Quote Originally Posted by boybi View Post
The Overdrive switch does not have any effect on your shifting. It is just an extra gear in your transmission that have above 1.0 gear ratio, hence the term overdrive. If it is switched ON, your transmission will engage it at the set speed. If it is switched OFF, then your transmission will engage up to 3rd gear only (for 4-speed trannies) or 4th gear (for 5-speed trannies).
So that's the 4th gear with OD "ON".

I thought it was shifting early , when it was shifting extra.