Oil maintenance is called small maintenance and is the most basic project in car maintenance. As we all know, the car is composed of tens of thousands of parts, the precision of the matching between the engine parts is very high, and the friction is inevitable during the work of the parts. It requires regular lubrication for maintenance.
The importance of oil for the engine is no different from the human body and blood. The maintenance of the oil often determines the service life and driving performance of the vehicle. So, how many kilometers does the car change oil? What kind of oil is good? What is its function? Today Let us talk about the knowledge of motor oil.
What is car oil?
In simple terms, oil is a lubricant for engines. Automotive lubricants are used in various types of vehicles to reduce friction, protect machinery and processed parts of liquid or semi-solid lubricants, mainly for lubrication, auxiliary cooling, and prevention. Rust, cleaning, sealing and cushioning. The engine is the heart of the car. There are many metal surfaces in the engine that rub against each other. These parts move fast and have a poor environment. The working temperature can reach 400 ° C to 600 ° C. Under the harsh working conditions, only qualified lubricating oil can reduce the wear of engine parts and prolong the service life.
The role of lubricating oil
1, lubrication
When the engine is running, if some friction parts are not properly lubricated, dry friction will occur. It has been proved that the dry friction generates heat in a short time enough to melt the metal, causing damage or even jamming of the parts (many leaks) Or the oil leakage of the car has a problem such as pulling the cylinder and holding the shaft. The main reason is this. Therefore, the friction part of the engine must be well lubricated. When the lubricating oil flows to the friction part, it will adhere to the friction surface. A layer of oil film is formed on the surface to reduce the resistance between the friction parts, and the strength and toughness of the oil film are the key to its lubrication.
2, cooling effect
Only a small part of the heat generated by the combustion of the fuel in the engine is used for the power output and the frictional resistance consumption and the drive of the auxiliary mechanism; the rest of the heat is discharged to the atmosphere by the exhaust gas, and is also used by the cooling medium belt in the engine. Take a part. Excess heat in the engine must be exhausted from the body, otherwise the engine will burn out due to excessive temperature. This is done by the engine cooling system. On the other hand, the lubricant absorbs heat from the surfaces of the cylinder, piston, crankshaft, etc. Bring it to the oil pan to distribute.
3, washing effect
When the engine is working, it will produce a lot of dirt. For example, the sand, dust and air generated by the inhalation of air, the carbon formed by the combustion of the mixed gas, the gel formed by the oxidation of the lubricating oil, the friction between the parts, the metal chips, etc. These dirt will adhere to the friction surface of the machine. If it is not cleaned, it will increase the wear of the machine. In addition, a large amount of glue will cause the piston ring to stick and cause the engine to malfunction. These dirt must be cleaned up in time. This cleaning process is done by circulating the lubricating oil in the body.
4, sealing effect
There are certain gaps between the cylinder and piston of the engine, the piston ring and the ring groove, and between the valve and the valve seat. This ensures that the operation will not be stuck. However, these gaps may cause the cylinder to seal poorly. The result of the combustion chamber leakage is to reduce the cylinder pressure. And engine output power. The oil film formed in these gaps ensures the cylinder's tightness, maintains cylinder pressure and engine output, and prevents exhaust gas from falling into the crankcase.
5, anti-rust effect
When the engine is running or storing, the atmosphere, lubricating oil, water in the fuel and the acid gas generated by the combustion will cause corrosion and rust on the parts, thus increasing the damage of the friction surface. The oil film formed on the surface of the machine, It can avoid direct contact between the machine and water and acid gas to prevent corrosion and corrosion.
6, eliminate shock loads
At the end of the compression stroke, the mixture begins to burn and the cylinder pressure rises sharply. At this time, the lubricating oil in the bearing clearance will alleviate the impact load on the piston, piston pin, connecting rod, crankshaft and other parts, so that the engine can work smoothly. And prevent direct metal contact, reducing wear and tear.
Oil maintenance cycle
The working condition of the vehicle determines the replacement and maintenance cycle of the oil. It is often said that the car should change the oil regularly. But how often does it take to change it regularly? Basically, the car's manual will clearly indicate. The past standard is Replace oil in 5000km. In recent years, the manufacturing standards for automobiles and oils have been continuously improved, and the time for regular maintenance and replacement of lubricants has been extended.
'General driving' means that you often drive on the highway, and rarely stop and go. If it is 'depleting driving' under urban road conditions, it is often traffic jam, and each time the journey rarely exceeds a dozen kilometers, you need Properly shorten the oil change interval. In the case of 'depletion driving', the engine wear is relatively large, and the requirements for oil are also high. It is recommended to shorten the interval between oil changes to effectively protect the engine. It is difficult for the naked eye or the touch. To judge whether the oil should be changed, but after long-term use, a large amount of impurities will accumulate in the oil. If the new oil is not replaced in time, these impurities will wear the engine and shorten the life of the car.
How to choose automotive lubricants?
There are many considerations for the choice of automotive lubricants, not the best, only the most suitable. However, we can consider the following four aspects, choose the right lubricant.
1, see word of mouth
People often say, 'When you buy an item, if you don't know which one to choose, follow the principle of choosing a restaurant. Which family do you go to. ' For the purchase of motor oil, this principle is very important. How is the owner's reputation? It can be said that it is the most authoritative reference for the application of oil. Therefore, you may wish to ask the owner's friends around you to listen to the experience and make choices.
2, look at the packaging
Every lubricant produced by a regular manufacturer will be marked on the outer packaging with its quality grade and applicable temperature range. Therefore, when you purchase it, you can clearly understand the outer packaging of the product. An overview of the product.
3, see the car condition
No matter how loud the brand of a motor oil product is, how beautiful the packaging is, the quality of the final test is still our car. Therefore, the response of the vehicle is the final basis for us to evaluate the quality of an oil product.
Listening - The engine oil product suitable for the engine can form a moderate thickness of oil film between the relatively moving parts inside the engine, allowing the engine to run smoothly and minimize engine operating noise.
Measure - If an oil product can effectively complete the lubrication of the engine, it will greatly reduce the internal resistance of the engine, which will reduce the load of the engine to a certain extent, which will reduce the normal fuel consumption of the car. Therefore, before and after the vehicle is measured The fuel consumption is an identification method.
Look - when using different models or brands of oil products, the engine pressure warning lights will change significantly when the vehicle owners start the vehicle. When the unsuitable oil products are selected, the oil pressure warning lights of some vehicles will be delayed. The phenomenon of lighting.
4, see the price
Of course, value has always been one of the most important attributes of any commodity, and it is also the last barrier that affects our purchase. The principle of 'one penny and one share' applies to most commodities, as well as for motor oil. However, in terms of specific choices, we also have to weigh, according to the cost of the vehicle to choose the oil we can afford.
