Tow haul button
I have a 04.5 duramax 3500 and I'm not sure when to use the tow/haul button on my gear shift also using this will it help my MPG? Thanks.
Forum Discussion
BenK wrote:
The Tow/Haul button/function was invented for those who do NOT know HOW2 manage
their automatics by manually shifting....to do down a gear or more...to hold a
gear longer, etc
Pretty soon the OEMs will increase the cost/price and complexity to manage folks
who will NOT and/or do NOT understand HOW2 use the Tow/Haul button.
My guess is electrical. Strain gauge and/or when the trailer plug has
a connection. The TV will then automatically switch on the Tow/Haul function for
the Automatic transmission
Not exactly true for most any vehicle sold this century. On the Allison transmission, for example, T/H will cause the torque converter to lock in 2nd gear (it locks in 4th or 45 mph in 'regular' mode), helping keep temps down when you're towing in stop and go traffic or climbing slow in the mountains. Really works. Also causes the grade braking to come into play, increases pressures in the transmission to afford quicker shifts, and a few other ideas that both improve performance when towing and help preserve your transmission. You can't do any of this by manually shifting.
My T/H is on whenever a trailer is hooked up. I even use it unloaded when driving 2-lane twisty roads up in the mountains.
