Formulated with high viscosity-index, paraffinic and synthetic base stocks and specialty performance additives, LUBRISTRONG 20W-50 SYNTHETIC BLEND HEAVY-DUTY MOTOR OIL exceeds manufacturers’ specifications per the American Petroleum Institute’s CI-4/SL categories. API service classes CI-4/SL were introduced in 2004 for the typical service of high speed 4-stroke, naturally aspirated, and turbocharged diesel engines as well as carbureted, fuel injected, and turbocharged gasoline engines. This oil can be used in place of CH-4, CH, CF, CF-2, CD, CE, SJ and SH Oil. LUBRISTRONG 20W-50 SYNTHETIC BLEND HEAVY-DUTY MOTOR OIL is multi-grade engine oil for use in gasoline and diesel engines in all seasons.