. However, the largest improvements to emission
controls and hardware durability came after 2000 with the introduction
of several new emission standards and durability requirements forcing
manufacturers to better account for the implications of in-use fuels on
the evaporative and exhaust emission control systems.
    The NLEV program for exhaust emissions began Federally with MY2001
(MY1999 in the northeast trading region within the NLEV program) for
all cars and light trucks up to 6000 lbs. GVW. This program essentially
adopted the existing California LEV certified vehicles as a national
vehicle program. These NLEV vehicles met more stringent emission
standards for all criteria emissions requiring substantial changes to
emission control hardware and strategies compared with Tier 1 vehicles.
The LEV and NLEV programs largely were the start of a migration to
emission control hardware and strategies resembling future Tier 2
program approaches (e.g. independent catalyst per bank on V engines).
Many of the improvements (i.e. catalyst designs, washcoat formulation)
may have been leveraged by the remaining new Tier 1 vehicles, mainly
the over 6000 lbs. GVW trucks not required to comply with the NLEV
standards, but to what degree is unknown.
    The CAP2000 program was implemented for MY2001 and later vehicles.
The CAP2000 program was designed to place more emphasis on in-use
performance of vehicle emission controls with vehicles operating
nationwide on the different available fuels. The IUVP introduced under
CAP2000 requires manufactures to perform exhaust and evaporative
emissions tests on customer vehicles. These tests must be performed at
low and high mileage intervals and include at least one vehicle per
test group \94\ at 75% of full useful life. This emphasis on real world
vehicle testing prompted manufacturers to consider different available
fuels when developing and testing their emissions systems.
---------------------------------------------------------------------------

    \94\ EPA certifies light-duty motor vehicles on a test group
basis. A test group is a group of vehicles having similar design and
emission characteristics.

