I have had good performance using Stabil in all my small engine gasoline, but also switching it out at not more than 6 weeks of age. I also use non-ethanol when possible, but I don't go out of my way too much for it during mowing season as 5 gallons only last about 2 weeks. For my last fill up of the year, it is definitely PURE GAS for it will be a small amount left in the tanks of the big stuff. For small push mowers, chainsaws, weedeaters, power washers, I drain all the gas from them and run the carb dry. I have a pressure washer that is 12 years old and never had to do anything to it and it still starts on 2nd pull. I recently serviced up a push mower that had been using Stabil for its lifetime, but had been setting with tank and carb dry for 30 month or so. I filled it with fresh gas and it started right up, ran it a bit and changed out the oil. It starts on the 2nd pull also. My riding mowers, I siphon all the gas that I can from the tank then add about 2 oz. of Stabil, run it for a bit and shut it down. Fill with fresh gas next spring and she's ready to go.