Kirkland Signature 5W-30 High Mileage Full Synthetic Motor Oil is specifically formulated for vehicles with over 75,000 miles. This premium synthetic oil provides advanced engine protection with superior wear resistance and thermal stability to extend engine life. Each pack contains two 5-quart (4.73 liter) bottles, providing 10 quarts total.

The formula features advanced additives designed to control thermal breakdown and prevent Low-Speed Pre-Ignition (LSPI), a critical issue in modern turbocharged engines. The oil meets API SN PLUS and ILSAC GF-5 performance standards and exceeds SAE J300 specifications for 5W-30 viscosity grade. Manufactured by Warren Distribution exclusively for Costco Wholesale.

Technical specifications include a high viscosity index of 176 for stable performance across temperature ranges, excellent cold-start protection with low pour point characteristics, and a robust additive package featuring zinc (845 ppm), phosphorus (795 ppm), and molybdenum (80 ppm) for superior antiwear protection. The Total Base Number (TBN) of 8.43 mg KOH/g ensures excellent acid neutralization capability for extended oil change intervals.