What is the role of engine oil?

The engine oil is also called engine lubricating oil, which acts to lubricate the engine, reduce the temperature, seal the leak, rust and corrosion, and cushion the shock. Known as the "blood" of the car, it is one of the important factors determining the service life of the engine.

How many kinds of engine oil are there?

At present, the oil on the market can be easily divided into two kinds of mineral oils and synthetic oils according to different base oils. The synthetic oils can be further divided into semi-synthetic motor oils and fully synthetic motor oils.

The biggest difference between mineral oil and synthetic motor oil is that synthetic oils use a wider temperature, longer service life and higher cost. The same oil film requirements, synthetic oil can be achieved with lower viscosity, and mineral oil needs to be used. This requirement can be achieved with respect to the richer viscosity of the synthetic oil. In the same working environment, synthetic oil is much more expensive because it is used much longer than mineral oil, but it is not much higher than mineral oil after the oil change.

What are the engine oil labels?

What are the meanings of SAE, API, SM, 5W-40, etc. appearing on the oil packaging?

1. SAE: SAE is the abbreviation of "American Association of Motor Vehicle Engineers" in English. The label behind SAE indicates the viscosity value of the oil, such as: SAE5W-40, where "W" stands for WINTER winter, and the number before "W" stands for low temperature. The lower flow viscosity, the smaller the value, the better the low temperature fluidity of the oil, the better the protection of the engine when the vehicle is cold started; the number behind the "W" is the viscosity of the oil at 100 ° C. The higher the viscosity.

2. API: The API is the abbreviation of the English "American Petroleum Institute", and the label behind the API indicates the quality level of the oil.

API oil is divided into three categories:

1. The beginning series of “S” stands for gasoline engine oil. The specifications are: API SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN.

2. The “C” series begins with diesel engine oil. The specifications are: API CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4.

3. When the two letters "S" and "C" are present at the same time, it means that the oil is a general purpose type.

The meaning of the letters after S or C is: from "SA" to "SN", the environmental protection level of the oil will be better than the former one for each letter. The higher the letter, the higher the environmental protection level, the international brand. The oil level is mostly above the SF level, and the oil with the highest environmental protection level is the “SN” level.

Frequently asked questions about engine oil in daily use

Question 1: How to judge true and false motor oil?

Choosing good oil can make the car more durable and more powerful. Good engine oil, especially fully synthetic engine oil, saves the engine and saves the fuel. At present, there are many kinds of oil on the market, and the purchase channels are also diverse. Therefore, many profiteers often shoddy in order to make money, and use low-grade mineral oil as semi-synthetic motor oil or fully synthetic motor oil to sell to consumers. How do we identify genuine and fake motor oil?

First, it depends on the appearance of the package. The brand-name oil seal cover is a disposable cover. There is a sealed tin foil at the notch. There are special labels on the tin foil. Without these features, it may be fake oil. In addition, the brand-name oil is anti-counterfeiting, and the label, the bottom of the can, the inside of the can lid, the handle and other inconspicuous places have special marks. If the illegal elements are custom-made and packaged, it can be distinguished by comparing the two outer packagings.

The second is to observe the oil, the true oil color is light and transparent, no impurities, no suspended matter, no sediment, and good fluidity when shaking. The fake oil or oil is darker, or there is impurity deposits, or the taste is irritating, the fluidity is poor when shaking, or the brushing phenomenon is felt by hand.

There are generally three types of counterfeit oil products:

First, the recovered waste oil is processed and filled and listed;

The second is to use a simple base oil blend without any additives;

The third is to buy low-grade oil filling, shoddy. Adjust the color of the fake lubricant to match the real oil.

For most consumers who have no relevant experience, purchasing through formal channels is the most secure.

Question 2: How to quickly understand the amount of oil in the car?

On the Internet, we often see some netizens arguing whether the hot car is measuring the oil accurately or the cold car is measuring the oil accurately. In fact, the correct way to observe the oil volume should be to measure the oil in the flat state. Before the measurement, pull out the oil dipstick and wipe it clean, then re-insert the oil dipstick measurement hole. Be sure to insert it into the end. Pull it out again to check the oil quantity accurately.

