Overdrive?

I just bought a 99 Prism. When I drive it the car sounds wound out. The gas mileage also isn't what I think it should be so I'm wondering if it has overdrive and it's not on. The only button I can find is at the top of the indicator when you change gears above Park but it's broken and doesn't stay down. I can see no indication of what that button is and I'm assuming there is an overdrive button somewhere. Is this an overdrive button? If so, is overdirve on when it's up or down.

Thanks,
Brandon

Brandon,

Since you posted this message so long ago, you probably won't see my reply or have already gotten your answer.

I have a '98 and easily get 30-34 miles to the gallon with a 3 speed transmission w/o overdrive. I believe this is excellant.

The button you are refering to is the emergency gear selector release to be used in the case were your gear selector is stuck even when your foot is on the brake. If you have overdrive, the button would be directly on gear selector itself.

This should help you.