No task is too tough for Valvoline Heavy Duty Diesel Full Synthetic 15W-40 Engine Oil. It's specially formulated with fully synthetic base oil and targeted additive technology for heavy duty diesel engines operating in extreme duty cycles or severe environmental contamination conditions, including construction equipment, on-highway fleets, agriculture machinery and more. Valvoline Heavy Duty Diesel Full Synthetic is the ultimate protection against severe temperatures, and it's engineered to control wear, deposits and oil breakdown in Cummins, Detroit Diesel, Volvo, Mack, Ford, Caterpillar and more. Proven to maximize diesel engine life and meet low emission requirements, our latest addition to the Valvoline Heavy Duty Diesel lubricant lineup delivers enhanced viscosity and oxidation stability. No matter the weather, you can count on excellent year-round performance. For superior wear protection in harsh environments and extreme applications, trust Valvoline Heavy Duty Diesel Full Synthetic 15W-40 to work as hard as your equipment.