Shift points when towing

[markrinker]

I am satisfied with the overall power of truck #3, but the shift points when using tow/haul mode are all wrong, especially when using cruise control. Seems that it wants to downshift into 2nd prematurely, causing 4500-4800 RPM windups.

The only way I can avoid this problem is to stay out of tow/haul mode, and not use the cruise control. Tranny temps are the same either way.

Any similar experiences?

[More Power]

Switching back and forth between a diesel and a gas truck can be an education in powertrain management. The diesel makes more power/torque at lower revs, and the gasser needs rpm to move loads. This is a normal consequence of different power/torque curves.

I'd suggest overlaying the power/torque curves for the diesel and gas engines. This'll help explain where to run each engine to produce the best performance.

I'd guess that the powertrain programming was written to produce the best performance - for the truck's intended purpose.

MP

[markrinker]

Very true. It is hard to watch the gasser wind, but that is what they do...

I'll probably learn to live with tow/haul mode for the transmission's sake, but won't be using cruise control while towing. The downshifts it causes can't be good.

[madmatt]

i had a 00' that did it and I just learned what speed and road terrain it was worse at and adjusted the cruise a few mph either direction and that seemed to help.