2006 Ford F-150 - when to use Overdrive button

Says overdrive off. So when do,I,need to,push this going up,a hill?

The only time you might WANT to turn OD off is driving is suburban traffic when the transmission is shifting to OD and then right back out in stop and go traffic or possible when towing a trailer.

Press the button so it is ON and leave it on. It will decide when to shift.

The overdrive should be on unless you press the button to turn it off . Also if you turn it off the next time you start the vehicle it should be on . Are you pressing the button by mistake or think it should do something ?

This is what it says in my owners manual… 03 E350. same transmission I believe.

“Use when driving conditions cause excessive shifting from O/D to
other gears. Examples: city traffic, hilly terrain, heavy loads, trailer
towing and when engine braking is required”

I think you don’t understand what “overdrive” is.
When your transmission is in “overdrive” mode, the engine turns over more slowly, and as a result it saves gas and reduces engine wear. However, it also reduces your available torque when you accelerate, unless you push the gas pedal hard enough to “kick down” to a lower gear.

The bottom line is that you should have overdrive engaged at all times, but you might choose to turn it off during stop & go driving.

My truck misfires when O/D is on. I turn it off before I drive, is that okay? I only drive highway.

It is OK if you do that but… If you turn it off before you drive on the highway, you are using much more gas than if you left it on.

You would be far better off if you found the cause of the mis-firing and fixed it.

Turning off the O/D is an acceptable short-term solution to that problem, but the source of the misfire needs to be diagnosed and fixed before it damages the catalytic converter and the engine.