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General recommendations for motor oils
The viscosity of the oil
The viscosity of the motor oil
Viscosity describes the fluidity of the oil. Depending on the temperature of the oil tends to reduce stress. With increasing temperature, the oil becomes more fluid. This impairs the ability of the oil to the adhesion and stability to withstand the high contact pressures. When cooling oil gets denser, fluidity decreases and increases the internal friction. Due to this property, the engine oil must be used with such a viscosity that varies with temperature in a range as small as possible. When starting a cold engine oil should be sufficiently liquid in order not to unduly overload the engine and that after start oil will penetrate into all the places where the need for lubrication. Turnover of oil equivalent to its internal friction and is denoted by units SAE (Society of Automotive Engineers - Association of Automotive Engineers), such as SAE 30, SAE 10. High indicator SAE means that oil dense, low - characterizes liquid oil. However, the viscosity of the oil is not completely characterizes lubricating oil properties.
Year-round oil
In engines of cars it is preferable to use multigrade oils. The advantage of multigrade oils is that they do not have to choose, depending on the time of year. They izgotavli vayutsya based liquid Monogrades oil (type 10W). In the hot state, this oil is stabilized by so-called thickener that provides appropriate quality lubricating oil at all temperatures. When using the multigrade oil should be used with modern varieties wide temperature range of viscosity e.g. 10W-40, 15W-50. Letter W (winter - winter) in designation SAE characterizes suitability of oil in the winter.
Classes of viscosity and range of use of oil
As the range of uses of neighboring SAE grades overlap, you can not pay attention to short-term temperature fluctuations. Allowed to mix oils of different viscosity grades, if you want to top-up the oil, and the ambient temperature does not correspond to the class of viscosity of oil poured into the engine. At long external temperatures below -20 ?� C is recommended to fill in oil SAE 5W-20.
A warning  Motor oil CD, which the manufacturer designates as oil for diesel engines, are not suitable for gasoline engines. There are oils, the use of which is possible in the two types of engines, in this case, as the oil indicated two labels, such as SG / CD.
Additional additives to the oil, irrespective of their type and destination, must be added to the oil.
Engine oils
For modern engines use only oil D. Oils HD are oils with high lubricity, enhanced by various additives. These additives provide the best anticorrosive protection, more favorable conditions against the effects of oxidation, the lowest tendency to form slag, the best change in viscosity, clearing and dissolving properties. Cleansing and solubilizing additives not only reduce the formation of residues in the engine, but at the same time are capable of all these residues and other contaminants in the engine oil to dissolve and keep in suspension so that the replacement of oil these contaminants are removed with the oil overflows. The quality of oil is determined by the HD system API (American Petroleum Institut). European manufacturers also adhere to this system. Designation grade oil is made by two letters. The first letter is characterized by application area: S - Servise, are intended for gasoline engines; C - Commercial, intended for diesel engines. The second letter defines an oil grade in alphabetic order. Oil of the highest grade of API classification are SG for carburettor engines and CD for diesel engines.
Gasoline engines And - all-weather oils with the raised antifrictional properties, specification VW 500 00. In - all-weather oils, specification VW 501 01;
- All-weather oils, specifications API-SF or SG.
Diesel engines
And - all-weather oils with the raised antifrictional properties, specification VW 500 00 (for diesel engines with a turbo-supercharging only in a mix with specification VW 505 00). In - all-weather oils, specification VW 505 00 (unlimited for all diesel engines);
- All-weather oils, specifications API-CD (for diesel engines with turbo charging only when absolutely necessary for topping up);
- All-weather oils, specification VW 501 01 (for diesel engines with a turbo-supercharging only in a mix with specification VW 505 00).
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