HP Ultra is a fully synthetic 2-cycle engine oil specially suited for high performance chainsaws and power tools. This oil has outstanding engine cleaning characteristics, plus “ultra” superior lubricating qualities in comparison to other 2-cycle engine oils. It is ideal for use in STIHL 4-MIX® engines. This oil is biodegradable, degrading by 80% in 21 days. •2.6 oz. bottle makes 1 gallon mix •5.2 oz. bottle makes 2 gallon mix •6.4 oz. bottle makes 2 1/2 gallon mix •12.8 oz. bottle makes 5 gallon mix STIHL recommends a mix of 50:1 high-quality 89 octane or higher unleaded gasoline to STIHL engine oil. This same mix ratio should be used during break-in. Unopened container shelf life: 4 years from the date of filling, in originally sealed containers.