For selecting a good motor oil, some factors and parameters must be considered. A desirable motor oil, offers satisfactory viscosity, a very small friction coefficient, and the potential for lubricating different moving parts of an engine. In addition, engine oil not only must comply with the existing polymer compounds but also should properly prevent corrosion, rusting, oxidation, and erosion.
The engine oil products of Sadra Naft Parsian Co. is designed and manufactured by high global standards for both gasoline and diesel engines oil and function in high performance as following characteristics:
* Reducing the friction of engine moving parts.
* Reducing engine parts erosion.
* Cooling the inner engine parts.
* Cleaning the engine interior parts from carbon black and compounds of oil degradation also sediments between different parts.
* Total sealing of cylinder and piston.
* Protecting engine parts from corrosion.
* Optimal function of moving engine parts at different temperatures.
Oil Physical Properties:
Viscosity is the oil resistance to flowing caused by internal friction of its molecules. Oil viscosity would be changed by different temperature. As the oil becomes warmer the viscosity will be decreased. Hence, viscosity must always be specified along with the temperature at which it is measured. Oil viscosity is normally measured at 40 and 100 temperatures. In old engines, due to specific engine parts structure and bigger gap between the parts (as compared to current engines) engine oil had higher viscosity. Therefore it was recommended the viscosity of 50 for old vehicles in the warm season.
The variations of viscosity related to temperature is measured by viscosity index. With an higher oil viscosity index, the viscosity changes less as a result of temperature variation (vice versa). In fact, oil engine products with higher viscosity indices are looser and more flexible to ambient temperature changes.
The pour point is the lowest temperature at which the oil is still fluid and flowing.
It is the highest temperature that, the oil would be evaporated adequately and makes a flammable mixture by air so that by closing a flame, it would be ignited and extinguished in a moment. This test is used for measuring of flammability and volatility of oil. For instance, the flash point of 50W-20 oil product is higher than 220 C.
Introduction to Additives:
Since the base oil is obtained by refining petroleum, it is not suitable for the engines of modern vehicles and industrial machinery by itself. Depending on the expected function, different additives are added to the oil to provide the optimum resistance for heavy duty works and high pressure and temperature of engine.
Hence, at the first, by adding polymer to the oil, the viscosity is increased to the required extent then by using the following substances, it would be provided on desired properties:
1- Detergents and suspensions.
2- Viscosity index optimizer.
4- Anti-erosion substances.
5- Anti-frothing substances.
6- Anti-corrosion and anti- rusting agents.
7- Pour point reducers agents.