Product Details: OTR 15W-40 Synthetic Blend Motor Oil ensures Expertise Built In™, being a new generation of diesel engine preservation made to respond to the different demands of diesel engine protection in applications that need API CK-4. This heavy duty synthetic blend has one-of-a-kind additives and technology that guarantee exceptional oxidation and thermal balance while protecting against the damaging effects of cold temperature start-ups. FleetPride is your First Click in Heavy Duty®.