Gas Pedal

What would be the best way to go about animating a gas pedal to match the throttle?

I have successfully rigged my vehicle to turn the steering wheel using the "steering" action, according to the steering angle, and was wondering if there is an action I can use for doing the same sort of thing for a gas pedal (like the more throttle is engaged, the further down the pedal goes - that sort of thing)?

Thanks a bundle!