Do You Wait Until the Fuel Light Comes on to Fill Your Gas Tank?

Dale Bertram
July 13, 2012

Are you one of those people who doesn't put gas into your tank until it beeps a warning? I’ve known a few people who do this on a regular basis and I’ve seen the damage first hand.

Most vehicles have an electric fuel pump. This sits inside the tank and is submerged in fuel, which keeps the pump cool and lubricated. Without this submergence in fuel, the pump can self destruct from overheating. The reserve fuel inside your tank prevents this from happening.

Some vehicles have a well that the pump sits inside and if this well runs dry, the pump also gets damaged. If your vehicle is fueled by diesel and this occurs, it also becomes necessary to “prime it” to get fuel to the pump.

Heat also plays a factor. When you have 90 degree days coupled with the heat from the pavement on the bottom side of the car where the fuel tank sits, it does not take much for the pumps to go bad.

If you regularly put in just enough gas to get by, your fuel pump can fail earlier than normal. Your pump will also be taking in the “bottom of the barrel” fuel, which is full of debris. This sediment in the bottom of the fuel tank can also clog the fuel filter, fuel injectors, and the pump pickup. I generally don’t let my tank get below 1/4 tank for this reason.

The best thing you can do for your vehicle is fill it up when it gets to a quarter tank. It will save you money in the long run and keep your car running well. Sure, it doesn’t have the same challenge as driving on fumes, but when it comes to your vehicle, it's always wise to consider damage control … both to your car and your wallet!

Happy Motoring!

Dale Bertram

About the Author

I am an ASE-certified technician and have owned my own auto repair business, Fairway Auto Repair, since 1991. I am also an AMI graduate with a AAM degree, and continue my education by taking various courses during the year. I am a hard core car guy. Basically if it isn't mechanical, I'm not interested in it. This passion for vehicles has driven me throughout my life. My hobbies are my cars. I have two 1968 Camaros and a 1971 Camaro that my son and I built. I also raced an IMCA modified dirt track car for 10 years. In the last few years, I have been involved with autocross and road course racing events.  I have been married to my wife, Lorie, for 28 years and we have two children, Kaila (16) and Landon (13). I also enjoy the outdoors and hiking. Please check out my shop's page at

1 User Comment

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By , February 07, 2014
So far I've only heard the second reason -- running it too low has the pump sucking up the debris at the bottom -- but how low can you go before that's really a problem? Most Japanese cars, at least, set off the warning light when there are still 3-4 gallons left, meaning you're good for another ~100 miles. With such a comfortable margin, filling up before that seems wasteful. As for the first reason, are fuel pumps really flimsy enough to fail without being totally submerged in fuel?