"Bill Putney" <bptn@kinez.net> wrote
> *BUT* - again - the fuel is constantly flowing thru and
> around all internal components of the pump whenever it is
> running providing cooling (unless you actually run out and
> the engine stops - but that is a different scenario
> altogether, and even then, the pump will still be full of
> fuel at that point with a full column of fuel from its
> lowest end to the fuel rail - only the pickup will be
> filled with air, and there won't be any flow - and most
> cars turn the pump off when the computer senses that the
> engine is no longer running).

"most"? I would think you would want to err on the side of
safety and not inconveniencing a driver with a sudden pump
breakdown.

Barring presentation of a study showing no detrimental
effects of either regularly running on a very low tank or
running to empty, I think not doing these things is easy
enough and indeed an investment that costs one only a litle
extra time getting gas over the life of the car. If possibly
burdening the pump by forcing it to move air is not really a
problem, then I remain concerned about dirt in the bottom of
the tank clogging the filter and lines downstream of the
pump prematurely, or possibly wearing mechanical parts on
the pump, causing the pump to have to work harder, meaning
it draws more current, aging electrical parts more quickly,
etc.

Does rust accumulate in fuel tanks? If so, does running it
near empty hasten the buildup of rust?

What are the leading causes of fuel pump failure? If it's
"age," what exactly causes aging to accelerate?

I do not want your speculation. I am well experienced in
pump design myself. I want facts from a study of pump
failure.