Generic question on fuel levels..

[mixwell]

Okay so I have heard from more than one person that it is good practice to fill up your gas tank before it hits empty so you aren't pulling crap from the bottom of your fuel tank. Anyone hear this? I can see why this is logical but didn't know if it was that important.

 

[rurouni20xx]

well since your pulling fuel from the bottom of the tank cuz thats where the inlet on the fuel pump is idk. i personally dont like to go below a 1/4 of a tank if i can help it cuz it lessens the stress on the fuel sending unit when it gets close to empty and starts to cavitate (pull air) and damage the diaphragms in the pump. if you have water or crap in the tank the fuel filter that is located underneath the cab on the drivers side inside the frame where the rabs on the older models is will contain most of it, if you have rough idle or just poor economy or driveability i would look into checking/changing that first along w/ the other common service parts (plugs wires etc...) to check it just disconnect it and let it run out a bit and see if you smell water in the fuel, if so change the filter and run it again for a bit.

 

[dru]

see if you smell water in the fuel

what does water in the fuel smell like

 

[MAKG]

Okay so I have heard from more than one person that it is good practice to fill up your gas tank before it hits empty so you aren't pulling crap from the bottom of your fuel tank. Anyone hear this? I can see why this is logical but didn't know if it was that important.

Yeah, I heard it too, but the two times I've been inside fuel tanks (on a Bronco II and a Dodge Caravan), they were SPARKLING clean.

I suspect it's one of those old wives' tales that never dies.

The REAL reason to fill your tank before it gets empty is that you don't stall when you turn a corner or hit the brakes hard. If you have an automatic, you've just lost your steering and perhaps your brakes (if you aren't careful and pump them too much), and you can't get it back until you stop.

 

[Viper Command]

one other thing

the fuel pump uses the fuel to keep it cool, like over heating your engine it can only take so much for so long. try not to go below 1/4 of the tank

 

[valleyvinyl84]

one other thing

the fuel pump uses the fuel to keep it cool, like over heating your engine it can only take so much for so long. try not to go below 1/4 of the tank

True. However, I always wondered why frame mounted pumps don't overheat?

 

[north44]

Besides the reasons already listed:

Keeping your gas tank full as much as possible means less air in the tank, means less water will form in the tank due to condensation.

Up here, driving with minimal gas in your tank is an invitation for increased water in the tank from condensation. In the winter, if water in your tank freezes and blocks your lines, your vehicle won't start.

In fact the gas up here contains gas line antifreeze (which you can also buy separately and put in your tank) in order to prevent this condition from occurring. But even this won't prevent the accumulation of water in the tank, if the gas level in the tank is always low.

Having a full tank means more operational time 'til empty - common sense, and important if you ever get caught in an emergency situation, a traffic jam, or otherwise stopped/stalled, especially in a snowstorm, or other winter condition - it means that you'll be able to keep your vehicle running that much longer, and it also means you'll have heat for that much longer.

 

[north44]

True. However, I always wondered why frame mounted pumps don't overheat?

I think it's more a matter of the in-tank fuel pumps lasting longer due to the extra cooling - i.e., the extra cooling (when/if surrounded by gasoline) extends their service life.

 

[mixwell]

I thought of it as a wives tale.. In So Cali wont be geting freezing conditions but if I remember I will try to fill up before it gets that low but appears it isn't a huge concern or anything so I won't worry about it.. Just wanted to see if anyone else has heard of this or had any 1st hand experience with it and any advantages of it.. thanks.

 

[Earl43P]

I'll tell ya.

My 2000 has always been run down below E. When my low light comes on, that means I've got to fill up in a couple days, within 50 miles. Every blessed tank I do this. Then I fill it. I'm still using my second fuel filter with 101k miles. Can't recall when I replaced the FF, but it's been YEARS.

I've done this with every vehicle I've ever owned. Never had a problem. I like knowing exactly how many miles I can get out of a tank. 340 seems to be the magic # I can count on. Usually takes over 18 gal. to fill it at that point.

Your fuel system has a return, so fuel is constantly circulating. I don't see low fuel state being an issue.

 

[Gotta_gofast]

I agree with North44. Usually what happens if you leave your tank low, condensation will start to corrode and rust the tank. Its not something that will happen to a newer vehicle. It takes MANY years. But some of the 15-20 year old gas tanks I've torn apart have rusted from the inside. Mind you, this is only with metal tanks and not the plastic ones. lol