Kirkland Signature SAE 15W-40 Heavy-Duty Diesel Engine Oil is formulated for diesel engines requiring superior protection and performance. This conventional motor oil meets API CK-4 specifications and is dual-rated for both diesel and gasoline engines (API SN). Each pack contains three 1-gallon (128 fl oz) jugs, providing 3 gallons total capacity.

The oil features advanced wear protection that promotes longer engine life and reduced downtime. It delivers superior oxidation control that exceeds the latest API CK-4 requirements, helping to prevent varnish and sludge formation even in demanding operating conditions. The highly shear stable formulation maintains viscosity protection throughout the entire oil drain interval, ensuring consistent performance between changes.

This product is manufactured by Warren Distribution, the same company that produces motor oils for major retail brands including Walmart Super Tech, Meijer, and AmazonBasics. The additive package includes 1270 PPM zinc, 1150 PPM phosphorus, 1050 PPM calcium, 1000 PPM magnesium, and 66 PPM molybdenum for comprehensive engine protection. Suitable for heavy-duty diesel trucks, farm equipment, and commercial vehicles. Always consult your OEM manual for recommended drain intervals and oil specifications.