Agreed on the p-pump 12v.. Anyway, mine in an untouched 2001.5 24v, 6 spd, 2wd, 3.54 axle, Michelin hiway tires.. I get about 18 in town and 24 hwy.. If you drive like most guys you see now where they get in the boost everytime they accelerate, they'll suck $4 fuel in a hurry.. I drive pretty easy, light throttle input, shift out around 1800rpm.. Maybe twice a week I'll spin it up full throttle to 2600-2700 rpm for 3rd and 4th gear but otherwise Im a pretty tame driver.. My dad had a 2003 2wd cummins with auto with no aftermarket tune all factory stock.. I drove from 550 mile one way to buy a single axle xb2002 rigged.. Going 66-68 mph on the way I got 24.3 mpg , with the boat on return trip going 60-62mph I got 21+... All hand calculated..