Efficiency, yes, but since we don't buy fuel by it's energy rating and the cost per KJ varies dramatically between fuel/energy sources, and because the energy density varies dramatically between fuels, etc., it's a useless number to the consumer.I think a better way to measure car efficiency is to do miles per energy consumed in Joules or KJ.
Incorrect. For the Volt, the current electric cost per mile is about 45% of the cost of gasoline per mile, so if you're using price of electricity vs price of gas on the volt, the Volt gets about 50MPG on gas and the same $2.70 would get you about 110 miles. 230MPG is based upon completely ignoring the cost of electricity and driving 80+% on of miles on battery only.You likely got marked down because they didn't "leave the utility bill out of the equation". The cost of the electricity is figured in to the EPA's MPG ratings for electric cars. That's why it is "230 MPG" instead of "Infinity MPG". The numbers are there to tell you it will cost you the same amount of money to drive this "230 MPG" electric car as it would to drive a "230 MPG" gas-only car. I think "230 MPG" may be a bit on the high side, but the point is they're trying to give you a comparison.
It starts with 'tree huggers' in this case, early adopters. They cheapen it down for the rest of us. It is a 'proof of concept' and at least an attempt by a major auto company to try coping with the inevitable increase in energy costs over the next 25 years.