Okay, I've read at least all the recent threads about O/D on/off on the 5th gen. There are always conflicting opinions about whether or not it affects acceleration at all speeds and whether it simply "turns off the 4th gear."

My opinion has to be a resounding "NO!" to the idea that the only thing it does is cancel out 4th gear.

Here's a simple take-home test. Accelerate like normal to 40 (2nd gear). Lay off the gas so you're holding a constant speed. Hit the O/D switch. You'll downshift, watch the tach go up. Hit it again and it upshifts.

I've tried this a few times at different speeds in the last few days and have to conclude that turning O/D off WILL cause you to shift later in all gears... EXCEPT at WOT. (unfortunately)

I've also noticed better acceleration- noticeably better- with the O/D off from a complete stop. My theory on this is that my ECU is trained to know that this driver likes to accelerate fast when the O/D is "off".

I just thought since there are a lot of auto owners out there looking to get the best acceleration out of our unfortunate choice in transmissions, it's good to know a definitive answer.

Please, if your results are otherwise, let's compare notes.

Try it.. you'll like it!!!!

 

No doubt that turning the OD off increases acceleration and also turns 4th gear off. If you are cruising at any speed in other than 4th gear and click it off, the revs jump quite a bit. You can also feel the responsiveness when hitting the gas.

 

When you accelerated to 40, are you sure that the transmission didn't slip into OD. If you let off the gas, at 40, the tranny will go into fourth gear. The shift into fourth will be almost unnoticeable since you will have very little line pressure built up for the shift.

 

UMD is right. When you cruise at a constant 40mph, you are actually in 4th gear. You just felt it shift down to 3rd. Again, all OD off does it lock out 4th gear. Try it when accelerating. Accelerate somewhat quickly from a stop to about 50 mph. You will notice that if you do your best to use the same throttle pressure both times, the switch will make no difference in shift points. Besides, when you go WOT the thing shifts near redline anyway, it cant raise the shift point any higher than that.

 

i have tried this several times and the performance is truly better with the overdrive off. i do have a question however, will it hurt the transmission to leave it off all the time or is it better to use it very little?

 

Is it just me or does anyone else finds it weird that when you turn your car on, "o/d off" is off-->thus, overdrive is on.

 

Sounds perfectly normal to me. Under most driving conditions you want to use all 4 gears. You get better fuel economy this way. Makes sense to make O/D on default.

 

I tried switching the O/D on and off while cruising at 30.

Once again, it upshifted/downshifted in response, just like at 40 but the jump in revs was lower.

Would O/D be on at 30 also?

As for perfroming better with the O/D off, I definitely agree- once again, I think it’s more the ECU knowing we "mean business" when O/D is off.

 

O/D could be on at 30...I will try and let you know to make sure

 

My max likes to shift into OD at about 25-30 when I'm really easy on the throttle. At about 35, the torque converter will lock up (which I can feel). The engine is turning < 1500 revs for 35mph.