Imagine a fuel stabilizer under real storage conditions lasting three years. I don’t believe it for a second. Draining the old fuel out of carburetor for storage is the tried and true method. I do not use or endorse fuel stabilizers.I have found if you keep a little good gas in them and try to run them every three months or so seems to work best. The fuel in the bowl goes bad alot faster than the stuff in the tank. As for extra gas storage i kind of think the same way. Keep it for three months or so then dump it in your car and fill the can again that way you know its always fresh.