F-350, 3.73 gears, deleted, S&B, H&S on Performance tune.
Towed 15.5 K, 40 foot, enclosed, 1 foot extended height GN
100 miles, cruise control along I-10 75 MPH. Never, downshifted uphill. 9.8 MPG
100 miles, cruise control along I-10 70 MPH, Never downshifted uphill. 10.5 MPG
Overall trip...