<Ron wrote: What about the Sun beating down on those containers and the volatiles passing off?> I am under the assumption, perhaps incorrectly, that a sealed container emits nothing. Now if you have it vented that's a different story. We have had containers of gasoline stored for the hurricane genset for a couple of years or perhaps even more. When finally used it has always run the genset OK. Now the same fuel left in the genset tank will go off so the conclusion here is that in the vented tanks(s) fuel goes bad. In non vented tanks it doesn't. A full tank doesn't get the expansion/contraction of a partially full one as the thermal expansion of the liquid is much less than the air. As always YMMV, Cheers Dave & Nancy Swan Song Roughwater 58 Caribbean Cruise '07