Well on a cost basis you can use this formula to compare the cost to a gallon of gas: ((kwh electricity cost)/(charging efficiency percentage))*34.02 . Then on

Well on a cost basis you can use this formula to compare the cost to a gallon of gas: ((kwh electricity cost)/(charging efficiency percentage))*34.02 . Then on a real cost basis you can compare the cost of an 'electric gallon' and an electric cars MPGe to your 'gas gallon' and your gas car's MPG. In the bay area, ironically enough, with residential electricity being around ~0.30/kwh, an 'electric gallon' is around the price of a 'gas gallon'. https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent#Conversion_to_MPGe https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equi...