I have the 2012 2500 crew cab 4x4 with the 5.7 hemi. Stock wheels and tires. 3.73 gears with 6 spd auto. I average 17-18 highway and 14-15 in town. I did put the freewheel hubs on the front to be able to shut off all of the rotating mass (wear and tear as well as fuel mileage) I thought 17-18 was pretty good for a 400 HP 4x4 3/4 ton truck?
