Castrol Cyltech 140 Cylinder Oil
Specifications
| OEM | Castrol Marine (bp) | |
|---|---|---|
| Product type | Slow-speed two-stroke crosshead engine cylinder oil | |
| Base Number (BN) | 140 mg KOH/g (ASTM D2896) — highest BN in the Cyltech crosshead range | |
| SAE viscosity grade | SAE 50 (kinematic viscosity approx. 19.5 mm2/s at 100C, consistent across the Cyltech crosshead range) | |
| Intended fuel / application | Super-long-stroke crosshead engines burning medium-to-high-sulphur residual fuels (HSFO, sulphur above 0.5%, typically with scrubbers) under all load conditions | |
| ACOM compatibility | Passed MAN Energy Solutions ACOM (Adaptive/Automated Cylinder Oil Mixing) testing; can be blended with low-BN Castrol Cyltech ACT (16 BN) to optimise minimum feed rate to fuel sulphur content | |
| Engine-OEM approvals | MAN Energy Solutions Category II No Objection Letter (NOL); WinGD and JEC approvals reported as expected by end of 2025 — confirm current status with Castrol/OEM |
Technical notes
Cyltech 140 is the highest-BN grade (140 mg KOH/g, SAE 50) in Castrol's refreshed Cyltech crosshead range, launched alongside 70f and 100f from March 2025. Its high alkalinity neutralises the acidic combustion products of high-sulphur residual fuel (HSFO), protecting cylinder liners and piston rings against corrosive wear in modern super-long-stroke engines, while its high reserve allows lower feed rates than 70/100 BN oils in severe conditions. It has passed MAN ES ACOM testing and can be mixed with low-BN Cyltech ACT (16 BN) so feed rate tracks fuel sulphur. Castrol holds a MAN ES Category II NOL; WinGD/JEC approvals were expected by end of 2025. Final grade and feed-rate selection must be confirmed with the engine OEM and Castrol for the specific engine and fuel.
Compliance
Cyltech 140 is a 140 BN SAE 50 cylinder oil for high-sulphur residual fuel (HSFO) in super-long-stroke crosshead engines, holding a MAN ES Category II No Objection Letter and having passed MAN ES ACOM testing, with WinGD/JEC approvals reported as expected by end of 2025 — verify current approval status with Castrol and the engine OEM before use.
Compatibility
Other parts in this series
Related
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Frequently asked questions
- What is the Base Number and viscosity grade of Castrol Cyltech 140?
- Castrol Cyltech 140 has a Base Number of 140 mg KOH/g (ASTM D2896), the highest in the Cyltech crosshead range, and is an SAE 50 grade with a kinematic viscosity of about 19.5 mm2/s at 100C, consistent with the rest of the range.
- What engines and fuels is Cyltech 140 intended for?
- It is intended for super-long-stroke two-stroke crosshead engines burning medium-to-high-sulphur residual fuels (HSFO, sulphur above ~0.5%, typically with scrubbers) under all load conditions, where its high alkaline reserve neutralises acidic combustion products and allows lower feed rates than 70/100 BN oils in severe conditions.
- Is Cyltech 140 compatible with MAN ES ACOM systems?
- Yes. Castrol states Cyltech 140 (140 BN) has passed MAN ES ACOM testing and can be blended with low-BN Castrol Cyltech ACT (16 BN) so the resulting feed rate is optimised to the fuel's sulphur content. Confirm setup with MAN ES and Castrol for your specific engine.
- What OEM approvals does Cyltech 140 hold?
- Castrol reports a MAN Energy Solutions Category II No Objection Letter for Cyltech 140, with WinGD and JEC approvals expected by the end of 2025 following over 75,000 hours of field testing. Always verify the current approval status directly with Castrol and the engine OEM.
Castrol Cyltech 140 Cylinder Oil
No public pricing — quoted per request