Photo courtesy of USDA

• Share

PRINT

When fuel prices spike, lots of tips and tricks to save on gas get trotted out. They’re not all worthy.

Here are several that don’t violate the laws of physics, compromise safety or insult your intelligence:

Get the junk out of the trunk

Car engineers spend a lot of time engineering pounds, ounces and grams out of today’s cars. Don’t undo their efforts by leaving anything unnecessary in the luggage compartment.

Golf clubs are a common violator, but so are those bags slated to go to the second-hand store or a case of water bottles.

Every time you accelerate, you’re using gas. How much more? This depends on your car, but the EPA estimates a 1% reduction per 100 pounds. On a per-gallon cost basis, that’s about $0.03, using the EPA baseline figures.

Combine your trips

Planning ahead can save gas because grouping trips means fewer miles driven.

But even if you have to go in multiple directions, all non-electric cars use more fuel when the engine is cold. So, the fewer times you to bring the engine up to temperature, the better. Cold starts aren’t good for your car (or the environment, for that matter).

Shut the engine off

Once you’re stopped, your car is wasting fuel after about 7 to 10 seconds of idling. That’s why newer gas cars (and virtually all hybrids) have a feature that shuts the engine off during stops when the brake is applied. The car’s still on, but the engine isn’t. Push the accelerator pedal, and the engine snaps back on — off you go.

Some people find this maddening (and in truth the smoothness of the systems varies among vehicles), but the gas savings is real. If you want to maximize mileage, don’t disable the auto on-off feature.

And everyone can stop leaving their car on while running back into the house or whatever short errand you’re doing.

Drive slowly but wisely

Lower speeds require less fuel, since aerodynamic resistance increases with the square of speed. But driving to save fuel doesn’t have to be a dull crawl in the slow lane. Try thinking of it this way: Brakes turn your money into heat, so can you avoid using them?

This isn’t meant to encourage dangerous behavior, like not stopping for stop signs. Rather, anticipate. Look down the road farther, and coast down when you know the traffic signal’s going to change to red.

As for accelerating, if you know you’re going to be holding a higher speed for a while, like when you’re merging onto a highway, go ahead and shove the gas as hard as you need. Not only is slow acceleration in this situation potentially dangerous, it doesn’t actually save fuel.

Don’t rely on the tire light

All cars built since 2007 have what’s called Tire Pressure Monitoring Systems (TPMS), which monitor the air pressure of your tires.

The hitch is this: That light may not come on until a tire is more than 25% lower than the recommended pressure. If you wait for that, you’re endangering yourself (an underinflated tire can compromise your car’s handling or even lead to a tire blowout) and wasting money (underinflated tires reduce your gas mileage by roughly 0.2% per pound that they’re low).

Doesn’t sound like much, but try this math: If your recommended inflation pressure is 40 psi, and you’re 25% low on air, that’s a 2% hit to your gas mileage. Plus, underinflated tires wear more quickly and unevenly, reducing your tire life.

There’s just no substitute for buying a decent-quality tire gauge (between $5 and $15) and using it at least once a month.

Get the apps and join the club

Phone apps like Gas Buddy, Gas Guru and Fuelzee make it easy to find the best gas deals. Since you can screen for brands, you can also make sure you’re getting good quality fuel, which, in the long run, matters to the health of your car.

Joining a membership club like Costco or Sam’s Club could also pay off. Figuring how quickly you’ll recoup your membership cost with the per-gallon savings on their discounted fuel is pretty easy math.

© The Kiplinger Washington Editors, Inc. Distributed by Tribune Content Agency, LLC.