A key provision of the Energy Independence and Security Act (EISA) of 2007 is the Renewable Fuel Standard (RFS) which requires the nation to use 36 billion gallons of renewable fuel in vehicles by 2022. Ethanol is the most widely used renewable fuel, and a significant portion of the 36 billion gallon goal can be achieved by increasing the ethanol in gasoline to 15%. In March 2009, Growth Energy (a coalition of ethanol producers and supporters) requested a waiver from the Environmental Protection Agency to allow the use of 15% ethanol in gasoline. In anticipation of this waiver being granted, uncertainties arose as to whether additional fuel ethanol, such as E15 and E20, would be compatible with legacy and current materials used in standard gasoline fueling hardware. The U.S. Department of Energy recognized the need to assess the impact of intermediate blends of ethanol on the fueling infrastructure, specifically located at the fueling station. This research effort was led by Oak Ridge National Laboratory and the National Renewable Energy Laboratory incollaboration with Underwriters Laboratories. The DOE program has been co-led and funded by the Office of the Biomass Program and Vehicle Technologies Program.