Bad for the Car if You Fill up Close to Empty?

[DJediMaster]

I usually fill up the gas when i have about 15% left. A friend of mine mentioned that it is bad for the engine if you fill up close to E. Is this true?

 

[Tominator]

It makes zero difference in a modern fuel system when you fill up.

 

[deftron]

Um...


More gas equals more driving
More driving equals more wear and tear
Therefore gas is bad for your car?

 

[NogginBoink]

I have to agree.

The engine itself has no way of knowing the difference between "lots of gas" and "almost empty."

The engine becomes acutely aware of the issue, however, when you cross the threshhold of "almost empty" to "empty."

 

[Zenmervolt]

The only thing I can think of is that when you're near empty, the gunk in the bottom of the tank is more likely to be sucked in. If course, this is why we have fuel filters.

ZV

 

[HappyPuppy]

You really should get some more intelligent friends.

 

[Heisenberg]

The only thing I can think of is it might make you have to change the fuel filter more often as it is sucking gas from the bottom of the tank along with dirt. It also can cause drops in fuel pressure. I notice when I'm really low on gas and corner hard the engine will hesitate.

 

[mztykal]

Hell, he's on AT, how much more intelligent can people get?

 

[DJediMaster]

Yeah, i think that is what his reasoning was behind it. He said that bad gas particles and debris settle on the bottom of the tank. When u fill it up close to E, the engine will be getting a lot of crap...

 

[Pacfanweb]

<<The only thing I can think of is that when you're near empty, the gunk in the bottom of the tank is more likely to be sucked in>>

Which is all the more reason you should fill it up.

 

[Triumph]

<< Yeah, i think that is what his reasoning was behind it. He said that bad gas particles and debris settle on the bottom of the tank. When u fill it up close to E, the engine will be getting a lot of crap... >>


Well then the problem really is letting your gas tank run until empty, not filling it up when it's empty.

 

[killmeplease]

You will not hurt your car's feelings by negecting to keep it full.

 

[skull]

Isn't the gas always sucked from the bottem?

 

[b0mbrman]

<<

<< Yeah, i think that is what his reasoning was behind it. He said that bad gas particles and debris settle on the bottom of the tank. When u fill it up close to E, the engine will be getting a lot of crap... >>


Well then the problem really is letting your gas tank run until empty, not filling it up when it's empty. >>


That's what I'd say...

 

[db]

Fuel filter filters whether tank is full or empty.

 

[Zenmervolt]

<< Yeah, i think that is what his reasoning was behind it. He said that bad gas particles and debris settle on the bottom of the tank. When u fill it up close to E, the engine will be getting a lot of crap... >>

He seems to have forgotten that all cars have fuel filters. None of that junk ever gets to the engine anyway. And yes, it's always sucking from the bottom, but it picks up more of the settled particles when the tank is near empty. Regardless, it doesn't matter because of the filter.

ZV

EDIT: <<I notice when I'm really low on gas and corner hard the engine will hesitate.>>

That's not from a fuel pressure drop (well, technically it is since it's from zero pressure). The fuel pump keeps constant pressure as long as the pickup is completely covered by fuel. When cornering, fuel sloshes to one side of the tank and away from the pickup, so when the engine hesitates while cornering on a low tank, it's because your fuel pump is sucking air for a little bit until the fuel covers the pickup again.

 

[Tominator]

<< He seems to have forgotten that all cars have fuel filters. None of that junk ever gets to the engine anyway. And yes, it's always sucking from the bottom, but it picks up more of the settled particles when the tank is near empty. Regardless, it doesn't matter because of the filter. >>



Generally that is exactly right. Newer cars have rust resitant fuel tanks and are not prone to rust as older cars were. Fuel systems have been sealed from the atmosphere for many years now so condensation and the resulting rust is not a problem and all modern cars suck from the lowest point anyway so if there were contaminates in the tank they would either be filtered out or would cause a problem.

Change your fuel filter at recommended intervals...

 

[Heisenberg]

<< EDIT: <<I notice when I'm really low on gas and corner hard the engine will hesitate.>>

That's not from a fuel pressure drop (well, technically it is since it's from zero pressure). The fuel pump keeps constant pressure as long as the pickup is completely covered by fuel. When cornering, fuel sloshes to one side of the tank and away from the pickup, so when the engine hesitates while cornering on a low tank, it's because your fuel pump is sucking air for a little bit until the fuel covers the pickup again. >>



I realize it's from the gas going to one side of the tank or the other and so not covering the pickup. It only happens when the tank is low so I mentioned it as a potential problem.

Edit: Of course, it is dependent on the fuel tank design and so may not apply as a general rule.

 

[Jejunum]

im pretty sure it is bad if only because u dont want that gunk getting into ur fuel filter (if u can avoid it why bother...) if ur fuel filter gets all nasty u will have less power (right?) heh hell if i know!

 

[RU482]

This thread gives me gas

 

[dionx]

maybe his reasoning is that if you feel the car up to the top from empty, you are adding more weight as if it were only to be half filled.. and that weight prolly adds to about 1-2 more miles per trip from 2 half filled tanks as oppossed to 1 full tank.

no matter the reason, im sure its stupid

 

[RedRooster]

<< That's not from a fuel pressure drop (well, technically it is since it's from zero pressure). The fuel pump keeps constant pressure as long as the pickup is completely covered by fuel. When cornering, fuel sloshes to one side of the tank and away from the pickup, so when the engine hesitates while cornering on a low tank, it's because your fuel pump is sucking air for a little bit until the fuel covers the pickup again. >>



At least someone around here knows something about cars. j/k
In modern cars, where the fuel pump is in the tank itself, the pump relies on the fuel level for cooling as well. When the fuel level isn't covering the fuel pump, there's a better chance that doing that too many times will result in fuel pump failure. It's a fact. And for anyone that doesn't believe me, just wait till you have to either change the pump yourself(drain the tank, pull the entire tank off, get inside to change the pump, etc.) or pay for it to be done. Then you'll see.

edit-as far as it being bad for the ENGINE, well that's a little hooey.

 

[Tominator]

Good point RedRooster!

 

[Kelvrick]

If gunk is his reasoning, won't your fuel tank eventually be filled with gunk?

 

[RedRooster]

<< Good point RedRooster! >>



Thanks.
My dad always used to(and still does) harp on me when I let my tank go below a quarter. In the winter it's even worse he says, and I'll tend to believe him.