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Mobilgard™ M20 Series diesel engine oils

View all products in medium speed engine oils

ExxonMobil’s Mobilgard™ M20 Series diesel engine oils are specifically formulated for use in medium-speed engines using 0.50% and 0.10% sulphur fuels and liquefied natural gas (LNG) due to their low base number formulation of 20 BN.

This formulation helps ensure that deep-sea and coastal vessels with dual-fuel engines can continue using a single lubricant, regardless of their fuel selection. It also helps vessel operators safely and efficiently comply with the International Maritime Organization’s global 0.50% sulphur cap.

Building on the proven effectiveness of the Mobilgard™ M Series, the Mobilgard M20 Series is designed to provide outstanding performance in medium-speed marine engines, even in severe conditions. The first oil in the Mobilgard M20 Series is Mobilgard™ M420 diesel engine oil, which helps:

  • Protect against deposits on under-crowns, crankcases, ring belts and camshafts
  • Extend the life of critical wear surfaces
  • Optimise component life
  • Minimise lubricant consumption
  • Reduce maintenance and operational costs

Mobilgard M420 oil has received No Objection Letters from leading engine builders, including MAN ES and Wärtsilä.

Where to buy

Effective early August 2019, Mobilgard M420 diesel engine oil will be available at key hub ports, including Houston, Rotterdam and Singapore. Before the end of 2019, Mobilgard M420 engine oil will also be available at additional locations throughout ExxonMobil’s extensive global network of more than 650 ports.

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Product information

Features and 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 M20 Series 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 M20 Series is specifically formulated for use in medium speed engines using 0.50% and 0.10% sulphur fuels and liquefied natural gas (LNG) due to its low BN formulation.  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.


Specifications and Approvals

This product has the following approvals:


MAN Energy Solutions Augsburg (Heritage MAN B&W) 4 Stroke medium speed engines for Alternating HFO / LNG operation


MAN Energy Solutions Augsburg (Heritage MAN B&W) 4 Stroke medium speed engines for HFO operation



This product meets or exceeds the requirements of:

WARTSILA No Objection (letter on file)



Properties and Specifications




SAE 40

Density @ 15 C, kg/l, ASTM D4052


Flash Point, Cleveland Open Cup, °C, ASTM D92


Kinematic Viscosity @ 100 C, mm2/s, ASTM D445


Kinematic Viscosity @ 40 C, mm2/s, ASTM D445


Pour Point, °C, ASTM D97


Total Base Number, mgKOH/g, ASTM D2896


Viscosity Index, ASTM D2270



Health and Safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @ http://www.msds.exxonmobil.com/psims/psims.aspx

Man ES


Cruise and Ferry

Inland and Coastal

Deep Sea Shipping Industry

Short Sea Shipping

Corrosion protection

Enhanced Wear Protection

Extended Life

High Temperature

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