---------------------------------------------------------------------------

    Under the CAP2000 program, manufacturers are allowed to design
durability processes that predict in-use deterioration. Prior to
CAP2000, manufacturers would run traditional durability programs to
calculate emissions deterioration which generally required that
vehicles accumulated mileage out to their full useful life under highly
controlled conditions and fuels. Under the new program with increased
emphasis on in-use emission levels, manufacturers must confidently
ensure that their in-use emission deterioration is as predicted.
    The Enhanced Evaporative Emissions requirements were fully phased
in for light-duty vehicles by 1999. These new requirements included
both new standards and new test procedures: The 2-day and 3-day diurnal
tests with new canister loading procedures. In addition, the durability
demonstration procedures that took effect with the Tier 2 program
beginning in 2004 required the use of at least the maximum ethanol
concentration permitted by Federal law that is commercially available
for the entire service accumulation period.
    Along with the Enhanced Evaporative Emissions requirements, OBD
requirements for evaporative leak detection monitors were introduced.
This required vehicles to detect a leak equivalent to .040 inch in the
fuel or evaporative emissions system. Beginning in 2001, EPA allowed
manufactures to comply with California OBD regulations, which required
vehicles to detect a leak equivalent to a .020 inch. While not required
Federally, many manufacturers developed one leak detection system for
sale in all 50 States, which complied with the more stringent
California requirement.
    By MY2004, the SFTP was fully phased in. Additional test procedures
were developed to better represent the driving habits and conditions
experienced in actual customer driving. These procedures expanded the
vehicle testing to include the US06 test, a high speed and high
acceleration cycle, the SCO3 test, an air conditioning test cycle run
in an environmental test chamber at 95 [deg]F, and a 20 [deg]F cold
test run on the FTP cycle. These additional test cycles coupled with
the in-use testing required under CAP2000 have pushed manufactures to
develop robust emissions control systems capable of withstanding the
higher temperatures experienced on these more severe cycles.
    The tightening evaporative emission standards, the durability
requirement to include prolonged exposure to ethanol in the fuel, the
CAP2000 requirement to test high mileage in-use vehicles, and the OBD
leak detection requirement have all combined to compel manufacturers to
develop more durable evaporative emission systems and focus on testing
with fuels that would be encountered in customer vehicles, including
fuels containing ethanol. Thus, MY2000 and older vehicles have not
benefitted from many of the design changes that MY2007 and newer light-
duty motor vehicles have. Therefore, we do not have the same confidence
with MY2000 and older light-duty motor vehicles as we do with MY2007
and newer light-duty motor vehicles with respect to operation on E15.
1. Growth Energy's Submission
    Growth Energy's waiver application covered all model years of motor
vehicles--they made no specific claims specific to MY2000 and older
motor vehicles. A summary of Growth Energy's submission with respect to
the potential impacts of E15 on (1) exhaust emissions, both long-term
durability and immediate impacts, (2) evaporative emissions, both long-
term durability and immediate impacts, (3) materials compatibility, and
(4) driveability and operability for MY2007 and newer light-duty motor
vehicles is discussed in the respective subsections within Section
IV.A. Since Growth Energy's waiver application was for all model years
of motor vehicles, the summary of their submission contained in Section
IV.A is also applicable here for MY2000 and older light-duty motor
