Mobilgard 525

Mobilgard 525

Diesel Engine Cylinder Oil

Mobilgard 525 is a marine diesel engine cylinder oil for crosshead engines running low and ultra low sulphur distillate fuels and meets the requirements of MAN and Wartsila engines. Designed to protect in extreme environments, Mobilgard 525 has an optimum viscosity of 20 cSt at 100ºC and low volatility to ensure lubricant distribution and oil film retention and help protect engine parts.


  • Combats the deposits and scuffing related engine wear associated with low sulphur fuels
  • Excellent thermal and oxidative stability to ensure performance in a variety of engine conditions
  • Formulated with detergent technology required to deliver excellent performance with low-sulphur fuel
  • Detergency system provides strong control of piston groove deposits which is a critical area for distillate fuel operation


  • Marine crosshead engines designed for increased power and fuel efficiency
  • Earlier engine designs and engines in slow speed steaming operation

Specifications and Approvals

Mobilgard 525 has the following builder approvals  
MAN Diesel X
Wartsila X

** Please refer to latest service bulletins from MAN Diesel & Turbo and Wartsila Switzerland for lubrication requirements.

To ensure achieving the maximum equipment life possible as well as appropriate feedrates, particular attention should be paid to the manufacturer’s special recommendations as published in the references as above or any other future manufacturer’s instructions.

Typical Properties

SAE Grade 50
Specific Gravity at 15ºC 0.909
Flash Point, ºC, ASTM D 92 286
Pour Point, ºC, ASTM D 97 -9
cSt, at 40ºC 226
cSt, at 100ºC 20
Viscosity Index, ASTM D 2270 102
TBN, mg KOH/g, ASTM D 2896 25

Health and Safety

Based on available information, this product is not expected to produce adverse effects on health when used for the intended application, following the recommendations provided in the Material Safety Data Sheet (MSDS). MSDSs are available upon request through your sales contract office. This product should not be used for purposes other than its intended use. If disposing of used product, take care to protect the environment.


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.