AeroShell SHAEW155-12 15W50 Shell Aviation Oil, 1 Quart, 12 Pack The non-ash forming, polymeric additive promotes engine cleanness High viscosity index semi synthetic oil protects engine components under high shear stresses Reduces oil consumption up to 50percent and fuel up to 5percent over straight grade engine oils Compatible with other approved aircraft piston engine oils; All season performanceallows for improved engine operation in temperature extremes