Mobil Delvac™ Super 1400 15W-40 is a high performance diesel engine oil that provides protection for diesel engines operating under severe service conditions for both on- and off-highway applications. Mobil Delvac Super 1400 15W-40 is recommended by ExxonMobil for use in a wide range of heavy-duty applications and operating environments found in the trucking, mining, construction, quarrying and agricultural industries.