Maximum Protection for the Long Haul When you’re hauling heavy loads or pushing your diesel engine through extreme temperatures, “good enough” oil isn’t an option. AMSOIL 15W-40 Synthetic Diesel Oil is engineered to provide the ultimate shield against wear, deposits, and oil breakdown. Designed specifically for the high-pressure environments of modern diesel engines, it maintains its viscosity under the harshest conditions, ensuring your engine runs cooler, cleaner, and longer.
Engineered to Outperform Your truck is an investment, and the right lubrication is its best insurance policy. By choosing AMSOIL, you’re not just changing your oil—you’re upgrading your performance. Our 15W-40 formula offers up to 6X more wear protection than required by leading industry standards, giving you the peace of mind that comes with knowing your engine is protected by the best synthetic technology on the market. From the job site to the open highway, experience the difference that premium lubrication makes.