Light oils can also be used (high power oils). They are all-weather oils, in which, along with others, friction coefficient reducers are introduced as additives. In light oils, so-called synthetic oils are used as a base.
Terms "mineral", "semi-synthetic" or "synthetic" is only an indication of the composition of the oil base. Depending on the complete composition, different qualities of oil can be obtained.
Scope of oil / viscosity grades
The SAE designation indicates the viscosity of the engine oil.
For example: SAE 10 W 40:
10 cold viscosity of the oil. The lower the number, the thinner the oil when cold.
W the oil is suitable for use in winter.
40 hot oil viscosity. The higher the number, the thicker the oil when hot.
BMW long life special oils p/n 07 511470 407
X can take values 30, 40, 50
The illustration shows the viscosity of the engine oil as a function of the outside temperature. These oils can be used for almost all outdoor temperatures. From the illustration it can be seen that the areas of application of adjacent SAE classes have common areas, which allows for short-term temperature deviations. However, at very low outside temperatures, the starting performance of the engine may deteriorate.
It is allowed to mix oils of different viscosity grades if it becomes necessary to add oil, and the outside temperature does not correspond to the viscosity grade of the oil in the engine.
It is not allowed to introduce additional lubricating additives of any kind either into the fuel or into the oil.
Engine oil specification
The quality of engine oil is characterized by the standards of the vehicle and oil manufacturer.
European manufacturers classify their oils according to specification "ACEA" (Association des Constucteurs Europeens de I‘Automobile), which takes into account, first of all, the European technology for the production of engines. Oils for gasoline engines of passenger cars have quality classes from A1-96 to A3-96 according to the ACEA specification, oils for diesel engines have classes from B1-96 to B3-96. The highest quality oils are A3 for gasoline and B3 for diesel engines.
The classification of motor oils by American manufacturers is carried out according to the API system (API: American Petroleum Institut). The designation consists of two letters. The first letter indicates the scope: S - Service, designed for gasoline engines; C - Commercial, designed for diesel engines. The second letter indicates the quality in alphabetical order. API oils of the SJ specification for gasoline and CF for diesel engines have the highest quality.
Engine oils that are intended by the manufacturer exclusively for use in diesel engines should not be used in gasoline engines. There are oils that are designed for use in both gasoline and diesel engines. In this case, both specifications (for example: ACEA A3-96/B3-96 or API SH/CD) indicated on the oil container.
BMW has established other standards for its engines and classifies engine oils as "Longlife-Öle" And "Spezialöle".