This is the third Cummins truck I have had. 2016 crew cab, Laramie 4x4. 68RFE transmission, 3.42 gears. It has 34" Michelin AT2 tires, just one size up from stock. Just about 54k miles.
My issue is that I am getting a solid 15-16mpg highway. Granted, the speed limit is 75 for most of my...