Classification of lubricating oils

Lubricating oils are divided into two categories: industrial lubricating oils and automotive lubricating oils. Among them, automotive lubricants include engine oil, water tank and cooling system oil, automatic gearbox oil, gear oil (for manual gearbox), brake and clutch system oil, grease, etc.

About the composition of lubricating oil and the concepts of synthetic oil and mineral oil

Lubricating oil is composed of base oil and additives. For engine oils, the base oil usually accounts for about 90%, and the rest is additives. The quality of base oil is crucial to the performance of lubricating oil. It provides the most basic lubrication, cooling, anti-oxidation, anti-corrosion and other properties of lubricating oil. However, in order to improve the performance of lubricating oil, additives are also included in the lubricating oil to improve its overall performance. The additives of engine oil mainly include: antioxidant additives, anti-rust additives, anti-corrosion additives, anti-foam additives, viscosity index improvers, pour point depressants, cleaning additives, dispersants, anti-wear additives, etc. It is not enough to add more of the above-mentioned additives. Multiple properties need to be comprehensively balanced. Therefore, lubricants need to undergo bench testing to determine or evaluate the performance of the formulation through its overall performance in the engine.

Because the content accounts for the vast majority, the performance of the base oil is crucial to the performance of the finished lubricant. According to custom, the base oil extracted from petroleum through physical distillation is called mineral oil (some non-deeply hydrogenated base oils should also be called mineral oil). Synthetic oil, as the name implies, is the base oil obtained through chemical synthesis (these are Most of the ingredients do not exist directly in petroleum). There is no precise definition of synthetic oil and mineral oil, it is a common saying. API (American Petroleum Institute) divides base oils into five categories, and the third and fourth categories of base oils are usually called synthetic oils.

Usual synthetic oils are usually: PAO, XHVI, and esters. In addition, the performance of VHVI base oil is between synthetic oil and mineral oil. Although some people call it synthetic oil, its performance (such as viscosity-temperature characteristics and oxidation resistance, etc.) is far behind PAO, XHVI and esters. PAO and XHVI are the most widely used base oils for engine oils. Among them, XHVI is a synthetic base oil with Shell's patented technology. Mobil's synthetic oil mainly uses PAO as raw material, and Castrol's synthetic oil mostly uses esters as base oil. XHVI and PAO have similar properties, but there is a certain gap between the ester engine lubricating oil and the first two in terms of oxidation resistance.

Now our industry is closely following Western new technologies, and many oil products are used in the United States, Japan, and Europe. Therefore, it has gradually begun to refer to the standards of these countries (such as American SAE, Japanese JIS, European CCMC, German DIN, etc.), my country's current lubricant standards (SY, SH, GB) are gradually moving closer to these standards, especially with reference to the American SAE standards. Global economic integration is an inevitable trend. The lubricating oil industry standards of various countries are gradually consistent or equivalent to each other. Our country is no exception. First of all, the classification is consistent with ISO (National Standardization Organization): *** Thirteen categories, the main categories of oils Products such as internal combustion engine oil, gear oil, hydraulic oil, etc. all adopt the latest standard classification of the national standard. As far as the standard is concerned, my country's level is in sync with the national standard.

However, in practical applications, there is a clear gap between my country's lubricants and developed countries. We generally use SD and SE grades for the internal combustion engine oil that consumes the most among lubricants, while developed countries have used SG, SH grade is 2 or 3 grades different (in alphabetical order); my country can now produce SE, SF, and even SH grade internal combustion engine oil, but the key raw materials: internal combustion engine compound additives are still basically dependent on imports; this is how my country and the world The actual gap between advanced levels. 1. Help you understand engine oil barrels

Whether it is Shell Helix or other brands of engine oil, there are many English and numbers on the oil barrels, and novices are often confused. Despite the repairman's recommendation, the average car owner still can't figure it out. In fact, as long as you understand simple rules, you can understand the logo on the oil barrel and easily choose the right lubricant for your car.

