E10 and other Low-Level Ethanol Blends

Low-level ethanol blends are sold in every state. In fact, nearly half of U.S. gasoline now contains up to 10% ethanol (E10) to boost octane or meet air quality requirements.

The Clean Air Act Amendment of 1990 (and subsequent laws) mandated the sale of oxygenated fuels in areas with unhealthy levels of carbon monoxide. This kicked off the modern U.S. ethanol industry growth. Problems with groundwater contamination from the use of methyl tertiary butyl ether (MTBE)—the only other available oxygenate and principal octane booster—accelerated the use of ethanol in low-level blends.

The U.S. Environmental Protection Agency classifies low-level ethanol blends as "substantially similar" to gasoline, meaning they can be used legally in any gasoline-powered vehicle. Auto manufacturers also approve the use of low-level blends because they work well in gasoline engines and create no noticeable difference in vehicle performance. Low-level blends do not qualify as alternative fuels under the Energy Policy Act of 1992 (EPAct).

To learn more about low-level ethanol blends, download the Low-Level Ethanol Fuel Blends Fact Sheet (PDF 268 KB) or go to the Ethanol Promotion and Information Council's Web site. Learn more about E10 Emissions. For more information on other fuel blends, go to the Blends page. Download Adobe Reader.