Gas Saving Tips that Make the Most 'Cents' ... and Ones that are 'Non-Cents'

NADAguides.com Offers Expert Advice for Saving Money at the Pump

COSTA MESA, Calif., June 20 -- With gas prices averaging over $4 per gallon for regular unleaded all across the nation, tips about how to increase your car's gas mileage and save money on gas are circulating widely. Much of this advice about how to increase gas mileage, however, is not worth the average driver's effort according to NADAguides.com, a vehicle pricing and information website. There are, however, some strategies to improve your car's gas mileage by 10 percent or more, which does make good sense at today's gas prices. "For example, if you drive an SUV or crossover that averages 16 mpg, a common mpg for many SUVs, including the 2008 BMW X5 4.8i, the average driver will save about $30 a month or $360 annually if he achieves a 10 percent gas mileage improvement," says Tara Baukus Mello, senior writer and lead market analyst at NADAguides.com. Below are fuel economy tips that make "cents" and ones that are "non-cents."

Makes Cents: Drive slowly and steadily. To improve a car's gas mileage, give yourself a few extra minutes to get to your destination, so you can drive the speed limit and avoid rapid acceleration. The faster a car accelerates from a stop, the more gas it uses, while driving more slowly overall improves gas mileage, because there is less aerodynamic resistance, making it easier for your car to move forward. "I've seen improvements in gas mileage of up to 15 percent when driving at 65 mph versus 75 mph," says Baukus Mello. "The least aerodynamic vehicles, such as SUVs, tend to have the biggest improvements," she noted. What's more, she suggests letting off the gas and coasting before applying your brakes to stop, as this also helps improve fuel economy.

Non-Cents: Fill up your gas tank when temperatures are coolest. A recent email circulated to households throughout the U.S. attempts to help people understand the physical components of gasoline and how fuel "behaves" in order to get better gas mileage. One theory states that gasoline expands with warmer temperatures, so a gallon of gas is actually less than a gallon when temperatures are higher. While this is true, the temperature in a gas station's underground storage tank is fairly constant, typically varying by about one degree, regardless of air temperature. "For a 20-gallon gas tank, a one-degree rise means about a 0.08 gallon change or about 32 cents total savings when gas prices are at $4 per gallon," explains Dr. Richard Cohen, associate professor of mechanical engineering at Temple University.

Makes Cents: Don't idle. "Every second spent with the engine running and the car stationary is a waste of fuel. That's why many hybrid cars shut off their gas engines when they stop moving," says Baukus Mello. To save gas, shut off the car if you'll be idling for more than 30 seconds, such as while you wait at the drive-thru or ATM. "If you commute during rush hour and often find yourself inching along, consider adjusting the times you're on the road," she suggests.

Non-Cents: Fill up when your tank is half-empty and use the slowest pump speed. Both pieces of advice stem from the idea that while gas is being dispensed, you want the most amount of gasoline and the least amount of vapors. But neither of these tips provides any significant gas savings, according to Dr. Cohen, who says following this advice is likely to save only an additional 10 to 30 cents on a 20-gallon tank of gas at $4 per gallon.

Makes Cents: Keep your tires properly inflated. If you do only one thing to improve your gas mileage, keep your tires properly inflated by checking your tire pressure monthly. "It's not unusual to see fuel economy improvements of about 10 percent with tires inflated at the recommended pressure," says Baukus Mello. Pressures should be checked when tires are cold, preferably with a digital gauge. Recommended tire pressures are listed in the owner's manual or on the driver's side door jamb.

Non-Cents (sort of): Lighten your load. Sure, everybody talks about getting rid of unnecessary junk in your car to lighten your load and improve gas mileage, but when it comes to noticing a significant improvement in gas mileage, you'd have to eliminate at least 100 pounds of cargo. "So unless you carry a huge amount of unnecessary gear -- or are willing to leave the family behind -- lightening your load is probably 'non-cents,'" says Baukus Mello.