SAE is the English abbreviation of the Society of Automotive Engineers, and the SAE grade represents the viscosity grade of the oil. SAE30 and SAE40 are single-grade oils, while SAE10W-30 and SAE15W-40 are multi-grade oils. Among them, the smaller the number in front of "W" indicates the lower the low-temperature viscosity, and the better the protection ability of the engine during cold start; the number after "W" is an indicator of the high temperature resistance of the engine oil. Taking Shell Helix Super Motor Oil as an example, the most typical data is SAE10W-40.

API engine oil is divided into two categories: "S" series represents gasoline engine oil; "C" series represents diesel engine oil; when the letters "S" and "C" exist at the same time, it means This engine oil is suitable for gasoline and diesel engines. If "S" comes first, it is mainly used for gasoline engines. On the contrary, it is mainly used in diesel engines.

2. Engine oil grade identification

Viscosity classification and quality classification are usually used to classify engine oil. The SAE (Society of Automotive Engineers) classification and API are widely used internationally. (American Petroleum Institute) classification, respectively, are typical representatives of the two classification methods.

According to the SAE method of classifying engine oils, there are 6 types of winter oils, 4 types of summer oils, and 16 types of winter and summer general-purpose oils. The winter oil grades are: 0W, 5W, 10W, 15W, 20W, 25W. The symbol W represents winter. The smaller the number before W, the smaller the low-temperature viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature; The summer oil grades are: 20, 30, 40, and 50. The larger the number, the greater the viscosity and the higher the applicable maximum temperature. The winter and summer general oil grades are: 5W/20, 5W/30, 5W/40, 5W/50, 10W/20, 10W/30, 10W/40, 10W/50, 15W/20, 15W/30, 15W/40, 15W/50, 20W/20, 20W/30, 20W/40, 20W/ 50, the smaller the number represents the winter part and the larger the number represents the summer part, the higher the viscosity and the wider the applicable temperature range.

According to API quality classification, engine oil is divided into gasoline engine oil series (i.e. S series) and diesel engine oil system (i.e. C series). The oils in each series are arranged in English alphabetical order and divided into several levels. .

The logo on the packaging of engine oil imported from abroad and from Hong Kong and other places consists of two parts: SAE viscosity classification level and API quality classification level. It usually starts with SAE, followed by the viscosity code; while engine oil labels classified according to API quality generally omit the API and directly indicate the quality grade code. For example: the label is SAEl0WSD, which means the viscosity classification is SAEl0W, and the quality level is API SD winter gasoline engine oil; the label is SAE30SD, which means the viscosity classification is SAE30. The quality level of summer gasoline engine oil is APISD; the label is SAEl0W-30SD (or SAEl0W/30SD), which means that the viscosity classification meets both SAEl0W and SAE30 winter and summer general gasoline engine oil, and its quality level is API SD level.

Before the 1980s, domestic vehicle oil specifications were few and the varieties were monotonous. Although there were traditional classification specifications, there was a lack of unified national standards. At present, my country has formulated a new national standard classification method for vehicle engine oils, including the GB7631.3-89 domestic internal combustion engine oil quality classification method and the GAEJ300APR84 engine oil viscosity classification method for equal effects.

Gasoline engine oil is divided into five grades: EQB, EQC, EQD, EQE and EQF. The usage characteristics and application occasions of these five kinds of gasoline engine oil are:

EQB grade - used for trucks or buses working under moderate conditions. and other gasoline engines, with certain cleanliness, dispersion and resistance to hydrogenation corrosion;

EQC grade - used for trucks or buses and other gasoline engines working under moderate conditions, and can also be used in foreign countries where SC is required Grade oil gasoline engines have good cleanliness, dispersion, oxidation resistance, corrosion resistance and anti-penetration properties;

