Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff, Lauren Vogel bomb here. Experts say you should keep your gas tank at least a quarter full at all times. Obviously, doing so we'll keep you from getting in a dangerous situation where you're low on gas and too far from gas station to fill up. But there are other less obvious reasons to keep a little gas in your tank. Driving on an empty tank, or even one that's getting close to the dregs in the bottom, can cause damage
to your car in a number of ways. You won't get very far driving on empty, but in the moments before you do stall out, your car's catalytic converter, which is part of the exhaust system, can be damaged. You could also get debris stuck in your fuel pump by running your tank too low. That's because any tiny particles that find their way into the gas tank settle at the bottom, and they tend to stay there until your car is trying to grab every last bit of fuel
that it can. When the fuel pump sucks up the last of your gas, any debris in your tank will go along with it, and the particles can get stuck in your pump. Or in your fuel filter. In early model cars from the nineteen eighties and older, the gas tanks are usually made of metal, and as they deteriorate,
harmful deposits can build up in the bottom. Newer cars have plastic fuel tanks, so sediment usually makes its way inside the tanks from contaminated fuel, But getting sediments stuck in your fuel pump isn't the only way that you could be damaging it. In some cars, the fuel pump is located in the gas tank and the gas acts like insulation and lubricant as it flows around the pump. If you're constantly running your gas tank dry, the fuel pump could be overheating, which will cause it to wear
out prematurely. But how far can you actually go when the gas gage hits e Well, that depends on your car. Different vehicles have the gas light configured in different ways, though most cars will illuminate the light when there are about two to three gallons that's seven point five to eleven liters left. Some bigger vehicles like trucks and SUVs, light up the empty indicator when there are about four gallons or fifteen liters. That's about to say exteenth of
a tank left. How far those amounts can get you is another variable that depends on your car's efficiency, you're driving style, and whether you're in the city, on the highway, or stuck in a traffic jam. Some newer cars have a display in the instrument cluster that keeps a running tally of your range or how many miles you can drive on your current tank of gas. These displays are
pretty accurate, but again they are just estimates. Changing road conditions or any number of other factors can affect the accuracy of this gauge, which could leave you stranded if you're really cutting it close. So it's a good idea to get in the habit of filling up before you strictly need to. That said, if you find yourself in a situation where you're running low, don't worry. You're not
going to ruin your car. Just get into the practice of filling up whenever your fuel gage reaches the quarter mark and you'll be fine. Today's episode was written by Sherry's three Wit and produced by Tyler Klang. If you enjoy our show and also like wearing T shirts, check
out our online shop at t public dot com. Slash brain Stuff we've also got a bunch of back to school stuff like laptop cases too, and of course, for lots more on this and other revd up topics, check out our home planet how Stuff Works dot com.