No I'll throw another complication in.
We are in the hilly scenario and the transmission starts hunting (we'll assume for the moment even with the T/H mode on it's hunting).
One option is to lock it in a lower grear and run at higher RPM. Not great for fuel economy but not horrible. It can be a bit noisy but shouldn't hurt anything otherwise.
Another option is to play the throttle. If the hills are short, the road is straight and traffic is light, let the truck build up a little extra speed going down the hill and that will help carry you up the next hill. While climbing the next hill let the speed gradually bleed off rather than mashing the pedal down to maintain speed. You will have to play with it to see how much throttle you can give it on the uphill without forcing a downshift. The transmission senses the greater torque of trying to climb a hill and if it get's too large, it downshifts.
- Obviously, don't go stupid fast and risk a crash.
- Don't let the speed drop so much that traffic behind you has to take evasive action.
- If the hills are too long it won't work because as you slow down you need more torque to maintain speed and eventualy the transmission will downshift.
