This weekend will be my first pull with my new truck and we are headed to the beach for the week. I live in the upper part of South Carolina and it is fairly flat with the exception of a few hills. Should I tow the trailer in the tow/haul mode? I know when we go to the mountains for Christmas I plan on putting it in Tow haul mode I was just wandering about fairly flat pulls.

 

I still use T/H mode.

 

it won't hurt you to do so. it mainly just gives a bit different shifting pattern for acceleration and the addition of the engine brake for deceleration.

 

i always use tow haul when hooked up to something...to me i like the downshifting and the sustained gear holding when driving around town.

 

I have not tried it, but I would imagine that you would probably get better mileage with out using tow haul due to keeping RPM down. You did not mention how much you are towing, but if it is a fairly light load your truck can probably handle it with out tow haul. Why not try it both ways and let us know?

 

Thanks for all the Info. My camper is a fifth wheel and it weighs just a shade under 10K.

 

always use it. the braking support alone is worth its weight in gold..
it can save your life.. I think it has for me already twice in a year, and I only tow 7000lbs.

Sam

 

it's worth noting that the tow/haul program only increases RPMs under acceleration, when you need them. Cruising it won't affect them at all.

 

Thanks for all your help. I am still learning all the bells and whistles on this truck.

 

T/H allows for higher RPMs between shifts but it will still shift into 6th.
I don't think the MPG would be that noticable.

 

I don't use the T/H unless I'm on a hilly section of highway. I do feel that the MPG takes too big a hit from the high revs. Note that I'm using a 6.2 gasser; you diesel guys may not notice it as much. The 6.2 revs too high as it is....

 

I hope to be corrected if I am wrong but I believe that the T/H strategy also changes the transmission fluid pressure and has a positive effect on cooling vs. running in straight D.

I really doubt the transmission could overheat regardless of the driving but over several thousand miles it might just make a difference in longevity.

BTW, I ran over 150K in my '08 and the trans fluid was never changed and I always used T/H. Looked as new as the day it was built, and that's using it as a towing truck over 90% of its duty.

 

I use tow/haul when I pull my 13000 # fiver. I have found that it takes longer to get the trans to shift into 6th gear on flat ground. I switch off the T/H and let it shift and then turn it back on. It works quite well. I probably save a shot glass of fuel...

Regards

 

Same here, it does take a bit longer to settle into sixth, so you can pop out of tow/haul or over-accelerate then settle down to the speed you like.

We're only running a 6500 lb TT but the engine braking on hills and when decelerating is a nice feature.

 

It does change the fluid pressure..but to my understanding it is to benefit firmness of shifting which is easier on the clutches...I don't believe it makes a difference on cooling because the trans cooling lines have an inline thermostat anyways to regulate the temperature...if it was straight through it might run cooler..but we all know cooler is not always better.