What is Ethanol?

Ethanol is a grain alcohol that can be blended with gasoline and used in motor vehicles. Many gasoline stations provide a blended fuel, typically 10 percent ethanol and 90 percent gasoline. Vehicles do not need any modifications to use this blend of fuel. Flex fuel vehicles modify the fuel systems and can use E85, a blend of up to 85 percent ethanol and 15 percent gasoline. With the modifications, these vehicles can use straight gasoline or any ethanol blend up to 85 percent. (Courtesy of University of Illinois Extension.)

Ethanol is a cleaner-burning alternative fuel produced from domestic renewable resources such as corn and other starch-containing plant materials known as biomass. It can also be made from cellulosic materials like switchgrass and crop residues.

How is ethanol produced?

In the United States, ethanol is primarily produced from the starch in corn grain. Recent studies using updated data about corn production methods demonstrate a positive energy balance for corn ethanol, meaning that fuel production does not require more energy than the amount of energy contained in the fuel.

There are several steps involved in making ethanol available as a vehicle fuel:

Biomass feedstocks are grown, collected, and transported to an ethanol production facility

Ethanol is produced from feedstocks at a production facility and then transported to a blender/fuel supplier

Ethanol is mixed with gasoline by the blender/fuel supplier to make E10, E15, or E85 and distributed to fueling stations.

How is ethanol used?

More than 95% of U.S. gasoline contains ethanol, typically E10 (10% ethanol, 90% gasoline), to oxygenate the fuel and reduce air pollution. Ethanol is also available as E85 (a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season). This fuel can be used in flexible fuel vehicles, which run on high-level ethanol blends, gasoline, or any blend.

Ethanol Benefits

The U.S. Department of Energy estimates for every one billion gallons of ethanol produced, 10,000 to 20,000 jobs are added to our domestic economy.

In 2014 alone, the ethanol industry created and supported nearly 400,000 new jobs nationwide that cannot be exported or outsourced. In addition, ethanol production contributed almost $53 billion to the nation’s GDP and generated $5.7 billion in federal tax revenues. Ethanol production also contributes to revitalizing America’s rural areas — some of the hardest hit by the economic downturn — by stimulating economic growth.

According to the Department of Energy’s Argonne National Laboratory, ethanol reduces greenhouse gas emissions by an average of 34 percent compared to gasoline. Moreover, advanced biofuels have the potential to reduce greenhouse gas emissions by over 100 percent. Ethanol from any source has a positive net energy balance — meaning it gives more energy than is needed to produce it.

In 2014, the 13.4 billion gallons of ethanol blended into gasoline in the United States helped reduce greenhouse gas emissions from on-road vehicles by approximately 38 million metric tons, equivalent to removing roughly 8 million automobiles from the road. Imagine if we were using more ethanol in our motor fuels.

Ethanol is already replacing millions of barrels of imported petroleum. That’s petroleum that could have ended up in our environment, devastating coastal industries, ecosystems, and communities. Ethanol is clean-burning, renewable, and grown here in America.

The EPA estimates that higher Renewable Fuel Standards will reduce Greenhouse Gas Emissions from transportation by a total of 6.8 billion tons of CO2 equivalent when measured over a 100-year timeframe. This is the equivalent of approximately 160 million tons of CO2 equivalent per year. The overall reductions would be like removing 24 million vehicles from the road.

Ethanol's Emission Reductions

The carbon dioxide released when ethanol is burned is balanced by the carbon dioxide captured when the crops are grown to make ethanol. This differs from petroleum, made from plants raised millions of years ago. On a life cycle analysis basis, corn-based ethanol production and use reduces greenhouse gas emissions (GHGs) by up to 52% compared to gasoline production and use. Cellulosic ethanol use could reduce GHGs by as much as 86%.

Ethanol In Action

Where is E85 available in Tennessee?

Pilot Travel Centers



Twice Daily

Where can I find a list of flexible fuel vehicles (FFVs) available for purchase?

Renewable Fuels Association (RFA) maintains a list of FFVs showing the OEMs/auto brand’s FFV offerings from 2018 to the 1990s! That means you can shop for used FFVs, too.

What are the different blends used by Tennessee fleets?

E10 and E85.

E85 is 51-83% ethanol blended with gasoline, now called “flex fuel.”

E10 is now the fuel you find at almost every convenience store from coast to coast.

Also growing in sales across the U.S. are E15 and “Mid-level blends” that include E30 and E40, although those are not widely available yet in Tennessee.