Money tip: How to save as gas prices keep climbing

Four-buck-a-gallon gasoline is a reality again for some American motorists. Only this time, unlike 2008, the price spike follows years of deep national recession and its aftermath, including rampant job loss and home foreclosures.

That means many households' battered budgets are less able to absorb higher gas prices, especially when the costs of such necessities as food and clothing are rising fast, too.

Paying $4 per gallon would mean a household spends $4,800 on gasoline in a year, assuming two vehicles getting 25 miles per gallon and traveling 15,000 miles. There's a 25 percent chance that the average price of gas nationwide this summer will exceed $4 per gallon, according to a forecast by the U.S. Energy Information Administration.

For consumers, a long-term solution to higher gas prices is to drive less or drive a more fuel-efficient vehicle. But in the short term it matters more "how" you drive than "what" you drive.

Here are suggestions for saving money on gasoline, with help from the U.S. Department of Energy, Consumer Reports, the Alliance to Save Energy and Edmunds.com.

• Don't spill the coffee: The biggest savings will come from avoiding aggressive driving. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town.

Not sure what less-aggressive driving is? Imagine a lidless cup of coffee in your car's cup holder. Drive like you don't want to spill it. That means gradual acceleration and gentle braking.

Potential savings vary widely, but are significant when you curb aggressive driving. At $4 per gallon, gas savings could range from 20 cents to $1.32 per gallon, based on Energy Department figures. That's a savings of $240 to $1,584 per year for that two-car household described earlier.

• Speed kills: Consumer Reports found that slowing from 75 to 55 mph boosted gas mileage 33 percent in testing performed on a family sedan and a large SUV.

• American idle: Idling yields zero mpg. Don't bother warming up your car or keeping it running while waiting for passengers. The rule of thumb is to turn off your car if you know you'll be stopped for more than 30 seconds, Consumer Reports says. Cars with larger engines typically waste more gas idling than those with small engines.

• Trunk junk: An extra 100 pounds in your vehicle could reduce your gas mileage by up to 2 percent, or about 8 cents per gallon. Roof junk — carrying large items on the roof of the vehicle — creates drag that can cut gas mileage 5 percent.

• Use cruise: Cruise control is steadier on the accelerator pedal than you are. You might try it on lower-speed suburban roads. Edmunds.com called it a "surprisingly effective way to save gas."

• Find cheaper gas: Compare gasoline prices at GasBuddy.com, GasPriceWatch.com and http://gasprices.mapquest.com. But you don't want to drive far out of your way to save a few pennies. Savings will be lost traveling to a distant service station.

Billshrink.com will send you an email alerting you to the lowest-price gas on your commute. Gas price information also is available via smartphone apps, such as Gas Buddy and AAA's TripTik Mobile.

• Use GPS: Computerized travel directions from GPS devices or smartphones can help find efficient routes. That can save time, hassle and gas. If you don't have a device, use a website such as mapquest.com/routeplanner.

Plotting a route by hand works, too, using a folding map or road atlas. Several devices and websites also alert you to traffic jams, a gas-mileage killer.

• Seek discounts: Be on the lookout for promotions and sales that allow you to acquire gasoline station gift cards for free or at a discount. And Choice Hotels, which owns such properties as Comfort Inn and Clarion, is offering a $50 gas card when you book two stays before May 4.

• Make radical changes. Change your work hours to avoid rush-hour traffic, use carpools and ride-sharing programs, take public transportation, walk or bike to work, or work from home.

Some advice on saving gas is dubious.

• Inflate tires: The U.S. Energy Department says underinflated tires can increase fuel consumption more than 3 percent. However, a test by Edmunds.com couldn't find much effect on gas mileage, although properly inflated tires are important for safety and to reduce tire wear.

• Gas additives: Advertisements for gas additives that supposedly improve mileage are exaggerations or outright lies, according to the Environmental Protection Agency, which has tested more than 100 of them.