hawwk11

Hello Guys -

I have a 99 auto GT and would like to know when to turn O/D off. I dont have a owners manual so i couldnt look in there but thought you guys would know.

Thanks a lot,

ackuric

turning o/d off just keeps the car out of 4th gear, so if you want to remain in 3rd gear at cruising speeds, then take o/d off, i usually keep it off unless im on the highway.

mustangman02232

yup, less then 50 mph i have it off, more its on.

hawwk11

Thanks guys.

Smooth_J

Is it bad for the trans if you leave OD off even on the HW?

Emann0007

Just more rpms which = more engine wear and poor gas mileage. At 70-75mph in 3rd, if you turn on your O/D (switching to 4th gear) will lower rpms about 250-350rpms. Makes a big difference in gas milage. That and if you have to pass someone, your cumputer will drop you back into passing gear (3rd) for a little more pull I leave my O/D on all the time unless I am at the track.

antiv6

if your at wide open throtle and it goes into o/d then it can hurt your tranny ive heard. So if your racing leave it off. Also is it just me or is the gas pedal stiffer when od is off?

mustangman02232

its just you, the SN-95s dont have a drive by wire so the pedal is the same, driving on the highway with OD off would probably be like driving with 4.56 gears, so if you do that, then leave OD on and go swap those in

GreyStang

It's good to turn off O/D if driving on very hilly roads, this allows a bit more enine braking on the downhills

Besides for that.. some truck owner buddies say in their owners manuals it's good to turn off O/D if hauling a heavy load or towing a trailer etc..

Emann0007

What the hell are you talking about? When I go to the track, I turn off my O/D. But when I'm trapping at 95mph you think I'm still in 3rd??? NO. The computer turns on the O/D and shifts you into 4th automatically. In my car at least, it is impossible to drive over 80ish MPH with the O/D off. Similarly, it is impossible for me to dissengage O/D at speeds above 80ish MPH (I don't recall how much I had to slow down before I could turn it off). But.... at 80mph if I punch it, my car will drop into 3rd and run through the last end of 3rd gear