I don't use any additives and my truck can set for months at a time during winter, dad's race car sets even longer. Best bet for long term storage is using 100% gasoline. We are lucky to have a couple of stations in the area that carry pure premium 91 octane gasoline. I fill up with it mid October, which can carry me over till spring if I don't drive to much. My truck is in a garage that stays 45 to 50 degrees, so that may account for some of the long term storage with out problems. I am also using two W-1 carbs, which are cast iron, so no worries about aluminum or pot metal damage.
Joe
