Tow Haul mode

rjstractor wrote:
Like has been said, it depends on the model of transmission you have. In my 2005 Chevy 2500HD (same transmission as the same year C motorhome with 6.0 V8), tow/haul changes the shift points for better towing performance. It does NOT keep the transmission out of overdrive but it will drop into 3rd more readily. It does nothing on downhill grades. Newer models like the 6L80E have grade braking.

Sounds like mine. 2004 Chevy Express 3500HD, 6.0 V8.

Like has been said, it depends on the model of transmission you have. In my 2005 Chevy 2500HD (same transmission as the same year C motorhome with 6.0 V8), tow/haul changes the shift points for better towing performance. It does NOT keep the transmission out of overdrive but it will drop into 3rd more readily. It does nothing on downhill grades. Newer models like the 6L80E have grade braking.

powderman426 wrote:
I can't speak to gmc, but on Ram trucks, the T/H mode is different by year. My friend has an 04 and T/H keeps it from going into overdrive while my 05 is the opposite. I would try to find someone with the same year. JMO

Good point.
At least the same make.

I have an E450, so our tranny may be different. It also depends on the year of the vehicle. I use our T/H mode on our 2011 year primarily as a method of slowing down the vehicle. whether going down hill, or pulling off the freeway. It works like an engine brake and saves on brakes. I have not seen any value when going up hills, but if someone sees a value, please let me know.

I can't speak to gmc, but on Ram trucks, the T/H mode is different by year. My friend has an 04 and T/H keeps it from going into overdrive while my 05 is the opposite. I would try to find someone with the same year. JMO

I have mine on most of the time, but in Southern Ca we are going up and down hills most of the time.

Only use in in the hills.
It helps keep the speed down while descending.

I use it on hills or if I'm towing something.

It won't hurt the engine/transmission to use the tow haul(T/H) mode all of the time. Basically it keeps the trans from shifting into overdrive. Overdrive provides better gas mileage on mostly level roads.

If you always use it you may use more fuel. Try a couple of test runs with it engaged and calculate your mileage and then try the same route and only use the T/H mode for up or down hills, compare your mileage.