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.