Here I go defending something I said THREE MONTHS AGO. We ARE moving backwards. That's why you have f'ing compact cars with 180HP getting 25MPG city and trucks still get 8-10MPG, just like in 1978. Unless you're into diesels, hybrids, or cardboard boxes gas milage stopped going anywhere a long time ago. What IS happening is better HP for that. The Hummer and H2 get knocked by thier owners for having poor fuel economy. The market is keeping them from just cramming a 502 in it and calling it fixed. They need a good diesel.
Look at the used truck market, V10s are common. What isn't so common are the diesels. Why? People buy the V10, get sick of getting poor gas milage, and get a diesel. The guys with a diesel stay with it. There was an article on Dodge's new '600', which said that 73% of the heavy duty buyers opt for the $5k option and very few regret it. 20MPG in a 3/4 ton 4x4? No, there isn't a hemi in that thang.