Formerly known as Shell Rotella® T Triple Protection, Shell Rotella® T4 Triple Protection Heavy Duty Diesel Engine Oil is the most technically advanced Shell Rotella® formulation ever. This 15W-40 motor oil uses advanced additive technology to protect under the most severe engine conditions found in modern, low-emission engines and older hard-working diesel engines. It effectively sustains emissions control system durability where diesel particulate filters and after-treatment systems are used. Plus, it provides enhanced protection against viscosity loss due to shear and improved oil aeration compared to the previous formulation. Shell Rotella® Triple Protection Technology. Shell Rotella® T4 15W-40 heavy duty engine oil uses a proprietary formula exclusive to Shell. It is designed to provide protection in three critical areas: - Acid control helps protect against corrosion from acids formed as fuel burns and the oil ages. - Deposit control helps keep engines clean for optimum performance and long life. - Wear control helps keep moving metal engine surfaces apart for a longer life. For Every Hardworking Need. With its wide range of specifications, and approvals from many of the world's leading engine makers, Shell Rotella® T4 15W-40 heavy duty oil is an excellent choice for on-highway fleets, general haul, construction, agriculture, public-transport operators, diesel pickup trucks, including high-power vehicles where resistance to increased heat and stress is required.