Cyltech is Castrol's brand of two-stroke marine cylinder oils for slow-speed crosshead engines, part of Castrol's wider marine lubricant range.

How do I choose a Cyltech cylinder oil?

Match the cylinder-oil base number (BN) to your fuel's sulphur content and your engine OEM's approval. See our cylinder-oil BN selection guide, and confirm with Castrol for the specific grade.

Where can I buy Castrol Cyltech?

Cyltech is supplied through Castrol's authorised marine distributors. Submit a request for quote with your port, engine and grade and we will route it to a supplier.

Castrol Marine Lubricants (Cyltech)

also known as Castrol, BP Marine, Cyltech

Castrol — part of the bp group — has supplied lubricants to commercial shipping for decades and markets its two-stroke marine cylinder oils under the Cyltech name. A Castrol lubricant slate spans the whole vessel: Cyltech cylinder oils and matching system oils for slow-speed crosshead propulsion, trunk-piston oils for four-stroke auxiliaries and gensets, and the hydraulic, gear and compressor fluids that keep deck and engine-room machinery turning. The pivotal call for a two-stroke main engine is cylinder-oil base number, which has to track the sulphur level of the fuel in use — a balance that grew more demanding once IMO 2020 pushed the fleet off high-sulphur fuel and onto VLSFO, LSFO and, increasingly, gas. This hub catalogues the Cyltech grades with their published datasheet figures — base number, viscosity, target fuels and engine-OEM approvals — and presents them strictly as a decision aid: the engine builder's approval and Castrol's own technical recommendation are always the deciding authority. Cyltech is distributed through Castrol's authorised marine supply network.

The Cyltech range

Cyltech spans two-stroke cylinder oils selected by base number for the fuel sulphur, alongside Castrol's two-stroke system oils and four-stroke trunk-piston engine oils. Each grade is approved by the relevant engine OEMs and chosen by engine type first, then by fuel and duty.

Selecting a Cyltech cylinder oil

For two-stroke engines, match the cylinder-oil base number to the fuel: high-sulphur fuel needs a high-BN grade, low-sulphur fuel a lower-BN grade. Confirm the specific grade against the engine OEM's approval and Castrol's recommendation for your fuel and engine model.

Series & families

Cyltech two-stroke cylinder oils

Compliance

USCG & MED compliance

Frequently asked questions

What is Cyltech?: Cyltech is Castrol's brand of two-stroke marine cylinder oils for slow-speed crosshead engines, part of Castrol's wider marine lubricant range.
How do I choose a Cyltech cylinder oil?: Match the cylinder-oil base number (BN) to your fuel's sulphur content and your engine OEM's approval. See our cylinder-oil BN selection guide, and confirm with Castrol for the specific grade.
Where can I buy Castrol Cyltech?: Cyltech is supplied through Castrol's authorised marine distributors. Submit a request for quote with your port, engine and grade and we will route it to a supplier.