Idk I towed my new 5th wheel with a rental ram 3500 dually a few weeks ago from Wisconsin to ohio... Then the truck broke and I got a ford f350 10 speed SRW to go from ohio to NJ and I almost feel like the f350 towed better.The 10 speed sucks. Maybe I am old school in thinking a high torque engine with a 3k redline doesn’t need to shift so much.
Though I was on 3 hours of sleep after driving for being awake for like 32 hours before that so my recollection may be skewed.