With the development of technology, more and more mechanical things are electronically, and the oil dipstick is no exception. Nowadays, the electronic oil gauge is not a fresh configuration. It can be used to observe the oil level more easily, without holding the toilet paper. Go to open the engine cover and observe. However, when using this electronic oil gauge, there is a detail to be noted. It is not the entire ruler but the upper and lower limits on the display, so if the bar is already "empty" on the display, It does not mean that there is no oil in the oil pan, but the oil has reached the lower limit of the reasonable range and can be replenished in time.

Question 3: When does the vehicle need to change the oil?

Use oil test paper to test whether the oil should be replaced. Just use a dipstick to pour a little oil from the cylinder onto the test paper. After 2 to 3 hours, compare it with the instructions on the test strip package. You can clearly know if the oil needs it. Replaced. The engine flush machine can be used to change the oil more thoroughly.

Question 4: Can different brands of engine oil be mixed?

Each brand of oil additives is different. Mixing may cause deterioration between chemical components. If conditions permit, we do not recommend mixing different brands of oil.

If there are some extreme situations, for example, if you find that there is not much oil on the high-speed, but the oil sold in the service station and you are not using a brand, you can mix it first. After all, organic oil is much better than no oil. But you should choose the same type of engine oil, as long as you can replace it as soon as possible afterwards.

Question 5: Which type of engine oil is best for the vehicle?

What kind of oil is added to the car is very particular. Many people think that synthetic motor oil is the best oil, so it will use fully synthetic motor oil for its own vehicles. In fact, it is not the best choice to add synthetic motor oil. Due to the low temperature fluidity of the fully synthetic motor oil, the viscosity is lower than that of semi-synthetic or mineral oil. For some cars with long age or overhaul of the engine. Vehicles, because the piston in the engine is worn or the assembly after overhaul is not fine, the gap between the piston and the cylinder may be relatively large. The use of fully synthetic motor oil with low viscosity may affect the air tightness of the engine. It is prone to burning oil or helium. Therefore, instead of choosing the most expensive engine oil, it is the most suitable engine oil for your own vehicle. It is most suitable according to the actual situation of the car.

Question 6: How to judge the vehicle burning oil?

The exhaust pipe emits blue smoke. There are two situations to distinguish here. Let's talk about the blue smoke from the exhaust pipe when the engine starts.

The exhaust pipe emits blue smoke when the engine is started:

After the vehicle has been placed for one night, the first time the next day, if the tail exhaust pipe emits blue smoke, the blue smoke disappears after a period of time, which means that the oil in the cylinder enters the combustion chamber to participate in the combustion.

The engine does not run for a long time, and the oil flows into the cylinder through the gap of the valve oil seal under the action of gravity. When you start the engine again, the oil in the cylinder will generate blue smoke under the action of high temperature and high pressure. Although this is a slight performance of burning oil, you should also pay attention.

The vehicle smokes blue during driving:

When the throttle is stepped on, the exhaust pipe emits blue smoke, and the phenomenon of burning oil can be much more serious. This is mainly due to the severe wear between the piston and the cylinder wall, resulting in poor sealing and increased clearance, resulting in different degrees of burning oil. When you step on the throttle, the piston ring moves up and down faster, and the residual oil on the cylinder wall is easily brought into the combustion chamber by the piston ring. The phenomenon of burning oil is also generated.

In addition, carbon deposits have a strong influence on the situation of automobiles, and carbon should be removed regularly by hho carbon cleaner.

If it is under any circumstances, the exhaust pipe will have blue smoke, and the blue oil will appear from the oil pipe from time to time, indicating that the engine wear is quite serious. The vehicle needs to be overhauled in time, otherwise there will be serious accidents.

In the process of using engine oil, we need to understand the basic knowledge. In the future, in the process of replacement, it is possible to avoid some misunderstandings, which is also a crucial part for us. In the process of selection, we must combine our actual needs, and at the same time, we must determine the dosage according to the specific situation. If you ignore certain situations in this process, it is likely to bring great influence and constraints. Therefore, we should actively learn some relevant knowledge so that we can choose a more suitable oil and avoid problems as much as possible.