Petro-Canada Lubricants added SAE 15W-40 and SAE 10W-30 Engine Oils to its DURON GEO LD product line. Both oils are API CK-4 licensed and approved for the Cummins natural gas engine oil specification CES 20092. DURON GEO LD is formulated to safely extend oil drain intervals while providing all-weather performance and engine protection.