Myth: Running low on gas will cause your car to suck up a bunch of debris from the bottom of the tank.

Dear Car Talk

Dear Car Talk | Mar 01, 2004

Dear Tom and Ray:

Please help me settle this debate with my dear husband. Going to the gas station is a pleasant ritual for him, where he gets coffee, maybe a fat-saturated, cholesterol-charged snack and kibitzes with the employees and other blue-collar workers who frequent this hot social Mecca in our town. I think it is because he likes these stops so much that he often buys only $5 to $10 worth of gas, therefore necessitating frequent visits to the gas station. I, on the other hand, hate to go to the gas station! Hence, I run my vehicle until the "gas is low" indicator comes on. I NEVER run out of gas -- in fact, there are still at least 4 gallons in my 21-gallon tank when the light comes on. My dear, concerned husband, however, always tells me the tank should never be allowed to get so low because it will suck up the nasty stuff that settles in the bottom of the tank. I say, since I always let it get near empty, that nasty stuff shouldn't have a chance to accumulate! Am I doing my car a disservice? Please let me know what you both think!

-- Martha

TOM: I think it was the famous 16th-century mechanic Vinnie Shakespeare who said, "To thine own self, be true."

RAY: It's a little-known fact, but he was giving advice to a married couple who disagreed about how often to feed their horses.

TOM: And I'd give you guys the same advice, Martha. Do whatever makes you happy. From what you tell us, neither of you is doing any harm to anything. Most cars have at least one filter in the gas tank and another in the fuel line to prevent any sediment from clogging the fuel injectors. So that's not a concern.

RAY: And the hinges on the fuel-filler door are sturdy enough so that your husband won't wear them out, even if he fills up twice as often as you do.

TOM: So, our advice is to fill up as frequently or as infrequently as you like. No harm will be done to anything.

RAY: Except maybe to your husband's cardiovascular system. Tell him to watch those cholesterol bombs, OK?

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One