Thanks. I'm just trying to get an idea of how avgas stores. I did find some
useful info on the Chevron site.
FWIW, I grew up in Ohio, and remember some stations selling white gas from a
small tank in the back, which I always related to the likes of Coleman fuel.
What I do know for sure, is that seasonal use small engines such as snow
blowers, lawn mowers, or rototillers would be fine after long term storage
as long as we used white gas in them. I remember several neighbors trying
this with gasoline, and no go. Answer from the shops that had to repair
their stuff was always 'shoulda used white gas'. Today I just treat the fuel
in my motorcycles with Sta-bil. People on the motorcycle boards that live in
cold weather areas say that the regular unleaded fuel they get is even
shorter lived today than it was in years past, so they make sure to use
Sta-bil. I don't think anyone uses white gas anymore. Av gas just seems so
much more refined. It quickly evaperates without any lingering smell,
similar to lantern fuel. I don't know how people that run auto gas in their
planes keep everything from smelling like gas all the time. For instance, I
sure wouldn't want to put my fuel sampling cup back in my flight bag after
sumping tanks with auto fuel in them. Seems like everything in the bag and
the plane itself would smell like gas for weeks. Av gas, no problem, no
smell.
Alex

My guess is that most planes for sale are still flying regularly.
There are exceptions to this (ramp or hangar queens and owners forced
into selling because of financial distress), but most owners realize
the worst thing they can do to an aircraft is not to fly it.

Regarding storage, you can 'pickle' an engine to allow VERY long term
storage, however as you point out this does not address the fuel
system. Some planes have bladder tanks, and I imagine it is quite bad
for them to sit dry. Probably the same goes for the fuel lines. Not
to mention the gyro instruments, vac pump, and vac lines.

-Nathan