CLIP 1A5350 - Caterpillar

Diesel Engine Oil
Caterpillar does not recommend the use of multigrade oils in the Marine Diesel Engines that are covered in this Operation and Maintenance Manual.Multigrade oils use high molecular weight polymers as viscosity index improvers. When the crankcase blowby flows through the turbocharger and the aftercooler, the viscosity index improvers can adhere to the turbocharger compressor and aftercooler core.The fouling of the turbocharger and aftercooler can cause reduced air flow, loss of power, and increased black smoke. The emission of black smoke results in buildup of soot on the transom of the boat.Cat SAEO (Special Application Engine Oil)
Caterpillar recommends the use of Cat SAEO in Cat Marine Diesel Engines covered by this Operation and Maintenance Manual.The factory-fill for these engines is Cat SAEO with the following properties:
Meets all requirements of API CF-4 category
Viscosity grade of SAE 30Caterpillar recommends the following engine oil for maximum performance:
Cat SAEO (SAE 30)
Cat SAEO (SAE 40)Note: Caterpillar recommends the use of single grade oils that pass all API CF-4 category requirements unless crankcase blowby has been routed away from the air cleaner inlet.Commercial Oils
Cat does not warrant the quality or performance of non-Cat fluids.
When Cat SAEO is not used, use the following commercial oils:
Single grade oil with a viscosity of SAE 30 or SAE 40 that meets all API CF category requirements is preferred.
Single grade oil with a viscosity of SAE 30 or SAE 40 with an API CF additive package and no viscosity improvers is acceptable oil.For an acceptable commercial single grade oil, consult your Cat dealer.Some commercial oils that meet the requirements API CF-4 category may require reduced oil change intervals. To determine the oil change interval, closely monitor the condition of the oil and perform a wear metal analysis. Cat S O S Services oil analysis program is the preferred method.
Failure to follow these oil recommendations can cause shortened engine service life due to deposits and/or excessive wear.
Refer to Special Publication, SEBU6251, "Cat Commercial Diesel Engine Fluids Recommendations" in order to obtain additional information about S O S Services oil analysis. You can also contact your local Cat dealer.Total Base Number (TBN) and Fuel Sulfur Levels
The use of Cat S O S Services oil analysis is strongly recommended for determining oil life.Note: The following information concerning oil life relative to used oil TBN level is provided for general information only, and is not the recommended method for determining oil life. If the one half of new oil TBN guideline that is stated below is used for determining oil life it must only be used in conjunction with a complete S O S Services oil analysis program.Note: TBN is also commonly referred to as Base Number (BN).The minimum required Total Base Number (TBN) for oil depends on the fuel sulfur level. For direct injection engines that use distillate fuel, the minimum new oil TBN must be ten times the fuel sulfur level. The TBN for new oil is typically determined by the "ASTM D2896" procedure.Note: The minimum TBN of the new