Mobil Jet Oil II  

Aviation Exxonmobil, United States

Aircraft-Type Gas Turbine Lubricant

Product Description

Mobil Jet Oil II is a high performance aircraft-type gas turbine lubricant formulated with 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 vapour phases, as well as excellent resistance to foaming. The effective operating range of Mobil Jet Oil II is between -40ºC (-40 ºF) and 204 ºC (400ºF). 

Mobil Jet Oil II is engineered for aircraft gas turbine engines used in commercial and military service requiring MIL-PRF-23699F-STD     level performance.  It also is recommended for aircraft-type gas turbine engines in industrial or marine service applications

Features and Benefits

Mobil Jet Oil II is formulated to meet the demanding requirements of aircraft-type gas turbines operating over a wide range of severe operating conditions. The product has a high specific heat in order to ensure good heat transfer from oil-cooled engine parts.  In extensive laboratory testing and in-flight performance, Mobil Jet Oil II exhibits excellent bulk oil stability at temperatures up to 204ºC (400 ºF).  The evaporation rate at these temperatures is low enough to prevent excessive loss of volume.  Key features and benefits include:

FeaturesAdvantages and Potential Benefits
Excellent thermal and oxidation stabilityReduces the formation of carbon and sludge deposits
Maintains engine efficiency and extends engine life
Excellent wear and corrosion protectionExtends gear and bearing life Reduces engine maintenance
Retains viscosity and film strength across wide temperature rangeProvides effective lubrication at high operating temperatures
Chemically stableReduces evaporation losses and lowers oil consumption
Low pour pointEases start-up in low ambient temperature conditions


Mobil Jet Oil II is recommended for aircraft gas turbine engines of the turbo-jet, turbo-fan, turbo-prop, and turbo-shaft (helicopter) types in commercial and military service. It is also recommended for aircraft-type gas turbine engines used in industrial or marine applications. Mobil Jet Oil II is approved against the Standard Performance (STD) 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 performance characteristics of Mobil Jet Oil II. Mobil Jet Oil II is compatible with all metals used in gas turbine construction, as well as with F Rubber (Viton A), H Rubber (Buna N), and silicone seal materials.

Specifications and Approvals

Mobil Jet Oil II has the following builder approvals
-Honeywell/Lycoming-Turbine enginesX
-Rolls-Royce/Allison Engine CompanyX
-CFM InternationalX
-General Electric CompanyX
-IAE InternationalX
-Pratt and Whitney GroupX
-Pratt and Whitney, CanadaX
-Rolls-Royce LimitedX
-Honeywell/Garrett-Turbine Engine CompanyX
-Honeywell-Auxiliary power units and air cycle machinesX
-Hamilton Standard-StartersX
-Hamilton Sundstrand corp.- APUs, Constant-speed drives and integrated-drive generatorsX

Mobil JetOil II
Approved against Mil-PRF-23699F-STD X

Typical Properties

cSt @ 40ºC (102ºF)27.6
cSt @ 100ºC (212ºF)5.1
cSt @ -40ºC (-40ºF) 11,000
% change @ -40ºC after 72 hours0.15
Pour Point, ºC (ºF), ASTM D 97-59 (-74)
Flash Point, ºC (ºF), ASTM D 92 270 (518)
Fire Point, ºC (ºF)285 (545)
Autogenous Ignition Temp, ºC (ºF)404 (760)
TAN (mg KOH/g sample)0.03
Density @15 ºC, kg/l, ASMT D 40521.0035
Evaporation Loss, %  
6.5 hr @ 204ºC, 29.5" Hg3.0
6.5 hr @ 232ºC, 29.5" Hg10.9
6.5 hr @ 232ºC, 5.5" Hg 33.7
(Equals pressure @ 40,000 Ft. altitude)  
Foam, ml 
Sequence I, 24ºC8
Sequence II, 93.5ºC10
Sequence III, 75ºC (after 200 F test)8
Foam Stability, after 1 min settling, ml0
Rubber Swell 
F Rubber, 72 hr @ 204º C, %15.6
H Rubber, 72 hr @ 70ºC, %16.4
Sonic Shear Stability, KV @ 40ºC, change, %0.9
Ryder Gear, Ave. lb/in % Hercolube A2750 ,115

Health and Safety

Based on available toxicological information, this product is not expected to produce adverse effects on health when used and handled properly. Information on use and handling, as well as health and safety information, can be found in the Material Safety Data Sheet (MSDS) which can be obtained from your local distributor or via the Internet on

The ExxonMobil logotype and Mobil are trademarks of Exxon Mobil Corporation, or one of its subsidiaries. PDSAV-03


Exxon Mobil Corporation
22777 Springwoods Village Parkway
Spring TX 77389

For additional technical information or to identify the nearest U.S. ExxonMobil supply source, call 1800 662-4525.

Due to continual product research and development, the information contained herein is subject to change without notification.  Typical Properties may vary slightly.