vehicles.
2. Public Comment Summary
    Similar to the broad applicability of Growth Energy's submission,
the public comments received tended to cover all model years of light-
duty motor vehicles, and the summary of comments received contained in
section IV.A. is also applicable here. However, the Alliance
specifically commented that historically, it has taken about 20 years
for an entire vehicle fleet to turn over, but with current depressed
sales due to poor economic conditions, the turn-over rate could be
slower in the near future and that a well-executed study should have a
test fleet that is proportionally similar to the model years that
comprise the national fleet. The Alliance argued that the bulk of the
emissions data cited in Growth Energy's waiver request focus on newer
(i.e., Tier 2) vehicles and do not adequately represent the national
vehicle fleet and that these older vehicles may be more sensitive to
the effects of higher ethanol blends and constitute a greater portion
of the number of vehicles currently in use. Specifically the Alliance
commented that the DOE Pilot Study presents data from R. L. Polk
describing the U.S. fleet but did not select the vehicles to
statistically represent that fleet. The study included no Tier 0
vehicles, for example, and the selected test vehicles did not
proportionally represent the vehicles in the Polk table. The test
program generally ignored pre-1999 motor vehicles, even though they
will continue to be a large portion of the legacy fleet for many years.
These older motor vehicles are most likely to have operational and
emissions issues with E15 and E20.
    The Alliance also commented that many years of automaker experience
with developing and producing vehicles capable of using E22, E85 and
E100 fuels have shown that engines need to be hardened for resistance
to ethanol. Use of ethanol blends in unhardened engines can result in
bore, ring, piston and valve seat wear. Deterioration of these
components can lead to compression and power loss, misfire and catalyst
damage
    Finally, EPA recently received a report by Ricardo \95\
commissioned by the Renewable Fuels Association specifically discussing
the potential impacts of E15 on MY2000 and older light-duty motor
vehicles. This report's conclusions stated that:
---------------------------------------------------------------------------

    \95\ Ricardo Inc., Technical Assessment of the Feasibility of
introducing E15 Blended Fuel in U.S. Vehicle Fleet, 1994 to 2000
Model Years, 10 September, 2010. EPA Docket EPA-HQ-OAR-
2009-0211-14007.1.

    ``While performing an engineering assessment on a fleet of such
magnitude as the current U.S. motor vehicle fleet, it was necessary
to make certain assumptions and approximations to allow an overall
assessment to be made. Due to this unavoidable circumstance, there
are certain exceptions to the overall findings of this study which
may occur in the field due to unpredictable conditions outside the
scope of normal operation. Without investigating each and every
vehicle in the fleet individually for its reaction to an E15 fuel
blend, there cannot be 100% certainty that some vehicles will not
observe adverse effects from the use of E15. However, using
statistical analysis, the fleet was reduced to a more manageable and
representative collection of platforms and manufacturers. The
vehicles arising from this methodology were evaluated and served as
representative vehicles for the time period.
    The effect of E15 on various vehicle systems were assessed for
vehicles in the 1994 to 2000 MY time period. Overall, moving from
the use of E10 to E15 in the current U.S. light vehicle fleet is
seen as a low risk from an engineering analysis perspective. While
certain risks do remain, they are manageable and exist in vehicles
that are outside the normal bounds of ``standard'' vehicles in the
1994 to 2000 MY timeframe.''

