The 5-star tune made a night and day difference in the drivability of our 2015 ACE 29.2! As important as the power and milage (+1/2-1 consistent) was the change in shift points (up and down). In tow haul mode, it would keep speed down on hills and I used it in town and would almost never use my brakes unless coming to a complete stop.
There is a before and after video on the 5-star sight showing the difference between two Ford trucks towing the same 14k lb trailer, same grade, same day, only difference was one had tune and one didn't and it was exactly the improvement I saw on my RV!
The second best mod was the "cheep handling fix" described on the IRV2 forum. It did for the handling what the tuner did for the power.
__________________
|