See the link below, EPA still measures data in MPGe probably so that people can better understand the energy efficiency compared to Internal Combustion Engines:
https://www.fueleconomy.gov/feg/topt...ction=AllYears
"For those vehicles that do not use liquid fuels—such as electric vehicles, plug-in hybrid electric vehicles operating on electricity, and compressed natural gas vehicles—the labels display miles per gallon of gasoline-equivalent (MPGe). Think of this as being similar to MPG, but instead of presenting miles per gallon of the vehicle’s fuel type, it represents the number of miles the vehicle can go using a quantity of fuel with the same energy content as a gallon of gasoline. This allows a reasonable comparison between vehicles using different fuels. For example, you can use MPGe to compare a compressed natural gas (CNG) vehicle with a gasoline vehicle; even though CNG is not dispensed or burned in gallons."
A true measure of efficiency for Electric Vehicles is in Miles per kWh.