What do the classifications and specifications on the back of the pack mean?
Lubricants vary in their use and quality. Some are only suitable for particular engines, while others can only be used in certain weather. Even two oils optimised for the same engine and weather conditions can have vastly different levels of performance. Universal criteria to describe oil performance and usage are therefore used. The main classifications boards are: Society of Automotive Engineers (SAE) – defines oil according to its viscosity. Oil can be monograde or multigrade, depending on its viscosity performance at various temperatures. American Petroleum Institute (API) – classifies oils according to their capacity to protect the engine. The letter S is used for petrol engines and the letter C for diesel. The letter that follows the S or the C indicates the degree of performance and protection, with A the lowest and X highest. Some oils can be used in petrol and diesel engines, so their classification is stated as SJ/CF or CF-4/SJ. Association des Constructeurs Europeens d’Autom
