How are car oil grades classified?

SAE viscosity grade (how the oil is selected in different seasons and regions).

Take "5w-40" as an example, look at the label of engine oil, mainly look at two values, the first is the main label, which is the "5w". Among them, W stands for Winter is the meaning of winter, and the higher the value in front of W, the better the low temperature fluidity of the engine oil, the lower the ambient temperature available for use, and the better the protection ability of the engine during cold start.

w"The following number is the viscosity index of the engine oil at high temperature, the larger the value, the higher the viscosity, the higher the viscosity, the better the engine protection, but the more fuel is consumed;

Oil quality grade.

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API (American Petroleum Institute), oil grade classification from SA SN and so on, this label is actually to describe the quality of engine oil, the lower the ranking of the letter after S, the higher the quality of the engine oil, so far, the SN level is the highest.

If it is a series starting with "C", it means that it represents diesel engine oil, and the specifications are: CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4. When the letters "S" and "C" are present at the same time, it means that the oil is a general purpose type of gasoline.

EU ACEA

Classification of ACEA EU standard grades.

Acea A B: Gasoline engine oil and light duty diesel engine series.

The A1 B1 series of stable and viscosity retention oils are suitable for long drain applications, especially in gasoline engines and light duty diesel trucks that can use low-friction and low-viscosity lubricants with high temperature, high shear viscosity or low viscosity.

A3 B3 is a stable and viscosity oil used in high-performance gasoline and light diesel engines.

A3 B4 is a stable and viscous retaining oil for use in high-performance gasoline and direct injection diesel engines, but at the same time meets the performance requirements of A3 B3.

More stringent OEM certification standards.

See SAE 5W W-40 (small value before W, large value after W).

api sn/cf

acea a3/b4

There are also the logos certified by major OEMs, so don't hesitate, this is the good engine oil you choose, of course, you must first make sure that you buy **; Saibeisa racing grade lubricating oil, the oil is good, it is good for you, and everyone is really good!

I know that there are only one and a half levels of car engine oil, synthetic engine oil and fully synthetic engine oil, which are distributed in this way.

The Society of Automotive Engineers classifies the quality of engine oil according to the oil viscosity grade classification, the first type is single-grade viscosity type, and it is divided into high-temperature environment type and low-temperature environment type. The number marked after SAE indicates the viscosity of the oil at 100 degrees Celsius, and the larger the number, the greater the viscosity of the oil.

Because the viscosity of this oil is relatively large, it is more suitable for use in high temperatures in summer, and the higher the temperature, you should choose products with larger numbers. The grades of engine oil for low temperature environment are: SAE0W, SAE15W, SAE20W, the W after SAE indicates winter, and the number also indicates viscosity, the smaller the number means the smaller the viscosity.

Since this type of oil is used for low temperatures in winter and has a low viscosity, the lower the temperature, the lower the number of the oil. The lower the viscosity of the oil, the greater the starting speed of the engine; At the same time, the lower the pour point of the oil, the easier it is for the oil to be pumped, which can reach the lubrication part more quickly, and shorten the time for the engine to withstand dry friction. The second type is the all-weather type of multi-level viscosity

The oil grades are: SAE5W 30, SAE15W 40, SAE20W 50. The first half of the bars indicates the winter low-temperature viscosity properties that the marking oil complies with, and the second half of the bars indicates the summer high-temperature viscosity properties.

The lower the number before w, the better the fluidity of the lubricant at low temperatures and the easier it is to start the car. The larger the number after W, the better the viscosity of the oil in the high temperature environment, the stronger the oil film is generated, and this oil can basically be used for all seasons.

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The oil classification is indicated using a two-letter combination. The series starting with "S" represents gasoline engine oil, the general specifications are from SA to SN (in alphabetical order, but there is no SI in it), each letter increment, the performance of the oil will be better than the previous one, and there will be more additives in the oil to protect the engine; The lower the letter, the higher the quality grade, and most of the oil grades in international brands are above the SF grade.

c" starts with the series to represent diesel engine oils. If the letters "S" and "C" are present at the same time, it means that the oil is a general purpose type of gasoline and diesel.

Hello: I'll give you a dividing icon, you will understand at a glance, how to divide.

Classification of oil grades.