How long does gasoline last?

Gasoline will break down over time, but the time it takes can vary based on the type (gasoline vs. e-10 for example). If you are storing a car long term drain the tank or drive it until its almost empty, if you are wondering about old gas in a can; don't run it through your car in large quantities (adding a little at each fill up might be ok if you want to get rid of it that way, but if you have a lawnmower, use it in that).

It can start to go bad as soon as 3 months.