(PRIME SERIES SYN BLEND 20W50 12/1) Prime Series Conventional Motor Oil's anti-wear additives provide excellent wear protection of critical engine parts. A high level of dispersancy in Prime Series Motor Oils protects against deposit and sludge formation in stop-and-go driving, sustained high-temperature operation, and protects against corrosion. Their excellent high-temperature oxidation stability helps prevent viscosity increase and oil gelling in the crankcase. They help keep PCV systems clean to maintain smooth engine performance. SAE 20W-50 is suitable for use in many older vehicles and a few late model cars and trucks, often those with larger 6-cylinder and V-8 high-performance engines. SAE 20W-50 is also designated as a "resource-conserving lubricant" by API