Is there any way to make it so that when you shut the truck off it Tow/ Haul that it will be in Tow/Haul when you turn it back on? Does anyone else have the habit of turning off the overdrive while in city driving? Is this even worth doing, both in terms of fuel efficency and performance?

 

Nope, that setting resets every time you start the truck. Haven't found any mods/tips/tricks that tell me otherwise. In fact (I'll test this tomorrow to be sure,) but I'm pretty sure that shifting to out of Drive from Tow/Haul or OD Off will reset the shift pattern as well.

 

Maybe some of the flash programmers have that capability. I don't know.
I know alot of them allow you to turn the traction control default to Off on start up, on alot of sports cars. This is similar to what you want to do.

 

Should you really be turning OD off while towing? Well let me explain, I'm not towing crazy amounts of weight, talking 2/3 snowmobiles at a time. I have the 4.7, I never turn it off. Doesnt struggle in OD.

 

The reason for turning off the OD while towing is to keep the shifting to a minimum. Shifting creates alot of heat. I tow a 20ft boat that wieghs about 3,500lbs and I always turn off the OD. I live in New England and there are some pretty long up hill streches where I turn off the OD even if I'm not towing anything just to keep the trans. from shifting every 30 seconds!

 

my personal experience is that i get better milage with OD on. even just driving around in the city. the more RPMs the more fuel. if you are towing that could be different. especially if the trannie keeps shiftig down.

when i am cruising down a street at 45mph in OD i can get well over 20 mpg. and i have the 5.9 with 90,000 miles. but if i turn the OD off while cruising it drops to 14 - 15 mpg.

 

Mileage is not the issue.....heat build-up (an automatic transmissions worst enemy) is what you avoid when towing by turning OD off.

 

I like the way the truck drives around town with O/D off. It holds a gear longer. I live in a hilly area and O/D off is much smoother. I would have liked the option to leave the o/d off or on when I start the truck.