December 6, 2007
Study finds that certain ethanol blends can provide better fuel economy than gasoline
Sioux Falls, South Dakota – A new study co-sponsored by the U.S. Department of Energy and the American Coalition for Ethanol (ACE) shows that mid-range ethanol blends can, in some cases, provide better fuel economy than regular unleaded gasoline, even in standard non-flex-fuel vehicles. The mixtures have more ethanol than E10 (10 per cent ethanol) but less than E85 (85 per cent ethanol).
The study says that previous assumptions that ethanol’s lower energy content directly correlates with lower fuel economy for drivers are incorrect. 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 study 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 ACE. “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 pump.”
The research, conducted by the University of North Dakota Energy & Environmental Research Center and the Minnesota Center for Automotive Research, conducted the study using four 2007 model-year vehicles: a Toyota Camry, Ford Fusion, and two Chevrolet Impalas, one flex-fuel and one conventional. Researchers used the EPA Highway Fuel Economy Test to examine a range of ethanol-gasoline blends, from straight Tier 2 gasoline to E85. All of the vehicles got better mileage with ethanol blends than the ethanol’s energy content would predict, and three out of four travelled further on a mid-level ethanol blend than on unleaded gasoline.
In addition, the research provides strong evidence that standard, non-flex-fuel vehicles can operate on ethanol blends beyond 10 percent. The three non-flex-fuel vehicles operated on levels as high as E65 before any engine fault codes were displayed. Emission results for the ethanol blends were also favourable for nitrogen oxides, carbon monoxide and non-methane organic gases, with a significant reduction in CO2 emissions for each vehicle’s optimal ethanol blend.