What is the difference between e15 and e85

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Forgot password? When drivers use E10 or E15 instead of pure gasoline, they will notice a decrease in miles per gallon. This is because compared to pure gasoline, ethanol has about one-third less energy. A percent blend is not a flex fuel. The Renewable Fuels Association defines a flex fuel as a blend of ethanol and gasoline that contains more than 15 percent ethanol and less than 83 percent ethanol. According to Cars.

They can run on anything from percent gasoline to blends containing 85 percent ethanol. All model standard vehicles and newer can run on E15 but can't handle the corrosiveness of higher ethanol percentages. The Society of Automotive Engineers and other supporters of E85 usage argue that if automotive manufacturers would recognize and take advantage of ethanol-based fuel's superior traits, they could make an ethanol engine that was as efficient as one powered by gasoline.

According to these proponents, an ethanol engine that can reach up to 22 percent more miles per gallon than a gasoline engine already exists. It's wrong, they say, to base ethanol engine design on that of a gas engine when ethanol is closer to diesel fuel. Critics of E85 and ethanol, in general, argue that its lower heating value outweighs any benefits. Supporters counter that argument by pointing out that heating value does not factor into overall efficiency.

Adding a fraction of gasoline to ethanol blends can counteract the low heating value. E85 also has higher octane content, which can provide more engine power. Thanks to an abundance of corn, E85 is only going to become more common in the United States. Increased support and government subsidies mean that E85 and other flex fuels are here to stay. New Cars.

Buyer's Guide. Type keyword s to search. Today's Top Stories. Tom Merton Getty Images. E85 Flex Fuel E85 is the most common form of flex fuel available on the market.

E10 remains the limit for passenger vehicles older than model year and for other non-road and small engines and vehicles that use gasoline, such as lawn mowers, motorcycles, and boats. There are additional regulations for stations selling blends above E For more information, visit the Codes, Standards, and Safety page. More Ethanol Publications All Publications.