6" PC Stage one, 35" Tires, Non-OR, Non-BT CC, All windows down, 80MPH+/- on PA turnpike with 2* Timing advance yielded 15 MPG for me. Prior to the 2* advance under same conditions, 16.5 MPG.
That includes my correction factor of 1.1 on the odometer, meaning that with the larger tires, I am really travelling 110 miles for every 100 shown on the odometer. Something you definitely have to consider.
Hope this helps. Expect less with BT gearing.
Oh yeah, with stock tires in the winter time, I average 13-14 MPG. Partly due to the winter fuel mix here in PA, but also because this truck doesn't have to work much harder to turn the 35's and your going farter with each revolution of the tire.
That includes my correction factor of 1.1 on the odometer, meaning that with the larger tires, I am really travelling 110 miles for every 100 shown on the odometer. Something you definitely have to consider.
Hope this helps. Expect less with BT gearing.
Oh yeah, with stock tires in the winter time, I average 13-14 MPG. Partly due to the winter fuel mix here in PA, but also because this truck doesn't have to work much harder to turn the 35's and your going farter with each revolution of the tire.