From what I've read, the tow/haul only effects the transmission settings. I have posted here before about my truck having less power than it should for my mods and didn't really get any answers. While driving today, I decided to hit the tow/haul button and see what happens. It took much less throttle to drive the same way and my aeroforce gauge was showing mpg and it instantly went up 3mpg. How can this be possible?

 

Tow haul only controls tranny parameters.
Shift points,shift pressure,converter lockup,TQ managment and so forth.Only tranny parameters.

 

I have a nelson tune that is supposed to have all TM removed. Does this mean that I might have a problem with TM since the truck runs much better in tow/haul mode?

 

When you hit the button, it probable changed when the torque converter locked under the conditions you where curently at. That would lower the rpm and read better instant MPG's and easier "cruise" feel to it.