In rec.aviation.piloting James Ricks wrote:

I'd like to know exactly how much fuel is useable, too, but think I'd probably
run a tank low, pump out the remaining gas, then either high idle or taxi
around until it sputtered, switch over, then fill the empty tank. Seems waaay
too much hassle to not just believe the manufacturer. If you choose to do this
when flying, please don't have either me or your insurance agent as a
passenger.

I routinely run tanks dry on long flights. As I know my plane and know
when a tank is about to empty, chances are that you, my insurance agent,
or my somewhat nervous wife or children ever notice that a tank went dry.

My first warning is a tank is about to dry is that my timer runs out.
A few minutes later I see a slight increase in my EGT (I've a good engine
monitor). About 40 seconds later, my fuel pressure gauge twitches. I
then switch tanks and the engine hasn't even burbled. Nobody notices.

BTW, Beech sez I've got 20 gallon tanks, with 17.5 usable. After running
my right tank dry, I can put fill with 20.8 gallons. My aux tank tank is
20 with 19 usable according to the book. After running it dry, I can put
19.7 in it. I don't know how much I can put in my left one as I only have
three tanks and I try hard not to have all three of them empty at one time
;-)

Fortunately, what Beech put in my owners book were written by engineers
with an engineers fudge factor. The books on later models were written by
lawyers using the engineers data (with the afore mentioned fudge factor).
Way lotta slop there.

In my day job, I operate a 2005 vehicle, and see the gunk that comes out of
fuel filters regularly. I can hardly imagine what could lurk in the +/- 30
year old tanks on aircraft we trust to keep us out of the trees.

Does your 2005 vehicle have sumps that you drain every time before you
start it?

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR