VALVE GP-RELIEF 3604588 - Caterpillar

the laboratory engine tests for this category were run with 0.05 percent sulfur diesel fuel. This category also defines oils that have superior soot discrepancy. CG-4 oils will provide improved viscosity control and improved crankcase cleanliness in applications where oil soot is a problem. CG-4 oils will provide improved viscosity control and improved crankcase cleanliness in applications where oil soot is a problem. CG-4 oils should also be used in engines that contain hydraulically actuated fuel injection pumps; these are the first oils to pass industry tests for foam control and viscosity shear loss. CG-4 oils must also pass recently developed tests for metals corrosion, and wear. CG-4 oils can be used in all Caterpillar engines where CF-4 oils are recommended. CF-4 oils service a wide variety of modern diesel engines. This oil classification was developed with 0.40 percent sulfur diesel fuel. The fuel used in the CF-4 tests represents the type of diesel fuels commonly available world wide. CF-4 oils provide improved piston deposit control and improved oil control when compared to the CE category oils. CF-4 oils also provide improved soot dispersancy compared to CD or CF category oils.Some commercial oils meeting these API specifications may require shortened oil change intervals as determined by close monitoring of oil condition and wear metals (Caterpillar S*O*S Oil Analysis Program preferred).Consult with your Caterpillar dealer for the latest oil recommendations or refer to the following Caterpillar Supplements: SEBU6250, SEBU6251, and SEBU6385.
Failure to follow these oil recommendations can cause shortened engine life due to deposits and or excessive wear.
Total Base Number (TBN) and Fuel Sulfur Levels For Caterpillar Prechamber Combustion (PC) Diesel Engines
New engine oil must have a TBN of 20 times (for Precombustion Chamber engines) and ten times (for direct injection engines) the percent fuel sulfur as measured by ASTM D2896 method. Refer to the following chart.
Y=oil TBN shown by ASTM D2896. X=percent of fuel sulfur by weight. New oil TBN (1). Change oil when the used oil TBN limit (2) is reached.Caterpillar's 20 times rule for TBN (Reference: Oil and Your Engine, SEBD0640) versus fuel sulfur was a general requirement developed in the early 1980's for Cat prechamber combustion (PC) system engines. Caterpillar still maintains 20 times TBN value for PC engines when using API CE or CF-4 oil (related to fuel sulfur above 0.5 percent). Engines built prior to 1990 can continue to use single grade viscosity oil or commercial oils, provided the engine operates to user satisfaction.Fuel sulfur neutralization of new oil formulations in direct injection (DI) system engines are more effective. Field results indicate that direct injection combustion (DI) systems and the oils now recommended for those engines will operate at an oil TBN equal to ten times the fuel sulfur.Total Base Number (TBN) and Fuel Sulfur Levels For Caterpillar Direct Injection (DI) Diesel Engines
The TBN for a new oil is dependent on the sulfur level of the fuel used. For direct injection engines running distillate diesel fuel, the minimum new oil TBN (by ASTM