# Use The Tow/haul Button?



## risnewski (Feb 20, 2005)

Anyone know what the Tow/Haul button does and how important it is to use? I found that I had pretty good pick up without it, but basically used it most of the time since it's part of the tow package. The Durango owners manual seems to make the use of the button optional--says something like "use as needed".

Any disadvantages to NOT using the feature?

Vehicle is a 2005 Durango with the best axle ratio (I forget what that is, but know I got it) and a Hemi.

Rick Bowling
Plymouth, MI
23RS--first trip just completed


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## Not Yet (Dec 13, 2004)

I do not know the specifics with the Durango but generally the tow mode changes the shift points in the trans. In other words the trans will stay in a gear longer to allow the engine full use of the power band before shifting. This should give better performance when towing. It can do other things like change the sensitivity on any vehicle stability control or otherwise modify some of the computer controls. The manual should say. If the performance is better without and you do not see any rising temps (engine or trans) then there should be no harm in not using.

Jared


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## Humpty (Apr 20, 2005)

Castle Rock Outbackers said:


> I have a Yukon XL 1500 that has tow/haul mode button. When I engage mine, small flames spray from the exhaust pipe as the motor taps into nitro-glycerine tanks that are mounted next to the battery in the engine compartment. The available horsepower gauge jumps from 285 to 425, and the torque gauge moves from 325 to 500. Really makes a difference for us when towing up Colorado mountains.
> 
> Randy
> [snapback]36865[/snapback]​


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## Castle Rock Outbackers (Jan 18, 2004)

Ha! I was wondering if someone was going to bring that post to this thread. Thanks, Humpty!

Randy


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## CamperAndy (Aug 26, 2004)

The only noticeable thing is the shift points change in my 1500 Ram but there could be some other computer issues that occur.


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## Ghosty (Jan 17, 2005)

TOW/HAUL

The tow/haul shift mode significantly changes the transmissionâ€™s shift pattern to reduce shift cycling and to deliver better performance, control and cooling when towing or hauling heavy loads. You can enable or disable tow/haul with the same selector button used for overdrive disable, simply tap the button one time.
When Tow/Haul is engaged, the following functions occur:

â€¢ Upshift points are raised from light- to mid-throttle to use more of the engineâ€™s available power for acceleration.

â€¢ Downshift points are raised to help slow the vehicle using engine braking.

â€¢ During deceleration, the torque converter clutch (TCC) remains applied to much lower vehicle speeds to significantly improve engine braking effectiveness.

â€¢ During acceleration, the TCC is applied in 2nd range and remains applied in 3rd, 4th and 5th ranges. [In normal shift mode, the TCC generally applies only in higher ranges and is dependent on throttle position.]

â€¢ Grade braking can command downshifts to 2nd range. [In normal shift mode, grade braking will not command downshifts below 4th range.] The result of these various tow/haul functions is a more positive shift feel especially when operating the vehicle lightly loaded.

http://www.allisontransmission.com/servlet...et=SA3931EN.pdf


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## chipb43 (Mar 22, 2004)

Humpty said:


> Castle Rock Outbackers said:
> 
> 
> > I have a Yukon XL 1500 that has tow/haul mode button.Â When I engage mine, small flames spray from the exhaust pipe as the motor taps into nitro-glycerine tanks that are mounted next to the battery in the engine compartment.Â The available horsepower gauge jumps from 285 to 425, and the torque gauge moves from 325 to 500.Â Really makes a difference for us when towing up Colorado mountains.
> ...


Sweet....mine must be broken. I am not getting the same response. Think I will call the dealer and take the truck in for service.


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## Parker Outbacker (Dec 17, 2004)

Ghosty- Nicely put. When I use the tow/haul on my PSD the down-shifting that occurs is great. Going down a 6% grade, I touch the brake, the TV downshifts, and I don't have to touch the brakes again.

I find it most useful when slowing/stopping as the TV slows you down with little brake inputs.

Ron


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## mjs518 (Oct 24, 2004)

Its seems logical that the use of the tow/haul function is good for hilly terrain but would lower your gas milage in normal driving situations, true?


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## camping479 (Aug 27, 2003)

I use the tow/haul all the time when towing and ALWAYS in third. I don't know about gas mileage, what's a half a mile per gallon when you're only getting 10?









I think on our Yukon, the tow/haul stiffens up the autoride suspension as well as changing the shift points.

Mike


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## cookie9933 (Feb 26, 2005)

Joe,

I don't think tow-haul would significantly affect milage, unless you were doing a lot of stop-and-go driving. Even though shift points are raised, once you get into top gear milage is the same. It isn't tow-haul that adversely affects your milage, it's that big thing closely following your TV.









Bill


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## risnewski (Feb 20, 2005)

Thanks everyone. Great stuff. I will religously use the Tow/Haul button in the future.

Next trip I plan to have my 4 year old grandson (he plans to be a Nascar driver before he's out of grade school) check out the tail pipes to be sure those flames are adjusted right.


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## Humpty (Apr 20, 2005)

Castle Rock Outbackers said:


> Ha! I was wondering if someone was going to bring that post to this thread. Thanks, Humpty!
> 
> Randy
> [snapback]38871[/snapback]​


Randy:

Your post on that thread is still my favorite post!

By the way, I definately use Tow/Haul mode with my rig.


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## Ghosty (Jan 17, 2005)

mjs518 said:


> Its seems logical that the use of the tow/haul function is good for hilly terrain but would lower your gas milage in normal driving situations, true?
> 
> 
> 
> ...


Yes -- tow haul is mainly a braking compression measure to help slow down the vehicle -- as for driving it shifts at a higher rev so you would get lower gas mileage... but i dont know by how much ...cant be much though


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## NDJollyMon (Aug 22, 2003)

I use TOW/HAUL mode on the TITAN.
I tow in 4th with it on. (5 speed tranny)


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