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tow/haul mode

Spudly

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Spudly Enthusiast

Spudly

Posted
Posted

What does this do for the allison? does it hurt gas milage when towing?

If you are not towing in the mountains and the trans temp is good

is there any reason to use tow haul mode?

Where is the trans temp senser located on the allison?

 

Rick

bobcat5544 Enthusiast

bobcat5544

Posted
Posted

Tow/Haul Mode

 

Tow/Haul mode significantly changes the transmission shift pattern to reduce shift cycling and to deliver better performance, control, and cooling when towing or hauling heavy loads. For instance:

 

• Upshift points are raised at light to mid throttle position to use more of the available engine power for acceleration. Downshift points are raised to enhance engine braking to help slow the vehicle.

 

• During deceleration, the torque converter clutch (TCC) remains applied at closed throttle at lower speeds to significantly improve the effect of engine braking.

 

• During acceleration, the TCC is applied in 2nd range and remains applied in 3rd, 4th, and 5th. This improves the drivetrain efficiency and significantly lowers transmission sump temperature when towing heavy loads. In Normal mode, the TCC generally applies only in higher ranges and is dependent on throttle position.

 

• Tow/haul is designed to be most effective when the vehicle and trailer combined weight is at least 75 percent of the gross combined weight rating (GCWR) of the vehicle.

 

• Operation of tow/haul in a lightly loaded or non-loaded vehicle will not cause damage. However, there is no benefit to the selection of tow/haul when the vehicle is unloaded. This situation will cause a firm shift. The tow/haul switch is not a performance switch.

 

• Selection of tow/haul when unloaded may result in unpleasant engine and transmission driving characteristics and reduced fuel economy. Tow/haul is recommended only when pulling a heavy trailer or a large or heavy load.

dewfpo Senior Enthusiast

dewfpo

Posted
Posted
What does this do for the allison? does it hurt gas milage when towing?

If you are not towing in the mountains and the trans temp is good

is there any reason to use tow haul mode?

Where is the trans temp senser located on the allison?

 

Rick

 

 

 

 

 

I understand that the temp sensor is located in the valve bod o nthe Allison.

 

I use tow/haul sometimes when not towing but driving in the mountains on hot days when the trans temps are hitting 200F. This locks the TC and lets the trans fluid cool down a little. Works great.

 

DEWFPO

BlackSilver Senior Enthusiast

BlackSilver

Posted
Posted
What does this do for the allison? does it hurt gas milage when towing?

If you are not towing in the mountains and the trans temp is good

is there any reason to use tow haul mode?

 

 

 

 

In a nutshell, there is NO reason not to use tow/haul mode when towing. It does NOT reduce gas mileage. To not use it is just plain dumb.

 

In mountain driving, even when not towing, I always use T/H mode for the grade braking feature. Until you try it, you can't believe how much it improves driveability. In my book the name should be changed to "Tow/Haul/Mountain"

dewfpo Senior Enthusiast

dewfpo

Posted
Posted
In a nutshell, there is NO reason not to use tow/haul mode when towing.  It does NOT reduce gas mileage.  To not use it is just plain dumb.

 

In mountain driving, even when not towing, I always use T/H mode for the grade braking feature.  Until you try it, you can't believe how much it improves driveability.  In my book the name should be changed to "Tow/Haul/Mountain"

 

 

 

 

I live in the mountains...... I wholeheartedly agree! "Tow/Haul/Mountain" even when empty if the conditions are right.

 

DEWFPO

Bobo9x New Member

Bobo9x

Posted
Posted

I like to use tow/haul in the city with the truck empty . It seems like i can boil both rear tires at every stop light and you can really intimidate those Honda Civics into leaving you plenty of room out there. :cheers: Hehe............

Oh , i guess on the practical side it does eliminate that annoying up/down shifting on some steady uphill pulls.

Polak Enthusiast

Polak

Posted
Posted

I'm in central Indiana, flat but not as flat as say, Kansas. I use T/H mode all the time when towing or loaded. The trans braking really helps, especially when one of the other lovely drivers out there stops 20 yards short of a green light :seeya: .

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