[Etheryte]

Yes, but the time scale varies widely depending on how it's treated. Gas you get at the pump might start degrading as fast as in a few months, as it's meant for immediate consumption and thus treated less to keep costs down. Gas that's treated for long term storage can go for up to a few years, but that adds extra cost. The main sources of degradation are oxidation and contamination, both from air and impurities. If you can, it makes economic sense to rotate the oil like you might rotate a log file so it's always reasonably fresh.