This subject came up on another site awhile back and got so many different answers it was unreal. This is for anyone with OD or Automatics.
Here in the mountains of WV where I live you may be driving along at 50mph for 5 minutes and then hit a curve where you will go no faster than 5 mph and then straight up a 40 degree grade mountain or climb up another with a 5 mile grade only to level out and hit 50 or 60 mph again for a short distance.
Don't think you will ever go over 60 mph in my area until you hit the expressway.

(1) So in this case do you leave the OD off to keep the tranny from working so hard or do you switch back and forth depending on the speed you reach?

(2) Is it alright to leave the OD off when you are doing 60 mph for maybe a minute or two at a time?

(3) Will it hurt the tranny if you hit the OD button to turn it back on when you are able to drive 50 or 60 mph or should you slow down first?

 

for short and hard jaunts and towing take it out of overdrive

for long cruising on the freeway put it in OD

 

All of the above?
You get a lot of answers because different folks find different ways the OD off switch can be useful. (Plus there are idiots but we'll leave them out..)
On my F150 sometimes I use it to cause a downshift when I want to slow down,like for an offramp for example. I use it when going down steep grades to try to reduce use of the brakes. I use it anytime the trans keeps hunting up and down between 3rd and 4th. I use it if I want to downshift while going up a hill but don't want to mash the gas pedal to induce the shift. I use it around town so it doesn't go ahead and ease into 4th at low throttle at 30 mph (waiting for the torque converter lock/inlock and downshift when I get back on the gas bothers me - I would so rather have a manual trans...) You can leave the OD off all day long if you like - if you try to drive too fast in 3rd the engine screaming should remind you to let it shift. (I've heard that Yotas will upshift anyway, but no truck I ever drove would do that, nor would I want it to...) And you can switch it on and off anytime you want - won't hurt a thing. If you switch if off and are going so fast the downshift would over-rev the engine, it simply won't downshift until you slow down a bit.

 

I agree with all of the above. If you are going uphill, even if you are moving pretty good, taking it out of overdrive will probably save you gas and it will help you slow down a little easier for those tight turns.

 

all the above , except the braking part. i use it to slow on a downhill, but not in place of braking to a stop. i learned a while ago that brakes are cheaper than transmissions.

 

[QUOTE=Flamedx4]if you try to drive too fast in 3rd the engine screaming should remind you to let it shift.

Is this why when I punch my auto trans on an uphill freeway, it just keeps revving higher and higher until I release gas and let the tranny shift? I always keep my OD on. Mostly street driving but on occassion will get on the freeway...

 

[QUOTE=ebelen1]Leaving the OD "ON" all the time is not a good idea and it's hard on the tranny in some cases as pointed out above.
After so many years of driving vehicals with OD it still amazes me how many people don't know how to use it and it's even more amazing as to how many people don't know how to use an automatic correctly.
Stick with the info the guy's above have given you and your tranny will love you for it and it will last for many years. Knowing when to use low and second, will really help also. Just do a search and some Googeling for the rights and wrongs for auto trannies. Mike