Slow Down.
Driving the speed limit and avoiding aggressive driving can improve gas mileage significantly. While each vehicle reaches optimal fuel economy at different speeds, gas mileage tends to decrease rapidly at speeds over 60 mph. According to the U.S. Department of Energy, driving over 60 mph is like paying an extra $.20 per gallon for gas.

Don’t store stuff in your vehicle. By removing extra weight in your vehicle, especially heavy objects, you can reduce your vehicle’s miles per gallon by up to 2%, according to the U.S. Department of Energy. This can end up saving you about $.04 - .07 per gallon.

Avoid idling. Idling gets zero miles per gallon. Save gas mileage by avoiding it whenever you can.

Maintain your car. Fixing a serious maintenance problem can improve mileage by as much as 40 percent, and repairing a car that is noticeably out of tune or has failed emissions can increase gas mileage by an average of 4 percent.

Other tune-ups you should do to save gas money include checking and replacing air filters regularly (save up to $.35/gallon), keeping tires properly inflated (save up to $.11/gallon), and using the recommended grade of motor oil (save $0.04-0.07/gallon).

Drive smart. Combine errands whenever possible. Multipurpose trips on a warm engine can use half as much fuel as shorter, more frequent trips covering the same distance. This will not only save you money but can reduce wear and tear on your vehicle.

If you can, plan to commute at a time with less traffic, avoiding gas guzzling stop-and-go traffic. Also, consider options that may be available in your community such as telecommuting, carpooling, public transportation, or other alternatives such as walking or biking.

The above information is from the U.S. Department of Energy.  Click here for more tips on saving gas and improving fuel economy.