A high quality, OE-approved, heavy-duty engine oil blended with high-quality base oils and a proven additive system to provide the highest level of wear protection. Meets the performance requirements of all diesel engines, enhancing the life of advanced emission control systems required for regulatory compliance when used in conjunction with Ultra Low Sulfur Diesel Fuel. CJ-4 engine oil is backward compatible with older engines and provides additional protection as compared with previous diesel engine oils.