Ethanol Benefits and Considerations
Ethanol is a renewable, domestically produced transportation fuel. Whether used in low-level blends, such as E10 (10% ethanol, 90% gasoline), or in E85 (flex fuel)—a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season—ethanol helps reduce emissions. Like any alternative fuel, there are some considerations to account for when contemplating the use of ethanol
In 2017, the United States imported about 19% of the petroleum it consumed, and that number would have been significantly higher if ethanol had not been domestically produced and consumed. Because transportation accounts for nearly three-fourths of total U.S. petroleum consumption, using ethanol fuel blends has a significant impact. This also supports the U.S. economy, helps diversify the U.S. transportation fleet, and reduces the impact of international supply disruptions. All of this adds to our nation’s energy security.
Fuel Economy and Performance
A gallon of ethanol contains less energy than a gallon of gasoline, resulting in lower fuel economy when operating your vehicle. The impact to fuel economy varies depending on the energy difference in the blend used. For example, E85, which contains 83% ethanol content, has about 27% less energy per gallon than gasoline (the impact to fuel economy lessens as ethanol content decreases). Engines in gasoline vehicles, including flexible-fuel vehicles (FFVs), are optimized for gasoline. If they were optimized to run on higher ethanol blends, fuel economy would likely increase as a result of increased engine efficiency.
Ethanol also has a higher octane number than gasoline, which provides increased power and performance. For example, Indianapolis 500 drivers often fuel their race cars with E98 because of its high octane. There are currently projects underway, including the Co-Optimization of Fuels and Engines initiative, to understand the potential for improving engine efficiency through the use of ethanol blends and other high-octane biofuels.
Ethanol production creates jobs in rural areas where employment opportunities are needed. According to the Renewable Fuels Association, ethanol production in 2017 accounted for more than 71,900 direct jobs across the country, $45 billion to the gross domestic product, and $24 billion in household income. (See the Pocket Guide to Ethanol 2018).
The carbon dioxide released by a vehicle when ethanol is burned is offset by the carbon dioxide captured when the feedstock crops are grown to produce ethanol. This differs from gasoline and diesel, which are refined from petroleum extracted from the earth. No emissions are offset when these petroleum products are burned. On a life cycle analysis basis, GHG emissions are reduced on average by 34% with corn-based ethanol produced from dry mills, and up to 108% if cellulosic feedstocks are used, compared with gasoline and diesel production and use.
To learn more about fuel economy, GHG scores, and EPA smog scores for FFVs, visit FuelEconomy.gov, or see the 2018 Model Year Alternative Fuel and Advanced Vehicles list.
Equipment and Availability
Low-level blends of E10 or less require no special fueling equipment, and they can be used in any conventional gasoline vehicle.
It is also possible to accommodate blends above E10 in existing fueling equipment, however, some equipment needs to be upgraded to comply with federal code. See the Codes, Standards, and Safety page and the Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends for detailed information on compatible equipment.
FFVs (which can operate on E85, gasoline, or any blend of the two) are available nationwide as standard equipment with no incremental cost, making them an affordable alternative fuel vehicle option. Fueling stations offering E85 (flex fuel) are located in 42 states. Find E85 fueling stations in your area.