EQD grade - used for trucks or buses working under more severe conditions, as well as The gasoline engines of some cars can meet the requirements of gasoline engines equipped with forced crankcase ventilation devices, as well as foreign gasoline engines that require the use of SD and SC grade oils, which have better performance than EQC grade oils;

EQE grade - gasoline engines used in cars and some trucks working under harsh conditions. And it can meet the requirements of gasoline engines equipped with exhaust gas conversion devices, as well as gasoline engines similar to foreign countries that require the use of SD grade oil, and has better performance than EQD;

EQF grade - used for working under more harsh conditions The gasoline engines of cars and some trucks can also be used in foreign gasoline engines that require the use of SF, SE, SD and SC grade oils, which have better performance than EQE grade oils.

The new viscosity classification method for domestic engine oils has been equivalent to the international SAE viscosity classification method.

3. Classification and different characteristics of engine oil

When friends choose engine oil, they often only consider the price and ignore its performance, thinking that all engine oils have similar qualities. The reason for this misunderstanding is that everyone has less understanding of the classification of engine oil and the different characteristics of various types of engine oil.

Characteristics and differences of engine oil

At present, the American Petroleum Institute (APT) quality classification system is the most widely used engine oil classification system. It uses simple codes based on the working ability of the engine oil. to describe engine oil. Among them, the "S" category is used for gasoline engines. From "SA" to "SH", with each increment of one letter, the performance of the engine oil will be much better than the previous one, and there will be more additives in the engine oil to protect the engine.

Among the characteristics of engine oil, the most important one is its viscosity. For those oils with low viscosity at low temperatures and high viscosity at high temperatures, which can ensure normal lubrication of the engine at any temperature, we define it as multi-grade engine oil. Currently, the engine oils on the market are divided into mineral oil and synthetic oil, and the highest-grade oil is synthetic oil.

Generally, high-end cars choose synthetic engine oil. Synthetic oil has a higher viscosity index than ordinary mineral oil, and its viscosity changes little with temperature changes. Therefore, it can still maintain appropriate viscosity and provide appropriate protection under high temperature and severe cold conditions. In addition, synthetic oil has less tendency to produce acidity and sludge due to oxidation. It can provide proper lubrication and effective protection for the engine under various harsh operating conditions, so it has a longer service life.

The selection and use of engine oil can be based on the following aspects.

Difference based on quality

Motor oils can be simply divided into mineral oils and synthetic oils due to their different base oils (vegetable oils are not included due to their rare production). The biggest difference between the two is that synthetic oil can be used at a wider range of temperatures, has a longer service life, and is more expensive; for the same oil film requirements, synthetic oil can be achieved with a lower viscosity, while mineral oil requires a lower viscosity than synthetic oil. Only thicker viscosity can meet this requirement. In the same working environment, synthetic oil has a much longer service life than mineral oil, so its cost is higher. However, after comparing the number of oil changes, it is not much higher than mineral oil.

(This article does not involve semi-synthetic engine oil) Distinguished by viscosity

Viscosity refers to the internal friction of a fluid (including gas and liquid) when it flows, that is, flow stagnation resistance. Generally, lubricants will provide viscosity at 40 degrees Fahrenheit and 100 degrees Fahrenheit. 40 degrees is relative to the condition when the car is cold, and 100 degrees is the condition when running at high speed or in a traffic jam.

If the viscosity is too thick, the resistance will be relatively high and the following adverse factors will occur: 1. It will affect the starting of the engine when the car is cold. This will be more obvious at low temperatures. For example, when you go to the snow-capped mountains to enjoy the snow in winter, 20W/50 is not as good as 5W/40 is easy to start; 2. Increased fuel consumption. Engine oil with high viscosity also has high resistance, which will cause higher friction resistance in the operation of internal parts of the engine, thus increasing fuel consumption; 3. Increased engine wear during startup When the engine is not started for a period of time, the oil originally attached to the upper part will flow back to the oil pan. The upper part lacks enough oil to protect the engine when it is started. If the oil viscosity is thick, the flow will be slow, so the chance of wear will increase; 4. If the viscosity of the engine oil is too thick, the internal resistance will be large, and the resistance will be converted into heat energy, causing the temperature of the machine parts to rise during operation.

