Periodically Run Fuel Tank Empty?

[rbattelle]

All you experienced guys out there,



I normally fill up when my fuel gauge reads 1/4 or slightly less. If I never let it get much below 1/4, will I build up dirt/sludge/whatever at the bottom of the tank, to be sucked up next time I run all the way to empty?

 

[illflem]

Build up in the bottom of the tank can be a problem with stationary tanks but rarely with a vehicle tank, the fuel sloshing around keeps things mixed up.

Good idea to keep your tank filled on the high side anyway. The fuller the tank the less air it contains that can condense and add water. Most heavy equipment manufacturers recommend filling the tank before daily shutdown for this reason.

The tank fuel also acts as a cooling reservoir for return fuel, cooling is less efficient the lower your tank is.

Best practice is to keep your tank as full as possible. I usually fill at 1/2 tank, about 20 gallons. Also keeps the sticker shock down when the fuel is high priced. I hate it when a fill up approaches 60 bucks.

 

[Steve M]

Very good post Bill. I hadn't thought of the cooling aspect of the fuel tank... I rarely let it get past 1/4. Filling at 1/2 tank would be easy to do also.

 

[CPG]

Bill, these are the kind of answers that makes me glad that I subscribe to TDR. Thanks.

 

[Ncostello]

At around 80K miles, I pulled the fuel module out for some mods I made to my fuel system. I took the bed off for easy access to the module. I can say that no "junk" was found in my tank after this many miles. The inside of the tank had a white poly liner and I'd say about 1/4 tank remaining. Using a flashlight, it was easy to see that only a few sand grain particles existed on the bottom here and there. There was no layer or anything. Thus its safe to say running it down to empty wouldn't hurt a thing... assuming your tank hasn't had years worth of extremely dirty fuel pumped into it.

 

[ndurbin]

Kid I know at college bought a 90 ferd. he let the tank run dry on him and it wiped out his pump.

 

[klenger]

I've never been able to figure out how running a tank to empty would cause it to suck up any debre/sludge in a fuel tank. Doesn't the lift pump take fuel from the bottom of the tank even when it's full? If not, how does use the fuel below the fuel outlet point ever get used?

 

[SEmerson]

Yes the sump is on the bottom all the time.

 

[illflem]

There is a little known screen on the bottom of our fuel tank modules that is actually pretty fine. Should keep the bigger stuff out if you get a load of dirty fuel.

 

[soslow91]

I don't think a new truck is going to build up sludge or whatever at the bottom of the tank very quikly but I can say if there is junk in the tank you do suck more of it up when its close to empty. My 70 barracuda had a rusty gas tank and it would plug up the fuel filter when you ran it low