Without intending to drift off-topic too much, I'll just make one comment. I've just done some sums and taking a typical high-ish UK current price for unleaded petrol (from our local Esso petrol station) of £1.20 per litre, per US gallon it would cost £4.54, which is $8.84 at the current exchange rate. A huge chunk of that is tax too, it's a big money spinner for our government. So Americans are getting a bargain in comparison to us Brits!
Incidentally, diesel in the UK costs more than petrol, it's about £1.30 per litre at the moment and rising.
Of course, the average car in the USA will likely do less MPG than the average UK car...