Jello wrote:

The pump doesn't know anything... it doesn't have to. Big cars with large unefficient engines will have to stop more often and fill larger tanks. Small cars with hybrid engines and small gas tanks will fill up less often with less gass.

Why should the more efficient cars be forced to pay this tax at all? If there's no differential, there's not much more incentive than there is now. Taxing everyone will only stifle traveling. I know people who can barely afford to get to work and back as it is, why should they pay a tax if they're using as little as humanly possible? Taxing excess makes more sense to me. Most people I know with SUV's do no off roading, and generally don't carry much load. They just like big cars. When you drive a Hummer around everywhere you need to go, just perhaps this is wasteful. If you can afford to create an unnecessary demand on the value of oil, you should be willing to pay that price. If you are living efficiently, you should be encouraged to continue.

RE: Why Gas Prices Are Too Low (washingtonpost.com)