Don't wait until tank is empty to fill up

[EvilEric]

I was reading this article and I wanted to pass this on to everyone. The article was talking about how the contaminants in the gas tank can be taken up when your near empty. It can help damage the fuel injectors, engine and filter.

They suggest filling up when you have 25% left.

Just a FYI

[mazda lover]

I was reading this article and I wanted to pass this on to everyone. The article was talking about how the contaminants in the gas tank can be taken up when your near empty. It can help damage the fuel injectors, engine and filter.

They suggest filling up when you have 25% left.

Just a FYI

Thanks, low fuel in the tank will also hurt the pump as the gas keeps it cool...

[Noisy Crow]

Can you guys provide evidence for these claims?

[dentinger]

ya, but ive head we have like, a 10L or so left once we hit the E.

[dr1ft3r]

Thats prolly why theres a 10 L buffer.

[EvilEric]

Can you guys provide evidence for these claims?

http://www.eforecourt.com/body.htm/p...tagory/general

http://www.autohausaz.com/html/fuelpumps.html

Why Fuel Pumps Fail
Electric fuel pumps run constantly, so after many years of service they can experience wear in the armature bushings, brushes and commutator. Pump vanes, rollers or gears can also wear causing a gradual loss of pressure and flow.

Accelerated wear may also occur if sediment or rust gets past the inlet filter sock. In some instances, a pump will fail because contaminants entered the pump and jammed it, causing the motor to overheat and burn out.

Your fuel pump relies on fuel passing through it for lubrication and cooling. Consequently, fuel starvation can be another factor that accelerates wear and may even cause pump damage under certain operating conditions.

*****

Obviously not the best sources. However it seems to make sense to me. When you have less gas in the tank, the contaminants that are in there are more easily picked up. That clogs the injectors and offer an opportunity to damage other parts.

[Noisy Crow]

Well, I view this with suspicion.

The pump pickup sits at the bottom of the tank. The crud that is heavy enough to sink is going to stay there. It doesn't really care how much fuel is above it. Any crud that does get picked up will be caught by the fuel filter. Besides which, injector problems are usually caused by varnish buildup not mechanical debris. As for the cooling aspect: as long as fuel is flowing through the pump, it is being cooled. If you run the tank dry, they the cooling will stop... but, then, so will your car.

I've had cars with over 300,000 km. All sorts of parts have failed... never the fuel pump.

[Wild Weasel]

Besides... isn't this what the fuel filter is for?

[p-o-g-i]

I was reading this article and I wanted to pass this on to everyone. The article was talking about how the contaminants in the gas tank can be taken up when your near empty. It can help damage the fuel injectors, engine and filter.

They suggest filling up when you have 25% left.

Just a FYI

I thought that this was a given...... but after reviewing everyone's response, I'm on the fence with this.

Either way, I rarely let the tank go past the halfway mark. It's just a rule of thumb for me as the last thing I want is my wife to get stranded somewhere with the baby in the car.

[1flycdnM3]

I am filling up twice a week as it is and still "occassionally" see the yellow light and put on another 20K or so before filling up. But yet again, this is why we have a fuel filter to pick up the crud, etc. However, I can see how this would damage the pump over time (if you did this ALOT) because it has to work more the less fuel you have?!

makes sense anyways...

[Flagrum_3]

I think something has to be understood here, the occasional running of a tank almost dry or to the light, should not effect the pump or anything else for that matter.It is when someone is in the habit of running the tank near empty for prolonged periods of time that your asking for trouble.Condensation is the main worry not crud, but crud could coat the strainer to the point where the pump must work harder to suck thru the fuel.Crud will tend to be lifted and sloshed around more so on a near empty tank as opposed to a near full tank, thank goodness to the baffles placed in our tanks designed to keep that to a minimum.

Anyways, moral of the story is; Re-Fill your tanks at 1/4 tank or higher and don't get into the habit of running it to the light!.....for many reasons!

_3

[x_o_k_x]

Well, I view this with suspicion.

