Science Energy Pros and Cons of Using Ethanol Biofuel E85 Look up your car to see if it is flex-fuel compatible By Christine & Scott Gable Christine & Scott Gable Writers Millersville University Christine and Scott Gable are hybrid auto and alternative fuel experts who have brewed their own biodiesel and traveled 125,000 miles on waste vegetable oil. Learn about our editorial process Updated June 19, 2017 Share Twitter Pinterest Email Science Renewable Energy Fossil Fuels Approximately 49 million ethanol flexible-fuel cars, motorcycles and light trucks were sold in the United States by mid-2015, yet many buyers still remain unaware that the car they own can utilize E85. E85 is 85 percent ethanol and 15 percent gasoline. Ethanol is a biofuel that produced in the U.S. with corn. Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages. It has been part of the nation’s fuel supply for almost 40 years. Research shows that ethanol may help lower fuel costs, improve air quality and increase octane. Ethanol can be used in any vehicle and is covered under warranty by every automaker in the U.S. Some cars can use more ethanol than others. What Is a Flexible-Fuel Vehicle A flexible-fuel vehicle is also known as an alternative fuel vehicle with an internal combustion engine designed to run on more than one fuel, usually, gasoline blended with either ethanol or methanol fuel, and both fuels are stored in the same common tank. Vehicles That Are E85 Compatible The U.S. Department of Energy tracks fuel economy information and helps consumers perform flex-fuel cost comparisons and calculations. The department also maintains a database of all E85 compatible vehicles. Flexible-fuel vehicles have been produced since the 1990s, and more than 100 models are currently available. Since these cars look just like gasoline-only models, you may be driving a flexible-fuel vehicle and not even know it. Advantages of Flex-Fuel Vehicles Switching to an ethanol-based fuel moves us further from using up our depletable fossil fuels and closer to U.S. energy independence. Ethanol production in the U.S. primarily comes from corn. In the American Midwest, corn fields are set aside for ethanol production, which has been shown to have a positive effect on job growth and stability. Ethanol is also greener than gasoline because corn and other plants absorb carbon dioxide from the atmosphere as they grow. The fuel still releases CO2 when you burn it, but it is believed that the net increase is lower. Any car since 1980 has been designed to handle up to 10 percent ethanol in the gasoline, letting you run that percentage of your miles on a domestic fuel rather than irreplaceable fossil fuels. Disadvantages of Flex-Fuel Vehicles Flex-fuel vehicles may not experience a loss in performance when operating on E85, in fact, some generate more torque and horsepower than when operating on gasoline, but since E85 has less energy per volume than gasoline, flex-fuel vehicles can get up to 30 percent fewer miles per gallon when fueled with E85. This means you will get fewer miles per dollar spent. If filling up with flex-fuel is what you want, then finding a flex-fuel station might be a little difficult. Only about 3,000 stations across the U.S. sell E85 at the moment and most of those stations are in the Midwest. To give you some perspective, there are about 150,000 gas stations in the country. Despite the promising research, there are still question marks regarding the agricultural impacts and real energy balance of growing crops to use as fuel.