Staten Island Auto Repair

Pushing the Needle Too Far: How Long Can You Drive on Empty?

Anytime the fuel gauge gets less than a quarter full, my mind starts to race. What if I run out of gas? Is this hurting my engine? Can I really “run on fumes”?

I am way too much of a worrier to let my needle get to “E.” I have a friend who always comes to pick me up with the fuel light already on before a night out. After freaking out in silence for twenty minutes, I finally suggest getting some gas. What does she do? Laugh and then drive further (my friends know I am a worrywart). We’ll be fine, she says. And you know what? We always are.

Some of us in this world like to push the limits, to see how far things can go before they break. These types will see a gas station on the next block, but will wait for the gas station forty miles away, just to see if they can. Others of us like to play it safe and don’t feel the need to test every limit. These folks will be in the passenger seat, white knuckled, praying that the car makes it to the next gas station.

We have all heard that you shouldn’t drive around with your fuel gauge on empty. Some of us are cool with that and will fill up when appropriate. And the others? They have to test the theory for themselves.

How Far Can You Really Go on “E”?

Short answer: It depends on your vehicle. Check your owners manual.

Long answer: Well …

Does It Hurt Your Car?
The reason automobiles have fuel level warning lights is to give you a warning before the car runs out of gas. Tests have proved that Americans like a buffer in this situation, and so manufacturers give them one.

But that’s not the only reason cars have fuel level warning lights. They also prevent you from burning up your fuel pump.

Here’s why. The internal mechanical parts of a fuel pump are lubricated by fuel traveling through the pump. When the fuel level is low, air can be drawn into the pump. If the pump has too much air, it isn’t properly lubricated, and can be damaged. This is similar to running an engine without oil.

Also, there may be small amounts of debris on the bottom of a fuel tank. When the fuel level is low, that debris is more likely to be drawn into the pump and/or plug the fuel filters, both of which can damage the pump. A partially plugged filter will cause the pump to have to work harder, therefore decreasing the life of the pump.

Sure, you won’t ruin your tank if you let it run out of gas once. Maybe even twice. But I say, why risk damaging your tank at all? Just get some gas!

So, How Long Can You Go?
For those of you who can’t let it rest and absolutely must know how far you can go once the fuel light comes on, check out TankOnEmpty.com. The site’s owner, a computer programmer, was fascinated by this issue and asked folks to submit their stories of pushing the needle too far. People name their make and model, note the conditions, and then provide data on how far they were able to go once the warning light came on.

The Bottom Line
Generally—depending on the car, how you are driving it, the load, road conditions, weather, and tire pressure—you can go about thirty to forty miles once the fuel light comes on. Don’t push it with hybrids though; running out of gas in a hybrid has the potential to severely damage the hybrid system.

But why press your luck? Fill your gas tank when you can—you will make the worrywart in your passenger seat feel much better! Trust me!