Modern cars use multigrade oil, meaning you'll see two numbers on their spec. For example, 5W-30. The numbers indicate the thickness of the oil when either cold or hot. The number before the "W ...

Castrol 5W-30 F-Trucks CK-4 has been designed to meet Ford Trucks’ WSS-M2C213-A1 specification, which is based on the Association of European Automobile Manufacturers’ (ACEA) Oil Sequences E6 and E9 ...