Mobil Avrex™ S Turbo 256 gas turbine lubricant is a combination of a highly stable synthetic base fluid and a unique chemical additive package. The combination provides outstanding thermal and oxidative stability to resist deterioration and deposit formation in both the liquid and vapor phases, as well as excellent resistance to foaming. It is uniquely suited for use when extreme low temperatures restrict the use of higher viscosity engine oils. In extensive laboratory testing and in-flight performance, Mobil Avrex S Turbo 256 exhibits excellent bulk oil stability at temperatures up to 176 degrees Celsius (350 F). The evaporation rate at these temperatures is low enough to prevent excessive loss of volume.