The other night I was going up an incredibly steep gravel back road with my truck. It's steep enough that you cannot make it up the hill without being in 4wd. With that being said, it does receive quite a bit of travel because it's a mountain pass that is a short cut between two counties, so it's not some rigorous trail. I didn't have a trailer hooked up, but it still requires quite a lot of torque to make it up the mountain. I had to travel the path twice that night and the first time up, I wasn't using tow/haul mode and kept it in 2nd gear using the "s" mode, and when I got to the top I could smell that typical smell you get when your transmission is hot. The second time up, I used tow/haul mode and didn't get any smells or signs of heat. Does tow/haul mode lock the torque converter? I've heard so many different answers to that question, and to what tow/haul does in general.