3. EPA Analysis and Conclusion
a. Scope of MY2000 and Older Data to Support a Waiver Decision
    As highlighted by the Alliance in their comments, Growth Energy did
not provide information to broadly assess the emission performance of
E15 in all motor vehicles in the in-use fleet, and this is particularly
true of MY2000 and older motor vehicles. Furthermore, there are
important differences in design between the MY2000 and older and MY2007
and newer (Tier 2) vehicles that makes it impossible to simply rely on
data collected on more recent model year vehicles.
    Growth Energy did make reference to the RIT and MCAR studies which
included some vehicles from MY2000 and older. However, as discussed in
section IV.A, these studies have the following limitations: The
vehicles tested in these studies do not fully represent the MY2000 and
older fleet. The RIT study only performed emissions testing on 2
vehicles from MY2000 and older and the mileage accumulated on E20 for
each vehicle was far less than the 120,000 mile FUL. Since the MCAR
study did not use Federal test procedures it would be difficult to
determine compliance to Federal emissions standards. Therefore, it is
not possible to draw adequate conclusions concerning the potential
impacts of E15 on the emission performance of MY2000 and older vehicles
from these studies.
    The Agency is not aware of any other information that would allow
us to fully assess the potential impacts of E15 on the emission
performance of MY2000 and older vehicles. The recently released Ricardo
study, despite its focus on MY1994-2000 motor vehicles, does little to
change this understanding. EPA believes that the Ricardo study offers
little additional data and information with which to assess the
emissions effect of E15 on MY2000 and older motor vehicles. First and
most importantly, Ricardo did not perform any emissions or durability
testing of E15 on MY2000 and older light-duty motor vehicles. Rather,
they conducted a literature search of existing data and information
already cited by Growth Energy, commenters, or otherwise available to
the Agency, and simply focused their discussion on MY1994-2000 vehicles
instead of all MY2000 and earlier vehicles. Second, the only new data
and information provided in the Ricardo study was their visible
inspection of fuel system components from 11 MY1994-2000 motor vehicles
that were evaluated for any visible signs of material compatibility or
durability issues. The fuel systems were collected from a reclamation
service in Southeast Michigan (Southeast Michigan has had varying
levels of E10 market penetration over the years). However, as the
authors acknowledge, since no vehicle history records were available to
indicate to what extent the fuel systems may have been exposed to E10,
if at all, during their lifetimes, it is impossible to draw any
definitive conclusions regarding the effects of ethanol on these
components. Finally, the authors did not draw any conclusions as to the
potential impacts of E15 relative to E0. The authors only concluded
that ``The analysis concluded that the adoption and use of E15 would
not adversely affect fuel system components in properly engineered
vehicles, nor would it cause then to perform in a sub-optimal manner,
when compared to the use of E10.''
    In addition to the paucity of data on MY2000 and older motor
vehicles, as discussed below, there are reasons for concern with the
use of E15 in these motor vehicles, particularly with respect to long-
term exhaust and evaporative emissions durability. This makes it
difficult to rely on an engineering assessment and makes the need for
actual emissions data critical.
b. Exhaust Emissions--Long-Term Durability
i. General Tailpipe Emissions Durability Concerns
    Ethanol enleans the A/F ratio, which leads to increased exhaust gas
temperatures and therefore potentially incremental deterioration of
emission control hardware and performance. Over time, the enleanment
caused by ethanol has the potential to cause catalyst failure. This
effect of E15 and the use of closed loop fuel trim to mitigate the
effect are discussed in more detail in section IV.A.1.c.i above.
    The A/F ratio of the carburetor is preset at the factory based on
the expected operating conditions of the engine such as ambient
temperature, atmospheric pressure, speed, and load. As a result,
carburetors have ``open loop'' fuel control, which means that the air
and fuel are provided at a specified, predetermined ratio that is not
automatically adjusted during vehicle operation. As fuel composition
can vary, an engine with a carburetor and open loop fuel control would
never know if it achieved the desired A/F ratio or not. Since the
vehicles at this time operated ``open loop'' all of the time with no
ability to react to changes in the A/F ratio, the addition of ethanol
to the fuel tended to make the A/F ratio leaner. This leaner operation
could increase catalyst temperature and therefore increase the
emissions deterioration rate.
    For MY2000 and older light-duty motor vehicles, which are capable
of operating with closed loop fuel control, the fuel trim range is
generally more limited than the range for newer vehicles, and these
vehicles may use their full range of fuel trim adjustment to account
for normal component deterioration. Injectors, sensors and changes to
fuel pressure may shift with time and aging to use all of the fuel
trim's range of adjustment. The additional oxygenate in E15 may
actually shift the A/F ratio more than the earlier introduction of E10
if the engine's A/F feedback cannot compensate because it has reached
its adjustment limit. In short, MY2000 and older motor vehicles and
earlier are at risk of having insufficient thermal margins to
accommodate ethanol blends up to E15 due to the limits of their fuel
trim authority.
    There is very little test data on the use of E15 in older vehicles
but the concern is more than just theoretical. Three studies--the CRC
Screening Study, DOE Pilot Study, and the Orbital Study--discussed in
section IV.A. highlight in particular the concern with MY2000 and older
motor vehicles. The CRC Screening Study (E-87-1) was a test program
developed to look at the effects of mid-level ethanol blends on U.S.
vehicles. This screening study was the first phase of a two-phase study
evaluating the effects of mid-level ethanol blends on emission control
systems. The purpose of this first phase of the study was to identify
vehicles which used learned fuel trims to correct open loop air-fuel
rations. Under the test program a fleet of 25 test vehicles was
identified and acquired with six of those vehicles being MY2000 and
older. The study collected vehicle speed, oxygen sensor air-fuel-ratio,
and catalyst temperature data for four fuels (E0, E10, E15, and E20).
The results of the three ethanol blended fuels compared to E0 showed
that four of the six MY2000 and older vehicles tested failed to apply
long-term fuel trim to open loop operation in order to compensate for
increasing ethanol levels. And that these same four vehicles exhibited
increased catalyst temperatures when operated on E20 as compared to E0.
While the subsequent DOE Catalyst Study concluded that this learned
fuel trim was not important for MY2007 and newer motor vehicles because
they are durable (and therefore can handle E15) as discussed in section
IV.A, there was no such follow on program for MY2000 and older motor
vehicles so the

