The fuel economy of a vehicle is dependent on many things, one of which is the fuel used in the vehicle. Two National Laboratories recently studied the effects that ethanol blends have on the fuel economy of light vehicles. The results are not surprising, since a gallon of ethanol does not have as much energy as a gallon of gasoline. A blend of gasoline with 10% ethanol (E10) will result in a 3.7% decline in fuel economy over gasoline without ethanol (E0), while a blend of gasoline with 20% ethanol (E20) results in a 7.7% decline in fuel economy over E0.

Fuel Economy Decline for Various Ethanol Blends

Supporting Information

Decline in Fuel Economy due to Ethanol Blends
FuelShare of Ethanol in GasolineFuel Economy Loss
E00% ethanol0.0%
E1010% ethanol3.7% from E0
E1515% ethanol5.3% from E0
E2020% ethanol7.7% from E0

Source: Oak Ridge National Laboratory and National Renewable Energy Laboratory, Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines, Report 1 – Updated, February 2009, Table 3.1.

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