I've got to say that the stories of the V10 FoMoCo's getting horrendous gas mileage are more related to what chassis they are in than the motor itself. Somebody above posted that their V10 truck is killing them on fuel. I'm not doubting that for a minute.

That hasn't been my experience, but I'm not in an AWD huge freekin' pick-em-up, either. I have a late ('04) E-350 van that gets 14-15 on the highway when empty, and similar MPG when towing a open 24 ft. steel trailer with the car on it. In fact, the worst mileage I've seen is 12, and that was running through the mountains coming home from BeaveRun. At 80. With the air and the cruise on.

Would I like a diesel? Sure, gotta love that clackety clatter. Is it worth the five grand premium those trucks are commanding, even used? Not for my usage - I put less than 5K miles on the truck this year. At that rate my grandchildren wouldn't see the ROI. Your mileage, of course, may vary. That, and the torque numbers for the V10 vs. the diesel are very similar, and according to the Ford forums the newer diesels (everything after the old 7.3 Powersmokes, basically) are not the happiest campers in the world.