durability of these vehicles on E15 is unknown.
    Another study suggests that many MY2000 and older motor vehicles
may also have emission exceedances if operated on E15. In 2003, the
Orbital Engine Company issued a report on the findings of vehicle
testing it completed to assess the impact of E20 on the Australian
passenger vehicle fleet. While the Australian vehicles in this study
were not representative of U.S. vehicles of the same model years, they
are similar to MY2000 and older U.S. motor vehicles with respect to
technology and emission standards. The testing program covered vehicle
performance and operability testing, vehicle durability testing, and
component material compatibility testing, on nine different vehicle
makes or models, five vehicles from MY2001 and four vehicles from
MY1985 to MY1993. Testing results showed increases in exhaust gas
temperature in five of the nine vehicles tested with three showing
increases in catalyst temperature. Enleanment was found to occur in six
of the nine vehicles tested, with three having closed loop control--the
old vehicles without closed loop control all displayed enleanment. In
general, the increase in exhaust gas temperature was found to follow
those vehicles with enleanment. Furthermore, one vehicle in the study
experienced catalyst degradation sufficient to make the tested vehicle
no longer meet its applicable Australian emission standards.
    Hence, based on this very limited test data and our engineering
judgment, we can conclude that MY2000 and older motor vehicles have the
potential to experience conditions when operated on E15 which may
ultimately lead to an increase in exhaust emissions. Specifically,
enleanment followed by higher exhaust temperatures could cause
accelerated catalyst deterioration. Furthermore, there are potential
concerns other than just catalyst durability for these older vehicles,
as highlighted by the Alliance in their comments. Absent actual
emissions durability testing, it is not possible to know the validity
of these emissions concerns with E15 in MY2000 and older motor
vehicles. Unlike for MY2007 and newer motor vehicles we are not aware
of any existing test program which can address the lack of data
concerning MY2000 and older motor vehicles.
ii. Immediate Exhaust Emission Impacts
    Growth Energy claims that the ACE Study, the RIT Study, the MCAR
Study, and the DOE Pilot Study show that E15 results in decreased
emissions of NOX, NMHC, and CO on average, and no increase
in NMOG emissions when compared to E0. Growth Energy argues that these
studies demonstrate E15 will not cause or contribute to the failure of
vehicles to meet their emissions standards. While much of the data
cited by Growth Energy was on E20, they argued that because the studies
they submitted with their application show favorable emissions
performance on blends that contained higher than 15% ethanol (i.e.
E20), those results should be applicable to E15 by interpolation.
    As discussed in IV.A.1, the ACE study, RIT Study, and MCAR Studies
offer little value in assessing the impact of E15 on immediate exhaust
emissions. Since the DOE Pilot Study focused only on motor vehicles
newer than MY2000, Growth Energy provided very little information of
value in assessing the immediate exhaust emission impacts of E15.
Furthermore, very little data has been collected on E15 on MY2000 and
older vehicles. However, also as discussed in section IV.A.1.b., the
Agency believes that there is sufficient data on older vehicles to
quantify the immediate emission impacts of E10 on older vehicles and
furthermore sufficient data from testing E15 primarily on newer
vehicles to have a reasonable projection of what the immediate emission
impacts of E15 are likely to be on MY2000 and older vehicles.
Specifically, as discussed in section IV.A.1.b., EPA would anticipate,
that the immediate emission impact of E15 will be similar for both
older vehicles and MY2007 and newer vehicles--to decrease NMOG (as well
as NMHC and total HC) and CO emissions and to increase NOX
emissions, with increases in NOX in the range of 5-10%. The
importance of this NOX increase is a function of what the
durability impacts might be, since they must be taken into
consideration together when evaluating potential impacts on compliance
with emissions standards.
c. Evaporative Emissions
    Much of the discussion in section IV.A.2 applies to MY2000 and
older motor vehicles. However it is important to note that this group
of vehicles has several key differences.
    First, the majority of these vehicles were designed and built prior
to the enhanced evaporative emissions requirements. These vehicles were
tested using the 1-hour diurnal plus hot soak procedure only. The CRC
E-77 test programs showed that permeation emissions are considerably
higher on pre-Tier 2 motor vehicles than on Tier 2 motor vehicles.
Therefore it is expected that permeation emissions with E15 on MY2000
and older motor vehicles will be much higher than that discussed in
section IV.A.3. for MY2007 and newer motor vehicles. However, given
that the evaporative emission standards that applied to MY1998 and
older motor vehicles (pre-enhanced evaporative emission control
standards), used only a 1-hour diurnal test, the increased permeation
emissions would not show up appreciably in the certification testing
and could not cause motor vehicles to exceed the emission standard.
    Second, the MY2000 and older motor vehicles were not required to
demonstrate evaporative emissions durability with fuels containing
ethanol. Furthermore, E10 had a limited market share during the time
when many of these motor vehicles were designed and built. This raises
the concern that the fuel and evaporative emissions system components
may not have been designed for constant exposure to E10, and especially
not E15. These older motor vehicles could experience significant
material compatibility issues (as discussed below) that could lead to
elevated evaporative emissions over time or both fuel and vapor leaks.
Thus, while the immediate evaporative emission impacts of E15 may not
be a waiver concern, evaporative emission durability would be a primary
concern for MY2000 and older motor vehicles. Finally, these motor
vehicles were not subject to OBD leak detection, so if problems did
occur there would be no OBD warning for the vehicle owner.
d. Materials Compatibility
    The Agency has reviewed the studies that have shown generally
acceptable materials compatibility in newer motor vehicles (i.e. Tier 2
motor vehicles) with ethanol up to 10% by volume, but degradation of
certain metals, elastomers, plastics, and vehicle finishes with higher
dosages.\96\ However, most of these studies, including the Minnesota
Compatibility Study, were on component parts using laboratory bench
tests rather than durability studies of whole vehicle fuel systems
simulating ``real world'' vehicle use. In addition, there is no way to
correlate the results of the study with MY2000 and older motor
vehicles. Many different materials were used over the years and we do
not have data that shows which manufacturers used which specific
materials at various points in time. We can conclude, however, that
some portion of the fleet may experience changes that could result in

