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Letting gas tank get below 1/4 full

I have been told by mechanics that one should never allow the gas tank to get much less than 1/4 tank because the gas is what cools the fuel pump since it is in the gas tank now. Of course that is not a problem in Chicago right now with temperatures well below zero, but here in Texas in the summer time with temperatures over 100 degrees, it seems that it could be a problem with low gas levels causing the fuel pump to overheat and fail in any car.

Yup, and driving during extreme cold with a quarter of a tank can get you stranded, without heat, when you run out of gas during a traffic backup.


Less fuel there is in a gas tank means there is more metal exposed allowing condensation forming on the interior of the tank causing more water in the fuel.


That’s good common sense advice. The word “never” seems a little strong, but keeping the tank at least 1/4 is still a good objective when such a thing is convenient to do. I have to say I’ve never followed that advice myself, and the only fuel pump I’ve ever had to replace was the mechanical pump in my 46+ year old Ford truck a few years ago. Never had to replace an electric fuel pump. I usually re-fill at about 1/8 to 1/10 tank left.


Yeah I wouldn’t feel very comfortable driving around Chicago when it’s 15 below out with a quarter tank. A quarter tank of gas means there is a 3/4 tank of air. Air contains moisture and if there is a temperature drop, water condenses out of the air and into the quarter tank of fuel. Especially if you park in a warm garage and then drive out into the cold or if there are temperature changes. Warm air can hold more water in it than cold air. May not be as much of a problem with ethanol but still it just is not a good practice and its no fun walking when it’s cold out.

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The only way running the fuel level low in the tank is gong to damage a fuel pump is if it gets low enough to where the pump is inhaling some air. In that case it will be easily noticed by the engine bucking.

As long as the pump pickup is submerged in any gasoline at all there will not be a problem.

I almost always wait until the tank is near empty and I’ve never had problems with the fuel pump in almost fifty years of driving.

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Same here. I think as long as it doesn’t suck in air, you’ll be fine. Of course since I’ve now said that, my fuel pump will probably crap out on me the next time I let it get down to 1/8th of a tank.

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Yes, I’ve spent hours in backed up traffic and you can’t always predict. A couple years ago we were on our way to NY and just crossed the Ohio line when all of the cars were being diverted off the tollway. Turns out a big accident 100 miles away had closed the road. At any rate we spent the next 3 hours in bumper to bumper traffic on two lane, unknown territory, with no cafes or gas stations. I’d probably still be there if I hadn’t decided to just break away and drive south for 40 miles to find another route and a mens room/gas station. I still had half a tank but filled up again anyway. Wait till low fuel light comes on? Not for me buddy. Always carry a lunch too.