Quick question. the Mitsubishi mechanic told me that I should always drive with my overdrive OFF especially when I am on surface streets and rush hour traffic when speeds are below 55/60 mph. He said I should have overdrive on, only when driving above 60 mph. Is this correct? Not that I don't trust the dealer mechanic, but i figure why not confirm his info in the forum.

Marc, the only thing that switch does is prevent the transmission from going into 4th gear. This is useful when going up a steep grade and you need the extra engine RPM's to keep your speed up. Also helpful if you want to use engine braking when going down a long grade. The switch doesn't change the transmission shift points between the first, second, and third gears, so it makes no difference in surface street or stop and go driving. Maybe his advice is good for some other vehicle, but not yours. Keep it in O/D all the time except for the above situations.

I leave mine on pretty much all the time on road, if I need more RPMs it usually kicks down automatically.

Sounds like a bit of fear mongering....

The OD on the Auto is pretty tough. Mine typicly kicks into OD at around 45-50 mph. If I'm not going faster than 45 sometimes I turn of the OD so it does not annoy me by shifting in and out a few extra times.

The factor here is its anannoyance and nothing else. I have rebuilt a few of these transmissions and IMHO this is not an issue.

Kevin C

I think it's worse than just a bad opinion. I have not been able to detect converter lockup in 3rd. This means you have extra heating of the atf from the converter losses. Heating the atf is not a good thing to do...

Not sure if the later years are different, but mine does not lock in 3rd.

The converter lockup valve only works in OD... I have always wanted to check out the valve bodies from other versions of the tranny (Volvo etc) to see if they had that option.

Kevin C