My son has an '02 Duramax/Allison 4WD Crew cab Dually. Not the easiest thing to maneuver in a parking lot but the thing has tons of power and pulls his 40' triple axle gooseneck like there's nothing behind him. He has an "Edge" programmable chip and on-the-fly controller in it, along with a K&N air box and 5" exhaust. Granted, he has some work on the truck but he's pulling down 20-22 mpg on the highway and still gets around 14 mpg towing the trailer with two 'Mud Trucks' on it. He constantly watches his mileage/fuel costs and is still convinced he's doing better $$$ wise with the Diesel vs. the 8.1. (However, he's very close to producing his own bio-diesel.) But he did tell me a few days ago that he has a lot of respect for the power of the 8.1.
With fuel costs as they are, you can buy these used trucks VERY reasonable right now.
For any upcoming long tows with my trailer (i.e. VF), I'll be borrowing his truck!
