Looking to keep your fuel system functioning 100% during the season? STA-BIL 360 Protection is the ultimate ethanol treatment. STA-BIL 360 Protection, America's #1 Ethanol Treatment, is engineered to combat the negative effects of ethanol-blended fuels. This industry-leading formula prevents corrosion, cleans the fuel system, and prevents the buildup of unwanted gum and varnish; ensuring your equipment will be ready to go whenever you need it. 1oz treats 5 gallons of gas. If using with small engine equipment pour directly into your gas can that way everything you fill with that can is already treated with STA-BIL 360. If adding to a vehicle it is best practice to add STA-BIL 360 before adding fresh fuel at the pump. STA-BIL 360 is designed to be added to the fuel as soon as you get it that way you know the fuel is fresh. This formula will also keep gas fresh for up to a year. Use throughout the season to make sure your engine runs top-notch year-round! Overtreating will not harm the engine.