Phillips 66 Type M Aviation Oils are designed for use in aviation engines where the operator prefers continued use of all-mineral type oil. It does not contain dispersant type additives. This oil can be used as break-in oil for newly overhauled engines when an oil of this type is recommended. Break-in is normally accomplished in less than 25 hours of engine operation. When compared to single-grade oils, Type M Aviation Oil 20W-50 offers improved cold temperature starting, quicker flow of oil to the cold engine, plus a full-bodied oil for high-temperature, high-load operation.