AeroShell W Oils were the first non-ash dispersant oils to be used in aircraft piston engines. They combine non-metallic additives with selected high viscosity index base stocks to give exceptional stability, dispersancy and anti-foaming performance. These additives leave no metallic ash residues that can lead to deposit formation in combustion chambers and on spark plugs, which can cause pre-ignition and possible engine failure.
AeroShell W Oils are available in four different viscosity grades:
- AeroShell Oil W65
- AeroShell Oil W80
- AeroShell Oil W100
- AeroShell Oil W120
The suffix for each grade corresponds to the viscosity of the oil at 2100 F in Saybolt Universal Seconds.
AeroShell W Oils are intended for use in four-stroke (fourcycle) certified reciprocating piston engines, including fuel injected and turbocharged engines. AeroShell W Oils are not recommended for use in automotive engines. For automotive engines converted for use in aircraft, the specific engine manufacturer or the conversion agency should be consulted for proper oil recommendation.
Most radial engine operators use AeroShell Oil W120 in warm weather operations with AeroShell Oil W100 or AeroShell Oil W 15W-50 being used in cooler ambient temperatures.
AeroShell Oil W100 or AeroShell Oil W 15W-50 are the common choices for most operators of Lycoming and Continental flat engines but, during colder parts of the year, use of AeroShell Oil W80 in place of AeroShell Oil W100 would be an excellent choice.
Although some aircraft engine manufacturers and rebuilders/ overhaul agencies suggest in their service bulletins the use of a straight mineral oil in new or newly overhauled engines, other rebuilders or manufacturers, especially for engines such as the Lycoming O-320H and O/LO360E, allow either ashless dispersant or straight mineral oil for break-in, whereas ashless dispersant oils are mandated for break-in for all turbocharged Lycoming engines. Operators should check with engine manufacturers or rebuilders for the correct recommendation for the specific engine and application.