In most cases drive with overdrive especially if maintaining over 45 mph. Take out of overdrive if on slippery pavement
No. You should not drive in overdrive all the time.
rear wheel drive ( and if equipped 4x4 capable )
As far as I know , you inflate the tire(s) to the correct pressure and then drive the vehicle
On a 1999 Ford Expedition : Overdrive is the normally allowed position It won't shift into overdrive ( the 4th " gear " of the transmission ) until the speed is higher anyway ( such as on a highway / freeway ) If you are towing something / or driving in hilly country and the transmission is shifting back and forth between overdrive and drive , then you want to shut off the overdrive on the transmission using the switch on the end of the gear selector lever . ( the word OFF will light up near the end of the gear selector lever )
how much for a new transmission?
Overdrive is the normally allowed position ( it won't shift into overdrive until the speed is fast enough )
The maximum height to the top of the roof rack is : 77.6 inches ( 2 wheel drive ) 80.4 inches ( 4 wheel drive ) According to the Owner Guide
30 U.S. gallons with the rear air suspension ( 26 U.S. gallons for 2 wheel drive / standard suspension )
2 wheel drive without air suspension--26 gallons 2 wheel drive with air suspension--30 gallons 4 wheel drive-- 30 gallons
2 wheel drive with standard suspension ( 26 U.S. gallons ) 2 wheel drive and 4 X 4 with rear air suspension ( 30 U.S. gallons )
Overdrive ON is the normal position But if you are towing something or driving in hilly country where the transmission is constantly shifting from overdrive to drive , then you want to switch the overdrive off
rear wheel drive or 4x4 capable