Engine Oil

Engine Oil Quality
Use only oil's conforming to API Service CI-4. A sulfated ash limit is specified for lubrication oil used in Cummins engines. Oils with a high ash content may produce deposits on valves that can progress guttering and valve burning. A maximum sulfated ash content of 1.85 mass % is recommended for all oil used in the engine.

Engine Oil Viscosity

Above 0°F (-18°C) 15W-40

Above -20°F (-29°C) 5W-40 Synthetic

The proper SAE viscosity of engine oil for the expected ambient temperature range should be selected, as indicated in the in the chart.

NOTE: The same oil change interval is to be followed for synthetic oil must meet the same petroleum based oil. Also, synthetic oil must meet the same performance specifications as petroleum oil.