Is it bad to let gas tanks run low on older cars?

[Stojakapimp]

A coworker of mine told me how she heard that it was bad to let the gas tanks on older cars get too low. She said the particulates settle at the bottom of the tank, and if you let it get to low, then those particulates will get into the engine, blah blah blah. Anyways, her car is only a 96 and she never lets it get below 1/4 of a tank. My car is a 91 and I always let it get within about 2 or 3 gallons of being empty and I haven't had a problem. So personally I think it's ridiculous, but does she have a point?

 

[SampSon]

Old metal tanks used to rust and rot and particle would get into the gas.
Not sure if the level of gas in the tank has any affect on it.

 

[HamburgerBoy]

I dunno much about cars, but my friend has a ('95?) Miata that had a similar problem. He would rarely drive and and didn't want to waste money on gas, so he's just fill it up partially. Shortly after the car wouldn't start up. He realized that the car wouldn't start not to long after his idea with conserving gas, so he filled up a plastic gas tank and filled the car. Now it's running again. Of course, correlation /= causation as many have said, but it's a story worth bringing up.

 

[Heisenberg]

The biggest issue I believe now with letting the fuel level get too low is overheating. The in-tank fuel pumps use the fuel to cool the pump, and by letting the level get low the pump won't be cooled as effectively.

 

[Shawn]

I usually fill up when I'm on E. Haven't had any problems. My car is a 94 Miata.

 

[PHiuR]

fill up when your tank has 1/4 left. it's easier on the fuel pump + won't have the chance to pick up particles in the bottom of the tank.

 

[greenwar]

Originally posted by: PHiuR
fill up when your tank has 1/4 left. it's easier on the fuel pump + won't have the chance to pick up particles in the bottom of the tank.

Exactly. May happen to a newer car in the case that the gas in your tank has some particle in it. So its recommended for all cars.

 

[halik]

Originally posted by: Stojakapimp
A coworker of mine told me how she heard that it was bad to let the gas tanks on older cars get too low. She said the particulates settle at the bottom of the tank, and if you let it get to low, then those particulates will get into the engine, blah blah blah. Anyways, her car is only a 96 and she never lets it get below 1/4 of a tank. My car is a 91 and I always let it get within about 2 or 3 gallons of being empty and I haven't had a problem. So personally I think it's ridiculous, but does she have a point?

FUEL FILTER FTW

Every car has one. Not to mention, how exactly would the level of fuel in the tank effect the probabiliy of sucking in the particles? Assuming that the fuel pump gets the gas from the bottom of the tank (otherwise you couldn't use the last 1/x of the tank) and the particles sit on the bottom of the tank, the level of the fuel would be irrelevant.

 

[Brutuskend]

Rust in older tanks. (as was said)

Some newer cars have two fuel pumps one of which is in the gas tank, running those low on fuel can lead to burning up the pump in the tank.

 

[HexiumVII]

Thats bs. Old cars (i'm talking cars like my '69) don't exactly have the most accurage gauges, so you run higher risk getting stuck on the road as they eat up more gas on top of that.

 

[Analog]

Originally posted by: PHiuR
fill up when your tank has 1/4 left. it's easier on the fuel pump + won't have the chance to pick up particles in the bottom of the tank.

I'm not sure if that makes any senses. The fuel pump is at the bottom of the tank, and rust particles will sink, meaning the level is not an issue.

I drive an '88 Fiero, and I run it pretty low. You've almost got to be below E to cavitate the fuel pump. If you have particulates, it won't be a problem if you change your fuel filter regularly.