I had the same concern in Oct when I took mine out. I had about 15 gallons of gas that had been in there for about 14 months. I had put Stabil in it. I decided that since my wifes vehicle is gas powered to simply use the gas station on the side (which pulls from the same tank as the generator uses) to fill her car up. The gas was fine and she drove it off zero issues. I then ran sta-bil through the generator under load, replaced the oil, replaced the spark plug, replaced the air filter. Fresh gas and another thing of stabil. I dont think I'll be so paranoid next time as it does say 24 months and the gas was fine in her GDI car. I also know if I am not using it much I dont keep a full 40 gallons in it.