We may pay more for fuel in Europe, but we don't have to drive as far. The Prius is doing 25000 miles in 14 months - that's about twice the average mileage for a family car in the UK. I have a family of 5 but we only do around 3000 miles per year! That's because we live and work in a small town were almost everything is within walking distance. My commute to work is a 5 minute cycle ride.

I've lived in Arizona, and it was impossible to live without driving long distances. Everything was so spaced out. If you really want to save the planet you need to greatly reduce the amount of driving you do, not just drive more efficiently.