Trunk piston oils for auxiliaries and gensets.
Thirteen grades across SAE 30 and SAE 40, BN 12 to BN 55. In a trunk piston engine one oil does everything — cylinder, piston, bearings and crankcase — so the base number has to carry the whole duty.
Where TPEO belongs on a vessel
On a vessel with a two-stroke crosshead main engine, the trunk piston oil is for the auxiliary engines and generators — not the main engine, which takes a cylinder oil plus a system oil. On smaller vessels with a medium-speed four-stroke main engine, TPEO covers that engine too.
Performance claims: MAN ES and Wärtsilä.
SAE 30 range
Lower viscosity duty and colder operating conditions.
| Product | TBNmgKOH/g | KV 100°CcSt | KV 40°CcSt | VI | Flash°C | Pour°C | Densityg/ml |
|---|---|---|---|---|---|---|---|
| TPEO 30 BN 12 | 12.0 | 11.50 | 106.4 | 95 | 248 | -24 | on request |
| TPEO 30 BN 15 | 15.0 | 11.60 | 106.7 | 96 | 248 | -24 | 0.897 |
| TPEO 30 BN 20 | 20.0 | 11.60 | 106.7 | 96 | 248 | -21 | 0.901 |
| TPEO 30 BN 30 | 30.0 | 11.30 | 101.2 | 98 | 246 | -21 | 0.905 |
| TPEO 30 BN 40 | 40.0 | 11.50 | 101.9 | 100 | 244 | -21 | 0.908 |
| TPEO 30 BN 55 | 55.0 | 11.80 | 105.9 | 100 | 244 | -18 | 0.916 |
SAE 40 range
The most common choice for marine auxiliary engines running on distillate or residual fuel.
| Product | TBNmgKOH/g | KV 100°CcSt | KV 40°CcSt | VI | Flash°C | Pour°C | Densityg/ml |
|---|---|---|---|---|---|---|---|
| TPEO 40 BN 12 | 12.0 | 14.20 | 146.7 | 94 | 250 | -18 | 0.898 |
| TPEO 40 BN 15 | 15.0 | 14.40 | 148.5 | 95 | 250 | -18 | 0.900 |
| TPEO 40 BN 20 | 20.0 | 14.30 | 148.1 | 94 | 250 | -21 | 0.904 |
| TPEO 40 BN 30 | 30.0 | 14.50 | 148.5 | 96 | 250 | -18 | 0.909 |
| TPEO 40 BN 40 | 40.0 | 14.70 | 148.9 | 98 | 250 | -18 | 0.913 |
| TPEO 40 BN 50 | 50.0 | 14.90 | 147.7 | 101 | 254 | -18 | 0.917 |
| TPEO 40 BN 55 | 55.0 | 15.00 | 146.7 | 103 | 258 | -18 | 0.920 |
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.