It is really wierd how these trucks are all different and they all like different things. A buddy of mine has on 06 3500 SRW quad cab short bed and his reads at about 18.5 and he's getting around 14-15mpg. My girlfriends 05 2500 QC long bed reads 24.5 and is pretty close to it. Both trucks are 6 speed manuals with leveling kits and 35's. Another friends 03 3500 DRW running a 175hp tune gets 21-22 with the lie-o-meter reading somewhere around 26 mpg.