How to calculate mpg for the electric GM Chevy Volt

Chevy-volt-a01 The General Motor Chevy Volt is a gas electric hybrid car like the Toyota Prius but with a twist.

The gas engine in the Chevy Volt charges up the car's battery which spins an electric motor which powers the wheels. Unlike the Toyota Prius, the Volt's engine never powers the wheels directly. This means that a Volt can run up to 40 miles on a full battery charge which is something the current Prius cannot do.

It also means the Volts battery can be charged up either by the car's gas engine or by a wall socket.

So how do you calculate the mpg of the Volt when the car can be driven daily without ever using the engine or any gas what-so-ever?

GM says that because the car can be charged up either at home or at work it will get 230 mpg in city driving, but how much will is cost to charge up the car's battery to achieve this number.

GM estimates it will need 10 kilowatt hours to recharge the Volt to go 40 miles. That will cost a total of about 40 cents at off-peak electricity rates in Detroit, said GM CEO Fritz Henderson.

In other words, the Chevy Volt will get .25 Kilowatts per mile or (.25 kpm).

That may sound strange, but in today's world of electric cars consumers might just have to get used to measuring millage in Kilowatts instead of gallons.

Check out how the GM Volt works below: