Zombie - in response to your original question, +20 mpg would be unusual IMO. I have a stock 2000 CC LB 4WD and best I've ever got for mpg is 19.5. Pretty good for a vehicle that's "heavy" and "square". I recently made a trip to Texas and back and averaged between 14-15 mpg pulling about 5K lbs. My buddy has a GM CC SB 4WD with the 8.0 liter. He gets 10-12 mpg empty. He complains about the noise when riding in my truck, but doesn't have much to say once I show him the mpg on the overhead computer. I made the jump to diesel 2 years ago - I'll never go back!