A blender pump draws two fuels from separate storage tanks and mixes them together in various percentages to form a variety of fuel choices for the station’s customers. Any combination of fuels is possible, and most blending systems allow changes in the percentages for the seasonal blends of E85. In theory, a marketer could have straight unleaded and straight ethanol in the two tanks, offering nothing but a variety of ethanol blends in varying strengths.
In the illustration, the blender pump offers E30 and E85 in addition to unleaded and E10. Separate hoses for the “flex-fuels” (blends of ethanol exceeding 10% that are designed for flex-fuel vehicles (FFVs)) and for the standard fuels ensure that a customer who purchases a small quantity of a standard fuel would not receive a higher ethanol blend if there was residual fuel left in the hose from a previous sale. Ethanol blends exceeding 10% are clearly labeled “for flex-fuel vehicles only.”