08.12.09
Stupid Statistics: Chevy Volt Actually Gets 50mpg
The “mileage” figure, as it’s presented, is really meaningless – because it’s being presented for a situation in which the gasoline engine almost never runs at all.
They compute it by basically saying: “If I fully charge the car battery every night, how far will I drive the car in typical city commuting conditions before it’s consumed a gallon of gas”.
What if you drive your volt around the city all day? Your mileage will drop to around 50 miles per gallon once you’ve driven more than 40 miles. If you drive your car 100 miles in a day, you’ll consume a bit over a gallon of gas. That’s very impressive. But it’s absolutely not what you’d expect after being told that it gets 230 miles per gallon.
The method that GM used to produce that mileage figure is extremely dishonest and completely uninformative. The “real” effective mileage (excluding the cost of charging the car – which will be significant!) varies depending on the length of your commute.
See the rest of the article at the Good Math Blog.
Daniel M. Ryan said,
August 13, 2009 at 6:32 am
They filled in the forms properly, I’m sure. At least, Mr. Chu-Carroll knows how to think beyond them: a habit we should all acquire.