Study Finds Certain Ethanol Blends Can Provide Better Fuel Economy Than Gasoline
American Coalition for Ethanol
Research findings released today show that mid-range ethanol blends--fuel mixtures with more ethanol than
E10 but less than E85--can in some cases provide better fuel economy than regular unleaded gasoline, even in
standard, non-flex-fuel vehicles.
Previous assumptions held that ethanol's lower energy content directly correlates with lower fuel economy
for drivers. Those assumptions were found to be incorrect. Instead, the new research strongly suggests
that there is an "optimal blend level" of ethanol and gasoline--most likely E20 or E30--at which cars
will get better mileage than predicted based strictly on the fuel's per-gallon Btu content. The new study,
cosponsored by the U.S. Department of Energy and the American Coalition for Ethanol (ACE), also found that
mid-range ethanol blends reduce harmful tailpipe emissions.
"Initial findings indicate that we as a nation haven't begun to recognize the value of ethanol," said Brian
Jennings , executive vice president of the American Coalition for Ethanol. "This is a compelling argument for
more research on the promise of higher ethanol blends in gasoline. There is strong evidence that the optimal
ethanol-gasoline blend for standard, non-flex-fuel vehicles is greater than E10 and instead may be E20 or E30.
We encourage the federal government to move swiftly to research the use of higher ethanol blends and make
necessary approvals so that American motorists can have the cost-effective ethanol choices they deserve at the
The University of North Dakota Energy & Environmental Research Center (EERC) and the Minnesota Center
for Automotive Research (MnCAR) conducted the research using four 2007 model vehicles: a Toyota Camry,
a Ford Fusion and two Chevrolet Impalas, one flex-fuel and one non-flex-fuel. Researchers used the EPA
Highway Fuel Economy Test (HWFET) to examine a range of ethanol-gasoline blends from straight Tier
2 gasoline up to 85 percent ethanol. All of the vehicles got better mileage with ethanol blends than the
ethanol's energy content would predict, and three out of four actually traveled farther on a mid-level
ethanol blend than on unleaded gasoline.
"I applaud the American Coalition for Ethanol for taking action and studying the impact of intermediate blends
of ethanol. I am encouraged by the findings of this study, which should benefit the federal regulatory process
for approving higher blends of ethanol," said U.S. Senator John Thune (R-SD). "Intermediate blends of
ethanol will offer consumers more choices at the pump, reduce dependence on foreign oil, and benefit our
domestic ethanol industry for years to come."
In addition to the favorable fuel economy findings, the research provides strong evidence that standard, non-
flex-fuel vehicles can operate on ethanol blends beyond E10. The three non-flex-fuel vehicles tested operated
on levels as high as E65 before any engine fault codes were displayed. Emissions results for the ethanol blends
were favorable for nitrogen oxides, carbon monoxide and non-methane organic gases, showing an especially
significant reduction in CO2 emissions for each vehicle's "optimal" ethanol blend (E20 for the flex-fuel Chevy,
E30 for the Toyota and Ford, E40 for the non-flex Chevy).
"These studies show that moderate 20-30 percent ethanol blends can reduce air pollution, improve
gas mileage, and save drivers money in the most popular cars on the road today," said Brett Hulsey ,
president of Better Environmental Solutions, an environmental health consulting firm. "Moderate ethanol
blends are homegrown in America, can be delivered with existing pumps to current vehicles, and cost less
than gasoline. Ethanol lowers CO2 emissions 20 percent from gasoline, making it one of our most effective
greenhouse gas reduction programs currently in place."
Ethanol's energy content was not found to be a direct predictor of fuel economy. A fuel's energy content in
British Thermal Units (Btu) is current standard practice for estimating fuel economy, a method that, because
of ethanol's lower Btu value, leads to estimates of decreased fuel economy in proportion to the percentage of
ethanol in the fuel blend.
-- This research, however, did not find ethanol's Btu content to be a direct predictor of fuel economy. All four
vehicles tested exhibited better fuel economy with the ethanol blends than the Btu-value estimates predicted.
E20 and E30 ethanol blends outperformed unleaded gasoline in fuel economy tests for certain autos. Contrary to
Btu-based estimates of fuel economy for ethanol blends, three of the four vehicles tested achieved their highest
fuel efficiency not on gasoline, but on an ethanol blend. Mid-level blends of ethanol E20 (20% ethanol, 80%
gasoline) and E30 (30% ethanol, 70% gasoline) offered the best fuel economy in these tests.
-- E30 offered better fuel economy than gasoline (a 1% increase) in both the Toyota and the Ford.
-- E20 offered better fuel economy than gasoline (a 15% increase) in the flex-fuel Chevrolet.
-- The non-flex-fuel Chevrolet more closely followed the Btu-calculated trend for fuel economy, but did
experience a significant improvement over the trend line with E40 (40% ethanol, 60% gasoline), indicating that
this may be the "optimal" ethanol blend level for this vehicle.
Standard, non-flex-fuel vehicles operated well on ethanol blends beyond 10 percent - All automakers currently
cover the use of up to E10 (10% ethanol, 90% gasoline) by warranty for standard, non-flex-fuel vehicles. In
this preliminary research, the three non-flex-fuel vehicles tested each operated successfully on ethanol blends
significantly higher than this 10% ethanol level.
-- The Ford Fusion operated on E45, the Toyota on E65, and the non-flex-fuel Chevy on E55. No engine fault
codes were displayed until these levels were surpassed.
The American Coalition for Ethanol (ACE) is the grassroots voice of the U.S. ethanol industry, a national
trade association for the ethanol industry with nearly 2,000 members nationwide, including farmers, ethanol
producers, commodity organizations, businesses supplying goods and services to the ethanol industry,
rural electric cooperatives, and individuals supportive of increased production and use of ethanol. For more
information about ethanol or ACE, visit www.ethanol.org or call (605) 334-3381.
Study shows higher ethanol blends may improve fuel economy
One of the criticisms of ethanol as a vehicle fuel is that fuel economy is reduced due to the lower BTU content
of a gallon of ethanol vs. gasoline. However, a recent research study has shown ethanol blends of up to E30
may actually improve fuel economy for cars on the road today!
The research was performed by the University of North Dakota Energy and Environmental Research Center
and the Minnesota Center for Automotive Research. Their report is titled Optimal Ethanol Blend Level
The testing was performed using four cars, all 2007 models, a Toyota Camry, a Ford Fusion, a regular fuel
Chevrolet Impala and a flex-fuel Chevrolet Impala. The vehicles were tested using the U.S. EPA fuel economy
test procedures and they were also tested using the EPA standard emission tests for pollutants. The vehicles
were each tested using regular gasoline, ethanol blends at 10% intervals up to E70 and E85. Here are some of
the more interesting findings:
Three of the four cars had better fuel economy at either E20 or E30 than with regular gas. The best was
the flex-fuel Impala, which had an improvement of 15% on E20. The others have a small improvement
All of the cars have significantly reduced emissions on higher ethanol blends.
The non-flex-fuel cars were able to run and perform without problems on blends of up to E45.
What I take from this is that cars on the road today could run on ethanol blends up to around E30 without a loss
of fuel economy or performance and flex-fuel designed vehicles may even have improved fuel economy. The
U.S. currently consumes 400 million gallons of gas per day. Replacing 25% of gasoline with ethanol would
reduce annual gasoline consumption by 40 billion gallons, and probably send the Saudis to the poor house!
The report said the government should do further testing to confirm the results of this relatively small sample. If
the results are verified it could be very good news for the ethanol industry.
Source: Alternative Energy News