Kirkland Signature Full Synthetic SAE 5W-30 Motor Oil is a premium lubricant engineered for extended engine life and superior performance. This 2-pack contains two 5-quart (4.73L) bottles of 100% synthetic motor oil designed to provide advanced wear protection for critical engine components while controlling thermal breakdown under demanding conditions.

The formulation meets SAE J300 specifications for the SAE 5W-30 viscosity grade and is labeled API SN PLUS/ILSAC GF-5, ensuring compatibility with modern gasoline engines including gasoline direct injection (GDI) systems. Manufactured by Warren Distribution for Costco Wholesale, this motor oil features a balanced blend of calcium and magnesium-based detergent additives that keep metal surfaces clean by controlling sludge and varnish deposits, preventing oil passage blockage and reducing engine wear.

Advanced antiwear additives containing phosphorus, zinc, boron, molybdenum, and titanium form a protective film between moving surfaces, guarding against impact friction and wear while also acting as corrosion inhibitors and antioxidants. The oil's Total Base Number (TBN) measures its ability to neutralize acids formed during combustion, providing enhanced protection against corrosive wear. Independent testing by the Petroleum Quality Institute of America confirms this product meets all SAE J300 specifications and API Service Category standards, with test results showing proper viscosity characteristics, appropriate detergent and antiwear additive levels, and minimal contaminants. The formulation is optimized to maximize fuel economy while delivering long-lasting engine protection suitable for vehicles where 5W-30 motor oil is recommended by the manufacturer.