should it be on or off i dnt understand it.

 

Normal driving, overdrive should be on. Heavy towing overdrive should be off.

 

yea i leave overdrive on when driving not pulling anything it keeps RPMs lower so you get better gas milage most time i dont worry aboutturning overdrive on when towing anyway got a '00 5.4 scab btw

 

The reason you turn overdrive off is basically when you're towing on the highway any kind of hill will make your truck downshift from OD to 4th and at the top of the hill it will shift back. It doesn't take much of a rise at all so you will end up shifting back and forth constantly which is bad for everything.