Will it hurt the truck to stay in OD all the time? I am not used to manual OD like this and find myself leaving it there all the time. Not on purpose, just because I never think about it. Is this going to harm the truck? I think I know the answer already to my next question but how about gas mileage? Bad?

 

In OD all the time?

I'm guessing you mean you have OD off all the time... which is really only recommend for towing. Leaving OD on, which is the norm when you start the truck essentially gives it an extra gear for highway cruising (better MPG, less wear and tear on the engine and drive train). I'm fairly certain it doesn't kick in till about 50-60mph.

Having it off all of the time is going to run the engine at a higher RPM during highway drives (not giving the engine that "extra" gear). This is obviously going to put more stress on the engine, and over time could cause problems.

 

Actually, I think he's saying he has a manual tranny and leaves the tranny in OD all the time (at "slower" speeds).

I had a 5 speed in my '97 4x4 Ranger. I was usually in OD before 45 MPH... I know it's a completely different truck, but it ran great till I sold it with 156,000+ miles and averaged 17 MPG with oversized meats.

I think as long as you're not lugging the motor, it's not going to hurt anything.

 

Sorry, I forget that you guys aren't psychic. lol. I'm not either so I don't know why I think you all should be. I have an auto transmission. The "Off" light on the dash is never on. I leave the OD alone, I never turn it off. I take it from you guys response that that is nto a bad thing. If that is the case, then my question is answered. Thanks.

 

In heavy traffic conditions & speeds less than 40 MPH I usually push the OD off button! Tranny seems more responsive in these conditions at this setting! Speeds above 40MPH I switch her back to OD on............

 

There are only two times I turn OD off:

Coasting down a steep hill when engine braking is needed

and

Towing

Otherwise, I let the computer manage the transmission's shifting.

Steve

 

And that is what I am used to, the vehicle managing its own. Ok, as along as its not causing problems I will leave it as is. Thanks.

 

I believe that it is best to leave the OD alone unless as they said, towing etc. I never touch mine. OD full time.

 

personally i turn OD off in traffic from light to light, when cruising back roads or towing under certain situations. if your engine is lugging in OD turn it off. traveling at high speeds w/ OD off creates a drivetrains worst enemy HEAT. keep your tranny COOL, dont let it shift if it doesn't have to. listen to your engine, feel your truck, it'll tell you what to do.

 

X2!

 

if you lift your truck and dont regear right away, turn off the OD
but thats stating the obvious

 

Really? Gee, I guess all us old timers were burning up our drivetrains on the highway in the days before overdrive automatics and locking torque converters. I seem to remember a 70 Grand Prix I had that got well over 200k with nothing but tranny fluid and filter changes about every 60k.

What heats up a tranny is an unlocked torque converter and/or constant shifting. The torque converter locks in your trucks in both 3rd and OD. Running in 3rd (direct drive) is actually less of a strain on the tranny guts than running in OD, but this is not a factor except under very heavy loading.

Other than for the price of gas, I would not hesitate to run all day at 80 mph with OD off if I had an automatic. However, OD is there for your benefit, use it whenever possible.

 

Most of my driving is city driving. I did an experiment and shut off my overdrive every time I started up the truck to see how it would affect gas mileage. I also kept my driving habits exactly the same. At half a tank, I could see that I was getting horrible gas mileage. I went back to normal, and when the tank was empty, I did a calculation. I was getting 1 mile less per gallon by turning the overdrive off in city driving....and that was just doing it for the 1st half of the tank. With gas prices the way they are, I couldn't go the full tank to see what it would have done.

So, in short, I let the computer do what it needs to do.

 

I leave mine in O/D mode. It knows when to shift.

 

In town my OD is off, Highway my OD is on. I got a year 2000 and been driving it like that since day 1 with no problems