[edwardsaddict99]

So I just got my Mustang a few months ago, and I am not exactly sure on the mechanics of what overdrive does for the car? From what I can tell just by driving it, it seems to be something I would want to use almost all the time, except maybe if I want to race with it or tow something (which doesn't make sense in a Mustang, I guess.) But anyways, I'd greatly appreciate it if someone could enlighten me on what overdrive does for the car, and the appropriate times to use it. Thanks!

[Bocephus357]

Overdrive is basically for gas mileage and top end speed (over 120ish range). 4th gear is 1:1, meaning 1 revolution going into the tranny = one revolution going out of the tranny. Over drive is one revolution going into the tranny = more than one revolution going out of the tranny.
Normal driving, use overdrive when ever possible for better gas mileage. Racing, dont use overdrive unless you are in a top end race which you would be well over 100 then so defenlately not in the 1/4 mile.
Somebody might be able to explain this better than I can, but hopefully that will help some.
Is your car an auto or manual?

[edwardsaddict99]

Mine is an automatic. I was looking for a manual, but there isn't a wide selection of Mustangs up here in northern Minnesota. I couldn't afford the GT, and almost all the V6's up here are automatic. And yeah, thank you, that information does help. I don't really do any racing, so I'll probably be keeping my O/D on most of the time, but it's good to know just in case. Thanks!

[Bocephus357]

Yeah, just keep o/d on and let the computer do its job for normal driving.
Congrats on the Mustang!

[hatawna]

yup explanation is correct.

OD can be likened to a 5th or 6th gear of a manual tranny. use OD for normal driving. turn it off when you're going uphill, passing another vehicle, going downhill, or if you wanna have a little fun. OD only works on "D"

[jerryt]

i have a rule with my v6 auto od-it is to us od when i drive over 50 mph, because most driveing is done in the city limits, like to go trafic.

[proteusthelder]

I was also told to turnoff the overdrive in snow and wet conditions. Why that's so I don't know.

[edwardsaddict99]

Thanks, everyone. And thanks proteusthelder, that is a good point I wanted to bring up. I only have maybe another month until we start getting some snow and ice up here in minnesota, and I have no other car to drive for the winter. Does anyone know for sure how overdrive acts in winter?

[GuitarstarX7]

Here is a pretty good description:

"Generally speaking, overdrive (OD) is the highest gear in the transmission. Most automatic transmissions have three speeds and overdrive (fourth speed). Overdrive allows the engine to operate at a lower rpm for a given road speed. This allows the vehicle to realize better fuel efficiency, and often quieter operation on the highway. When you switch it on, you allow the transmission to shift into overdrive mode after the certain speed is reached (usually 70+ km/h [45+ mph] depending on the load). When it is off, the transmission shifting is limited to the lower gears. For normal driving conditions, operation of the overdrive should be enabled only if the average speed is above 70 km/h (approx. 43 MPH)."
from: overdrive: Definition from Answers.com

I haven't noticed an acceleration difference in my car with o/d on or off. O/D gear doesn't kick in until after the the last main gear.

I haven't really turned off my o/d when it's raining. They say turn o/d off because, if you are driving in extreme conditions (uphill, towing, maybe snow) the transmission might try to shift back and fourth between the 3rd and 4th gears constantly, so turning it off would help prevent that and just keep it in the 3rd gear for more stable rpms/power.

[SilverBullet07]

so will turning off overdrive increase my acceleration?

[edwardsaddict99]

For me, I haven't noticed a big difference in acceleration if I floor it from a stop. But if I am cruising down interstate and I want to get on the gas a bit, it feels like it accelerates faster with O/D off.
I know that's not a real technical answer, probably because I don't have the technical answer. But that's how it feels in my car, at least. Hope it helps...

[amustangrocks]

i`m not sure either but if your cruizin about 30, and you turn off the od, then put it to the floor, i think it kicks down a extra gear than it would in od. i turn mine off alot on big hills, and its the only way to get any kind of engine breaking( where the car will actually slow down when you back off the gas) with the auto trans in traffic on hilly roads. if traffic is slowing down, sometimes i`ll turn off the od instead of riding my brakes, kinda the same as shifting from 5th to 4rth in a man

[zelpus]

I've toyed around with overdrive myself and never could figure out the real difference between it being on and off. Thanks for clearing this up