Mobil Pegasus™ 801 is an SAE 40 premium performance gas engine oil intended for the lubrication of all classes of gas engines operating at low, medium and high speeds where low ash or ashless oils are recommended. It provides outstanding engine cleanliness and performance by helping to prevent the formation of carbon and ash deposits on pistons, in ring belt areas, on exhaust and intake ports, on valves and valve stems and in combustion chambers.