AAA recommends that you keep your gas tank at least three-eighths full to avoid long-term car troubles.
Your vehicle may give you a few miles of grace, but tempting fate is not really the point here. The important thing to know is what to do when the gauge approaches empty, and the ways that driving with a nearly empty tank can affect your car.
In many modern cars, the fuel pump sits inside the gas tank. It uses gasoline for cooling and lubrication, so when gas runs very low the pump tends to heat up. You might not do major damage if you let this happen once, but making a regular practice of driving with just a few quarts of gas in the tank can eventually kill the pump.
Another peril involves the stuff that collects at the bottom of a gas tank, such as sediment from fuel and water from condensation. With a full tank, condensation doesn’t have much space to form and sediment sits harmlessly at the bottom. When fuel runs low, there’s a chance that the pump will suck in debris and push it to the engine, or that enough of it will collect on the pump’s filter to block the flow of gas.
The easy cure for these troubles is a few gallons of prevention: Keep your gas tank at least three-eighths full.
For vehicle services from inspections to repairs, and for links to driving tips that can help you save gas, visit AAA.com.
This article was first published in January 2012. Some facts may have aged gracelessly. Please call ahead to verify information.