The degree of oil viscosity, determined according to the international SAE standard. Viscosity is one of the key physical characteristics of an oil that determines its compatibility with a particular engine. Most modern brands of oil are all-weather and are designed for use, incl. and at low temperatures. Therefore, the SAE index for them includes information not only on the viscosity characteristics in a warm engine, but also on frost resistance.
Such an index is usually written in the form of two digits separated by the letter w:
0w-8,
0w-12,
0w-15,
0w-16,
0w-20,
0w-30,
0w-40,
0w-50,
5w-20,
5w -30,
5w-40,
5w-50,
5w-60,
10w-30,
10w-40,
10w-50,
10w-60,
15w-40,
15w-50,
15w-60,
20w-20,
20w-50,
20w-60,
...25w-40. There is also the format SAE 10w, SAE 20, SAE 30, SAE 40 and SAE 50. The first number describes only the cold resistance of the oil, and does not apply to its properties when the engine is warm. If 35 is subtracted from this number, you get the minimum temperature at which the engine can be cranked over to start. In our example, this temperature will be 15-35=-20 °C. Of course, such values are rather arbitrary, because In practice, other factors must also be taken into account. For example, with a “dead” battery (which is not uncommon in cold weather), a cold start can cause difficulties even at a higher temperature than follows from the characteristics of the oil.
The second number determines the characteristics of the oil in a warm engine in normal mode, at normal operating temperatures. It is this indicator that is the main one for choosing a brand of lubricant for a particular car - you must strictly adhere to the manufacturer's recommendations. The fact is that each engine is designed based on strictly defined viscosity values. An oil that is too viscous will linger in large quantities in moving parts, and one that is too fluid will leave them without lubrication at all; In both cases, power drops and wear increases. Therefore, first of all, when choosing according to SAE, the second number and its correspondence to the characteristics of the engine should be taken into account.International standards, compliance with which is stated in the characteristics of this brand of oil. In modern brands of oil the following options may be found:
— API is a standard developed in the USA by the American Petroleum Institute. Provides two separate classifications - for gasoline (
API SG,
SH,
SJ,
SL,
SM,
SN,
SN Plus) and for diesel engines (
API CI-4,
CH-4,
CG-4,
CF,
CE,
CD); in the first case, the first letter in the standard designation is S (for example, API SL), in the second it is C (for example, API CI-4). If the oil is suitable for both types of engines, a double designation is used - for example, API SL/CI-4; in this case, the index of the type for which the oil is best suited is put first (in our example, this is gasoline). The standard also includes the classification of two-stroke engines - TA, TB,
TC,
TC+,
TD.
— ACEA is a standard used by the association of European automakers of the same name,
...an alternative to the American API. Includes three classes: A/B - all oils developed before 2004 for different types of engines. Actually, until 2004 there were two classes here - A for gasoline engines and B for diesel engines; then they were combined ( A1/B1, A3/B3, A3/B4 and A5/B5). However, separate designations can still be used. C - oils for all types of engines, meeting the Euro-4 environmental standard and compatible with additional equipment such as catalysts and particulate filters. APEA C1, C2, C3, C4 and C5 occur. E - a separate class for diesel engines of heavy equipment, including special ones. It is marked APEA E4, E6, E7 and E9.
— JASO — developed by the Japanese Auto Standards Association. It is one of the main modern standards for oils for gasoline motorcycle engines, within this purpose it has two classes - F for two-stroke engines, namely FA, FB, FC, FD and M for four-stroke (subclass MA for wet clutch MA-1 and MA -2, MB for dry). As well as a new GLV-1 approval for ultra-efficient gasoline engines and hybrid power plants.
— ILSAC is a standard created jointly by the American and Japanese Automobile Manufacturers Associations. Used for oils designed for passenger cars with gasoline engines. There are only five ILSAC categories ( GF-2, GF-3, GF-4, GF-5, GF-6A), in general they are similar to certain API categories (see above), but differ in increased requirements for energy saving and limitation of harmful emissions .
A list of specific oil standards recommended by the manufacturer for a particular engine is usually indicated in the official vehicle specifications. Note that many standards are interchangeable; compatibility data (as well as a description of each individual category) can be found in specialized sources.
