Mobil Delvac 1™ ESP 0W-40 is a synthetic heavy-duty diesel engine oil that was designed to protect modern diesel engines operating in severe on- and off-highway application. This high-performance engine oil meets the API CK-4 specification utilizing state-of-the-art lubricant technology to deliver exceptional performance in modern low emission engines, including those with Exhaust Gas Recirculation (EGR) and After Treatment systems with Diesel Particulate Filters (DPF's) and Diesel Oxidation Catalysts (DOC's). Mobil Delvac 1 ESP 0W-40 is recommended for use in a wide range of heavy-duty applications and operating environments found in the on-road transport and off-road, mining, forestry, construction, and agricultural industries. It can also be used in refrigeration units and older, well-maintained engines. Mobil Delvac 1 ESP 0W-40 also meets the API SN specification for gasoline engines.