Gasoline-Equivalent Fuel Economy Determination for Alternate Automotive Fuels

Due to the growing use of alternate automotive fuels, it is necessary that the U.S. EPA provide a method of calculating fuel economy values for vehicles using these fuels so that equitable average fuel economies can be determined. The relevant legislation is reviewed, and various methodologies are discussed.

Possible fuel equivalency factors are presented for Diesel fuel, ethanol, methanol, gasohol, and natural gas. The methodologies considered range from the simplest (using the ratio of fuel heating values) to the more complex (attempting to account for processing energy and raw material differences).