What precisely is the overdrive for?

[Tacquito]

ok, so I know this sounds stupid, but I have no clue what the overdrive in my car is for.... anyone care to tell? People have told me before, but I don't really understand. So, if you know the answer, please tell me... if you don't, can you at least tell me what you use it for?

Thanks!!!

 

[colonialmotion]

i never use it but i see people push the buttom which turns it off to make a pass on a hill and they claim it gives a boost in power....
id say ignore it....

 

[AeLeVe]

overdrive.
is a gear use at speed over 50mph
has nothing to do with driving under 50 mph
only purpose for an overdrive gear is to help with gas milage or MPG "miles per gallon"
when you are going around town at 30 40 45 mph your car will not use overdrive
dont worry just leave the overdrive on and the transmission will do the work for you

 

[Deaner1]

I believe that the overdrive is used for towing purposes. It can be useful when you have alot of weight in or behind your vehichle. It basically gets more out of each gear, so it reaches a higher rpm before it changes to the next gear to maximize each gear. Hope that this helps.