4. What kind of engine oil to use for EFI cars

More and more of the new cars are EFI cars, and many car owners are proud to own EFI cars. . Indeed, EFI vehicles have many advantages. For example, its engine power is increased by 15-20% on average compared to carburetor engines. However, its requirements for engine oil, especially technical indicators such as high oxidation resistance, are becoming more and more stringent.

Electronic injection engines equipped with three-way catalytic converter devices have even stricter requirements for engine oil. Two conditions must be met to install a three-way catalytic converter. One is that the gasoline must be lead-free, because the lead in the gasoline will poison the catalyst and render it ineffective; the other is to install the three-way catalytic converter. Spray vehicles must use engine oil with a phosphorus content of less than 0.12. If the phosphorus content in the engine oil is too high, it will cause the catalyst to fail, shorten the life of the three-way catalytic converter, and exhaust gas emissions will not be minimized. The phosphorus content in the engine oil must be lower than 0.12 to ensure the normal operation of the three-way catalytic converter. Engine oils with a phosphorus content below 0.12 are classified as APISH and above. Therefore, if your car is an EFI car and is equipped with a three-way catalytic converter, you should use oil of SH and above when adding engine oil, so as to ensure that your car drives smoothly and safely.

6. Identification of engine oil quality

The lubrication system of the engine is very similar to the blood circulation system of the human body. The human body is inseparable from healthy blood. Once excessive blood loss or qualitative changes in the blood occur, life will be seriously threatened or even lost. The working quality and service life of an engine depend to a large extent on the quantity and quality of engine oil. A healthy human body has a hematopoietic function and can replenish fresh blood in a timely manner, but the engine cannot do this. On the other hand, understanding and paying attention to the role of engine oil will play a decisive role. The "life" of the engine is in your hands. For example, some domestically produced EQ1091 trucks do not require major repairs for 600,000 kilometers, while others require major repairs for tens of thousands of kilometers. There is a huge difference. Although there are other factors involved, lubrication is the main reason. The following focuses on the identification and replacement methods of engine oil quality under simple conditions.

1. Identification and selection of engine oil quality

(1) Identification and selection of new engine oil quality

At present, the engine oil sold on the market is not so "pure" , the phenomenon of inferior products being passed off as good ones and inferior products being passed off as excellent products is common. When you need to buy engine oil, if you do not have the ability to identify quality and brand, you should ask a specialized technician or an experienced mechanic to help you choose.

1. Observe the color of the engine oil

Domestic genuine bulk engine oil is mostly light blue, has a bright luster, and flows evenly. Any oil that is uneven in color or has different colored lines when flowing is fake or deteriorated oil. If this type of oil is used, it will seriously damage the engine. The color of imported engine oil is golden and slightly blue, crystal clear, the oil barrel is exquisitely made, the edges of the pattern and code are clear and neat, and there is no color leakage or overlap, otherwise it is a fake.

2． Identify the engine oil brand and test viscosity

Domestic barreled engine oil is divided into two types: gasoline engine oil and diesel engine oil.

According to the viscosity, gasoline engine oil is divided into four grades: HQ-6, HQ-6D, HQ-10 and HQ-15. If the temperature is low, you should choose the engine oil with a small grade number or with a "D". If the temperature is high, choose the engine oil with a large grade number. Motor oil. Diesel engine oil is divided into three grades: HC-8, HC-11 and HC-14 based on viscosity. The selection principles are the same as those for gasoline engines. As my country's machinery industry gradually integrates with international standards, the brands of engine oil have gradually adapted to international standards. Currently, some domestic engine oil brands have used imported engine oil standard brands. The specific selection method is the same as below.