accelerated component failures beyond what would be expected on E0 or
E10. We are especially concerned that older motor vehicles may not have
been designed to accommodate ethanol blends.
---------------------------------------------------------------------------

    \96\ SAE J1297, revised July, 2007, Surface Vehicle Information
Report, Alternative Fuels.
---------------------------------------------------------------------------

    The Agency believes, based on its review of the literature and
automotive industry comments, that a number of pre-Tier 2 motor
vehicles, including Tier 0 motor vehicles (from the 1980s to 1995) and
Tier 1 motor vehicles (from 1996 to 2001), may have been designed for
only limited exposure to E10 and consequently may have the potential
for increased material degradation with the use of E15 even though they
are beyond their useful life requirements. This potential for material
degradation may make the emissions control and fuel systems more
susceptible to corrosion and chemical reactions from E15 when compared
to the certification fuels for these motor vehicles which did not
contain any ethanol, and therefore may increase vehicle emissions. For
MY2000 and older motor vehicles, especially, E15 use may result in
degradation of metallic and non-metallic components in the fuel and
evaporative emissions control systems that can lead to highly elevated
hydrocarbon emissions from both vapor and liquid leaks. Potential
problems such as fuel pump corrosion or fuel hose swelling will likely
be worse with E15 than historically with E10, especially if motor
vehicles operate exclusively on it. Since ethanol historically
comprised a much smaller portion of the fuel supply, in-use experience
with E10 was often discontinuous or temporary, while material effects
are time and exposure dependent. Thus, issues may surface with E15 that
have not surfaced historically in-use.
    The authors of the Ricardo study acknowledge that ``Many materials
have been used in the fuel systems of light duty motor vehicles, small
engines, and off-road equipment. Limiting the scope to light duty motor
vehicles, including passenger cars and light trucks, from the target
range of model years (1994 to 2000) it is impractical to complete a
comprehensive survey of the materials that might be exposed to liquid
fuels.'' This highlights the concern that older motor vehicles could
experience significant material compatibility issues.
e. Driveability and Operability for MY2000 and Older Light-Duty Motor
Vehicles
    Very little test data was submitted regarding driveability and
general operability of MY2000 and older light-duty motor vehicles
operating on E15. However as discussed in the MY2007 and newer light-
duty motor vehicle analysis, past issues with driveability and
operability of older technology fuel controls have been observed with
fuels containing ethanol. Hence, absent data to prove otherwise, there
is uncertainty regarding the ability of MY2000 and older motor vehicles
to handle E15. We have concerns that these motor vehicles could
experience driveability and operability issues that may also lead to an
emissions increase.
f. Conclusions
    It is the burden of the applicant to demonstrate that any new fuel
or fuel additive that requires a waiver under CAA section 211(f)(4) of
the substantially similar prohibition in CAA section 211(f)(1) will not
cause or contribute to the failure of motor vehicles to meet their
emissions standards over the vehicles' full useful life. Growth Energy
has not made this demonstration for MY2000 and older light-duty motor
vehicles as Growth Energy has not provided sufficient data and
information to broadly assess the performance of these motor vehicles
while using E15. Additionally, based on our own engineering judgment
after review of all available data and information for MY2000 and older
light-duty motor vehicles, we find that there are concerns about
potential emissions increases with the use of E15 in these vehicles,
particularly regarding long-term exhaust and evaporative emissions
(durability) impacts and materials compatibility. Therefore, the Agency
has concluded that it cannot grant a waiver for the use of E15 in
MY2000 and older light-duty motor vehicles based on existing data.

V. Nonroad Engines and Equipment (Nonroad Products)

A. Introduction

    Past waiver decisions were made solely on the basis of the emission
impacts of the fuel or fuel additive on motor vehicles. However, with
the passage of the Energy Independence and Security Act of 2007, CAA
section 211(f)(4) was expanded to require that the emissions impacts on
nonroad engines and nonroad vehicles (collectively referred to as
nonroad products in this section) also be taken into consideration when
reviewing a waiver application. Nonroad products for the following
discussion is defined as those nonroad products that contain spark-
ignition engines and are used to power such nonroad vehicles and
equipment as boats, snowmobiles, generators, lawnmowers, forklifts,
ATVs, and many other similar products. These nonroad products are
typically used only seasonally and occasionally during the season which
is very different from the daily use of automobiles. Due to the
seasonal and occasional use, consumers can hold onto and use their
nonroad products over decades with some being 30 or 40 years old.
Nonroad engines are typically more basic in their engine design and
control than engines and emissions control systems used in light-duty
motor vehicles, and commonly have carbureted fuel systems (open loop)
and air cooling (extra fuel is used in combustion to help control
combustion and exhaust temperatures).
    EPA received authority to regulate emissions from nonroad products
with the Clean Air Act Amendments of 1990. Through a series of
subsequent rulemakings, EPA has promulgated exhaust emission standards
for the categories of new nonroad engines that use motor vehicle
gasoline: (1) Small spark-ignition engines, (2) large spark-ignition
engines, (3) marine spark ignition engines, and (4) recreational
engines. Evaporative emission standards (tank permeation, hose
permeation, diurnal and running loss) have been promulgated on a
portion of the nonroad products in these categories. Thus, like for
motor vehicles, EPA's emissions impact analysis for nonroad products
concentrates on the following four major areas: (1) Exhaust emissions,
both immediate and longer-term durability, (2) evaporative emissions,
both immediate and long-term; (3) materials compatibility, and (4)
driveability.
    The following table summarizes the various nonroad products and
their applicable emissions standards. The current standards are to be
met after a period of engine aging which is done on either a
dynamometer or chassis per regulation requirements per nonroad sector.

