Marine Engine Oil

Castrol Cyltech ACT


Castrol Cyltech ACT Crosshead Engine Cylinder Lubricant


Castrol Cyltech ACT (Ash Control Technology) is a premium marine diesel engine cylinder lubricant specifically developed to provide protection when using low sulphur fuels and LNG.
With a low ash content, the product provides optimum protection against potential ash deposits that may be formed as a consequence of using low sulphur fuels with traditional lubricants of high ash (or high base number (BN)). The low ash content is achieved by a careful balance of low BN additives that also succeed in maintaining the piston ring zone cleanliness.


Castrol Cyltech ACT is suitable for the cylinder lubrication of all crosshead engines burning low sulphur fuels that comply with current IMO Emission Control Area (ECA) legislation where a maximum sulphur content of 0.1% (1,000 ppm) is mandated. It is also suitable for other low-sulphur and zero-sulphur fuels such as natural gas.


If high BN lubricants (with high ash content) are used for extended periods when burning low sulphur fuels, there is a tendency for ash deposits to build up on the piston and in the exhaust system and turbochargers. The use of Cyltech ACT, as a low ash lubricant, effectively mitigates this potential problem.

  • Reduced potential for ash deposition on engine components
  • Reduced risk of cylinder bore polishing as a consequence of ash deposits rubbing on the liner
  • Maintains a clean piston ring zone, keeping rings free to move in the grooves
  • Extends the durability of the engine when using low-sulphur fuels for extended periods
NameMethodUnitsCyltech ACT
Density @ 15C, Relative


ASTM D4052g/ml0.9


VisualClear & Bright
Viscosity, Kinematic 100C


ASTM D445mm²/s19.5
Total Base Number, TBN


ASTM D2896mg KOH/g16
Flash Point, PMCCASTM D93°C206

Cyltech ACT has full No Objection Letters from MAN Diesel & Turbo, Winterthur Gas & Diesel (Wärtsilä) and MHI (Mitsubishi) for use in all engine designs.


All packages should be stored under cover. Where outside storage is unavoidable, drums should be laid horizontally to avoid the possible ingress of water and the obliteration of drum markings. Products should not be stored above 60°C, or exposed to hot sun or freezing conditions.

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Product Data Sheet 

Safety Data Sheet 

Castrol Clytech Act Marine Engine Lubricant Oil

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