The U.S. has a reputation for guzzling gasoline, especially in summer, when increased demand and processing costs drive up the price by an average of 10 to 20 cents per gallon. And while the recession has helped reduce U.S. gas demand in recent years, summer heat — combined with unforeseen variables like hurricanes and oil spills — can still wreak havoc with prices at the pump.


But whether you're planning a cross-country road trip or just trying to avoid spending your paycheck on commuting, there's plenty you can do to save money on gasoline. The best strategy is to simply drive less often, maybe carpooling or biking instead, but don't feel discouraged if that's not an option. Check out these 10 ideas for ways to cut back the amount of time and money you spend at gas stations this summer:


1) Slow and steady wins the race: Gasoline mileage drops off in most cars once you're going faster than about 60 mph (see chart at right). For every 5 mph you drive over 60 mph, you're essentially paying an extra 24 cents per gallon of gas. Try using cruise control on interstates and other highways to maintain a constant speed. It can also help to use your car's overdrive gears, which save fuel and engine wear by reducing your speed.


2) Be cool in traffic: Aggressive driving — speeding, swerving, sudden acceleration and braking — is not only dangerous, it can lower your gas mileage 33 percent on highways and 5 percent on city streets. Revving your engine while stopped is even more wasteful.


3) But not too cool: Air conditioning can be a big drain on gasoline, so make sure you don't just leave it on absentmindedly, and certainly don't leave it on while windows are open, even if they're just cracked. You can improve your fuel efficiency in stop-and-go traffic by turning off the A/C and rolling down the windows instead, but that's not necessarily always the best idea. When driving above 55 mph, especially for long periods on highways, the opposite is true — open windows make a vehicle less aerodynamic by letting in air, which increases air resistance and decreases fuel efficiency. On long road trips, using air conditioning could actually improve your mileage by up to 20 percent.


4) Don't just sit there: On top of pointlessly pumping out greenhouse gases without actually getting you anywhere (as the public-service announcement at right points out), idling automobiles also contribute to ground-level ozone, airborne particulate matter and other near-surface air pollution. These emissions can aggravate asthma and even hinder breathing in otherwise healthy people, especially children and the elderly. If you're just idling to warm up your car in winter, it still only needs to run about a minute. Anything beyond that is just wasting gas. 


5) Stay in tune: Fixing a car that needs a tuneup or has failed an emissions test can improve its fuel efficiency by an average of 4 percent. More serious problems, like a faulty oxygen sensor, can reduce mileage by up to 40 percent. And don't forget to get regular oil changes based on the manufacturer's recommendations (or you could look into installing an Electro-Lube Oil Refiner, which reportedly eliminates the need for oil changes while boosting efficiency 3 to 4 percent).


6) Get pumped: Keeping a car's tires properly inflated can improve fuel efficiency by about 3.3 percent. It's also safer and lengthens the lifespan of your tires, since underinflated tires lose their tread quickly in addition to wasting fuel. Regular checkups for your tires' alignment and balance aren't a bad idea, either.


7) Take a load off: While it mainly affects smaller cars, carrying extra weight means burning extra gasoline, no matter how big your vehicle is. On average, you may be cutting your fuel efficiency by up to 2 percent for every 100 extra pounds you haul.


8) Develop motor skills: Using the manufacturer's recommended grade of motor oil can boost mileage by 1 to 2 percent. Try to also use the lowest grade of gasoline that's appropriate for your car, since high-octane grades cost several cents more per gallon. Check your owner's manual to be sure, but as long as your engine doesn't start knocking, you're probably OK. Switching from premium to regular gasoline would save hundreds of dollars every year.


9) There's a cap for that: Gasoline can evaporate from a vehicle's fuel tank if it's able to find an opening, which is bad for your wallet and your lungs. Make sure your gas tank's cap is tightened securely after you fill up, and if the cap's threading is stripped or it fits too loosely, you might want to buy a new one.


10) Join the masses: Carpool or, even better, don't take a car at all — walk, ride a bike or take mass transit. It saves you money, improves your personal health and helps the planet by keeping greenhouse gases out of its atmosphere. See MNN's guide to greening your commute for more ideas.


Do you have other money-saving tips we left out? Please leave them in the comments below.


And for more ideas and information about gas prices and other fuel-efficiency issues, check out these related articles from MNN:



Image credits:

Fuel efficiency/speed chart:

Idling PSA: [skipwords]New York[/skipwords] Department of Environmental Conservation

Loaded truck bed: DiamondBack Truck Covers/Flickr
MNN homepage image: AtomicCupcake/iStockphoto