Originally posted by KJ_dragon:
The "overdrive" button isn't actually a gear. It just changes the settings of the auto to shift at different intervals - no mechanics involved.
The Nissan Automatic is a 4-speed with overdrive.
Ratios
1st: 2.785
2nd: 1.545
3rd: 1.000
O/D: 0.694
Rev: 2.272
And "The Button" electronically disables the transmission from shifting into O/D, as well as changing the shift points.