Hope I have got my maths right in doing the conversions.
1 gallon of petrol contains approx 40 kwh of energy and you might do 40 miles on that so 1 kwh per mile.
1kwh of energy will power an electric car for between 2 miles and 4 miles according to wiki " Miles per gallon gasoline equivalent". The difference comes about because a good petrol engine is still only beatween 25% and 50% efficient - diesel being inherently more - and an electric motor is way more.
There is the debate about the efficiency of power stations and line losses but there is no realistic way of quantifying this given the changes going on as new capacity comes on line both from solar / wind and nuclear. It takes 6 kwh of energy to distill petrol so really that gallon only gives 34 kwh
As for range, a 15 gallon petrol tank hold 600 kwh. A Tesla battery pack is somewhere around 100.
Hmm.
