MPGe' stands for 'miles per gallon equivalent,' where one gallon of gasoline equates to 33.7 kilowatt-hours (kWh) of electricity in terms of energy. Formulated by the Environmental Protection Agency (EPA), it is the standardized way to compare the energy efficiency of plug-in electric vehicles and hybrid vehicles to gas-powered vehicles. EPA numbers, e.g., MPGe and range, are based on data results from testing.