According to unverified data, lubricants were used by humans more than 6 thousand years ago. Oil has been known for a long time, but they began to use it in its pure form relatively recently, and there was no talk of refining it. When people learned how to process it, they took only kerosene, and the most valuable thing - fuel oil - was used as fuel or simply burned. And it makes up to 90% of the bulk of oil.
But technology does not stand still - and now at oil refineries we have learned how to divide fuel oil into different fractions. Subsequent processing made it possible to obtain valuable oils from it, later called petroleum or mineral. In modern car engines - high mechanical thermal loads, so fuels and lubricants for them must meet certain requirements.
You can improve the quality of lubricating oil by adding special substances (additives) to it. Each of these additives increases the performance of one or several points at once. For example, anti-wear additives are added to fuels and lubricants to reduce the level of wear of working parts, and detergents reduce the amount of deposits and protect the piston rings from burning. In modern lubricating oils, more than ten increases can be counted.
Thanks to a wide selection of additives and the ability to combine them, the assortment that manufacturers offer has increased. These are the lubricating oils that they release. And besides, several of their target varieties appeared - motor, transmission and others. Before purchasing lubricating oils (even a well-known manufacturer), you need to know the basic principles of their choice.
Combustive-lubricating materials have many indicators specified in the technical specifications, but when buying, you need to pay attention to only two of them. The level of oil quality indicates the compatibility of your car with this material, and the viscosity indicates its suitability for use in a particular climate and season.
Determining whether this is a lubricant will help marking, present on any commercial grade, with the same global indexing system. In foreign standards, the technology for determining and indicating the viscosity index is described according to the methodology adopted by the American Society of Automotive Engineers SAE, so it is easy to guess that the viscosity will be indicated after the SAE marking letters. Winter grades of fuels and lubricants are denoted by the letter W , and summer grades are indicated by a simple indication of viscosity.
There are also standard notation. For example, under the designation SAE J300 hides as many as six viscosity classes of the winter regime - 0W, 5W, 10W, 15W, 20W, 25W. All these classes guarantee a cold start of the machine, and the movement of fuels and lubricants occurs freely throughout the system at a temperature of -30- + 5 degrees. Summer varieties do not have additional letters in the marking, but with an increase in viscosity, all these varieties are divided into SAE classes: 20, 30, 40, 50, 60.
Now you know what fuels and lubricants are and what their classification is!