To increase the number of ethanol blends available in the United States, several states have 'blender pumps' that blend gasoline with flex-fuel vehicle (FFV) fuel. No specification governs the properties of these blended fuels, and little information is available about the fuels sold at blender pumps. No labeling conventions exist, and labeling on the blender pumps surveyed was inconsistent.
Thesurvey samples, collected across the Midwestern United States, included the base gasoline and FFV fuel used in the blends as well as the two lowest blends offered at each station. The samples were tested against the applicable ASTM specifications and for critical operability parameters. Conventional gasoline fuels are limited to 10 vol% ethanol by the U.S. EPA. The ethanol content varied greatlyin the samples. Half the gasoline samples contained some ethanol, while the other half contained none. The FFV fuel samples were all within the specification limits. No pattern was observed for the blend content of the higher ethanol content samples at the same station. Other properties tested were specific to higher-ethanol blends. This survey also tested the properties of fuels containingethanol levels above conventional gasoline but below FFV fuels.