Fareed Zakaria's Newsweek column "Imagine: 500 Miles Per Gallon," in which he argues that a combination of flex-fuel and plug-in hybrid vehicle technologies could significantly reduce our dependence on petroleum, is getting quite a bit of attention in the sustainasphere (see, for example, here and here). That's fine -- it's always good to see the idea that we do, in fact, already have the technologies at hand to build a better planet get wider play -- but I have to admit some exasperation with the way the story is presented. "500 miles per gallon," it turns out, refers not to the fuel consumption of these green cars, but to their relative consumption of oil.
The current crop of hybrid cars get around 50 miles per gallon. Make it a plug-in and you can get 75 miles. Replace the conventional fuel tank with a flexible-fuel tank that can run on a combination of 15 percent petroleum and 85 percent ethanol or methanol, and you get between 400 and 500 miles per gallon of gasoline.
As long as you mentally add that "of gasoline" every time he tosses out the "500 miles per gallon" figure, it's a decent article. And it is good to get this argument in front of a mainstream audience. I just wish Zakaria had been a bit more careful with his phrasing.
Neat idea, but one other disturbing oversight is this comment of Mr. Zakaria's: "And ethanol and methanol are much cheaper than gasoline, so fuel costs would drop dramatically." If ethanol is cheap, it's mainly due to the subsidies of one sort or another: either from the USDA or from pillaging the topsoil. When you consider that it takes 100 BTU of fossil energy to make 134 BTU of corn-based ethanol, the allure of flex-fuels is even further diminished.
It's also worth pondering where the electricity to charge up those plug-in hybrids would come from. Most places, that would be coal-fired generation - hardly a good way to make a dent in the climate problem.