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), E15 (10.5% to 15% ethanol), or 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, the use of ethanol involves several considerations.
The United States became a net exporter of petroleum in 2020 with exports surpassing imports, although imports of 7.86 million barrels per day remained an important part of balancing supply and demand for domestic and international markets. Overall, the transportation sector accounts for approximately 30% of total U.S. energy needs and 70% of U.S. petroleum consumption. Using ethanol and other alternative fuels and advanced technologies to reduce fuel consumption continues to strengthen national security and reduce transportation energy costs for businesses and consumers.
Fuel Economy and Performance
The impact to fuel economy varies depending on the energy difference in the blend used. For example, E85 that 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. Several projects currently under way, including the Co-Optimization of Fuels and Engines initiative, seek 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 2020 accounted for more than 62,000 direct jobs across the country, $35 billion to the gross domestic product, and $19 billion in household income. (See the Pocket Guide to Ethanol 2021.)
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, greenhouse gas (GHG) emissions are reduced on average by 40% with corn-based ethanol produced from dry mills, and range between 88% and 108% if cellulosic feedstocks are used depending on feedstock type, compared with gasoline and diesel production and use. (See the Life-Cycle Greenhouse Gas Emission Reductions of Ethanol with the GREET Model.)
To learn more about fuel economy, GHG scores, and U.S. Environmental Protection Agency smog scores for FFVs, visit FuelEconomy.gov, or see the Alternative Fuel and Advanced Technology 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 ethanol (E85) fueling stations in your area.