For imported engine oil, take Toyota pure brand engine oil as an example: luxury cars should use 5W-40 all-weather engine oil. Although the price is higher, it can ensure the lubrication effect of luxury cars; supercharged diesel engines should use CD-30 Engine oil: Generally, vehicles use SG10W-30 engine oil in winter and SG-30 engine oil in summer.

3． Smell

Qualified engine oil should have no special smell and only be slightly aromatic. Any engine oil that is highly irritating to the sense of smell and has a peculiar smell is spoiled or inferior and must not be used.

(2) Identification of engine oil in use

Identifying the quality of engine oil in use is the basis for determining whether the oil needs to be replaced.

1. Twist identification

Take out a little engine oil from the oil pan, put it on your fingers and rub it. When twisting, if there is a sticky feeling and stringing phenomenon, it means that the engine oil has not deteriorated and can still be used, otherwise it should be replaced.

2． Oil dipstick identification

Pull out the oil dipstick and point it to a bright place to see if the scale line is clear. If the scale line cannot be seen through the oil on the dipstick, it means the engine oil is too dirty and needs to be replaced immediately.

3． Pour identification

Put a small amount of engine oil in the oil pan into a container, then slowly pour it out from the container and observe the gloss and viscosity of the oil flow. If the oil flow can remain slender and uniform, it means that there is no colloid and impurity in the engine oil and it can be used for a period of time. Otherwise, it should be replaced.

4. Oil drop inspection

Put a drop of engine oil in the oil pan on white paper. If the black spot in the center of the oil drop is large, dark brown, uniform and particle-free, and the surrounding yellow infiltration is very small, it means that the engine oil has deteriorated. replace. If the black spot in the center of the oil droplet is small and light in color, and the yellow infiltration marks around it are large, it indicates that the engine oil can still be used.

The above inspections should be carried out after the engine is shut down and the oil has not yet settled, otherwise the correct conclusion may not be obtained. Because after the engine oil precipitates, what floats on top is often good engine oil. This inspection is only a superficial phenomenon, while the deteriorated engine oil or impurities remain at the bottom of the oil pan, which may cause false detection.

7. What kind of engine oil should you use

According to informal statistics, among domestic automobile products, there are more than dozens of brands of engine oil alone. As long as you go to an automobile department store In the store, I was really confused by the full synthetic and semi-synthetic mineral oils, SG, SH, etc. I didn’t know how to pick them up, and I really didn’t know which one to use. And almost all the products recommended by merchants are highly profitable products, which may not be truly useful or applicable. We have compiled some concepts from the requirements of the car manufacturer, the recommendations of the engine oil manufacturer, and the experience of some internationally renowned fleets. We hope that you can find the basis for your choice of engine oil.

Difference based on quality

Motor oils can be simply divided into mineral oils and synthetic oils due to their different base oils (vegetable oils are not included due to their rare production). The biggest difference between the two is that synthetic oil can be used at a wider temperature range, has a longer service life, and has a higher cost. The same oil film requirements can be achieved with synthetic oil at a lower viscosity, while mineral oil requires a lower viscosity than synthetic oil. Only a thicker oil viscosity can meet this requirement. In other words, in the same working environment, synthetic oil can achieve the purpose of engine protection with a lower viscosity. Similarly, in the same working environment, synthetic oil has a much longer service life than mineral oil, so although the cost is higher, after comparing the number of oil changes, it is not much higher than mineral oil.

(First statement: This article does not consider the so-called semi-synthetic engine oil.)

