Tim Haab on the question of which is better, a fuel consumption-based or mileage-based motoring tax:
The answer comes down to one simple question: What is the goal? If the goal is revenue generation then a mileage tax makes sense. If the goal is fuel efficiency then a gas tax makes sense. If the goal is revenue generation and improved fuel efficiency, then a graduated mileage tax may make sense.
Insert appropriate comment about walking and chewing gum while cooking dinner in the shower.