Formulated with high viscosity-index, paraffinic and synthetic base stocks and specialty performance additives, HELIOS 15W-40 SYNTHETIC BLEND HEAVY-DUTY MOTOR OIL API CI-4/SL exceeds the American Petroleum Institute’s specifications per the CI-4, SL categories. API service class CI-4, SL was introduced in 2004 for the typical service of high speed 4-stroke, naturally aspirated, and turbocharged diesel engines as well as gasoline engines. This oil can be used in place of CH-4, CH, CF, CF-2, SJ, and SH Oils. HELIOS 15W-40 SYNTHETIC BLEND HEAVY-DUTY MOTOR OIL API CI-4/SL is multi-grade engine oil for use in diesel and gasoline engines in all seasons.