zaghloul

I’ve done a search on the forum and found some very conflicting statements about the function and use of the O/D button on the automatics. Most people seem to think all it does is just disable 5th gear. I believe that it does more than that. It completely changes the shift points, it improves throttle response considerably (especially noticeable before I got tuned), and once you take your foot off the gas the rpms will start dropping much faster than normal. Does this sound right to you guys? Does it change anything else?

Also, at what speed should you turn the overdrive back on?

Does it harm anything if you drive with O/D off at 75MPH for a min or two?

Does switching it on and off repeatedly increase the wear on the transmission?

Does a tune change anything with the O/D off shift points?

AWmustang

Only the contents of your wallet. Your Gas mileage will suffer if you cruise in anything lower than the highest gear available.

nynvolt

I drive with OD off most of the time. I usually turn it back on if I'm going over 50 for any amount of time, like if/when traffic on the freeway opens up. I also use it if I want to pass and am moving 65 or less, just so the transmission doesnt drop two gears and make it sound like I'm being an ***. As I understand it, having OD off is better for your transmission if your not maintaining a constant speed over 50. Keeps it from up then down shifting over and over.

I won't say your wrong about the shift schedule changing but I haven't observed any change when I disable it or leave it on, if I punch it she goes and tach's out the same in my opinion and throttle response feels the same to me.

I don't think it causes damage or rather is incorect usage clicking it off alot, if you try cruising with it enabled around town the car will shift into and out of 5th alot more than when I'm engaging and disabling it. Mechanically it shouldn't cause any more wear than the car does on it's own. Thats my thoughts anyway.

And as for running 70 with it off, I do that sometimes, puts the car in the sweet spot of rpm. Feels awesome, but wouldn't drive it all the time at 70 in fourth. Doubt it does any damage but over the long term it might shorten the life of the engine, I don't know.

Twisted

I have a Bama Chips tune and Doug did it so the car won’t shift into over drive until 50+ mph. He has done some really great work with the tranny shift points as well.

mhk

True!

StangMahn

I leave my O/D on, unless Im going through the gears. I can't see where it would harm a new transmission. It should be fine, the transmissions computers and valves/springs or w/e should be able to compensate.

zaghloul

Well thats the least of my worries. I pay $0.56 per gallon of 95 premium gas over here. Pays to live over an oil field.

Thats possible, but with the O/D off at 70MPH my rpms are about 4k. I guess longer cruises at faster speeds with O/D off will reduce the life of the cams and other engine components.

I'm still wondering if a tune changes anything with the O/D off button. Are the O/D off shiftpoints a certain set percentage above the normal shiftpoints, or are they also independantly set? My predator doesn't show me any options to change the shift tables with the O/D off.

poldrv

I drive with the OD off in town, if I am going over 70k then I put it back on.

zaghloul

You're speaking kilometers and I'm talking miles. 70km/h is only 43mph, thats not much at all. I was talking about 70mph which is 112km/h. All this mile vs kilometers crap confuses the heck out of me too. I'm Canadian, so i know kilometers, but my stang's spedo is only marked in miles, and I live in Kuwait which posts its limits in kilometers. Luckily, the limits are suggested limits and not enforcable, so I don't worry too much about calculating in my head.