Shell Rotella T6 5W-40 Full Synthetic Motor Oil, which is formulated with fully synthetic base oils, provides 1.5% improved fuel economy over conventional oils. The oil has been approved by the National Highway Traffic Safety Administration (NHTSA) for use in heavy-duty diesel engines. It also meets or exceeds the requirements of the following OEMs: Allison, Cummins, and MAN.

SynShield Durability Advantage 15w40 engine oil is formulated to provide maximum protection against wear, oxidation, soot contamination and aeration. The oil has been tested in the harshest operating conditions including high-temperature environments such as those found in heavy-duty diesel engines. It also meets or exceeds API CK-4 standards. The oil can be used for up to 10 years without changing its formulation. It is highly recommended for use in extreme temperatures. Notably, it was approved by the government in 2015.

Shell Rotella T4 Triple Protection 15W-40 engine oil provides superior wear protection for longer life and reduced fuel consumption. The oil has a low friction coefficient, which reduces the amount of friction between the piston and the oil. It also helps to prevent oil loss due to increased friction in the combustion process. Notably, diesel engines have been subjected to stricter emissions standards than those of petrol engines. Diesel engines are classified as heavy-duty and high-performance. However, it does not meet API requirements.