The pump pickup sits at the bottom of the tank. The crud that is heavy enough to sink is going to stay there. It doesn't really care how much fuel is above it. Any crud that does get picked up will be caught by the fuel filter. Besides which, injector problems are usually caused by varnish buildup not mechanical debris. As for the cooling aspect: as long as fuel is flowing through the pump, it is being cooled. If you run the tank dry, they the cooling will stop... but, then, so will your car.

I've had cars with over 300,000 km. All sorts of parts have failed... never the fuel pump.

I think you're right, I always drive till the light comes on and another 50km past that and nothing. The filter itself is siting at the bottom of the tank, it will never get dry since you always have gas in there. If you dont, your car will simply stop and so is the pump.

[nicker]

but what if you like to live on the edge! Then run it low! (reminds me of that episode of Seinfield with Kramer test driving that car LOL).

I think as stated its not good to run your car low to the point of the light being on for days. Just not a good habbit for many reasons......

But then again with the price of gas I bet its happening more often now.

[shootemup]

I have had to replace a few fuel pumps in cars during the few years I worked in a shop. For the majority of cars, the fuel filter is located in line, somewhere between the fuel pump and the injectors. The only filter inside the tank is just a mesh screen and that is used to just filter out the large chunks of debris. Common cause for failure is running the pump dry. A lot of people think that it is fine as long as the engine runs; however, what they don't realize is that they run the tank low, they are sucking up a mix of air and fuel. This causes the motor to run inconsistently, as it speeds up when it has air in it (less resistance) and does not get proper cooling. However, most of the pumps I have replaced were on older vehicles or ones with high mileage.

[doughboyr6]

i guess my fuel pump is gonna go soon then....cuz ever since new, I've always only filled up when the light comes on and then some. I always wanted to see how far i could drive w/ the light on, so i incrementally increase each time the light comes on by about 1-2 kms...lol (near my neighbourhood).

[x_o_k_x]

I have had to replace a few fuel pumps in cars during the few years I worked in a shop. For the majority of cars, the fuel filter is located in line, somewhere between the fuel pump and the injectors. The only filter inside the tank is just a mesh screen and that is used to just filter out the large chunks of debris. Common cause for failure is running the pump dry. A lot of people think that it is fine as long as the engine runs; however, what they don't realize is that they run the tank low, they are sucking up a mix of air and fuel. This causes the motor to run inconsistently, as it speeds up when it has air in it (less resistance) and does not get proper cooling. However, most of the pumps I have replaced were on older vehicles or ones with high mileage.

If air gets inside the fuel pump etc your engine wont run properly meaning you would actually loose power for a sec or two. IF it does happen then most likly you have less then a litre or two. Now thats bad. When the light comes on you have another 10 litres or 100-150km to go. I dont think you will have any problems fith fuel pump when the light hits. Thats ony if you suck air inside the pump, which means you need to run a litre or less of gas.

[shootemup]

If air gets inside the fuel pump etc your engine wont run properly meaning you would actually loose power for a sec or two. IF it does happen then most likly you have less then a litre or two. Now thats bad. When the light comes on you have another 10 litres or 100-150km to go. I dont think you will have any problems fith fuel pump when the light hits. Thats ony if you suck air inside the pump, which means you need to run a litre or less of gas.

I never said that this would happen when the light comes on. This is definately the result of someone running their tank down to fumes. The light comes on exactly when it should with a little less then 1/4 of a tank. As long as your filling up when the light comes on, or shortly after, you will be fine.

[wingnut12]

I've been told to never let the car get below 25% by several mechanics I trusted, (including a couple Mazda ones).

I know that a lot of us sometimes just want an answer to have an answer, but if a lot of people say that this is good advice, no one says that it's bad, and it doesn't cost any more money, why not just adopt it instead of arguing about it?

[bubba1983]

whats the filter size on car filters? the diesel trucks usually run 2 filters, with the secondary filter filtering out about 2atms......i don't know how fine a filter the automobiles use?

[Flagrum_3]

I've been told to never let the car get below 25% by several mechanics I trusted, (including a couple Mazda ones).

I know that a lot of us sometimes just want an answer to have an answer, but if a lot of people say that this is good advice, no one says that it's bad, and it doesn't cost any more money, why not just adopt it instead of arguing about it?

BIG +1, You took the words right out of my mouth Wingnut....good point!

_3