Distinguished by viscosity

Viscosity refers to fluids (including gases and liquids) Its internal friction during flow is called flow stagnation resistance. Generally, lubricants will provide viscosity at 40 degrees Fahrenheit and 100 degrees Fahrenheit. 40 degrees is relative to the condition when the car is cold, and 100 degrees is the condition when running at high speed or in a traffic jam. If the viscosity is too thick, the resistance generated will be relatively increased and some situations will occur. Such as: 1. It affects the starting of the engine when the car is cold. This will be more obvious at low temperatures. For example, when you go to Yushan to enjoy the snow in winter, 2OW/50 will be harder to start than 5W/40. 2. Increase fuel consumption. Oil with high viscosity also has high resistance, which will cause higher friction resistance in the operation of the internal parts of the engine, thus increasing fuel consumption. 3. Increase engine wear during startup. When the engine has not been started for a period of time, the oil originally attached to the upper part will flow back to the oil pan. The upper part lacks enough oil to keep the engine in starting condition. If the oil viscosity is thick, the flow will be slow, so the chance of wear will increase. . 4. If the viscosity of the engine oil is too thick, the internal resistance will be large, and the resistance will be converted into heat, causing the temperature of the machine parts to rise during operation.

Depends on the temperature of the operating environment.

Almost any automobile manufacturer will recommend the most appropriate engine oil viscosity in the owner's manual. The car manufacturer that is the most picky about engine oil in the world is undoubtedly Porsche. Because it is an air-cooled engine, everything is cooled only by engine oil. In its internal technical bulletin, every engine oil is submitted for inspection (required by the oil manufacturer). Make a conclusion. But the most basic thing is that it still requires car owners to decide what kind of engine oil to use based on the temperature of the environment. In Taiwan, the minimum temperature is not lower than 5 degrees Celsius, and the maximum temperature is not higher than 40 degrees Celsius. Within this range, generally speaking, 10W/40 and 10W/30 are not suitable, and synthetic oil must be at least 5W/40. . Neither 5W/30 nor 10W/30 is suitable. The above is the common sense you must know when choosing engine oil. First use the temperature of the car environment to determine the viscosity of the engine oil, and then consider mineral oil or synthetic oil based on your budget.

What kind of oil should I use for pure transportation?

If the car is just a means of transportation and you only use it when commuting to and from get off work, car enthusiasts really want to persuade you to sell the car. Forget about taking the bus instead, why bother adding tail to the traffic queue? 15W/40 ordinary mineral oil is enough for you. If you want to save money on gas, fully synthetic 5W/40 can meet your requirements because it flows quickly and reduces engine wear when you start it.

What kind of oil should you use if you like the engine speed?

The higher the engine speed, the higher the relative temperature will be, so you should use engine oil with a higher viscosity. Such as 5W/50, 10W/50 or 15W/50. But as mentioned before, the higher the viscosity, the greater the relative resistance, and the engine performance will be somewhat weakened, so synthetic oil can make up for this shortcoming. Because synthetic oil can use a lower viscosity to meet the working conditions that must be met with a high viscosity compared to mineral oil. But at this time, you have to consider the engine volume output of the vehicle itself. For example, a four-cylinder vehicle with less than 2,000 rpm will quickly reach the red line after a high speed. Perhaps a slightly thicker engine oil (for example, 10W/40 versus 5W/40), would be more appropriate. Because the gap between the cylinder and the piston ring is sealed by engine oil, the sealing effect of high viscosity is of course better. For cars with more than 3,000 cylinders and more than six cylinders, the engine speed of such cars usually does not reach the red line (of course) There are exceptions), so there is less need to pay attention to it. Another way to determine the viscosity is to listen to the sound of the engine valve after running for a while. If the "dada" sound is obvious, then you should increase the viscosity.

What kind of oil should be used in high compression ratio engines?

We tell you very subjectively that synthetic oil with high viscosity is the only choice. Such as 5W/50, 10W/50 or 15W/50. If you also often pull the rpm to the red line, you can consider 10W/60.

8. The appropriate amount of engine oil to consume

First of all, a correct concept should be established about engine oil consumption (commonly known as "burning" engine oil). As long as the engine is running, there will be oil consumption. Normal engine oil Consumption is necessary to maintain the operation of the engine, so it will not cause harm to the engine. It is a very normal phenomenon for the engine to "burn" oil and "burn" gasoline during operation, but the amount of oil consumed during normal operation of the engine is far greater. It is far lower than gasoline consumption (international oil and fuel consumption ratio is <1%).

