Mobil Delvac Extreme 15W-40 is a high-performance synthetic diesel engine oil that helps to deliver extended performance for up to two times beyond OEM recommended oil drain intervals(1) for modern diesel engines operating in extreme conditions. Mobil Delvac Extreme 15W-40 is recommended for use in a wide range of heavy-duty applications and operating environments found on- and off-highway conditions, including engines operating under heavy loads. Fully backward compatible, it delivers excellent performance in both newer and older heavy-duty engines, meeting or exceeding the requirements of API CK-4, CJ-4, CI-4 PLUS, CI-4, and other service categories. This diesel engine oil provides exceptional high temperature performance, oxidation stability(2), and resistance to corrosive and abrasive wear to help promote long life of critical wear surfaces. Mobil Delvac Extreme 15W-40 also offers excellent low-temperature performance for increased oil flow to critical bearing surfaces at startup, controlling fluidity and pumpability for smooth starting in cold weather. ((1) Results may vary based on vehicle/engine condition, driving and environmental conditions Consult OEM or ExxonMobil before implementing extended ODIs. (2) Based on the performance in the Volvo T-13 engine test).