Motor craft SAE 15W-40 Super Duty Diesel Motor Oil is a high-quality light and heavy-duty diesel engine oil recommended by Ford Motor Company. It is particularly recommended for use in Ford vehicles equipped with power stroke engines as in truck, bus, construction and other heavy-duty diesel engine applications. It meets API service category CJ-4, required for use in diesel engines designed to meet 2007 on-highway exhaust emission standards and requiring ultralow sulfur diesel fuel. Do not use in gasoline engines equipped with catalysts.