[GRAPHIC] [TIFF OMITTED] TN04NO10.007

[GRAPHIC] [TIFF OMITTED] TN04NO10.008

    Typical emission control strategies for nonroad products include
enleanment and engine redesign with some limited number of nonroad
products adding catalysts. A limited number of nonroad products have
also incorporated electronic fuel injection; however the vast majority
of all nonroad products still use open loop fuel systems (either
carbureted or fuel injected) and hence do not adjust automatically for
oxygenated fuel. The result of all this is that there is a broad range
of nonroad engine and equipment designs across the nonroad sector,
making it difficult to apply data or conclusions from one nonroad
product broadly. For example, the following list shows the various
trends in design changes in nonroad engines due to emission
regulations.
---------------------------------------------------------------------------

    \97\ On-highway motorcycles have separate emissions standards
and minimum useful life requirements, which may be found in 40 CFR
Part 86 Subpart E.
---------------------------------------------------------------------------

     Small spark-ignition Class I and Class II (nonhandheld)
engines are typically open loop carbureted 4-stroke, side valve or
overhead valve design, air and fuel cooled engines. Engine
manufacturers have incorporated changes to the engine designs
(improving combustion chamber design, adding valve guides, improving
cooling, etc.), incorporated catalysts on some models and enleaned
engine operating A/F ratios from past richer operation approaches.

     Small spark-ignition Class III-Class V (handheld) engines
are typically open loop carbureted 2-stroke,air and fuel cooled
engines. Engine manufacturers have incorporated changes to the 2 stroke
engine designs including reduced scavenging, lean out the A/F ratio,
from past richer operation approaches, and catalysts (on some models).
Some manufacturers have switched to 4-stroke design or mixed (2- and 4-
stroke) design where the application allows.
     Large Spark Ignition Engines are typically retrofitted
automobile engines and a number of them do run on motor vehicle
gasoline. These engines are water cooled and run feedback electronic
controls much like their automotive equivalent.
     Marine outboard and personal watercraft engines were
typically open loop carbureted 2 stroke engines. Today these engines
are typically open loop 4-stroke engines or direct injected 2-stroke
engines. Engines are water cooled.
     Marine sterndrive/inboard engines are typically open loop
4-stroke carbureted or electronic fuel injection and emission
regulations in 2010 are expected to result in catalysts on sterndrive/
inboard engines and possibly closed loop electronic fuel injection.
Engines are water cooled.
     Off-highway motorcycles and ATVs have typically been open
loop carbureted 2-stroke and 4-stroke engines but are becoming more 4-
stroke design with some fuel injection. These engines are typically air
and fuel cooled.
     Snowmobile engines have typically been open loop
carbureted 2-stroke engines but have recently started to migrate
towards fuel injection and even some 4-stroke engines.

