What kind of engine oil is good? How to choose the best engine oil for cars?

Friends who have a car know that the car should be maintained every time it reaches a certain mileage, and it is essential to change the oil every time. The role of engine oil is to protect the engine from wear and corrosion, keep the engine clean, prevent impurities from depositing, and provide better power output for your car while lubricating.

If you want to know what the standard of good engine oil is, you have to start with the "standard" of engine oil. There are many standards in the oil industry that can be used as a basis. For example, at present, most lubricating oil industries in the world implement the standards of API gravity (API) and American Society of Automotive Engineers (SAE), which stipulate the quality grade and viscosity index of lubricating oil respectively, while most oil products in China implement API and SAE standards.

The quality grade of engine oil can be divided into four grades: SG, SJ, SL and SM (S stands for gasoline engine and C stands for diesel engine). The higher the letter, the higher the quality grade. The grade of engine oil will be marked on the bottle body, and API certification above SL grade is what we usually think of as "good engine oil".

Speaking of this, many people may ask me, Xiao Pang has many kinds of engine oil on the market at present, such as 5W30, 0W-40, 10W-40. What do these things mean? How to choose?

In fact, these labels mainly refer to the viscosity of engine oil and the fluidity of engine oil at high and low temperatures. Today, we will talk in detail about how to identify these labels of engine oil.

What is "oil viscosity"

Viscosity is an important index to measure the lubrication performance of engine oil to various parts of the engine. The viscosity of oil can be regarded as "thickness" or flow resistance. Only when the engine oil is "thick" can it form an oil film to protect the engine, but at the same time it should not be too thick, otherwise the engine oil will not flow to all parts of the engine in time. Viscosity index is a measure of the ability of engine oil viscosity to adapt to temperature changes. To put it simply, the engine oil should flow quickly at low temperature and not be too thin at high temperature, which will make the engine lose its protection.

The secret of viscosity is hidden in the oil label. According to the SAE (American Society of Automotive Engineers) oil viscosity standard currently implemented in China, the form of oil label is similar to "0W-40", and "W" generally refers to "winter". The smaller the number before W, the better the low-temperature fluidity. In most parts of China, 5W, 10W and 15W can be used normally.

The value after "W" indicates the high temperature viscosity index of engine oil. The higher the value, the higher the viscosity, indicating that the cold car can adapt to the approximate temperature range when it starts in high temperature climate. Common engine oils on the market have a high temperature viscosity of 20 to 50. Generally speaking, we think that 20-30 engine oil belongs to low viscosity engine oil.

Having said that, I believe everyone has a more intuitive understanding of the choice of engine oil. In this place of Shenzhen, it is quite common to use low viscosity engine oil. So is low viscosity engine oil really that good? Xiao pang then tells you:

Nowadays, more and more vehicles use low viscosity engine oil. There are two main reasons for this trend:

1. With a large number of high-tech application materials entering the field of automobile manufacturing, all-aluminum engine is widely used, which makes the engine manufacturing develop towards light weight, high density, high precision and low clearance. Precision engine no longer needs to rely on high viscosity engine oil to improve the sealing performance of the engine, and low viscosity engine oil can completely meet the sealing requirements of precision engine.

Secondly, the low-viscosity engine oil still flows rapidly at low temperature, and the engine can be quickly pumped to all friction surfaces during cold start, which reduces the wear and movement resistance of the engine, thus reducing fuel consumption and exhaust emissions, and adapting to the mainstream of energy conservation and environmental protection. From these two points of view, low viscosity engine oil can be regarded as "good engine oil" today.

However, everything has two sides. Low viscosity engine oil is good engine oil, but it is not a panacea for all engines. It depends on what kind of engine you have.

It is usually recommended to use low viscosity engine oil for newly purchased vehicles, but with the increase of vehicle service life, the wear of each engine is different. I often hear from car owners around me that using low viscosity engine oil (5W-20 or 5W-30) will also lead to excessive engine oil consumption. This is because the low viscosity engine oil with good fluidity but relatively poor sealing performance may burn oil if it encounters an engine with low machining accuracy or increased wear, and it will also reduce the cylinder pressure and engine power. Therefore, low viscosity engine oil is not a suitable choice for engines with large cylinder clearance and serious wear.

Next, I would like to share with you which brands of engine oil are currently on the market, and what are their characteristics?

Castrol

Castrol is a recognized expert in lubricating oil in the world. A sub-brand of BP. It is mainly divided into Yinjiahu, Jinjiahu, magnetic protection and polar protection. Yinjiahu and Jinjiahu are mineral engine oil, magnetic protection is semi-synthetic engine oil, and magnetic protection is spread all over synthetic engine oil. Castrol engine oil is the main protection function, which is protected before starting. When the engine stops, its protection factor will be adsorbed on the engine surface, giving the engine enough protection.

flowing

Mobil engine oil is a product of ExxonMobil Oil Company, which is generally divided into Ba Li, Suba and Mobil 1. Subara is divided into Subara 1 000 and Subara 2000, Subara1000 is mineral engine oil, Subara 2000 is semi-synthetic engine oil, and Mobil1is all synthetic engine oil. Mobil engine oil is the main power, the engine sound is thick and the power is good;

shell

Shell engine oil, Shell belongs to Royal Dutch Shell Group; Royal Dutch Shell Group is currently the largest oil company in the world, headquartered in The Hague, the Netherlands and London, England, and formed by the merger of Royal Dutch Oil Company and British Shell Company.

Shell engine oil is generally divided into red shell, yellow shell, blue shell and gray shell. Red shell is the worst, gray shell is the best, yellow shell, blue shell and gray shell are the most commonly used. The yellow shell contains mineral oil and synthetic oil, which are hx5 and hx6 respectively. The blue shell is hx7, semi-synthetic engine oil; The gray shell is hx8, all of which are synthetic engine oil. Shell engine oil is characterized by silence, especially the gray shell, which focuses on silence. The engine sound is relatively low after use, of course, it depends on the specific situation.

Finally, Xiao Pang wants to remind everyone that there are too many fake engine oils on the market, and even the engine oils sold by Anton are reported to be fake. Therefore, when you buy engine oil, you must confirm whether there is a brand authorization letter in the place where you buy engine oil, and pay attention to whether the date on the brand authorization letter is within the validity period. Xiaopang found you two really effective power of attorney as samples, namely Castrol and Mobil, for your reference!