But did you know that another huge gas saver won't cost you anything at all? That's right, it's free, and you can start right now. This important change involves your everyday driving habits. Believe it or not, the way you act behind the wheel can really affect your gas mileage.

Saving gas while you drive involves a generally less aggressive demeanor behind the wheel. These easy tips can really make a difference:

Accelerate more gradually. The harder you press the gas pedal the more juice you're pouring down the hole.

Anticipate stops. By keeping an eye ahead of you by half a block or so, you can see a light changing red and take your foot off the gas earlier. By coasting instead of driving under power, you're burning less fuel.

Drive more slowly on the highway. We all want to get there fast, but shaving 5 or 10 miles per hour off your highway speed saves lots of gas, and probably won't add much time to your trip.

Shift gears earlier. If your car has a manual transmission, try shifting gears at a lower RPM. The higher your engine revs the more gas it burns.

You could also try some untested methods like installing a team of gerbils in each tire or cutting holes in the floor of your car for Flintstones' power, but there are no guarantees. Change your style of driving according to the list above, and you can be guaranteed you'll save