Yup... turning off OD just knocks out 5th gear. In fact, the lowest level Stangs don't have the OD trans, they just have 4 gears.

OD is like 10th gear on your 10 speed bike... ever get going fast on a level road with a bike and shift into a high gear where you are barely moving your legs (low RPM) but you are just rocketing down the road? But, as soon as you hit any incline in the road, you just can't stay in 10th because you have no torque, so you can't get up the hill, so you downshift, and pedel faster (higher RPM's) to get the same amount of wheel movement, but, you have torque and can get up the hill.

 

Your best time to 100 MPH would probably have you at high RPM's in 4th... because you are hard on the throttle, the car won't shift into overdrive. The computer is looking at speed, engine load, throttle position, 1st derivative of throttle position, etc. to decide if you can shift into OD. So, doing what you are saying will have no effect on 0-100 time.

 

So if I was doing this (0-100) you would recommend to have OD off? and if iam already going than leave OD on? Sorry for being a pain. LOL!

 

It doesn't matter if its on or off. You are stomping the gas so hard, and putting such a load on the engine at high RPM's that the computer won't even try to get into 5th gear. You'll hit 100 as you approach redline in 4th gear. At least that's what I've seen....

 

Gotcha! Thank you very much for the explanation! Ill just always leave it on like I have before.

 

Well again, the time to turn it off is when you are tooling around back roads, and you are whipping through turns, and stomping the gas as you exit the turns... here, you don't want to be in 5th, which forces a downshift every time you apply extra throttle pressure. If you are driving in the 25-45 mph speed zone, tooling around the back roads, I turn it off. But, for regular driving, high speed driving or driving where you are absolutely stomping the gas from a dig up to very high speed, leave it on.

 

then again when you say off road I think of mudding and sht like that....lol[sm=nothatway.gif]

 

I have been wondering this about OD. My girlfriend has a V6 2000 Mustang and she gets the gas milage of a V8, about 15-17 miles a gallon. My friend let me borrow his Mustang for a month and it's a '95 and has a V6, and it got about 21 miles a gallon.

I have no idea if the '95 was in OD all the time or not, I never paid attention or had a problem with it. But in my girlfriend's Stang, it gets near terrible milage. For driving under 40MPH should I tell her to have it off? Around this town, there are only two places where you would exceed 40MPH. I've noticed I can zip around easier with OD off and I enjoy it being off but haven't driven her car with it off for long periods of time to see if fuel economy is better. It sounds like it shouldn't make a differance. I just want to know why she gets bad milage and if turning OD off when not nessicary will help.

Thanks

 

I am pretty sure ALL the s197 automatics are five speeds. Unless you were talking about the older mustangs

 

I had to read your question multiple times because it sounds so stupid. Either look at your rpm gauge or listen to the motor to know how much stress is put on the engine. Overdrive is at a low ratio to save gas thus acceleration is slower that is why you downshift to pass. The higher the gear the less gas you burn.