How Far Can You Push a Low Fuel Light? Why It’s Hard on Cars

Posted 2/4/19

Our car mechanics probably get asked this on a daily basis: Just how far can you push a low fuel light, and will it hurt the car?

The short answer is you can get away with it a little longer than you might think, but running the tank that low isn’t good for your car, especially if you make it a habit.

We’ve all been there when the gas needle hits bottom and you’re in no sight of a fueling station, especially on those back roads that head out of Cincinnati. Once driving State Route 22 to West Virginia, I didn’t see a street light for nearly 30 miles, much less a gas station. When the low fuel light goes off deep in No Man’s Land, you just have to take your chances.

Yet lighting up that warning light every once in a while isn’t as dire as you might think. Most cars have at least 1 to 2 gallons of fuel in reserve before the light goes on. The amount can vary, and how long that fuel will last depends on how fuel efficient the car is. Good luck if you’re driving around in a big SUV. Those beasts can really suck it down fast.

“Some of the newer ones are more of an electronic, fly-by-wire type thing that actually senses it by the liquid touching an electric element inside the gas tank,” Rex Brown, director of information services at Petroleum Equipment Institute, tells Urbo.com. “The low fuel light is just simply [a light that], at a certain level that the manufacturer determines, indicates the need for the [light] to come on. Different manufacturers have different theories on when that’s supposed to happen.”

Why Pushing the Fuel Gauge is Bad for Your Car

Yet you shouldn’t make a habit of letting your fuel tank get that low. It’s kind of like letting the brakes on your Jaguar run thin, skipping a radiator flush, or ignoring your vehicle’s scheduled maintenance plan. You can get away with it for a little while, but it’s not good for the car. Eventually, it catches up with you.

“You shouldn’t allow your car to get that low on fuel to begin with,” states mechanic John Pagano. “Your tank is like any other gas tank, so dirt and stuff gets in it. It will start sucking up the dirt particles in your tank and actually harm the engine and the fuel system as it’s going through.”

What to Do If Low On Fuel

If you do find that needle dipping low, slow down. Driving at a higher speed is bad for gas mileage and pushes you closer to the edge.

Coast down hills. If you are driving a standard transmission, take the car out of gear whenever you’re going downhill.

And roll with the windows up, especially if you are driving over 40 mph. The wind coming through the windows is bad for aerodynamics, which isn’t good for your gas mileage.

Habitually Refuel at the 1/4 Mark

Make it a habit to always refuel before your gas gauge dips below the quarter mark. Nobody likes to sink $30 to $60 into their tank, but putting off a fill doesn’t save you any money. And if you refuel before it’s absolutely necessary, you can choose a station that has a lower price. Paying just 10 to 20 cents less can mean a difference of $5 to $10 in cost for the same gas. That’s a savings that can add up fast.

MENU