Tow/Haul

[WY Husker Fan]

Always when towing. In addition to the reasons already given, on my 2013 Sierra 2500HD it causes the alternator charge voltage to increase and it changes the number of times the turn signals flash on the lane change function.

[Cypressloser]

Originally Posted by Teetime

I guess I'm the contrary one, an say NO, never used it. We have plenty of truck for the load, and engine braking if needed.

Tow/Haul causes high engine revs when not needed. I may only use it when at steep inclines starting out, but that's what 6 speed transmissions are for, unless you're heavily loaded.

You may want to read up on the subject in your owner's manual and/or ask the service manager at your dealership how much a transmission failure caused by overheating and from constant 'gear hunting' under heavy load can cost you. There are other benefits as well in tow haul mode, some for safety and some for longevity of the powertrain.

[aceinspp]

I use as needed. Years ago each manufacture gave you guyed lines when to use. New truck do not reallgive you a good answer except use your judgement. I do this now and pick and choose when to use. Have done this since 2010 with no ill affects on trany. Newer traneys are so much different than years past. Not always needed. I just drove to Bowling Green KY and had to ascended a 8% grade for 8 miles yep was the only time I use TH. And I sure get a heck of a lot better mileage. Trans temp never an issue. Towing 9000# I watch the Terran as I'm driving and if I think I'm going to need to use TH then I do. So bottom line is no you do not always need to use. Later RJd

[rlh1957]

Always. Follow you owners manual recommendation and any extra equipment needed.