Here’s a simple fuel saver that can really add up over time. Don’t let your car or truck idle unnecessarily. It sounds almost too simple to make a difference, but when a vehicle is stopped and the engine left running, it is producing zero mpg. Actually, if you look at in a practical sense, idling moves you into the negative mpg zone since no work is being done. Even if you are an efficient driver, idling effects overall fuel economy because it drags down the average. With modern fuel injected engines, very little fuel is required to restart the engine, so any period idling over 30-seconds puts your car in the negative fuel economy zone.
Modern gasoline/electric hybrid vehicles are designed with an auto start/stop function that shuts the gasoline engine off at a stop and automatically restarts it when the brake is released. While it isn’t a good practice at traffic lights, there are times when it is wise to turn the engine off and restart when it’s time to go. If you are stuck at a railroad crossing with a long, slow freight train or an accident on the highway has traffic blocked with no sign of moving, consider shutting the engine off. Naturally, in the case of temperature extremes you should keep the car running to maintain cabin comfort.
For most people allowing their car to idle is simply a habit. Stuck waiting on your kid after school or practice? Shut the car off. Or how about when you pull into your favorite fast food joint and the drive-through line is long. Consider parking the car and walking inside. It’s a good chance to stretch your legs and it will make that Big Mac a little less expensive.
Most drivers let their car warm up for longer than actually needed on cold mornings. New cars generally need very little if any warm-up time. The only time you really need to bring the car up to temperature is if heat is needed to clear the windows. Safety always comes before fuel saving techniques.