No, you do not, overdrive was design only for some extreme situations such as mountains, steep heals... If you keep on all the time your transmission fill fail because it was not made to extreme driving.
Overdrive really wont affect you in a town or city, so you can just leave it on. On the highway, it helps reduce the strain on your engine, so just keep it on all the time.
No. You should not drive in overdrive all the time.
yes. it will only shift into overdrive when it is needed.
all the time
Overdrive should always be on unless you are towing something heavy.
It's usually on all the time unless you press the button each time you start the car. I think that normally the overdrive kicks in around 45 MPH.
I have a 2002 Accent with the overdrive button. The owners manual suggests that the switch should be engaged to have overdrive on all the time. However, I have found that since I do a great deal of stop and go driving the transaxle shifts and performs better with the overdrive off. The car isn't trying to put itself into overdrive every two seconds and makes for a smoother drive. Again this is mostly for heavier stop and go driving.
Overdrive is the normally allowed position but it won't shift into overdrive until the speed is fast enough
YesYes
keep the overdrive shaft button pressed, there is a panel light called "O/D" that should light indicating the overdrive is OFF. In that case make sure the light is OFF which means overdrive is ON.
The only reason not to leave it in overdrive would be if you are towing and going uphill. The car's computer will tell the transmission when to shift safely, but when under a very heavy load it may shift a lot. I usually only take overdrive off when I am towing going up hills where the grade changes frequently. If you are unsure, then it is better to keep it in overdrive all of the time and let the computer do the calculating. Fords actually have a pretty good system in place to remember how you drive so the computer will make the ride most comfortable.