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Mobilgrease™ 28

Aircraft component in a factory

Trusted for more than 50 years

Mobilgrease 28 grease – the first synthetic product Mobil™ offered – has been trusted for more than 50 years. With a 10-year shelf life, it offers more than three times the life of similar-type competitive greases.
Mobilgrease 28 is the polyalphaolefin (PAO), clay-based multipurpose airframe and wheel bearing grease of choice for many aircraft operators around the world. It is designed to lubricate plain and rolling bearings at low to high speeds, and splines, screws, worm gears and other mechanisms where high-friction reduction, low-wear and low-lubricant friction losses are required.
It meets the performance requirements of key military and commercial aviation specifications and offers operators increased flexibility and potential inventory consolidation benefits. Mobilgrease 28 grease is fully approved for use in multipurpose airframe grease applications and in wheel bearings.

Why trust in Mobilgrease 28 aviation grease? Because it’s been specifically formulated to:

Common grease point applications

  • Gears, actuators, jack screws
  • Helicopter rotor bearings
  • General airframe (splines, slats, stabilizers, elevators)
  • Landing gear assemblies
  • Flight controls
  • Aircraft wheel bearings

Product information

Data sheets


ExxonMobil Jet A meets the following industry specifications:ExxonMobil Jet AExxonMobil Jet A-1


MilitaryExxonMobil Jet AExxonMobil Jet A-1
Approved against Mil U.K. DEF STAN 91-91Not applicableX
Approved against Mil and the JIG (Joint Inspection Group) Aviation Fuel Requirements for Jointly Operated Systems (Check List)Not applicableX


Product Properties

 Jet AJet A-1
Acidity, mg KOH/g0.10 Max.0.10 Max.
Aromatics, Vol. %25 Max.25.0 Max.ax.
Sulphur, mercaptan, Wt. %0.003 Max.0.003 Max.
Sulphur, total, Wt. %0.300.30
10% Distillation, ºC205 Max.205.0 Max.
Final Boiling Point, ºC300 Max300.0 Max
Distillation Residue, %1.5 Max.1.5 Max.
Distillation Loss, %1.5 Max.1.5 Max.
Flash Point, ºC38 Min.38.0 Min.
Density @ 15ºC, kg/m3775/840775/840.0
Freeze Point, ºC-40 Max-47.0 Max
Viscosity @ -20ºC, mm/s8.0 Max.8.0000 Max.
Net Heat of Combustion, MJ/kg42.8 Min.42.80 Min.
One of the following shall be met  
1) Smoke Point, mm, or25 Min.25.0 Min.
2) Smoke Point, mm, and18 Min.19.0 Min.
Naphthalenes, Vol. %3.0 Max3.00 Max
Copper Strip Corrosion, 2 h % 100ºCNo. 1No. 1
Thermal Stability  
Filter pressure drop, mm Hg25 Max.25 Max.
Tube Deposits< 3 Max.< 3 Max.
Existent Gum, mg/100 mL.7 Max.7 Max.
Water Reaction, Interface Rating1b Max.1b Max.
MSEP Rating  
Without electrical conductivity additive8585
With electrical conductivity additive7070
Electrical conductivity, pS/m 50 Min. 600 Max.


Health and Safety

Based on available information, this product is not expected to produce adverse effects on health when used for the intended application and the recommendations provided in the Material Safety Data Sheet (MSDS) are followed. MSDSs are available via the Internet at ExxonMobil.com. This product should not be used for purposes other than its intended use.

Keep away from ignition sources.
Discharge your static electricity before fueling.
Fill portable containers on the ground.
Handle/Transport in closed or properly vented containers and systems, consistent with all applicable laws.
Harmful or fatal if swallowed.
Avoid breathing the vapors and skin contact.
Do not wash down spills with water. Prevent all spills from reaching water.