When to use OD

[BrianBird]

This may be a simple question, but when do you use over drive? Do you just keep in OD or only on the highway? Will it make a difference in gas mileage? I usually just keep it in OD, but i drive in the city and traffic alot and got to wondering. :confused:

[STEVEN LONG]

I drive a 6 speed C5 ... think 6th is OD (?) Basically, the lower the TACH ... the better your fuel mileage will be. If you are driving for speed ... forget about OD. If you are dricing for fuel mileage ... then I'd use OD. Local speeds are 45MPH ... and I am frequently in 6th. Highway crusing is ALWAYS in 6th (at 30MPG). REAL City traffic might not let you get to OD. Hopefully, other C4 owners will provide input.

[PeteB]

I have a 4 speed auto. Generally I find that if I'm in D(overdrive)
and below 40mph, I like to shift down to D(regular). It seems once I'm in that 35 to 40 window, the transmission in overdrive wants to shift back and forth.
I live in the mountains and I normally shift down into D(regular) after the transmission shifts on its own for more power for ascending long hills. I then leave it in that gear to descend the hills for the engine braking.
As Steve mentioned someone else may do it differently, but it's what works for me.

Pete

[Rick and Arleen Ball]

When Arleen had her 88 coupe and 93 40th they were both automatics. We always just put them in overdrive for local and highway driving.