23 Research-Driven Ways to Save Money on Gas

Employ these tricks and tips for getting more mileage out of every dollar when you're behind the wheel.

Gas prices have been all over the place the last few years. Heading to the pump is sort of like that box of chocolates Forrest Gump described — you never know what you're going to get. We bring back some certainty to your gas spending with 23 data-backed methods that will help you use less gas and hang on to more of your cash the next time you hit the highway.

1. Don't put the pedal to the metal.

If you slam on the brakes at stop signs or rev the engine every time you start up, those bad habits could be costing you fuel mileage. Edmunds conducted experiments that gauged the impact of driving moderately versus driving aggressively; they found that easing your foot off the gas and the brake saved 31% more fuel on average.

2. Accelerate smoothly.

Peeling out at the stop light won't do you any favors, but you don't want to take off at a snail's pace either. According to a test by Popular Mechanics, accelerating to a driving speed of 50 mph within a 15-second period yielded an average fuel economy of 14.7 miles per gallon versus 10.7 mpg when it took 30 seconds to get going.

3. Wait to fill up on the weekends.

The day of the week you buy your gas plays a big part in how much you pay. A GasBuddy survey found that in 65% of states, gas prices are lowest on the weekend. The middle of the week, Tuesday and Wednesday in particular, are when you'll see prices soar.

4. Choose premium fuel if possible.

It may seem counterintuitive to spend more money per gallon on premium gas, but it could yield savings in the long run. A group of researchers from MIT found that when vehicles run on fuel with a higher octane rating, they gulp down between 3% and 4.5% less gas.

5. Ditch the rooftop gear.

If you're driving around with a cargo box or a rack of bikes strapped to the roof, you're sabotaging your gas mileage. The Oak Ridge National Laboratory found that the fuel economy for SUV drivers decreased by 9% when a rooftop cargo box was present. Sedan drivers fared even worse, with a drop of 22%.

6. Pick the right tires.

The kind of tires you put on your car matters, especially if you're trying to be more conscious about your fuel use. The National Academy of Sciences Transportation Research Board recommends low rolling resistance tires, which can reduce overall gas consumption by 1% to 2%.

7. And keep them pumped up.

Driving around on underinflated tires is dangerous: it ups the risk of having a blowout and makes it harder to stop suddenly if you run into an obstacle on the road. As if that wasn't bad enough, it also drags down your gas mileage. In the Oak Ridge study, letting tires run low on air resulted in a decrease in fuel efficiency of up to 10%.

8. Slow down.

If you've got the need for speed, your wallet's going to feel the consequences when you're constantly having to refuel. Driving the speed limit may not make you any friends as far as rushed drivers go, but according to Edmunds, it'll increase your gas savings by an average of 12%.

9. Choose the right motor oil.

Unless you perform your own oil changes, you probably don't think much about what's going on under the hood, but there's a good reason to pay closer attention. Another report from Oak Ridge National Laboratory found that using the wrong weight oil for your vehicle's engine type could actually reduce your gas mileage by 1% to 2%.

10. Get a tune-up.

Scheduling regular tune-ups can have a dramatic effect on your gas savings, especially if it uncovers a problem with part of your emissions system. According to the Oak Ridge report, your gas mileage could improve by as much as 40% after a tune-up if you need to have something like an oxygen sensor replaced.

11. Ditch the extra weight.

For every extra 100 pounds your vehicle is carrying around, your fuel economy declines by about 1%, according to The Aluminum Association. Cleaning all the extra junk out of your trunk can help, especially if you drive a smaller vehicle.

12. Let the breeze in when you're tooling around town.

When the weather gets hot, it's tempting to blast the AC nonstop, but you're better off cooling your vehicle naturally if you can. Another study from Oak Ridge National Laboratory demonstrated that when the mercury shoots sky high, running the air conditioning can use up to 25% more gas when driving at lower speeds.

13. But roll the windows up on the open road.

Having the windows open does create more drag and the faster you go, the more resistance there is. The result is that your engine has to burn more gas to maintain speed. According to Oak Ridge researchers, driving with all four windows down on the highway decreases fuel efficiency by as much as 8.5%.

14. Use cruise control.

Constantly speeding up or slowing down won't do you any favors if you're trying to stretch your gas dollars. According to research from Edmunds, setting the cruise control to keep your speed in check can save you as much as 14% more fuel.

15. Don't idle.

Gas burns at a surprisingly fast rate when the car is idling. The Environmental Defense Fund estimates that idling wastes as much as 7/10 of a gallon of gas per hour. If you're going to be sitting still for longer than 10 seconds, you're better off putting it in park.

16. Replace your spark plugs.

Spark plugs are what keep your car's engine functioning properly, and if one of them is misfiring, it can put an extra strain on your gas tank. A bad plug can reduce your mileage by up to 30%, according to the National Institute for Automotive Service Excellence, so it's worth switching them out at the first sign of a problem.

17. Keep your wheels in line.

When your car is out of alignment, it causes unnecessary wear and tear on your tires, which results in a reduction in your gas mileage. The Consumer Federation of America advises that investing a few bucks in an alignment could improve fuel efficiency by 10%, which translates to a savings of roughly 39 cents per gallon.

18. Say no to the tow.

Hauling stuff around on top of your car is bad for your gas budget, but so is dragging a load behind you. Oak Ridge National Laboratory estimates towing a 3,500 pound cargo trailer can cause you to use anywhere from 30% to 50% more gas, depending on what kind of car you're driving and how fast you go.

19. Coast when you can.

Taking your foot off the gas altogether when you're cruising down an incline or up to a stop can shave a few pennies off your fuel costs. Popular Mechanics encourages stick shift drivers to avoid shifting into neutral when coasting, since this actually wastes more gas than relying on the vehicle's natural forward motion.

20. Choose your route carefully.

The next time you're driving somewhere, pay attention to how many left-hand turns you make. According to a series of time studies conducted by UPS, sticking with right-hand turns as often as possible saved the company a whopping 10 million gallons of gas. That's something to keep in mind when you're planning future road trips.

21. Check your gas cap.

The next time your dash light comes on, don't ignore it; it could be telling you that your hard-earned dollars are flying right out of our gas tank. According to the Consumer Federation of America, tightening up your gas cap can save you roughly 3 cents per gallon.

22. Park indoors when it's cold.

Fuel tests conducted by the U.S. Department of Energy have shown that when the temperature drops, your gas mileage decreases by as much as 22%. If you're able to store your vehicle in a garage during the winter months, you can diminish some of the cold's impact.

23. Electrify your drive.

While shelling out big bucks for an electric car may seem a little extreme, it's guaranteed to cut down on what you spend for gas. The Union of Concerned Scientists estimates that electric vehicle drivers use 6,100 fewer gallons of gas for a savings of $13,000. On an annual basis, that breaks down to about $1,200, which means that over time, an electric vehicle effectively pays for itself.