I'll pick up the bowser tomorrow (Wednesday) and do the test.
Meanwhile I found out that oxidation causes precipitation and loss of clarity but I have not found over what time scale
reference
http://www.royalpacificpetro.com/htm...as_content.htm
I also saw a reference to sunlight affecting the dye but it wasnt too specific.I have lost the URL to that and cant find it again.
Edit: Found it
http://www.eaa.org/education/fuel/re...practices.html
Digging in Flingwings chevron link, I found this.
Instability of avgas during storage is generally not a problem because of the way the fuel is manufactured, and most fuel is used within a few months of its manufacture. Storage stability can be an issue at locations where fuel is stored for occasional or emergency use. Avgas that has been properly manufactured, stored, and handled should remain stable for at least one year. Avgas subjected to longer storage or to improper storage or handling should be tested to be sure it meets all applicable specification requirements before use.
Full text at:
http://www.chevron.com/prodserv/fuel...8_ag_perf.shtm
also
Microbial contamination in avgas is much less common than with jet fuel, although it does occur. Presumably, the lower occurrence in avgas is due to the toxicity of tetraethyl lead.
full text at
http://www.chevron.com/prodserv/fuel...#contamination
Both pages worth reading if you store avgas