So we’re all over the Prius in one post, and then in the next we come down hard on it? Make up your mind Greenthinkers!

As Matt Power notes in this month’s issue of Wired, hybrids get great gas mileage but it takes 113 million BTUs of energy to make a Toyota Prius. Because there are about 113,000 BTUs of energy in a gallon of gasoline, the Prius has consumed the equivalent of 1,000 gallons of gasoline before it reaches the showroom. Think of it as a carbon debt — one you won’t pay off until the Prius has turned over 46,000 miles or so. There’s an easy way to avoid that debt — buy a used car. The debt has already been paid. But not just any used car will do. It has to be something fuel efficient. Like, say, a 1998 Toyota Tercel that gets 27 mpg city / 35 mpg highway miles. The Prius will have to go 100,000 miles to achieve the same carbon savings as the 10-year-old Tercel. Get behind the wheel of a 1994 Geo Metro XFi, which matches the Prius’ 46 mpg, and the Prius would never close the carbon gap, Power writes.

Via Gizmodo.