During the normal operation of the engine, a very small amount of oil will enter the cylinder through various channels and be burned and then discharged into the atmosphere. There are three main ways for oil to enter the cylinder. One way is through the gap between the intake and exhaust valve stems and the valve guide. A small amount of oil must pass through the valve oil seal to prevent the valve from getting stuck in the valve guide; the other way is through the piston and cylinder Through the gap between the walls, the piston ring brings the remaining lubricating oil film on the cylinder wall into the combustion chamber during its upward movement; another way is that mist oil particles enter the combustion chamber through the forced ventilation pipe of the crankcase. It can be seen from this that all consumed engine oil is eventually "burned" in the main combustion chamber and discharged into the atmosphere through the exhaust system. Therefore, people usually refer to engine oil consumption as "burning" engine oil. Although this The oil consumption is not large, but after a period of use, you can still notice that the oil level is decreasing, so you must check the oil level regularly and add an appropriate amount of oil as needed.

So, what is the normal amount of engine oil consumption? This may be the issue that most drivers are most concerned about. According to my country's international regulations GB3743-84, the oil-to-fuel consumption ratio is <1%. According to this calculation, the engine displacement is 1.6-2.0 liters, and the fuel consumption for 100 kilometers (15 working conditions urban cycle) is 10 liters. For a car, its oil consumption should be less than 1 liter/1,000 kilometers. There are no legal regulations on car engine oil consumption in foreign countries. It is generally believed that during the first 10,000 kilometers of running-in period, the oil consumption may reach 0. 3 liters/1000 kilometers. After driving 10,000 kilometers, the oil consumption will remain within 0.2 liters/1000 kilometers. The maintenance manual indicates that as long as the oil consumption is less than 1 liter/101,000 kilometers, it is normal.

Although all consumed engine oil is burned through the combustion chamber and then discharged into the atmosphere through the exhaust system, if the engine oil consumption does not exceed the standard requirements, it will not affect the vehicle emission indicators and will not Users need not worry if the catalytic reactor fails or is damaged.

Of course, if the oil consumption is indeed too high, the reasons may be as follows: 1. Oil leakage in the lubrication system; 2. Excessive wear or damage to the cylinder wall and piston rings; 3. Valve oil seal Damaged or hardened and aged; 4. Adding too much oil exceeds the oil gauge limit. If you encounter the above situation, you should go to the designated maintenance service station for maintenance. Of course, drivers should check the oil dipstick frequently during daily driving, regularly replace the oil and oil filter according to the product instruction manual, add oil of the brand designated by the major manufacturer, and replace genuine oil filter spare parts.

In short, as long as the car engine is running, there will be "burning" of oil. As long as the "burning" of oil by the engine does not exceed the standard requirements, and there are no abnormalities in engine operation, it will not affect the vehicle's emission indicators, nor will it affect the vehicle's emissions. It will not cause the catalytic reactor to fail, and it will not cause harm to the engine. Users do not have to worry and can drive your car with confidence.

9. The role and purchase of automotive additives

Generally speaking, there are five major categories of lubricating oil additives, namely detergents, dispersants, viscosity index improvers, anti-wear agents, and Antioxidants. In order to further improve the performance of lubricants, companies continue to introduce new additives such as rust inhibitors, metal deactivators, anti-foaming agents, emulsifiers, demulsifiers, adhesives, pour point depressants and synthetic sealing expansion agents. Lubricant additives are an indispensable part of modern lubricants. Although they are added in small amounts, they play a decisive role in improving lubrication performance and meeting working requirements under various specific conditions.

Based on actual use, people often hope to obtain additives with excellent comprehensive performance, which requires the addition of multiple additives, that is, the use of formula technology or compounding technology, to produce multiple additives through appropriate formulation processes to produce products with excellent comprehensive performance and a wide range of properties. It is not easy to develop a good additive formula for the applicability of composite additives, because so far the quantitative relationship between the amount of additives and performance has not been established, and the use of additives mainly relies on experimental results. There are synergistic effects between additives, which can be positive or negative, so researching and developing new composite additive varieties is an arduous task.

