I have a generator which I have never used - thank goodness! But I do crank it up every month and make sure it's o.k. I need to buy gas for it -- and I have several 2 1/2 gallon cans. I don't want to use anything larger because they are too heavy to lift. My question is: What is the shelf life of a gallon of gas? I bought StaBil and put that in the last time I added gas. What I will do (and did before) is fill the generator and then fill the empty gas cans. I use the gas for lawn mower too so it will eventually get used even if we don't have a hurricane. Just wondering if I need to add StaBil to all of it -- thanks.