Cut Your Gas Costs

When it comes to putting a cap on gas guzzling, how you drive is almost as important as what you drive. “Fuel economy suffers at speeds higher than 60 and drops like a stone above 70,” says Chris Grundler of the National Vehicle and Fuel Emissions Laboratory, in Ann Arbor, Michigan. Adds Richard Beard, an associate professor at Utah State University who researches fuel efficiency, “Slowing from 70 to 55 can increase your miles per gallon by 15 percent.” Putting the brakes on “jackrabbit starts” (stomping on the gas after a red light) cuts use by 25 percent, says Grundler, and cruise control also saves fuel. Limit use of gas-chugging air conditioners and defrosters, and unload extra junk, since “you lose one mile per gallon or more for each 300 pounds,” notes Beard. Avoid idling, he advises: “One minute of idle is almost equal to starting the car.” Finally, leave the car lot with the best gas hoarder by consulting before you buy.

Inflate those tires. Soft tires slow you down and can cut gas mileage by 10 percent or more, according to the tire-sales and research website tirerack.com. Follow the inflation instructions in your owner's manual or on the decal at the inside edge of the driver's door. Ignore the numbers on the tire sidewall, as they are more general and not specific to your make of car. Aim to check your tire pressure once a week―at least once a month is crucial. Keeping tires properly inflated will also help you avoid rollover and other tire-related accidents.

Maintain the engine. A reduced air supply or a sluggish ignition can cut into mileage. Change the air filter twice a year and the spark plugs every 50,000 miles. When you change the oil every 6,000 to 7,500 miles, have the mechanic check your cooling system, too. Even cars with computer-controlled engines, which need fewer tune-ups, require these chores.

Take a load off. Extra weight in the car can hurt mileage. Reduce the clutter in your trunk by removing tools, golf clubs, and other weighty and hardly used items.

Drive the thriftier car. If your family owns both a sport utility and a sedan, get into the habit of taking the smaller vehicle whenever you can. By driving the Toyota Camry instead of the Ford Expedition to the mall, you are saving about nine miles per gallon in suburban driving. After 20 10-mile trips, you'll have saved about $11.

Steer away from rush hours. Idling in bumper-to-bumper traffic uses precious gas unnecessarily, and it pollutes more, too. Don't waste time in lines at the fast-food drive-through; go inside for your Extra Value Meal―and get extra value from your gas.

To calculate what you can expect to spend on gas for a weekend getaway, go to AAA’s fuelcostcalculator.com, then type in your starting city, destination, and vehicle make, model, and year. Staying put? Go to gasbuddy.com, which will help you find the cheapest gas in your area. Driving those extra few miles to fill up might be well worth it.

At any time, the price of a gallon of gas can vary by as much as 20 cents within a metropolitan area, says Brad Proctor, founder of GasPriceWatch, a consumer-advocacy website. To get the best bargain, avoid buying gas on weekends, when most people travel or run errands and gas stations raise prices accordingly. Also, stay away from stations on toll highways, which charge high prices to their captive customers. If you can stick to pumping once a week, says Proctor, you can often find the best prices on Tuesdays.

For a real gas saver, consider the Toyota Prius, a hybrid gas-and-electric sedan that gets about 50 miles a gallon, and feels like a car, not a golf cart. The competing Honda Civic gets about 44 miles per gallon. "I wave at the people lined up for gas," says Dan Becker, energy and global-warming director of the Sierra Club who drives a Prius, “and keep right on going."