Cylinder oils from BN 40 to BN 140.
For low-speed two-stroke crosshead engines. Six base numbers so the feed can be matched to the fuel actually in the tank rather than to whatever is on board.
CYN 50 BN 100 is WinGD validated
Listed in Validated Engine Oils for WinGD Engines, Version 18 (January 2026) — valid for WinGD X, X-DF, X-DF-A, X-DF-M, RT-flex and RT-flex-DF engines, plus Wärtsilä RTA / RT-flex / X and Sulzer two-stroke engines. CYN 50 BN 70 additionally holds an Everllence No Objection Letter.
See the documentsChoosing a base number
BN is matched to fuel sulphur content. Running too high a BN on low-sulphur fuel is as damaging as running too low a BN on HFO.
ULSFO / distillate (≤ 0.10 % S)
BN 40 Cat II ULSFO
Low-sulphur operation; excess BN causes deposit build-up.
VLSFO (≤ 0.50 % S)
BN 40 Cat I · BN 55
Balanced neutralisation for compliant fuel.
HFO (up to 3.50 % S)
BN 70 · BN 100
Higher reserve to neutralise sulphuric acid formation.
High-sulphur HFO with scrubber
BN 100 · BN 140
Maximum neutralisation for sustained high-sulphur running.
Guidance only. Always follow the engine builder's prevailing cylinder lubrication instructions and feed rate guidelines for your engine type.
Typical properties
| Product | TBNmgKOH/g | KV 100°CcSt | KV 40°CcSt | VI | Flash°C | Pour°C | Densityg/ml |
|---|---|---|---|---|---|---|---|
| CYN 50 BN 40 Cat I | 36.5 | 19.00 | 211.8 | 101 | 258 | -24 | 0.916 |
| CYN 50 BN 40 Cat II ULSFO | 40.0 | 19.10 | 220.6 | 98 | 266 | -18 | 0.920 |
| CYN 50 BN 55 | 55.0 | 19.10 | 218.2 | 99 | 260 | -18 | 0.925 |
| CYN 50 BN 70 | 70.0 | 19.05 | 219.7 | 98 | 264 | -21 | 0.920 |
| CYN 50 BN 100 | 100.0 | 19.50 | 222.6 | 100 | 272 | -21 | 0.945 |
| CYN 50 BN 140 | 140.0 | 19.60 | 218.0 | 103 | 274 | -18 | 0.955 |
All grades SAE 50. Performance claims: MAN ES and WinGD. Typical values from Sinova Group technical data sheets (Form 002-EN, 5 January 2025); properties are based on current production and may vary within specification.