Owners manual info GMC

Meh, I use tow haul a lot of the time empty too.
I spose it uses more fuel around town, but on the highway, locked in high gear is the same in either mode.
It definitely is not detrimental in any way.
You're good to use it whenever. One of the better features added to trucks.

It is my understanding that Tow/Haul mode keeps (or delays) your computer controlled transmission from up-shifting into the top-most gear when on the highway, delays (or slows) up-shifting in the lower gears when in stop-an-go traffic, and reduces gear hunting when driving in hilly terrain. All of these have a negative effect on your fuel mileage when not actually hauling a load and therefore not recommended in the owners manual.

Use it anyway you feel like.......

I understand what your manual says but I note no difference in mileage towing with or without T/H. I do notice a difference in performance however and use T/H when going up, down or against a headwind.

My 2015 Tahoe manual says: “The Tow/Haul Mode adjusts the transmission shift pattern to reduce shift cycling. This provides increased performance, vehicle control, and enhanced transmission and engine cooling when driving down steep hills or mountain grades, towing, or hauling heavy loads.”

You do as you wish. I’ll use T/H.

nevadanick wrote:
My point is what the manual states, its useless until you are at 75% of gvwr. And actually detrimental to your mpg.

Incorrect on both counts - from my 2012 Silverado owner's manual ...

"Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75 percent of the vehicle's Gross Combined Weight Rating (GCWR)"

Gross Combined Weight Rating, NOT the truck's Gross Vehicle Weight Rating.

I've been towing since 2006 with 3 different GM trucks, all with GM's ubiquitous 5.3L engine, all with a 3.42 axle ratio, the first 2 with the older, wide ratio 4-speed transmission, my current Silvy with the newer, narrow ratio 6-speed, and I've never seen any meaningful difference in fuel mileage whether Tow / Haul was engaged or not but all 3 certainly have towed far more easily with it on. :B

I've never understood why people are so hesitant to use TH mode.

Says the same thing in the manual for my 2001 Chevy 2500.

My point is what the manual states, its useless until you are at 75% of gvwr. And actually detrimental to your mpg.

Reading the manual. Good start. Like Soundguy, your question is?

And your point, or question, would be? :h

I do use Tow/Haul in my own Silverado whenever I'm towing. :)