you farted and it stinks alot
No it is not Overdrive is the top gear that has a higher ration than 1 to 1. So if you have a 4 speed automatic with overdrive, then 4th is not overdrive. Overdrive is beyond 4th.
its always best to use your overdrive when on highways at higher speeds
overdrive
Overdrive allowed is the normal position - it actually won't shift into overdrive until the speed is higher
Overdrive is the normally allowed position , but unless the speed is higher it won't shift into overdrive anyway
Overdrive is the normally allowed position . It won't shift into overdrive until the speed is higher anyway , such as on the highway / freeway
On a 2007 Ford Focus : That is the " upshift " light To maximize fuel economy , when the light comes on shift to the next higher gear
Overdrive is the normally allowed position ( in overdrive the engine doesn't rev as high , the gas mileage is better , the transmission will run cooler etc. when you drive at higher speeds )
If the rest of the Transmission continues to function, then result is that the engine RPM's will be higher when cruising than is normal. Overdrive reduces the RPM's at the speed where it engages.
You have to use it when you are driving in mountain areas where to have high speed is not a good idea. The overdrive function does allow the transmission to switch to higher gears.
On a 1998 Ford Crown Victoria : Overdrive is the normally allowed position , although the transmission will not shift into overdrive until the speed is higher If the overdrive is switched off , on the gauge cluster just to the right / and above the speedometer you will see the O/D OFF warning light ( if you have the digital dash it will show overdrive off in the upper right )
The answer is oil. Injection cleaner will help on a car with higher mileage.