Driving on Empty: Reasons to Keep Your Tank at Least a Quarter Full

You may think it’s efficient to use all the gasoline in your fuel tank before filling up again. But driving on empty can cost you much more than paying for a tank of gas.

AAA recommends that you keep at least a quarter tank of fuel in your car. Here’s why.

Driving on empty can leave you stranded

Let’s address the obvious first. Driving on empty can leave you stranded if you misjudge how much gasoline you really have left or if you simply can’t find a nearby gas station.

Running out of gas is not only inconvenient, it can also put you and others in danger. Power steering and brakes can be lost when your engine dies, which could leave you stuck in a precarious place on the roadway.

Remember, running out of gasoline is completely avoidable.

Driving on empty can damage your car

Next, let’s take a look at your car and how fuel gets from your gas tank to your engine. In most newer cars, your fuel pump provides pressurized gas to the fuel injection system. If the fuel pump stops working, your car’s engine will not run.

On most vehicles, the fuel pump is located inside the fuel tank. Gasoline in the tank helps keep the fuel pump cool. When there’s too little gas, the fuel pump can overheat, causing it to wear out faster. So, you need enough fuel in the tank to keep the pump submerged.

Sediment is another concern when you’re driving on empty (or close to it). The sediment and contaminants that sit in the bottom of your gas tank can be pulled into the fuel pump when the fuel level is low. These contaminants can clog and stress the pump if they build up significantly. This is possible—though less likely—even in modern fuel pumps equipped with adequate protective screens or filters.

Replacing a fuel pump costs a lot more than a tank of gas: $500 or more in parts and labor, depending on your car.