Not Seeing Any Substantial Value To Using Tow/Haul Mode

[jamoody]

I just returned from our maiden trip with our spanking new 2017 Yukon SLE - a 2K mile trip through northern New England, southern Canada towing 5K lbs through maybe 3K foot elevation. I tried tow/haul mode on/off at 100 mile increments and found little difference in performance between on/off with the exception that tow/haul on reduced the gas mileage from 11 mpg to 10 mpg. My understanding is tow/haul will hold the gears a little longer which would explain the mpg reduction. I did not notice (via tachometer) any obvious gear toggling with tow/haul off even on reasonable up grades.

My questions -
* Is tow/haul needed mostly for heavier loads or longer/steeper grades than what I was doing or am I getting some other benefit that I'm not aware of?
* Is gear toggling, whether noticeable or not, more just annoying or does it cause excessive wear to the engine/transmission?

Thanks.

 

[latapx]

Tow/Haul mode will hold lower gears longer for better accelaration and will downshift automatically to aid in braking. Once on the highway, I've never towed faster than 65MPH and the truck stayed in 5th...it never engaged 6th gear. This prevented hunting between 5th and 6th gears as you go through inclines, etc. and saves wear and tear on all components. Once at highway speed though, you shouldn't see any difference...the difference is in the accel/decel.

 

[dbbd1]

^ and uphill/downhill.

It is easier on the trans too...

 

[sumo]

Changes the alternator output when to accommodate the extra load of lighting of trailer or electronic braking to keep battery well charged also changes the blinker of partial pressed from 3 blinks to 6

 

[swathdiver]

Tow/Haul Mode was designed to be used when your GCWR is 75% or higher. If your truck and whatever you're towing weighs more than 10,500 pounds, use the Tow/Haul Mode.

In addition the Cruise Grade Braking feature is only active while in Tow/Haul Mode.

As Sumo wrote, it also boosts the charging system to charge a remote battery. Turning on your headlamps will do the same thing if running light.

 

[TahoYukon Forum]

Don't know if this helps, but I researched on my 03 Tahoe for adding OEM trans temp gauge and found sumwhere that tow-haul will increase line pressure making trans shift a bit quicker and act a bit like a mild shift kit to reduce fluid temp. I think you may notice the tach needle move a bit quicker but you may not notice a firmer shift with a load. I'll bet it is similar to urs.
I don't use hauling my 1 1/2 ton Caterpillar mower. Will when I start restoring my Gutlass & Sport-Box though.

 

[Fifty]

Tow/Haul Mode was designed to be used when your GCWR is 75% or higher. If your truck and whatever you're towing weighs more than 10,500 pounds, use the Tow/Haul Mode.

In addition the Cruise Grade Braking feature is only active while in Tow/Haul Mode.

As Sumo wrote, it also boosts the charging system to charge a remote battery. Turning on your headlamps will do the same thing if running light.

My grade braking works when it's not in tow mode.

 

[Cliffmeister2000]

First Post

My 2003 Yukon XL 2500 (new to me) would shift twice in rapid succession in and out of lower gears when climbing modest hills at 65mph on a recent trip to Flagstaff pulling a 1997 Coleman Cheyenne Pop up. Experimenting, I tried lower speeds and higher speeds, in and out of tow/haul. I found that at 70mph in tow/haul, the Yukon would only shift once, much lest often.

 

[2011SSVHOE]

First Post

My 2003 Yukon XL 2500 (new to me) would shift twice in rapid succession in and out of lower gears when climbing modest hills at 65mph on a recent trip to Flagstaff pulling a 1997 Coleman Cheyenne Pop up. Experimenting, I tried lower speeds and higher speeds, in and out of tow/haul. I found that at 70mph in tow/haul, the Yukon would only shift once, much lest often.

First off welcome Cliff, from North Carolina,

I noticed pulling my 12ft enclosed trailer, maybe with a 2500 lb. payload the fuel economy sucks, but I think overall tow/haul is better on the tranny. I also like the downshift coming down steep hills. I still was keeping an eye on the trans temp.

 

[swathdiver]

My grade braking works when it's not in tow mode.

Interesting, what year is yours? I reported the information from my 2009s owner's manual.