Product Description

Mobil Jet Oil 254 is a third-generation, extra high performance, synthetic aircraft-type gas turbine lubricant engineered to meet the performance requirements for gas turbine engines used in commercial and military aircraft.  This product is formulated from a specially prepared, hindered-ester base stock and fortified with a unique chemical additive package. The result is a product having superior thermal and oxidation stability that resists deterioration and deposit formation while maintaining the physical characteristics required by builder and military specifications.  The physical properties of Mobil Jet Oil 254 are similar to those currently available, earlier-generation gas turbine lubricants. The effective operating range of  the lubricant is between -40°C (-40 °F) and 232°C (450°F).

Features and Benefits

Mobil Jet Oil 254 is formulated to meet the demanding requirements of latest technology  aircraft-type gas turbines operating over a wide range of severe operating conditions.  When compared to a typical Type II lubricant, Mobil Jet Oil 254 reduces bulk oil oxidation by up to 50 percent and shows deposit control capability 50 F higher.  These properties have been confirmed in various laboratory tests including; the Corrosion-Oxidation Stability Test,  Alcor Deposition Test, Vapor Phase Coker, Erdco High-Temperature Bearing Test, Ryder Gear and the Mobil Thin Film Oxidation Test.The closely controlled low-temperature viscosity of Mobil Jet Oil 254, along with its low pour point (below -54 ºC), ensure good low-temperature fluidity to permit starting and lubrication at temperatures as low as -40 ºC.  In extensive laboratory testing and in-flight experience, Mobil Jet Oil 254 also exhibits excellent bulk oil stability at temperatures up to 232 ºC (450 ºF) for extended periods.  The evaporation rate at these temperatures is low enough to prevent excessive loss of volume.  The load-carrying ability of Mobil Jet Oil 254 comes from its synthetic base stock viscosity and, therefore, is not subject to loss from viscosity index additive shear.  The lubricant has excellent resistance to foaming.Key features and benefits include:

Features Advantages and Potential Benefits
Excellent thermal and oxidation stability Reduces the formation of carbon and sludge deposits

Maintains engine efficiency and extends engine life

Reduces bulk oil oxidation by 50% and increases deposit control by 50 ºF

Excellent wear and corrosion protection Extends seal, gear and bearing life

Reduces engine maintenance

Viscosity and shear stability across wide temperature range Provides effective lubrication at high operating temperatures
Chemically stable at high operating temperatures Reduces evaporation losses and lowers oil consumption
Excellent resistance to foaming Maintains film strength under rigorous operating conditions
Good low temperature fluidity Permits start-up and ensures effective lubrication of critical components at temperatures as low as -40 °F


Mobil Jet Oil 254 is recommended for aircraft gas turbine engines of the turbo-jet, turbo-fan, turbo-prop, and turbo-shaft (helicopter) types used in commercial and military service.  It is also suitable for aircraft-type gas turbine engines used in industrial or marine applications.Mobil Jet Oil 254 is approved against the High Thermal Stability (HTS) classification of U.S. Military Specification MIL-PRF-23699.  It is also compatible with other synthetic gas turbine lubricants meeting MIL-PRF-23699.  However, mixing with other products is not recommended because the blend would result in some loss of the superior performance characteristics of Mobil Jet Oil 254.Mobil Jet Oil 254 is completely compatible with all metals used in gas turbine construction, as well as with F Rubber (Viton A), H Rubber (Buna N), and other commonly used seal materials.

Mobil Jet Oil 254 has the following builder approvals *


• Honeywell/Lycoming-Turbines

• Rolls-Royce/Allison Engine Company

• CFM International

• General Electric Company

• International Aero Engines

• Pratt and Whitney Group

• Pratt and Whitney, Canada

• Rolls-Royce Limited


• Honeywell/Garrett Turbine Engine Company


• Honeywell-Auxiliary power units and air cycle machines

• Hamilton Standard-Starters

• Hamilton Sundstrand Corp.-APUs, constant-speed drives and integrated-drive generators

 * Specific engine or equipment approval must be verified with the builder

Specifications and Approvals

This product has the following approvals:

Properties and Specifications

Autogenous-ignition temperature test, deg.C, 30 CFR 35.20 399
Change in Kinematic Viscosity, 72 h @ -40 C, %, ASTM D2532 -2.2
Elastomer Compatibility, AMS-3217/4 (72hrs @204C), % swell, FTMS 791-3604 20.8
Elastomer Compatibility,AMS-3217/1(72hr @70C), % swell, FTMS 791-3604 20
Evaporation Loss, 6.5 h, 204 C, mass%, ASTM D972(mod) 7.4
Evaporation Loss, 6.5 hr @ 232 C, 5.5″ Hg, mass %, ASTM D972(mod) 25.2
Fire Point, °C, ASTM D92 288
Flash Point, Cleveland Open Cup, °C, ASTM D92 254
Foam, Sequence I, Tendency, ml, ASTM D892 0
Foam, Sequence II, Tendency, ml, ASTM D892 10
Foam, Sequence III, Tendency, ml, ASTM D892 0
Kinematic Viscosity @ 100 C, mm2/s, ASTM D445 5.3
Kinematic Viscosity @ 40 C, mm2/s, ASTM D445 26.4
Kinematic Viscosity @ -40 C, mm2/s, ASTM D445 11500
Pour Point, °C, ASTM D5950 -62
Shear Stability, %KV loss, ASTM D2603 0.7
Specific Gravity 60 F / 60 F, ASTM D1429 1.0044
Total Acid Number, mgKOH/g, ARP 5088 0.08
Ryder Gear Load Carrying, % vs ref., FTMS 791-6508 114

Health and safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @


It cannot be guaranteed that the product information given above is up to date. For the latest version of the Product Data Sheet we refer to the product library of ExxonMobil.