Super Heavy Duty Engine Oil; SAE 15W50 grade provides outstanding protection for Heavy Duty engines where this SAE grade and API service level are desired - including turbocharged low emissions diesels. Mystik JT-8 Synthetic Blend formula is engineered for extra performance in challenging service conditions. Well suited for hard working trucks, farm and construction equipment, pickups, and stationary engines where long engine life is desired. Exceeds API CJ-4, CI-4 Plus, CI-4, CH-4, CF/SM, SL. 5 Gallon. Brand InformationMystik has produced quality lubricants since 1922 for every major U.S. industry, from farming, petroleum, mining and automotive to trucking, textiles, construction and food processing. Each industry benefits from the dependability and long service life of high-quality Mystik lubricants. Trust a decades-long commitment to quality, durability, cost-effectiveness and reliability.