Basically they have cheap gas and much lower taxes on cars then in Europe. This goes back to the 60's and 70's when the US had a lot of oil reserves and it seemed like it never ended so they just made huge, cheap and heavy gas guzzlers, to use that oil and have fun, also know as muscle cars. Also, why 3 speed gearboxes if you have to travel a lot during long straight lines ? Going 70mph at 4000rpm in a V8 ? Oil won't get any cheaper so that way of life won't work very well in the next years. They seem to try to change but their mentality of big and heavy=comfort isn't very good for mileage. Just want to say that cars like the Hummer and other giant SUVs are just plain retarded. The Hummer has less mileage then a 1000hp Bugatti Veyron!!