Shell AeroShell Turbine Oil 390
Shell AeroShell Turbine Oil 390 is a 3 mm²/s synthetic diester lubricating oil developed for aircraft turbine engines requiring DEF STAN 91-94 performance. It incorporates a carefully selected and balanced additive system designed to enhance thermal and oxidation stability while increasing the load carrying ability of the base oil.
Originally developed as an improved 3 cSt oil for British turbo-jet engines, Shell AeroShell Turbine Oil 390 is now fully approved for a wide range of turbine engine applications. Its strong low-temperature characteristics have also made it particularly attractive for use in auxiliary power units (APUs), where cold soak conditions can lead to starting difficulties.
In APU applications, prolonged exposure to low temperatures during cruise can significantly increase the viscosity of standard 5 cSt turbine oils, resulting in high viscous drag and potential hung starts. Shell AeroShell Turbine Oil 390 exhibits a much lower viscosity increase at sub-zero temperatures, typically around 2000 mm²/s at –40°C compared with approximately 10,000 mm²/s for standard 5 cSt oils. This reduced viscosity rise minimises viscous drag, contributing to improved cold-start reliability and reduced risk of hung starts.
The oil provides strong thermal and oxidative stability, passing high-temperature oxidative stability and corrosion testing in accordance with DEF STAN requirements. It demonstrates controlled foaming characteristics, low particulate contamination and reliable corrosion protection performance. Load carrying ability testing confirms that the formulation supports dependable lubrication under demanding operating conditions.
Shell AeroShell Turbine Oil 390 also meets stringent elastomer compatibility requirements across nitrile, fluorocarbon, LCS fluorocarbon and silicone materials, supporting seal integrity in service. Its pour point is below –60°C, ensuring reliable fluidity at very low temperatures, while flash point exceeds minimum specification requirements for safe high-temperature operation.
The oil meets DEF STAN 91-94 and carries Joint Service Designation OX-7. It is approved for use in Honeywell APUs requiring 3 cSt oils and Pratt & Whitney APS series, PW901 and PW980 units. It is also approved for Rolls-Royce Spey and Tay engines in industrial and marine applications.
