The other day I was pulling a Uhaul auto transport with a small vehicle on it. I figure I was pulling about 4500 lbs combined trailer/vehicle weight. Obviously, I had no problem pulling it, but it got me to wondering at what weight should I use tow/haul? I tried it out, and it still allowed the truck to go into 6th gear on the highway. In fact, I don't think the truck ever downshifted unless I was stopping. Is tow/haul designed to compensate for lighter loads, or would I actually be hurting my mpg by altering the shift points when I don't really need to?

2016 F250 PSD

 

If a light load, probably not needed for pulling, but makes a big difference when decelerating or stopping. Even more so when not on flat land.

 

I like using mine in the snow when I'm in 4hi, deceleration is accomplished safely and smoothly. And I like running the rpm's a little higher than the default range.
BTW I'm driving a '15 now... haven't posted in a long time and need to update my ride.

 

I use it when empty on steep grades down. I like the EB in that case too. And I use it in the snow in 4HIGH on the downgrades to stop myself from picking up too much speed.

I do not use TH at highway speeds on slick roads (rain or snow) as a quick downshift is like slamming the brakes. And I don't use Cruise Control in the slick either.

When hauling heavy or pulling ANY trailer - TH is rarely off. 4500 pounds is nothing for these trucks, but I like the TH shift strategy for any towing. And for the reason already mentioned that slowing down is a whole lot easier and easier on the brakes.

 

The TH strategy is to prevent the transmission from hunting gears. Up and down shifts when pulling are reduced when you are at that threshold for shift to next gear when not towing. I doubt it will affect fuel mileage that much if any.

From 2015 Owner's Manual

The tow/haul feature improves transmission operation when towing a trailer or a heavy load. All transmission gear ranges are available when using tow/haul.


To activate tow/haul, press the button on the end of the gearshift lever. The TOW HAUL indicator light will illuminate in the instrument cluster. Tow/haul delays upshifts to reduce frequency of transmission shifting. Tow/haul also provides engine braking in all forward gears when the transmission is in the D (Overdrive) position; this engine braking will slow the vehicle and assist the driver in controlling the vehicle when descending a grade. Depending on driving conditions and load conditions, the transmission may downshift, slow the vehicle and control the vehicle speed when descending a hill, without the accelerator pedal being pressed. The amount of downshift braking provided will vary based upon the amount the brake pedal is pressed.

To deactivate the tow/haul feature and return to normal driving mode, press the button on the end of the gearshift lever. The TOW HAUL light will no longer be illuminated. When you shut-off and restart the engine, the transmission will automatically return to normal D (Overdrive) mode (tow/haul off).

WARNING
Do not use the tow/haul or engine brake features when driving in icy or slippery conditions as the increased engine braking can cause the rear wheels to slide and your vehicle to swing around with the possible loss of vehicle control.

 

A lot of people question whether they need Tow/Haul mode engaged when towing "a light load."

Look at it this way: the function is both Tow and Haul. How much payload can you add? 3,000lbs? So yeah, I'd definitely be running T/H on a 4500lb trailer. It is still a lot of weight.

 

I live in an area of routine steep grades .... 7% and tight turns. I pull a 9000 lbs trailer and use the engine braking proactively and it works fairly well as long as engine RPM is greater than about 2500-3000. So, before the down grade starts and in T/H mode, I touch the bake to demand a downshift. Touch again and again until 2500-3000 RPM. In the end in order to hold the speed, the tranny could easily be in 3rd or 2nd and doing 35-40 mph. After the grade the computer sometimes takes too long to shift back up. I switch out of T/H mode momentarily to allow the shift up to happen. Towing on the flats I usually do not have T/H mode selected. 👍😉

 

We all have our unique terrain and things we do with our trucks. Regarding using TH and EB. What I did was experiment with it, until I knew when I wanted (or did not want) to use it.

If I am empty and on the flat it's annoying to use it...

 

Tow/haul is designed to work with any load from zero load to maximum load. You should always use tow/haul when you like the way the truck operates in tow/haul, and not use it when you don't like the way it operates. You won't hurt it either way.

 

I had this very same question the other day. And found the answer (so to speak) under the truck apps section of the in-dash display. Had my trailer connected while browsing the truck apps and noticed I had the option to name the trailer. After doing so the display offered info on the tow/haul mode.

Tow/haul mode extends the shift points and adds engine braking when decelerating. It went on to explain this mode is not necessary for light towing or towing on level ground. This mode also locks up the torque converter earlier to reduce transmission heat and will reduce fuel economy as a result.

I tow 8000lbs around flat city streets and personally like the added engine braking on the downshifts, it's much easier on the brakes. Only concern I would have, does this add unneeded engine and/or transmission wear?

 

Dirthawg, read Mark's post right above yours. He's the resident expert here, and he says no problem. You can use it or not use it, loaded or unloaded, and no worries about engine or trans.

 

I have always just hit the tow haul button when pulling. If Ford designed it that way why not use it. I'm sure they have smarter people engineering these things than the average user.

 

We engineered tow/haul to make the truck easier and more fun to drive while towing. We also engineered the system to be just as durable with tow/haul on or off, loaded or not.

But thanks for the compliment! I'll keep that one.

 

I like it when you chime in Mark. Nice to see a transmission engineer answer our questions.

 

Since using T/H may decrease your fuel economy because of the higher shift points, how do you know that is not offset by the the TC being locked up earlier and in lower gears?

Transmission longevity is not going to decrease in either mode. Still using the same gears. And the locked converter will help decrease temps. Automatic transmissions do not work like manual transmissions at all except, for input and output shafts achieving the same goal.