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Mobilgard M440 

Mobilgard™ M440

Mobilgard M440 by ExxonMobil is a premium, extra high performance 40 TBN engine oils designed for use in the most severe residual-fuelled medium-speed diesel applications found in marine and stationary power industries. These market leading trunk piston engine oils are formulated utilizing the latest in additive detergent technology and provide outstanding residual fuel compatibility characteristics for excellent engine cleanliness, especially in crankcase, camshaft areas, ring belt and piston undercrowns. They also demonstrate excellent high temperature oxidation and thermal stability, low volatility, and high load carrying properties and corrosion protection.

Mobilgard M440 oils have industry-leading thermal and oxidation stability. They have excellent TBN retention and resistance to viscosity increases over long operating periods. They also promote a high level of engine cleanliness with protection against wear. Compared to other medium speed engine oils, they have superior lube/fuel compatibility and separate easily from water.

When used as recommended, Mobilgard M440 oils provide the following benefits:


Advantages and Potential Benefits

Excellent thermal and oxidation stability

Reduced deposits in piston undercrown and ring belt areas

Improved anti-wear properties

Extends the life of critical wear surfaces

Advanced detergency/dispersancy

Clean camshaft and crankcase spaces

Outstanding rust and corrosion properties

Protects wear surfaces from water and acidic corrosion

High residual fuel compatibility

Reduced sludge formation, longer oil life, cleaner engines

Low volatility base stocks

Reduced lubricant consumption

Excellent TBN reserve and retention

Combats fuel/combustion related corrosion and deposits

Mobilgard M440 oils can be used in most medium-speed trunk piston engine applications. They are recommended for use in main propulsion and auxiliary engines on deep-sea vessels; in main propulsion engines on coastal and river ships; and in stationary power plants. This new Series of oils is the result of an extensive research and development program, incorporating ExxonMobil's patented DAC (Detecting Aspahltene Contamination) Test.

Mobilgard M440 oils are designed to meet the needs of engines operating on heavy fuel. They are recommended for use in the latest model medium speed diesel engines and are especially beneficial in engines having low crankcase oil consumption or operating with low cylinder liner temperatures. Relatively high alkalinity reserves in these oils provide superior protection in neutralising the strong acids resulting from the use of high sulphur fuels that find access to the crankcase to promote oil degradation and ring, cylinder, and bearing corrosion.



SAE Grade


Specific Gravity at 15ºC


Flash Point, ºC, ASTM D 92


Pour Point, ºC, ASTM D 97


Viscosity, ASTM D 445


cSt, at 40ºC


cSt, at 100ºC


TBN, mg KOH/g, ASTM D 2896


Sulphated Ash, wt%, ASTM D 874