i have recently purchased a 300zx and have alot of questions but i'll start with this one. what is the overdrive button on my auto box and is it best to drive with it on or off?

With my old auto, I had it off most of the time and would only put it on if coming up to steep hills, climbs or where ever the car is under load. With overdrive, It won't shift a higher gear then needed to (when turned on). Basically it's like you wouldn't drive up hill in your highest gear, but appart from that, overdrive didn't make much of a difference in my old Z anyway. Someone told me once that it's like a go faster boost button which didn't help :P Keep it off/on to load.

Leave overdrive on unless you're caining it. Its like an extra top gear. Leaving it off for prolonged periods will cause the 'box to fail prematurely

Defo, leave it on. useful to switch off sometimes on twisty roads to stop it going up and back down all the time when driving fast. also useful to get a bit of extra engine braking going down hill when off.

Leave it off when giving it some beans, but otherwise might aswell leave it on. :)

thanks for the help.

I def read somewhere that O/D needs to be off when driving between 0 - 40 mph and on any speed over 40mph. I also heard from a Nissan dealer that driving in excess of 70mph with O/D off will wreak the box.

 

Driving with O/D on less than 40mph also consumes more fuel than driving with O/D off.

 

And BTW my definition of ON is that the O/D OFF light is off and OFF is that the O/D OFF light is on on the dash board - Could someone confirm this please?

 

Its not helpful when some says leave off other say leave on we need to be definate

 

Thanks

Gear box designed for o/d to be engaged all the time i.e. ON. for all normal driving situations. swithch it off for reasons, such as gear hunting on twisty roads etc.