6 Things to Do When You're Running Out of Gas

Admit it: You've been there. We all have. You were making great time. You were trying to beat rush hour. You wanted to wait until the next food stop or bathroom break. But you overestimated your gas mileage and cut it too close. Your fuel light came on. And now you're in the middle of nowhere, with no idea how far it is to the next gas station. What do you do?

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"The first step is, repeat after me: 'Our father, who art in heaven ... ,' " AAA Technical Services Manager Michael Calkins suggested in jest.

But once you're done praying and/or panicking, it's time to dab the sweat off your forehead, let the blood flow back into your white knuckles and make some rational decisions. We consulted automotive experts at AAA and Universal Technical Institute to compile a list of best practices while on the road when you're running on empty with no fuel pump in sight. Some of these may seem like common sense, but in an informal survey of even our automotive-savvy team members here at Cars.com, there were plenty of misconceptions.

Here are six things you should do when running out of gas:

1. Get Your Bearings

Calkins said the first thing you should do is pull over and locate the nearest gas station using your vehicle's navigation system or your smartphone (AAA has an app for that).

2. Slow Your Roll

Cars are the most fuel-efficient at 35 to 45 mph, Calkins said. You have to consider state traffic laws and safety if you're on a fast-moving interstate highway, but the point is: Don't speed up to try to get to the gas station faster. Slow and steady wins this race.

3. 86 the A/C

Scott Keene, education manager at UTI in Lisle, Ill., explained that turning off the air conditioning reduces engine stress, saving precious fuel, and should be done immediately. In addition to the air-conditioning compressor that runs off a belt (in virtually all cars), air conditioning also turns on the cabin fan and a more power-hungry fan behind the car's radiator. "As the electrical load in the car increases, you are increasing the strain on the alternator, which in turn increases the demand from the engine that results in a decrease in fuel economy," Keene said. This also applies to the few models that use electric-powered air-conditioning compressors, primarily gas/electric hybrids.

4. Ax Accessories

For the same reason as above, turn off the stereo, especially a high-powered one, along with all other electrical devices, such as charging phones. The fuel savings may be small, but: "It could be the difference between pushing the car two blocks and coasting up to the pump," Calkins said.

5. Roll 'Em Up!

Keep your windows rolled up to reduce wind resistance on your vehicle. We know, we know, but yes: You have to turn off the air conditioner and keep the windows rolled up. You should've thought of that before your tank got low.

6. Drive Downhill

OK, it's unlikely you'll have the choice, but if your navigation app finds two nearby gas stations and one is downhill, pick that one. It takes less gas to coast downhill than to climb a grade. What you shouldn't do is shift into Neutral when coasting. There was a time when this made a little bit of sense, but today's cars are designed to turn off their fuel injectors and save gas while coasting, even though the car's inertia keeps the engine turning. Putting the transmission in Neutral is actually more wasteful, because it requires gas to keep the engine running so you don't lose power steering and brakes.

With these tips and some luck, you'll be able to make it to a gas station on fumes. But if you don't, Marty Kucha, also an education manager at UTI, said to have your roadside assistance plan in place.

"Take the time to figure out if your car came with roadside assistance from the dealer, or if you belong to AAA," Kucha said. "Put that information into your phone, or have it easily accessible somewhere. You're paying for it; don't be afraid to use the services — that's what they are there for. They can come out and provide you with a quick fill-up to get you to the nearest station."

Even if you luck out, though, the stress of the situation just isn't worth it. Plus, running yourself dry isn't great for your car as the crud settled at the bottom of your tank can get sucked into the engine, and possibly cause the fuel line to freeze.

All agree that prevention is always the best way to avoid trouble. Make it a habit not to let your fuel gauge dip below a quarter-tank (a half-tank if you live in a rural area). Keep your tires inflated to the proper pressure listed in your owner's manual, and remember that when you're loaded up with passengers, luggage, golf clubs, etc., you're not going to get the same fuel economy you would get with an empty car. A big "don't," is carrying an extra gallon of gasoline in your car for emergencies; it's a fire hazard, plus the gas goes bad eventually.

While no industry standard exists as to how much gas is left in your tank when the fuel light comes on, it's generally about 40 miles' worth, Keene said. But because "your results may vary," he suggested this experiment.

The next time your fuel light comes on, go immediately to a gas station and fill up.

Make note of how many gallons your car took.

Subtract the number of gallons from the capacity of your gas tank. So if you have a 14-gallon tank, and your car took 12 gallons, the fuel light came on at 2 gallons.

Multiply that number by your car's average estimated fuel economy, and the result is about how many miles you can go once the light comes on. Two gallons times, say, 26 mpg equals 52 miles.

The bottom line to avoid paying the price is to never get to that point in the first place, no matter how you rationalize the risk.

"If your fuel is getting down to a quarter tank," Calkins said, "try to shut down that inner voice and just stop."

Editor's note: This story was updated on May 11 to add information on coasting downhill when low on gas and the benefits of turning off the car's air conditioner.