Ok spent the last 2 days working on the factory tow/haul mode strategies with trailer in tow running our 87 perf-tow calibration. Background on trailer is it’s a max 7000 lb. capacity trailer and with the dyno gear in it, it is approx 4000 lbs. The crappy part about the trailer is it’s a brick moving through the air. Also our truck has 3.55 gear set.
Factory tow/haul strategies in a nut shell i think are weak. 6th gear is useless under 60 mph towing even this trailer. Coasting or slowing down the downshifts do not come on soon enough to keep the rpms up in torque range and when back in throttle multiple down shifts occur. Gears 2nd, 3rd and 4th are the gears the truck likes to run at under 60 mph towing this trailer but its in 6th gear at 50 mph lugging engine. Once rpm builds to 3000 plus the truck pulls like a champ but factory strategies keep rpms low.
For you guys going to tow a travel trailer camper or trailers over 5000 lbs the factory strategies will hunt all over the place in tow/haul mode. This is the same thing we have seen with the 6.2L SD tow/haul mode. Lugging the engine and not knowing what gear to stay in is terrible. (my opinion) And after about 150 miles and multiple changes the tow/haul mode works like what I feel it should keeps the engine RPMs elevated to take advantage of the torque band in this 5.0 less downshifting and taking advantage of gears 2nd, 3rd and 4th more. And by the way in our testing we avg. 10.4 mpg pulling this trailer at speeds to 65 mph and in stop and go traffic.