I have gas in my boat that is 2 years old. (just not enough time to use it) I took it out and it ran excellent. I use Stabil and Star Brite Star Tron. I keep 100 gallons on hand between the 6 gallon cans and the boat and I have never had a problem. I rotate the cans so that they are never more than a year old. Generator runs great and I've never had a problem when I've used it in my truck.