We also have a 2015 Excursion 33D and tow a Jeep Liberty weighing in at about 4300 pounds. Compared to our previous Ford Triton/transmission rig, the Cummins/Allison combination is so smooth and intuitive that I run with the cruise control on almost all the time, including uphill. Generally I only go off cruise for traffic congestion, significant curves and downhills. With the cruise set about 60 mph, give or take, I rarely drop below 50 mph on hills, on the steepest hills maybe into the mid-40s.
A related question for those with the 33D, have you figured out the transmission selector "Mode" button that selects a red light on or off? An allison tech rep thought it might select an economy mode as does the 3000 and 4000 series transmissions, but referred me to Freightliner as the selector for the Allison 2100MH transmission in the 33D is labelled "Freightliner", not Allison. The Freightliner Manual doesn't accurately address the 2100 series transmission saying it is an Arens 5-speed with a park pawl and Park position on the selector. Not so. The Freightliner tech guy says the "Mode" selector selects an economy mode when the red light is on. I haven't had the RV out since investigating the transmission, so has anyone figured out what the "Mode" button selects when the red light is on? If so, what mode do you use when on hilly/mountainous roads?
