Make sure your tires are properly inflated. According to www.gasbuddy.com, a single tire under-inflated by 2 PSI increases fuel consumption by 1percent.
Get regular oil changes and fluid checks, and make sure you've got clear air and fuel filters. Dirty air filters, old spark plugs or low fluid levels can contribute to poor fuel economy.
Use the air conditioner conservatively, using the "economy" or "recirculation" setting, which reduces the amount of hot outside air that must be chilled.
Don't drive over the speed limit, and do use cruise control to maintain a constant speed. Driving 62 mph versus 75 mph will reduce fuel consumption by about 15 percent.
Don't drive with a lead foot: accelerating or braking hard uses a lot more gas. Slow, steady driving can increase your fuel economy by as much as 20 percent.
Don't let the engine idle for more than a minute.
Don't top off your gas tank. Continuing to pump after the nozzle clicks wastes gas.
Unless your car requires premium-grade fuel, buy regular.
Don't waste more gas driving to a distant location for cheaper gas that will only save you a few cents. That said, gas is usually pricier in more affluent areas and right next to major freeway exits.
Consider buying gas at a wholesale club, grocery store or department store that uses low gas prices as a loss leader to get you into the store. There also are a number of gas rebate credit cards available; check out www.gasbuddy.com for more information.
Keep track of gas mileage. If you notice a steep drop in fuel economy, your car may need to be serviced.
Avoid heavy loads, i.e., those unnecessary sand bags you keep in the car all winter.
Get rid of that unused roof rack -- it causes wind drag and uses extra gas. Ditto for open windows, especially at highway speeds.
Consider carpooling, taking public transportation or riding a bike to work.
Make your next car more fuel-efficient. Hybrid gas/electric vehicles can get 45 mpg or more - nothing to sneeze at when gasoline is topping $4 a gallon.
Sources: www.gasbuddy.com; AAA Chicago; "Beat High Gas Prices Now! The Fastest, Easiest Ways to Save $20-$50 Every Month on Gasoline" by Diane MacEacher