High quality crankcase and cylinder oils for modern medium or high speed marine diesel engines operating on distillate fuels. Regatta TPEO 312 and 412 are SAE 30 and SAE 40 engine oils with TBN 12 mg KOH/g, suitable for use with fuels up to maximum 1% sulphur. Similarly Regatta TPEO 330 and 430 apply when burning fuel up to maximum 3% sulphur, while Regatta TPEO 340 and 440 are indicated in case of maximum 4 % fuel sulphur use.