Ethanol is blended with gasoline in various amounts for use in vehicles.
E10 is a low-level blend composed of 10% ethanol and 90% gasoline. It is classified as "substantially similar" to gasoline by the U.S. Environmental Protection Agency (EPA) and is legal for use in any gasoline-powered vehicle. The use of E10 was spurred by the Clean Air Act Amendments of 1990 (and subsequent laws), which mandated the sale of oxygenated fuels in areas with unhealthy levels of carbon monoxide. This kicked off the modern U.S. ethanol industry growth. Today, E10 is sold in every state. In fact, more than 95% of U.S. gasoline contains up to 10% ethanol to boost octane, meet air quality requirements, or satisfy the Renewable Fuel Standard. E10 doesn't qualify as an alternative fuel under the Energy Policy Act of 1992 (EPAct).
E15 is a low-level blend composed of 15% ethanol and 85% gasoline. In 2011, EPA approved E15 for use in model year 2001 and newer conventional vehicles. There are several EPA requirements and regulations that stations must adhere to when selling E15. The most significant requirements are implementation of a misfueling mitigation plan and registration for an annual fuel survey. (Misfueling is a concern for conventional vehicles older than model year 2001.) While E15 doesn't qualify as an alternative fuel under EPAct, it does help meet the federal Renewable Fuel Standard.
E85 is a high-level gasoline blend containing 51% to 83% ethanol, depending on geography and season and qualifies as an alternative fuel under EPAct. E85 can be used in flexible fuel vehicles (FFVs), which have an internal combustion engine and can run on E85, gasoline, or any blend of the two. E85 cannot be legally used in conventional gasoline-powered vehicles.
Blender Pump Blends
Federal and local initiatives to increase the use of ethanol in transportation have resulted in an increase in new ideas and applications for FFVs. One option is the ethanol blender-pump dispenser. Blender pumps offer FFV owners a variety of ethanol-blended gasoline products between E15 and E85. E20 (20% ethanol, 80% gasoline) and E30 (30% ethanol, 70% gasoline) are the most common blends selected. Stations offering blender-pump blends to FFV owners are concentrated in the Midwest. Blender pumps are also a legal method to dispense E15 to conventional vehicles of model year 2001 and newer.
Blender pumps draw fuel from two separate storage tanks (E10 and E85) and can dispense preprogrammed blends of those two fuels. Labels must clearly indicate blender pump fuels for FFVs.