Shell Rotella T6 15W-40 diesel engine oil is a full synthetic motor oil that features exclusive Triple Protection Plus technology, formulated with fully synthetic base oils plus advanced additives to protect against wear, deposits, and oil breakdown. It also provides better low-temperature flow and increased fuel economy performance, without compromising durability (compared to conventional SAE 15W-40 oils). Shell Rotella T6 15W-40 Full Synthetic motor oil is suitable for virtually all modern low-emission heavy duty engines and older hard working diesel engines (consult your owner's manual for heavy duty engine oil recommendations). With its wide range of specifications and approvals from many of the world's leading engine makers, it is an excellent choice for on-highway fleets, general haul, construction, agriculture, public-transport operators, and diesel pick-up trucks.