Mobilgard™ 5100 cylinder oil

Mobilgard™ 5100 advanced cylinder oil is designed for two-stroke marine diesel engines operating on heavy fuel oil. It is engineered to help prevent cold corrosion – and reduce maintenance and operational costs – in modern and slow-steaming engines.

Designed to meet the demands of the latest modern engines, Mobilgard 5100 cylinder oil offers:

  • Balanced formulation to protect against liner and piston wear, and help maximise engine cleanliness
  • Exceptional deposit control, oxidation stability and acid neutralisation to help prevent cold corrosion
  • Help in optimising engine performance and cylinder oil feed rates
  • Help to reduce maintenance costs and lengthen piston overhaul intervals

For maximum results, we recommend using our Mobil Serv℠ Cylinder Condition Monitoring service with Mobilgard 5100 cylinder oil to help optimise engine performance.

Mobilgard 5100 oil has received No Objection Letters from MAN Diesel & Turbo, WinGD (formerly Wärtsilä) and Mitsubishi Heavy Industries.

Compared to 70 BN oils, Mobilgard 5100 oil helped reduce cylinder oil consumption in corrosive engines by up to 30%**. Mobilgard 5100 oil successfully protects engines when operating at the engine builders’ recommended minimum feed rates. Based on MAN recommendations for engines Mark 8.1 and above. Actual performance may vary based on engine type and condition, fuel sulphur and operating conditions.

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Product Information
Technical resources
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Features and Benefits
  • Excellent corrosion protection in newer, more demanding engine types during slow steaming operation.
  • Excellent thermal and oxidation stability can lead to reduced deposits and sludge formation. Cleaner engines can lead to reduced component wear rates.
  • Exceptional anti-wear properties lead to potentially reduced liner and ring wear and excellent anti-scuffing control.
  • Outstanding detergency capability leads to potentially cleaner pistons and liners and can help extend periods between overhauls.

Specifications and Approvals
Meets OEM requirements
MAN Diesel and Turbo X
Wartsila/WinGD* X


*Please follow all OEM guidelines for engine model, feed rate and fuel sulfur use

  • Marine crosshead engines
Typical Properties
SAE Grade
Specific Gravity at 15ºC 0.953
Flash Point, ºC, ASTM D 92 244
Pour Point, ºC, ASTM D 97 -24
Viscosity, ASTM D 445  
cSt, at 40 ºC 242
cSt, at 100 ºC 21.1
Viscosity Index, ASTM D 2270 103
TBN, mg KOH/g, ASTM D 2896 100


Equipment builders
  • MAN
  • Mitsubishi
  • Wartsila
Industry Sectors
  • deep sea shipping industry
Product Features
  • Corrosion protection
  • Enhanced Wear Protection
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