I add either StaBil or Seafoam (which ever is on sale at the time), run it down the road to circulate, fill the gas tank with regular gas (topping it off). I then park it in its' car igloo, attach a battery tender, put a Cover King cover on, and not start it until the next April. I then put moth balls in a number of tuna fish cans around the car, but NO moth balls in the car (hate the smell) to discourage rodents from entering the igloo. I've been using this procedure since 2013 (the year I bought the '91) and have had no adverse situations arrise.