Overdrive

I have a 1995 Eclipse RS with automatic transmission... I was wondering if I would harm the transmission if I turned off O/D and only turn it on when I'm on the highway. Does it have to be on at all??? Thanks

no u wont harm ur transmission. it might harm it more while usin overdrive when not on the highway.

you'll just get worse gas mileage, all Overdrive is is 4th gear on your transmission.

ok , it good to use it all the time ?

No, you don't want to use OD unless you are cruising. It shifts too often for daily driving and wears the transmission.