2021 1500 Hemi 4x4. I will be hauling a 6'x12' U-Haul trailer from Northern Colorado to Somerset, KY. Almost all of the trip is Interstate Highway.
My truck came with the class IV receiver hitch, Electronic Roll-Mitigation and Stability-Control, Trailer Sway Damping and Trailer Brake-Controller. Is the tow/haul feature something I should use on the highway?
So.... I read these replies and it brings to light this:
The Tow/Haul mode is for what purpose?
As a factory trained automatic transmission technician for Ford and GM, I'll weigh in with the facts as I see them:
That function was/is put there for a reason. So, asking for whether or not to use it based on the seat of the pants type thinking is a HUGE blunder.
I replaced/repaired MANY MANY MANY automatic transmissions over the decades for people who would FAIL to use the Tow/Haul function (I can't figure out why), and, when I'd ask them why they didn't while I repaired their truck(s), their response was laughable.
"I just pull a pop up, and it doesn't weigh that much"! And yet, they bar-b-qued the transmission. Consistently.
Weight is NOT the only issue. I'm guessing you will be using an enclosed trailer. If so, there will be a hell of a lot of load from wind resistance, not to mention the weight.
Now to the juicy bits: What exactly happens in the To/Haul mode? First, this tells the PCM that a severe duty set of parameters for the entire vehicle are going to happen.... Extra load on the brakes, the cooling system, the chassis proper, etc.
The PCM will employ the particular algorithm programmed into the operating files for that function to mitigate damage.
Put on your reading glasses and seek the information in the owner's manual for whether or not you need to use the function for your particular event. Asking the buddies at the country club is risky at best.
Some of the stories I've heard of how a guy didn't use the function and got away with it evoke thoughts of dumb luck, perhaps, or maybe there was damage done that was not perceived or had any symptoms immediately, only to be someone else's problem when the truck is traded or sold.
Based upon my own knowledge and training, I always err on the side of caution. I have always used the function of Tow/Haul any time I load up my SUV, or pull a trailer. I had a 1976 Suburban that I retrofitted a TH700R4 into. I thrashed that truck with all the towing/hauling I did (a heck of a lot) for north of 100,000 miles. I sold that truck to a fellow employee several years later. That trans was still functioning perfectly years later.
Did I burn more fuel doing that? Yup! In today's world, a trans costs what? 8 Grand on your truck? My thinking is that I can buy a LOT of gas for 8 thousand dollars! Cheers! And Happy trails!
