ROTELLA T6 Full Synthetic 15W-40 Heavy Duty Diesel Motor Oil, 5 Gallon Product details Shell Rotella T6 15W-40 Full Synthetic Heavy Duty Engine Motor Oil consists of fully synthetic base oils plus advanced additives to protect against wear, deposits, and oil breakdown. Through the use of Shell’s most advanced technology, Shell Rotella T6 15W-40 Full Synthetic Heavy Duty Engine Oil offers enhanced fuel economy capability of 1.5% that can save money in fuel consumption, without compromising engine protection or durability, compared to 15W-40 oils. Shell Rotella T6 15W-40 Full Synthetic Heavy Duty Engine Oil resists breakdown by heat to provide continuous protection throughout the service interval. Advanced low-ash formulation helps control blocking of or poisoning of exhaust after-treatment devices, helping maintain vehicle emission compliance and diesel engine fuel efficiency. Resists viscosity loss through shear and will maintain optimal pressure in your heavy duty diesel engine. Shell Rotella T6 5W-40 Full Synthetic Diesel Motor Oil, 5 Gallon