Why is it so

Wish you could get the formatting here. Reckon someone in Repco is trying to get some sophistcation into their catelog
Ref:
http://dictionary.reference.com/wordoftheday/archive/2005/04/27.html

Word of the Day for Wednesday April 27, 2005

detritus \dih-TRY-tuhs\, noun;
plural detritus:
1. Loose material that is worn away from rocks.
2. Hence, any fragments separated from the body to which they belonged; any product of disintegration; debris.

The water was smooth and brown, with detritus swirling in the eddies from the increasing current.
--Gordon Chaplin, Dark Wind: A Survivor's Tale of Love and Loss

If they [flying cars] were easy to produce, we'd be walking around wearing helmets to protect us from the detritus of flying car crashes.
--Gail Collins, "Grounded for 2000," New York Times, December 7, 1999

The loose detritus of thought, washed down to us through long ages.
--H. Rogers, Essays

Detritus derives from the past participle of Latin deterere, "to rub away, to wear out," from de-, "from" + terere, "to rub." It is related to detriment, at root "a rubbing away, a wearing away," hence "damage, harm."

I think what they are getting at is that with very low levels of fuel the sloshing action is going to stir up more of the cr%p on the bottom of the tank. You'll find that most tanks will have an area of "depression" that is lower than the fuel pick up line for the crap to settle in. This should correspond with the fuel tank drain hole.

Just remember that the longer the tank is left with low levels of fuel the more chance you have of getting condensation in the tank and hence the dreaded RUST.

I always leave my tanks full if the beast will sit for any length of time.

Redeye,

Dunno about detritus, but it is recommeneded to leave 10-25% in the tank.

Caterpillar suggests keeping >10% in tanks of their machinery. With toyotas, with their dual tanks, and solenoids, "stuff" can get caught in solenoids, and they stick open. Know a bloke who ran fuel out in one tank, trying for max range, and had solenoid leaking air so bad, he had to syphon fuel back into the empty tank.

As mentioned above, sloshing of fuel, in near empty tank, picks up everything, that goes into your filter. Good advice also, to keep tanks full, at all times. Way fuel is going up these days, you could call it an investment!!!

Hooroo...

Have had this happen to me.
Ran the tank down and got a clogged fuel filter.

So before a big trip now (or at least once a year) as part of doing the filters etc, I run the tank down to about 10 litres and pull the drain plug. Then flush the tank. Amazing the rubbish that comes out. Have had sand, hair, rust come out after one trip out west where I know I picked up a load of dirty fuel. Any rust helps the tank rust too.

Then I know I am right for the trip, bar dirty fuel I might pick up :-)

Hve to agree with OldPlod, I use to typically run my tank almost dry (down to 3 litres remaining) before refuelling and was replacing fuel filters quite regularly.

I do a fair amount of highway miles and generally refuel at same spots each time. I also do my own servicing and check vehicle before each run and more often than not would find a lot of water (and sludge) in water trap and a lot of crap in filter and yes had drained tank. Tried changing refuel points but much the same result. I now typically refuel with 20 litres remaining (or thereabouts).

This very topic created a discussion between a friend and I who insisted by replacing fuel filter so frequently was over servicing as his vehicle manual stated the filter was good for X,000 klms. My argument was that the manual was a guide and may be practical in an ideal world however if the filter is clagged it needs replacing.

Except for the short time that the tank is full the fuel will be sloshing all the time that the vehicle is moving. Any bit of rubbish will soon be picked up and caught in the filter. However I read somewhere that some vehicles have a floating fuel pickup. In this case as long as the tank is never run down too low it would be easy for rubbish to accumulate in the bottom of the tank for a long time and then for a great load of it be picked up if the tank is run down.

Stephen.