Help Your Car Breathe Easier

Replace your air filter at every other oil change. A clogged filter restricts airflow into the engine, which reduces mileage by as much as 10 percent, or $200 a year, says Shawn Crosby, business manager of 3M Automotive Aftermarket in St. Paul, Minn. For detailed DIY instructions on installing a new part, check out ehow.com. An air filter costs anywhere from $2 to $50.

Check Your Oil

Stick to the recommended grade of oil for your car the next time you change your oil, and you can save one to two percent (or up to $40) off your gas bill because your system will be running at its maximum efficiency, says Rozanne Weissman, director of communications and marketing for the Alliance to Save Energy. Check your manual to find the one that's right for your vehicle — mistakes are not uncommon.

Know Where You're Going

Your sanity isn't the only thing to be saved by having good directions: Idling while you figure out where to turn next is a big gas guzzler. Always keep maps in your glove compartment, or use your GPS system. The Alliance to Save Energy estimates that by following the most efficient routes to get from point A to point B, you can cut your gas bill by five percent, or nearly $100 a year!

Lighten Your Load

Forget the excess baggage — added weight increases air drag for your car. An extra 100 lbs. could reduce fuel efficiency by as much as two percent, which equals about $40, according to Weissman. Remove whatever you've got stashed in your trunk or backseat!

Next page: More gas-saving steps -- and your savings tally!