2005 Dodge Ram 2500 Pickup Owner Manual Diesel - Page 345

MAINTAINING YOUR VEHICLE 345 NOTE: Most vehicles are operated under the conditions listed for Schedule ЉB.Љ Engine Oil Selection 1. Engine Oil Quality Use only oils 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 to guttering and valve burning. A maximum sulfated ash content of 1.85 mass % is recommended for all oil used in the engine. 2. Engine Oil Viscosity (SAE Grade) The proper SAE viscosity of engine oil for the expected ambient temperature range should be selected, as indicated in the following chart: NOTE: The same oil change interval is to be followed for synthetic oil as for petroleum based oil. Also, synthetic oil must meet the same performance specifications as petroleum oil. 7