I recently drained ten gallons of gas from an onboard boat fuel tank. The fuel was from August of 2020. When it was stored, I had put slightly over the required amount of stabilizer in the tank. I also put in any popular type of ethanol treatment or injector cleaner that I had. A few years passed and the boat was unused. At some point a few years back I put more various treatments in it. This is a plastic tank stored in an outbuilding anywhere from 15 to 100 degrees. The fuel that was drained had a heavy dark color to it, but no smell of varnish and wasn't rank. I put a small amount in an old push mower that had been completely run out of fuel till dry. Pumped the primer a few times and it started on the first pull and ran well. Have used the rest in lawn tractor and it starts right up. You may have different results, but it has worked for me. The boat motor is a V6 outboard with three two barrel carbs and many adjustments that i do not want to touch. I have always used these snake oil supplements with good results. I turn the fuel supply off and run the carbs empty as well as I can in the fall. The motor is a 1991 and I have never touched a single carb adjustment. If you read the manual you will understand, DIFFICULT. I put five gallons of fresh fuel in the boat tank to mix with the two or three gallons of almost six-year-old fuel that sits in the bottom and the boat started as well as ever this spring.