Aeroshell Turbine Oil provides exceptional thermal stability and lubrication at sustained high temperatures in helicopter turbine engines. Turbine Oil 500 contains a carefully balanced combination of additives to improve thermal stability as well as oxidation stability, while Aeroshell Turbine Oil 560 provides low coking, improved thermal and oxidation stability for today's high powered, high compression turbine engines. Turbine Oil 555 meets MIL-PRF-23699F requirements and it is DOD-L-85734 approved for high temperature/high load applications including Bell helicopter transmissions, while Turbine Oil 750 is a higher viscosity aviaton turbine oil designed for use in older gas turbine engines and in heavy duty helicopter transmissions applications.