Shell Rotella T5, Gallon, 15W40, Synthetic Blend Heavy Duty Engine Oil, With Triple Protection Plus Technology Uses Synthetic Base Oils Plus Advanced Additive Technology To Provide Protection Against Wear, Deposits & Oil Break Down, Improved Oxidation Protection Under Extreme Conditions, Demonstrated Protection Against Oxidation & Corrosion In The Presence Of Biodiesel, Extended Drain Capabilities, Fuel Economy Savings Up To 1.6%.