I mix Sta-bil with my gas every time I fill the cans. The reason being is sometimes the equipment gets put away sooner than I think and this way, I don’t have to worry if I added Sta-bil, as it’s all been treated. Sta-bil is less than $10 to treat 80 gallons and I don’t go thru that much in a year. The only exception is my boat and jet ski. They use too much gas (always non-ethanol) and get treated at the end of the season.
