Neither one of my trucks get great mileage. I have done it all: Towed real heavy(25,000 lbs) Drove it like I stole it, babied it, and put miles on it. One truck has DDII injectors and an EZ on it, the other is stock. The stock truck is 2wd and gets 16 mgp. The Bombed truck is 4wd and gets 12-14 mpg. I think if you can afford a $40,000 truck you can afford to put fuel in it. Would I like my mileage to go up? Sure. Will It? Probably not. My 01 never got better than 17 mpg and it had over 60,000 miles on it when it was sold. I see alot of claims of 24 mpg and the like but don't see it a very possible. You are driving a 7000+ lb truck. It takes alot of fuel to keep it moving 65 mph. The best thing you can do is keep good clean oil in it, clean oil filter, clean fuel filter and buy fuel from a station that goes through alot of fuel. Keep your tires aired up to max capacity and most of all try to run with low boost numbers. Higher boost means more fuel... ... Greg