Electronic Overdrive
 

Just lookin for clarification of when u turn on and off ur Overdrive...i know one of the two (on/off) is for highway driving, and the other is city driving...but which is which and its just for gas mileage right?

I believe it has to do with locking/unlocking your TCC in your Tranny.. In my truck when we yanked the computer and put in carb, my TQConverter had a wire that ran up to my dash so I could turn the OD on and off, since the computer was no longer in the loop..