Just returned from 2000+ towing 3100 LB auto. Went up and down several 5% grades with speed sometimes dropping to 50. Downshifting on the climb allowed my speed to increase to 60. Tows exceptionally well with mileage above 13 most of the time. On the lesser grades I had no problem maintaining 65 which is the max I do when towing. I would hate to try the same thing with a gasser.
Linear Mode
