# Truck Tow Button Question



## TimU

Ok - wife and I disagree (what's new). Like any newer truck, ours has the tow button. I know the tow button was originally put in to change shift points for automatic transmissions, especially overdrive transmissions, so they didn't constantly go "in and out" of gear at 55-65mph. My wife thinks that since the button is there, and you are towing - it MUST BE USED.

Now, has anything really changed for the purpose of the tow button? Or is it still just to change the shift points? Once I get to cruising speed, I usually turn the tow button off, and just pay attention to the shifting. If it starts that "in and out" - button goes on. If engine is lugging down too much - it goes on, or goes into a manual gear.

So - what says the community?


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## thefulminator

What kind of truck? In my 2009 Silverado, when towing over mountain passes I get about a 30 degree drop in transmission temperature when using the tow/haul button. After taking with GM about it I always use tow mode when the trailer is attached.


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## TimU

thefulminator said:


> What kind of truck? In my 2009 Silverado, when towing over mountain passes I get about a 30 degree drop in transmission temperature when using the tow/haul button. After taking with GM about it I always use tow mode when the trailer is attached.


2009 1/2 ton Silverado, 6 speed tranny, 3.08 rear end. I haul around KS, so no mountains - yet. I'm assuming that anytime I start hitting a grade - I'm going into tow mode. Even on sorter runs, I've noticed a 5-6mpg difference.


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## Todd&Regan

I leave the tow/haul mode engaged whenever I tow.


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## thefulminator

Just realized that I must have been asleep when I made my post. It was the right time of day for that. It is the manual mode switch on the shift column that reduces the transmission temperature. Not the tow/haul button.


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## CaptFX4

I call it a split decision. Depends on truck, what motor and gears etc. If your running normal and the tranny is not hunting for gears by up and down shifting its fine. You may even see a little better gas mileage. If lots of shifting or terrain issues run in tow/haul mode. Keep your truck and DW happy.


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## TimU

CaptFX4 said:


> I call it a split decision. Depends on truck, what motor and gears etc. If your running normal and the tranny is not hunting for gears by up and down shifting its fine. You may even see a little better gas mileage. If lots of shifting or terrain issues run in tow/haul mode. Keep your truck and DW happy.


Yeah - that's my plan. I'll wait until the DW nods off, then turn it off as long as it's not causing problems. I've got a few obvious hills to drive through - it'll be on then - but for the flat spots - probably off.

I've got the HD towing package on the truck - so it's got the tranny cooler, and oil cooler.


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## Stumpy75

ob277rl said:


> On our truck the Tow/Haul button allows the use of all six gears. It changes the shift points to allow for the load, but it will also down shift the transmission when going down a long grade with the brake applied for a given amount of time. Good Luck.
> 
> Robert


Mine does the same thing. However, on my previous vehicle, a 2003 Sport Trac, the tow/haul button kept the tranny out of the highest gear.


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## CamperAndy

Well I will voice a different reason for using it. On my truck the tow/haul mode also changes the way the torque converter locks (gear and speed point) and I actually use the tow/haul 100% of the time I drive.

Autos were called slush boxes for years and that is due to the soft way they transfer power and all that soft easy feeling does is burn fuel and heat up the transmission. With the torque converter locked (more often when in tow/haul) the transmission temps are lower, fuel mileage is improved and the only trade I have found is that the shifts are a little firmer. I see no problem in feeling the truck shift gears.


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## Justman

I tow in tow/haul all the time as well. My preferred combo is tow/haul engaged, manual mode selected, 5th gear. I only tow at a max of 65 - 70 mph, and this seems to keep the truck happy. I was using 6th gear with the same combo, but found the truck was slow to downshift going up and down the frequent hills in East Texas. Keeping it in 5th gave me more power to get up hills. The truck rarely down-shifts in 5th. However, your truck is significantly different from mine in the engine department, so your results may vary.


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## MO7Bs

Just to add to an older discussion...

When researching my new TV (2015 GMC Sierra 2500HD) I came across a note that by pressing the TOW/HAUL button it ramps up the charging ability of the vehicle.

From the Owner's Manual "If charging a remote (non-vehicle)battery, press the Tow/Haul Modebutton, if equipped, at the end of theshift lever. This will boost thevehicle system voltage and properlycharge the battery. If the trailer istoo light for Tow/Haul Mode, or thevehicle is not equipped with Tow/Haul, turn on the headlamps as asecond way to boost the vehiclesystem and charge the battery."

This is a neat feature.

Best!


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## SirCIII

I too would like the know what others think on this. I use the TOW pretty much full time accept when at cruising speed (65 - 70ish when allowed) and when conditions don't cause the transmission to frequently look for the right gear. As mentioned in a previous post, I too noticed trans temps stay around 180 range while in TOW mode and it does raise 10 - 20 degrees when not engaged. However as also previously mentioned, I have experienced a noticeable increase mpg (obviously higher if at 55pmh).

We just got back 2 days ago from an Oregon to Montana and back trip visiting family. Route was I-5 to I-84 to HWY 395 to I-90 (and back same route). If you know the route you know the terrain traversed. Some areas, like Eastern WA on HWY 395, I had to keep TOW engaged heading toward Ritzville but was able to turn TOW off going the other direction towards the tri-cities. Made a 25% -30% increase in fuel economy while maintaining highway speeds.

Community thoughts/suggestions?


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## ManCave

C.E. = Cadillac Escalade??

On the Escalade the tow haul button function depends on years.

- On newer models (2012+?) it increases the charge voltage and amperage output of alternator to compensate for loss of voltage from front of TV to trailer.

- changes gear shift RPM's associated with up shifts and down shifts.

- Changes the torque converter lock up to limit slipping and heating of the transmission

Its Designed for when you need more torque from drive train: up down hills, parking, starting/stopping at lights, etc while being close to vehicle max GCWR

- Changes settings for magnetic ride control and traction control for newer vehicles equipped with these features

In some years the tow haul mode will not engage and will automatically disengage at speeds over 60 MPH as could can cause damage to the drive train.

If you are at speed, on level ground, are not accelerating or decelerating, it can actually be beneficial for the drive train to disable tow haul mode to lower RPM's and allow transmission to use the higher gears. Lower RPM's = Less heat and less wear. But YRMV because as you can see from the list above the tow/haul buttons may effect many driving parameters other than the shift points.

The route from Ritzville down into the Tri-Cities is a drop of about 1500 feet, so other than dodging the occasional badger or coyote its generally not a situation where you would need much torque. So can see why tow mode=off would give you better mileage on the way back.

FYI, be careful in Washington. They will ticket you for towing at the higher of the two posted highway speeds. When towing in Washington your highway speed is the same as that as posted for Trucks.


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## RLM5150

I'm not sure why someone wouldn't use the tow/haul mode when towing? It changes the behavior of the transmission to benefit performance AND longevity of the transmission. In mine (2012 RAM 1500) it locks out 6th gear and enables 3rd gear. Specifics vary by model and Manufacturer on what all that mode will do. But again, why would you not use it?


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## Snow

Only time I have ever used the tow haul mode was when we towed the 21RS thru Kentucky when we visited Nashville a few years ago..


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