It's been my experience that diesels get 30-50% better fuel economy than their gasoline-fed brethren (presuming same truck, same load). Right now gas is 2.85 and diesel is 3.45 here. The Powerstroke is an $8000-ish option. At 18 mpg highway that's a minimum 240,000 mile payback figured solely on fuel economy using today's prices.
If you don't need a diesel for specific reasons, it's a waste of money or an I-just-want-one thing. However, if you need a truck that'll tow hugemongous loads and keep driveline breakage/service costs down, there's nothing better. Diesels from any of the big three are pretty much bulletproof these days, and the power they're getting out of them right from the factory is staggering. And it's reliable power, too, not something you can have for the few miles it takes to roast the tranny, thrash the mains, or grenade the diff. Impressive as heck, that.
Brad
