[vel0city]

There's a lot of variables there. How well sealed is your tank? Was there much air there? How humid?

Its definitely much shorter than a decade, but if stored really well more than a year is pretty doable. 2+ years can be a gamble though. And if it causes problems, it might cause some serious problems. Want to gamble on your generator during an emergency?

I've definitely had some gas sitting in a tank with stabilizer last a couple of years. I've definitely had gas sitting in a tank go bad in under a year.