Originally Posted by Todouble
I've always heard you should use tow/haul mode when towing heavy. It provides engine braking and changes the trans shift points. Don't know for sure but was told you can tear up a tranny if you don't when towing heavy. Anyone else know what's correct?? Aside from that I run about 68 mph towing a 12k fiver!
I was told the same thing with every truck we've had.
We've been towing between 90 - 100 KMph (55 - 62 mph). Run into sway issues, so still working on getting everything dialed in better.
We have friends that used live in the Canadian Rockies. When we'd go out to visit them, they had told me while traveling through the mountains even without a load, the truck should be in tow/haul as to not burn up the tranny.