• Lubrication of moving engine parts
• Cooling the engine with rapid heat transfer, especially from components such as movable bearings, crankshafts, pistons, and valve stems.
• Seal the distance between the piston rings and the cylinder body and catch the impact on the bearings and other engine parts
• Keeping the engine clean due to its cleaning properties and keeping dirt suspended
• Maximum stability in terms of physical and chemical properties and resistance to thermal decomposition
• Protects the metal surfaces of the engine against rust, chemical corrosion, erosion, and wear
• Having the ability to pump and viscosity suitable in different temperature conditions

Blackening of engine oil is due to three main reasons:
• In high-quality engine oils due to the presence of detergents and detergents
• In low-quality oils due to oxidation of engine oil
• Defective vehicle ignition system

It is normal to reduce the engine oil to a certain extent. In these cases, by adding proper oil, you can compensate for the lack of oil. In general, the main reasons for low engine oil are:

• Normal evaporation of oil
  When the piston is turned up, a very thin layer of oil is still present in the cylinder wall to reduce friction, some of which evaporates at the moment of combustion. This evaporation can vary depending on the vehicle type and working conditions.

• Damaged engine (oil burn)
  Such as: gluing the rim, wear of the rim, dilation of the valve gate, oil leakage from distinct parts of the engine, dilution of oil with fuel.

• Low-quality engine oil
  If the base oil used to prepare the engine oil has a low flash point, then the engine oil also has a low flash point and its evaporation percentage is higher than the standard.

With increasing engine oil performance, it is recommended to replace the oil filter, air filter, and fuel filter each time of oil changing.
In unfavorable environmental conditions such as dust, it is better to replace the air filter sooner. Also, if the fuel is not standard, the filter is better. Fuel systems should be replaced sooner.

By referring to the card catalog in the section of lubricants or LUBRICANTS, it is noted what characteristics the proposed type of oil should have. Routinely, three critical parameters represent the level of oil quality.

(API), Oil Viscosity (SAE) and European Automobile Manufacturers Standard (ACEA) are mentioned.

For example API: SN / CF SAE: 5W-30 ACEA: A3 / A4-12

Presently, according to the numbers offered by the car manufacturer, we supply the desired engine oil from reputable engine oil production companies.

Engine oil companies may specify the recommended mileage of engine oil, but several factors must be considered when estimating engine oil change time. By replacing each of these factors, the mileage of the engine oil also changes. The most critical factors are:

• Environmental conditions such as dry environment, humid environment, dust, and...

• How to drive such as: driving with the loads, pressure, speed, acceleration, go-stop driving (Go-Stop)

• Engine type, design, and year of manufacture

• Quality of engine oil and fuel consumption

• Oil filter function, air filter, and fuel filter

• No malfunction of engines, injector system, and car power

It should be employed as an overflow like the oil in the crankcase. Otherwise, due to the chemical complexity of the compounds in the engine oil, the possibility of incompatibility between the components in the oil is exceptionally high. In case of emergency, another oil can be consumed in limited amounts by observing SAE and API.

In multi-grade oils, the changes in viscosity of the oil relative to temperature are somewhat controlled, so it is recommended to use multi-grade oils like SAE: 5W-40 or SAE: 10W-40 instead of single-grade oils. (Monogrid) to be used.

These types of oils with good viscosity at different temperatures provide better lubrication than single-grade oils and have a higher viscosity index (Viscosity index).

A good viscosity index (VI) means:

The lubricant at high temperatures still has a good viscosity and less wear occurs due to the protective film.

The lubricant remains at a low fluid temperature, providing easy ignition and proper pumping with less energy to pump the fluid.

At excessive temperatures, the additive molecule becomes larger and prevents the oil from becoming too fluid.

Therefore, engine oil that has a higher viscosity index performs better in different temperature conditions.

Due to the presence of sulfur in the fuel during combustion, sulfur reacts with hot gases to produce acid.
Sulfur + Oxygen + H2O + Heat = Sulfuric Acid
Detergents and dispersants neutralize acidic substances and ultimately increase engine oil life.
The stronger these additives, the longer the life of the engine oil and the healthier and cleaner the internal components.

Engine oil is exposed to contaminants such as dust, water, soot, acid, and fuel after a period of operation. Moreover, additives are consumed and reduced during operation. Also, oxidation of the oil causes sediment, sludge, and glaze. For instance, increased viscosity and increased acidity minimize engine oil performance. Therefore, after working for a while, it must be replaced.

Another oil used in cars is gear oil (Vascazin) and ATF. Vascazin is the Russian word for gear oil. These oils are used in the gearbox and differential of the car and are different from engine oil.
In general, cars have two types of gearboxes:
• Automatic transmission (DCT, CVT,..)
ATF Automatic Transmission Fluid is used to lubricate its gears. The most important standards and technical specifications of ATF by General Motors companies.
(Dexron), Ford (Ford Mercon) and Hyundai / Kia (SP) designated.
Manual gearbox: MFT (Manual Transmission Fluid) or Gear Oil is used to lubricate its gears. Most essential standards and technical specifications are formed by API and SAE.