Check out this article in The Seattle Times about the "cash for clunkers" program just ended. The bottom line is that lots of people swapped their old pickup trucks for new trucks, which get very little better mileage. I understand what motivated people to do this, pickup trucks are great.
I've driven a series of five diesel "pick-em-ups" for the last 26 years. Diesel pickups are noisy, smell bad, and are very "guy" vehicles. You sit up high where you can really see everything, the seats are at chair-height instead of low down, and you feel like there is enough metal around you to protect you in a crash (due diligence: probably only in front and back crashes, much less so in side crashes or roll-overs).