Currently there are many types of additives on the market with varying prices, which often discourages purchasers. In fact, buyers only need to pay attention to the following matters during the purchase process to make a purchase with confidence:

1. Check the manufacturer’s trademark and barcode to see if it has been certified by an authoritative department, such as ISO-9002 and other international quality standards certification, look for the brand of additives to buy.

2. Choose affordable products. The price of additives varies greatly. If the price difference between two different brands of similar additives is not large, the technical content of the products is basically the same, and the only difference is a matter of market positioning. If there is a huge gap, it often indicates that there is a large gap in the inherent technical level, and buyers can choose according to their needs.

3. Usage experience. In the history of additives, usage experience is indeed the most important. If buyers have no experience in using additives, they can consult friends or collect more information to learn, because no matter what, protecting your vehicle is the most important thing. .

10. Discuss the oil change interval

According to general terms, the oil change interval of vehicle oil is 5,000 kilometers. Many car owner friends regard this as a fixed understanding. In fact, each vehicle has different engine conditions, oil used, and operating environment, and its reasonable oil change intervals should also be different to a certain extent, and cannot be generalized.

1. Engine condition

Please clean the inside of the engine of a new car. There is little carbon deposit and other impurities, so the oil change interval can be extended appropriately. But it should not exceed 7,500 kilometers. No matter how good the engine oil is, its chemical properties will change after a certain mileage, especially the additives in it will gradually lose their effectiveness and will no longer protect the engine. Old engines, especially engines that lack maintenance, have a lot of carbon deposits inside. After new oil is added, it is easy to be contaminated, causing discoloration and qualitative changes. Therefore, the oil change interval should be shortened appropriately. Of course, if possible, it is best to thoroughly clean the inside of the engine.

2． Oil used

There are two standards for identifying engine oil: quality grade (API) and viscosity (SAE). Quality grades generally range from SC, SD to SJ. The higher the grade, the better the quality. Modern cars, especially sedans, mostly have high-speed engines and have higher oil requirements. Generally speaking, engine oils above SF grade have good oxidation resistance, anti-wear properties, clean dispersion and viscosity stability under high temperature and high shear. They can provide reliable protection for the engine and the quality stability will not change for a long time. Under normal circumstances, it can fully meet the oil change interval of 5,000 kilometers. Some car owners, mostly taxi owners, use SD or even SC grade engine oil in order to save money, which makes it inappropriate to follow the 5,000-kilometer oil change requirement. Because low-grade engine oil has poor stability under harsh working conditions, deteriorates quickly, and is prone to carbon deposits. From the perspective of caring for the vehicle, if this type of engine oil is used, the oil change interval should be shortened to 3,000 kilometers or even less. It is best to use the engine oil recommended in the vehicle manual, otherwise you may not save money due to the shortened oil change interval.

8. Influence of the use environment

The environment also has a certain impact on engine oil. High temperature, extreme cold and dusty environments can easily accelerate the deterioration of engine oil. Car owners should not only choose engine oil of appropriate grade and viscosity for the environment, but also shorten the oil change cycle appropriately. The specific requirements depend on the situation. Generally, it is appropriate to shorten the cycle by 1/5-1/3.

Many car owners have a vague understanding of the use of engine oil, thinking that as long as it is engine oil, it can be changed every 5,000 kilometers.

As everyone knows, if the type of engine oil is not properly selected and the oil change interval is not properly grasped, long-term use will have a great impact on the vehicle. Some models of the same model are still in good condition after driving for 20,000 to 300,000 kilometers. In addition to driving methods, the rational use of engine oil is also very important. As long as you can sum up your experience, make careful comparisons, choose engine oil scientifically and master the oil change intervals, your car will stay young and look new for a long time.