Mobil Delvac 1320, 1330, 1340, and 1350 are high performance, heavy duty diesel engine oils formulated from advanced technology base oils and a balanced additive system. They are specifically engineered for performance in intercooled, turbo-charged engines operating under severe on and off highway conditions. Mobil Delvac 1300 monogrades are used in a wide range of applications where a monograde lubricant is recommended.