Your units are off. You're calculating dollars per mile per year. The article talks about dollars per mile, which could be an imprecise way of talking about dollars per mile per year, but taking the words at face value gives about 1 cent per mile at 20 mpg, the Department of Transportation's average fuel economy as of 2005. If you include the federal 18.4 cent tax, you get 1.92 cents per mile.