Tow/Haul Mode?

[beretta01]

Hi...I've always used the towhaul function for towing trailors and stuff but today I decided to try it out on regular driving. I actually really like it, higher shift and better response. I have a 2000 GMC Sierra 4.8(145k)....any reasons why I shouldnt do this?, other than it works the engine harder. Thanks!!

[95Sierra2500]

It's just like the Performance Shift on my Grand Prix. All it really does is ups the line pressure in the transmission and allows the engine to run into higher RPMs before it shifts. It's actually BETTER for performance than normal mode, but it'll hurt your mileage a bit.

[C & A s Dad]

I am not sure why but I do know the owners manual says use it only when loaded at 65% of max load or greater.

[Starrman]

Agreed with C & A s Dad above.....the manual says that its not good for it if used when not loaded or under normal driving conditions and can actually cause damage

[tjr508]

Mine shifts hard enough in regular mode. If you want higher rpm shifts, use more gas.

[Reeper27]

The two haul mode actually changes the transmission shift points, firmness, and line pressure in the tranny so that way the transmission wont slip as much, slipping causes heat and heat is a automatic trannies worst enemy. If you do a lot of towing another tranny cooler would be a great investment, and a tranny temp gauge. You can usually pick up a tranny temp guage for around 100 or less, if your like me and want to keep a factory look and not just one gauge on your dash or a pillar, www.stylinconcepts.com has a Esclade gauge cluster that gives you a factory look Transmission temp gauge. It also changes the igntion timing and injector pulse width and a few other parameters in the engines computer to give you the best performance while towing, or playing, and the best milage too, which really isn't as good as these trucks can actually be.

[gmc55]

I use mine sometimes going through down town just because it sounds really good but thats very rare. I've been told it's actually worse for performance and not good for normal driving.

[Sierra67]

To preserve your powertrain, I suggest using the Tow/Haul switch for the first 3 gears (automatic) then when at hiway speeds switch to OD or take it off of Tow/Haul. This will give you better mpg and not work your engine as hard.

[jjrobo]

My truck shifts really hard with tow/haul mode on until I get alteast 3k pounds behind it. Once I get some weight behind the truck it shifts really nice. And I need atleast 1000 lbs to get the second to third clunk to stop.

 

Jeff

[tex99gmc]

Hi...I've always used the towhaul function for towing trailors and stuff but today I decided to try it out on regular driving. I actually really like it, higher shift and better response. I have a 2000 GMC Sierra 4.8(145k)....any reasons why I shouldnt do this?, other than it works the engine harder. Thanks!!

[Hoopster]

I use mine descending steep hills when going to or from mountain bike rides. It really saves the brakes. No harm so far unless that caused the TFP switch to fail. 5th reply so I can post my question now!

[tommbo]

I like the tow haul option