According to unverified data, lubricants were used by man more than 6 thousand years ago. Oil has been known for a long time, but it has been used in its pure form relatively recently, and there was no talk of processing. When people learned how to process it, they took away only kerosene, and the most valuable thing - fuel oil - was used as fuel or simply burned. And it also makes up to 90% of the bulk of the oil.
But technology does not stand still - and now oil refineries have learned to separate fuel oil into different fractions. Subsequent processing made it possible to obtain valuable oils from it, later called petroleum or mineral oils. In modern car engines, there are 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 supplements increases performance in one or several areas at once. For example, anti-wear additives are added to fuels and lubricants to reduce the level of wear of working parts, and detergents reducethe amount of deposits and protect the piston rings from burning. In modern lubricating oils, you can count more than ten increases.
Thanks to a wide range of additives and the ability to combine them, the assortment offered by manufacturers has also increased. These are the lubricating oils they produce. And besides, several of their target varieties appeared - motor, transmission and others. Before purchasing lubricating oils (even from a well-known manufacturer), you need to know the basic principles for their selection.
Fuels and lubricants have many indicators indicated in the technical specifications, but when buying, you need to pay attention to only two of them. The quality level of an oil indicates the compatibility of your vehicle with a given material, while the viscosity indicates its suitability for use in a particular climate and season.
Determining whether this is the right lubricant will help the markings present on any commercial grade, with the same global indexing system. Foreign standards describe the technology for determining and indicating the viscosity index according to the methodology adopted by the American Society of Automotive Engineers SAE, so it is easy to guess that 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 simply indicated by viscosity.
There are also standard symbols. For example, under the designation SAE J300, there are as many as six viscosity grades of wintermodes - 0W, 5W, 10W, 15W, 20W, 25W. All these classes guarantee the start of the machine in cold mode, and the movement of fuels and lubricants occurs freely throughout the system in a temperature regime 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!
