I know the manual says to turn "O/D" off when driving and only use for specific driving conditions. In the beginning I didn't, but now I am wondering how safe is it to drive in "O/D.

 

Always drive in overdrive it will save fuel. All O/D does is keep it in gear longer before shifting into the next. So you'll turn it off i.e. when you climb a steep incline, or need to pass a car, etc.

 

I though OD was a fourth, higher gear (in the automatic- 5th in manual) specifically for crusing (i.e. to save fuel economy)??

Isn't that what overdrive, by definition, is?

Does turning it off actually leave you in lower gears for longer before shifting? I thought the computer just knew when I had it floored and therefore took it to redline (or almost) with or without O/D.

 

O/D runs at lower RPMs no matter what gear - reason for better fuel economy. To test, proceed in "Drive" at a constant speed (30MPH) then switch to O/D, you'll see the RPMs drop. I think the idea is meant for 4th gear but O/D does seem to keep it in gear longer. I usually always use "Drive" when I'm in traffic, although it sucks down a lot more gas...

 

K... theoretically, it should prevent your maxima from shifting into 4th... But it does seem like it delays shifting into each of the first three gears as well (i'm not sure, it may just be a perception thing), and yes.. if you floor your automatic max, it does almost redline before switching gears...

By default O/D is on (that's reset every time you start your car).. Hitting the O/D button toggles on/off ***(the light on your console is O/D OFF!!!)***
I use it when going uphill in traffic..., or when I want to have the computer push the rpm's up as far as it can.. (ie.. when I need to accelerate quicker).. Occasionally, when I'm going downhill in traffic, it saves a little wear no the brakes... (does this harm my tranny??)

Its official purpose (according to the Nissan manual), is to prevent uncomfortable shifts when going uphill... (when going uphill at certain speeds, the auto tranny does not shift as smoothly as it could)

-Tom

 

Using OD will give your MAX access to the full range of gears. This will translate into smoother driving, better fuel economy, and longer engine life. The OD off feature take away your top gear..thats it. Use it for low traction situations, or to speed brake (like when a cop is on your tail and you want to slow down without your brake lights coming on) ;-)

 

in the city. Your transmission will hunt through to many gears causing excessive heat and increase wear and tear on your transmission leading to premature failure. I always leave it off in the city, if it is busy. I guess it all depends on the traffic situation. More stop-n-go, no o/d for me, but if it is steady cruising at 45mph ( city street limits ) I leave o/d on. I have not noticed any difference on WOT in O/D on or O/D off. Both shift at 6,100rpms.

 

O/D does not change shift points (as far as I know). Thus, turning O/D off will not allow you to hold gears any longer. It simply locks out 4th gear. I use it in stop-and-go traffic or city driving below 40 mph.

 

yeah, if you want to downshift from higher speeds, just hit the overdrive button and it will go to 3rd...then you can shift it to second if you want (in an auto i'm talking about)...od just takes out 4th gear so if you try to drive w/ it off, you will only have 1st, 2nd, and 3rd...lower speeds, this doesn't really matter but when you are on the highway, unless you are racing, you will probably want your 4th gear (the shift between 3rd and 4th for me happens at exactly 110 mph)

 

Ya but the 110 mph for 4th, is with your gas floored.... right??..

cuz it will shift into 4th a LOT faster if you just accelerate "normally"

 

If you drive with it off, you get a whole lot better acceleration when ya floor it, and when you get into high gear in third, you just turn it back on to get maximum acceleration.