The 230 MPG Marketing Lie - Why electric cars are going to be "hot"

Chevy Volt is doing major advertising around a 230MPG theme. They've developed this number, though it's not certified by the EPA (the government body that gives out the real values).

The Volt is somewhat of a hybrid electric car: you plug it in to an electric socket, charge up the batteries, drive up to 40 miles on that charge, and can use a regular gasoline engine after the batteries are dead.

I've been thinking about this a lot, but read a blog post by Joe Wein that really got me thinking about it. He did some calculating and decided that Chevy's test must be based on a 51 mile trip. 51 miles is longer than my average drive, but less than some other people's. It's about exactly what I did every day when commuting to work in Boulder/Broomfield for 3 years.

Joe made a statement, which is held by most everyone else I've read that analyzes the Volt, about an all-electric driving situation:

Its mpg rating would be infinite, because its only fuel is measured in kWh and shows up on your electric utility bill.

Yes and no...I think we're going to need some new measure beyond MPG. Yes the "miles per gallon of gasoline" would be infinite, but the "Pounds of CO2 per mile" or "Cost per mile" are certainly not zero when the Volt is running in all-electric mode.

I left a comment about this and Joe was kind enough to point me to an article in the international business times about the real efficiency and costs of electric vs. hybrid vs. traditional cars. That article comes out saying that all-electric are not as good as pure hybrids, but both are better than traditional cars.

However, that study seems to ignore the transmission costs. In the United States, electricity is generated somewhere and then transmitted along power lines. Along the way it gets upconverted, downconverted, released into heat emission (look at all the cooling panels on a typical electrical junction box), etc. This is not an efficient system. According to some info porn on the usable markets blog, the United States energy infrastructure loses 68% of the energy from point of generation to point of consumption.


Fortunately we've got a little over a year before the Volt goes on sale. In that time people can start calculating and using some new metrics like "Pounds of CO2 per mile" or "Cost per mile" when comparing cars rather than just the simple "miles per gallon."