AeroShell straight mineral oils are blended from selected high viscosity index base stocks. These oils do not contain additives except for a small quantity of pourpoint depressant (which is added when improved fluidity at very low temperature is required) and an antioxidant.
AeroShell Oils are available in four different viscosity grades: AeroShell Oil 65 – AeroShell Oil 80 – AeroShell Oil 100 – AeroShell Oil 120 The suffix for each grade corresponds to the viscosity of the oil at 99°C (210°F) in Saybolt Universal Seconds.
The appropriate grades of these AeroShell Oils are approved for use in four-stroke (four-cycle) certified aircraft reciprocating piston engines (except Porsche) and other aircraft radial engines which use oil to specification SAE J1966 (MIL-L-6082) and which do not require use of an oil containing a dispersant additive. AeroShell Oils are used primarily during break-in of most new or recently overhauled four-stroke aviation piston engines. The duration and lubrication recommendations for break-in vary, so operators should refer to the original engine manufacturer and/or overhaul facility for specific recommendations.
The U.S. Specification SAE J1966 replaces MIL-L-6082E.
Although it was planned to replace the British Specification DERD 2472 with a DEF STAN specification this has now been put into suspension and instead the SAE specification has been adopted.