Victor said:
Do you have a reference for this "fact"? Considering the number of
people who run ther cars with less than 1/4 tank of fuel, I have a
hard time believing this is true.
Though there are some here who I respect but who would (no doubt
politely) disagree with me, I also question this accepted "fact".
As a veteran fuel pump components designer, my 2 cents is this: Cool
fuel flows thru the pump (all around the armature and inside the
case/magnet housing). Though the fuel surrounding the "can" certainly
would contribute something to the overall cooling, my guess is that it
has, at most, a second-order effect to local peak pump temperatures
relative to the internal flow (primarily because the external flow is
not in direct contact with the primary heat-generating components, such
as armature and brush/commutator interface). Because of this, I believe
that the most that can be said about running with the tank low in fuel
is that it reduces the design safety factor a little. I'm only a sample
of one, but I sold my '86 turbo wagon last year with 275k miles on it
and the original fuel pump, and I never paid much attention to keeping
the fuel level up.
Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")