Modern motor oils, consisting of base oils and a selected set of additives, are divided into two main types:
– mineral (obtained by distillation from petroleum) Their viscosity is highly dependent on temperature. To stabilize the properties, various additives are used, which, in turn, are quickly destroyed due to high mechanical and thermal loads, reducing the life of the oil;
– synthetic (obtained by chemical synthesis) – possess high uniformity and stability of properties. They remain thinner in cold weather and thicker in hot weather, burn less in the engine, form fewer deposits, and last longer.
NOTE: Synthetic oils do not damage engine seals, however, they may cause leakage through worn seals due to the greater fluidity of synthetic oils compared to mineral oils.
NOTE: The service life of synthetic oils is only slightly longer than mineral oils. The rapid darkening of the oil only indicates its good cleaning properties and a contaminated lubrication system.
An intermediate position is occupied by the so-called semi-synthetic oils. They are made on a mineral basis, but with the addition of synthetic components, so they are close in quality to synthetic oils, but much cheaper than them.
One of the main properties of engine oil is its viscosity, which determines the temperature range of application of engine oil. At low ambient temperatures, engine oil must have a low viscosity in order to start the engine and supply engine oil to its components. At high temperatures, the engine oil must be more viscous in order to maintain the required oil pressure in the lubrication system. By viscosity, motor oils are divided into three types:
- winter - due to their low viscosity, they provide engine start-up and lubrication of the main components at negative ambient temperatures;
- summer - due to their high viscosity, they provide lubrication of engine parts at high ambient temperatures;
- all-weather - at low ambient temperatures they have the viscosity of winter oils, and at high temperatures they have the viscosity of summer oils.
WARNING: It is strictly forbidden to use engine oils:
- not intended for gasoline automobile engines;
- with inappropriate performance characteristics;
- viscosity not appropriate for the season (according to SAE classifications).
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