hello everyonei have an automatic, and i was wondering whether having O/D on or off would give me the most performance? and mpg since i cant change my shift points like a manual?

 

there is no performance difference with it on or off. Car still shifts the same, but with it off, it won't shift into 5th (over drive). My car shifts into OD at 45mph, which can become annoying when the highway is moving at 45mph. So I usually leave it off until I hit 55-60. With it off, the RPM's are higher, meaning your mpg's would be lower. The easiest way to understand it is to envision driving a manual and not shifting into 5th.

 

I only use it on the freeway.

 

You can change your shift point manually. Best mpg is when it is on.

 

+1 With my 3.31 gear, OD is too tall for city driving. I turn OD off as soon as I start the car and dont turn it on unless I'm highway driving.

 

I lollygag around our small town. We have several cops with itchy radar gun trigger fingers. I let it shift if it wants to. Speed limit is 30 so it seldom gets into 5th.