Petrol will begin to degrade in as little as 30 days, higher octane fuel can be even more volatile. Sta-Bil is a chemically engineered blend of additives that will act together to prevent fuel from degrading and oxidising during storage, safely protecting your engine from stale fuel related issues. Sta-Bil works by encapsulating fuel cells when added to your fuel tank, protecting the fuel from elements and moisture that cause fuel quality to degrade. Sta-Bil fuel stabiliser is the world leader in fuel stabilisation technology and will keep fuel fresh for up to 12 months with one dose. Sta-Bil Fuel Stabiliser has more original engine manufacturer endorsements than any other fuel stabiliser, and is safe for use in ALL petrol engines. Remember, if you stores it, cover it, or leave it for more than a monthâ€šÃ„Â¶. Protect it with Sta-Bil.