B. Growth Energy Submission

    Growth Energy provided only limited information in support of their
waiver request application regarding the potential emission impacts of
E15 on nonroad products. For addressing the potential long-term exhaust
emission (durability) impacts, Growth Energy refers to a single study
of ethanol blend use in nonroad engines: the DOE Pilot Study. Growth
Energy states in its application that the DOE Pilot Study compared
regulated emission levels from a comprehensive and nationally
representative fleet of 28 small nonroad engines (SNREs), and that the
DOE Pilot Study showed that regulated emissions were no worse for E15
and E20 when compared with E0. Growth Energy argues that the DOE Pilot
Study demonstrates that E15 will not cause or contribute to nonroad
engines failing to meet emissions standards.
    For addressing immediate exhaust emission impacts, Growth Energy
referenced a 1999 SAE report, ``The Effect of High Ethanol Blends on
Emissions from Small Utility Engines.'' \98\ The study conducted
emissions testing on three MY1994 small (12.5 hp) engines using SAE and
EPA procedures. Ethanol was splash blended with a commercial RBOB to
produce E0, E10, E25, and E50. The small engine set included two 12.5-
hp (9.3 kW gross rating) Briggs & Stratton side-valve engines, and one
12.5-hp Kohler overhead-valve engine. The engines started out running
rich on E0, but became leaner with increasing ethanol content. As the
ethanol concentration increased, HC and CO emissions decreased, and
NOX emissions increased. The emissions results were fully
consistent with the observed stoichiometries. Because NOX is
regulated by standards for HC+NOX, from a regulatory
perspective, the overall emission performance was relatively unaffected
by the changes in ethanol content. Growth Energy claims this study
demonstrates that E15 should not have any impact on HC+NOX
emissions.
---------------------------------------------------------------------------

    \98\ Bresenham, D. and Reisel, J. ``The Effect of High Ethanol
Blends on Emissions from Small Utility Engines,'' SAE 1999-01-3345,
JSAE 9938100, 1999.
---------------------------------------------------------------------------

    Growth Energy did not submit any test data that evaluated how the
use of E15 would impact evaporative emissions and evaporative emissions
controls for nonroad products, either for immediate emission impacts or
long-term evaporative emission impacts (durability).
    They did, however, cite the Minnesota Compatibility Study to
address potential materials compatibility concerns with E15; materials
compatibility issues could also lead to evaporative (short-term
permeation or long-term durability) as well as long-term exhaust
emission impacts. Growth Energy suggests that the Minnesota
Compatibility Study tested commonly used materials in the construction
of nonroad engines and that the DOE Pilot Study concluded that ``no
obvious materials compatibility issues were observed during [the]
testing'' of SNREs.\99\ Growth Energy argues that the Minnesota
Compatibility Study demonstrates that SNREs should experience no
significant materials compatibility problems with E15.
---------------------------------------------------------------------------

    \99\ EPA Docket Number: EPA-HQ-OAR-2009-0211-0002.6: Growth
Energy Application, 34.
---------------------------------------------------------------------------

    Growth Energy did not provide any data or information quantifying
the potential impacts of E15 on the operability or driveability of
nonroad products. Instead, they pointed to the DOE Pilot Study
discussed above which evaluated long-term emission performance of
SNREs. Growth Energy claims that the DOE Pilot Study demonstrates that
the use of E15 will not have a discernable impact on the performance
and operability of SNREs. They stated that since the DOE Pilot Study
shows that the engine performance of SNREs varies considerably
regardless of fuel type used that it is not possible to isolate the
effects of ethanol on the operability of SNREs.\100\
---------------------------------------------------------------------------

    \100\ EPA Docket Number: EPA-HQ-OAR-2009-0211-0002.6:. Growth
Energy Application, 34.
---------------------------------------------------------------------------

    In their comments, Growth Energy wrote that there ``is no
scientific basis'' for excluding SNREs in a waiver for E15, and further
states that the DOE Pilot Study ``found no statistically significant
impact on operations from higher-blend ethanol, including E-15.''
Growth Energy also argues that there are no studies that show that E15
will create problems for nonroad engines (marine engines specifically).

C. Public Comment Summary

    AllSAFE and several other commenters argued that the DOE Pilot
Study's test program is too small and unrepresentative of the national
SNRE population. The commenters pointed out that the DOE Pilot Study
only looked at 10 different small spark ignited engines <19kW.\101\ The
commenters noted that those engines were only from three of the
possible seven main classes of SNREs.\102\ The commenters stated that
in 2008, over 1,000 individual SNREs were certified by EPA, so the 10
engines tested were not comprehensive and nationally representative.
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    \101\ The study contained two parts; (1) a pilot (new engine)
emission study and (2) a study of emissions after a full life
durability dynamometer aging. Four different engines were used in
the full life durability portion (Briggs & Stratton, Honda, Stihl,
Poulan) and multiple engines for each of these were utilized in the
study. The multiple engines were used to age different engines on
different ethanol blend fuels (E0, E10, E15 and E20).
    \102\ Small spark ignition engines are grouped into seven
Classes and include Class I, Class I-A, Class I-B, Class II, Class