The manual recommends to keep the overdrive on at all times, except when towing. I beg to differ.

I can think of a few reasons why one should turn the O/D off when driving at low speeds (25 and under). For example, the automatic transmission goes through a lot of shifting up and down (which puts more wear and tear on the transmission).

For another, the engine does not idle that much more at low speeds, and contrary to what the manual says, you are not going to use up more gas than if you had it turned on.

Lastly, I dislike the repetitive "shift shock" that occurs whenever I press and release the gas pedal -- thanks to the torque converter having to deal with the low RPMs.

What is your opinion?

 

i dont know what it does, but i never use that button

 

All it does is keep the transmission from UP shifting into 4th gear... I understand that not everybody is 'car savy', but if you dont know what an OD ON/OFF button does, maybe you should not be driving.

 

Don't you mean 5th gear?

Actually, it does a little more than that. Overdrive allows the engine to rotate at the lowest possible rate while generating enough torque to attain optimal fuel economy. That is why RPMs increase when O/D is turned off.

That is the reason why O/D should never be used in high torque situations, such as pulling a load up an incline, or towing a reasonably heavy load for a long distance.

 

I leave mine on most of the time, but there are situations where i turn it off, like when driving in stop n go traffic when i know i wont be able to get above say 30. Or when i'm on the highway and need the extra umph get fly past the idiot driver or truck jamming traffic. But yeah like the manual says itz usually on.

 

...and especially going up a steep hill at low speed

 

when stuck in BQE during rush hour.. turn that ***** offf..

 

No 4th. 5th comes after 4th and it is not even really a gear, it is just your TC locking...

Where did you hear that?!?

 

I thought while driving in the city, o/d was better left off? Seems to work better,imo.

 

I just use it as sort of a "sport" mode. I like the tranny to hold in at least third if i am driving aggressively through the twisties. You dont waste any time shifting as you are coming out of the turn.

The only other time I use it is when Im in traffic cuz I dont like the tranny having to shift unneccesarily.

 

Overdrive control switch sends a signal, which prohibits a shift to D4 (overdrive) position, to the TCM. Page AT-49 in 2001 FSM.
Here is some more. Page AT-32 in 2001 FSM

Lock-up Control
The torque converter clutch piston in the torque converter is locked
to eliminate torque converter slip to increase power transmission
efficiency. The solenoid valve is controlled by an ON-OFF duty
signal sent from the TCM. The signal is converted to an oil pressure
signal which controls the lock-up piston.

Conditions for Lock-up Operation
When vehicle is driven in 4th gear position, vehicle speed and
throttle opening are detected. If the detected values fall within the
lock-up zone memorized in the TCM, lock-up is performed.
..........Overdrive control switch /.........ON....../........OFF
........................Selector lever /..........D position
.........................Gear position /.........D4....../.........D3
..............Vehicle speed sensor /....More than set value
...........Throttle position sensor/....Less than set opening
..Closed throttle position switch/................OFF
...A/T fluid temperature sensor/.....More than 40°C (104°F)


I hope this clears up things.

 

you don't have a 5th gear

 

Yes I do. It's called "reverse."

 

I htink it would have been easier to say that turning O/D off gives us that 3rd gear setting that should have been our gear selectors!

 

After reading all that, only a triple shot of espresso would clear things up for me.

I think it would have been easier to say that turning O/D off gives us that 3rd gear setting that should have been put on our gear selectors!

 

True, but it's more reputable since it's directly from the FSM.

 

Are people really this slow...

 

I sense a little oximoron here

 

I sense an extremely stupid thread that should be locked so this bullsh!t does not continue...How many times has this EXACT thing been discussed?...Good God I cant even keep track

 

No, the I35 guys seem to be much faster than the I30s....

 

Not manual I30s.. not even an option on the I35...