I am sure this has been discussed before, but who uses it and how? I have a 1 ton diesel dually and will be towing a 5500 lb (dry) trailer. I am assuming it will lower fuel economy? Am I correct in as...
When towing I put it in tow/haul. Haven't noticed any difference in mileage, but haven't looked closely either.
On my truck, in addition to changing the shift points a bit, it keeps the torque converter locked up between shifts which reduces over-heating.
Also like it for the automatic engine braking, keeping the brakes cooler. Can't imagine the additional wear from decelerating on mountain downgrades is significant, but then I don't live in the mountains.