What does the label of motor oil such as 5W30, 0W30, 0W40 mean, and how to choose engine oil

The choice of engine oil is very particular, and the owner can choose the engine oil in combination with the local maximum and minimum temperature, the grade of the vehicle and the condition of the vehicle. If the oil is too viscous, it will increase the movement resistance and affect the engine power; If you choose an oil with too little viscosity, the lubrication quality cannot be guaranteed, and it will aggravate the wear of the engine. For engines that have been seriously worn and the gaps between the fittings are large, a higher viscosity oil can be used to strengthen the sealing performance of the fittings.

To put it simply, it is better to choose a thinner engine oil for new cars, and it is better to use a more viscous engine oil for cars with higher kilometers.

Choosing engine oil is not the more expensive the oil, the better the effect, if you are really unsure, you can refer to the car's "user manual" to choose, you will not go wrong. But there is a principle that must be followed, that is, choosing engine oil can improve the grade, but not reduce it. For example, the original loading oil is fully synthetic engine oil, and the oil is changed once every 10,000 kilometers, but you can't choose mineral oil, which is changed every 5,000 kilometers, which is obviously not suitable.

In short, what's right for you is the best.

w(w stands for winter w, 10w, the smaller the number in front of w, the better the low temperature operation, in addition to the low temperature viscosity grade, there is also a high temperature viscosity grade sae, the larger the number behind the horizontal bar, the higher the viscosity of the oil.

The standard for choosing engine oil is to choose according to the instruction manual of the original car.

1. High temperature stability is different.

The number after w indicates the kinematic viscosity of the engine oil at 100, and the larger the number, the greater the viscosity, which means that the guarantee is better and more stable at high temperatures, that is, it is less likely to thin at high temperatures. That is, 5w40 is more stable at high temperatures than 5w30.

2. The objects of use are different.

5w40 has a better viscosity than 5w30, so it is more suitable for old cars, 5w30 is more effective in reducing fuel consumption, making the engine faster and better heat dissipation, and at the same time, it is also less noisy, suitable for new cars or naturally aspirated engines.

The symbol w stands for Winter (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.

Mainly: 0W, 5W, 10W, 15W, 20W, 25W.

0 means that -35 or more can be used, 5 means -30 or more can be used, and so on, 25 means -10 or more can be used.

There are many types of motor oils.

Labels, different labels indicate different oil properties. Take 5W-30 as an example, 5 means that the temperature applicable to the oil is above minus 25 degrees, if it is 10 means above minus 20 degrees, the smaller the value in front of W, the better the low temperature fluidity. In other words, it is more suitable for northern winter, and has good cold start performance.

W means winter, and the applicable temperature range is relatively large, which means that the engine oil can be used in all seasons.

The value after 5w-30 is the viscosity index, which means that the viscosity index of the oil is 30 in the working state of 100 degrees Celsius, the higher the number, the higher the viscosity, the better the protection of the engine at high temperatures. However, depending on the driving situation and the type of vehicle, it should be filled with the appropriate grade of oil.

The main difference between 5W30 and 5W40 is that 5W-30 has relatively better fluidity and is more capable of reducing fuel consumption and making the engine dissipate heat faster and better. At the same time, for some older cars, the use of 5W-30 will cause the engine noise to be slightly larger, and some strictly require the use of 5W-40 engines and choose to use 5W-30 will cause greater fuel consumption than normal.

At high temperatures, 5W-40 will have better oil stability.

Secondly, the same quality level of engine oil:

The W-30 flows better than the 5W-40, reduces fuel consumption (fuel) more, and dissipates heat from the engine faster. (Low viscosity oils flow better than high viscosity oils).

2. For old cars, the engine noise of 5w-30 oil is slightly louder than that of 5w-40 oil.

3. For engines that strictly require the use of 5W-40, if 5W-30 is used, there may be a situation where the oil consumption is greater than normal (commonly known as: burning oil).

The W-40 has better oil stability than the 5W-30 in the particularly high engine temperatures.

How to choose car engine oil? What do the numbers and letters on the oil mean, and what is the difference between 5w30 and 5w40? Let's take a look.

China is too big, the temperature difference between the regions is huge, especially in winter, the so-called all-season general purpose engine oil is just a general concept, so it is necessary to explain which region to use it in.

w" means winter, and the more ** the number in front of it, the better the low temperature fluidity of the engine oil, that is, the more resistant to low temperatures! This means that the lower the ambient temperature available for use, the better the protection of the engine during cold starts; The number after the "W" (after a horizontal line) is an indicator of the high temperature resistance of the engine oil, and the higher the value, the better the protection performance of the engine oil at high temperatures. For example:

0w w w-40, etc., winter oil selection see the following standard number seated! Avoid improper oil selection and damage to the engine caused by oil solidification!

The applicable ambient temperature (°C) and the minimum limit value is neither safe nor optimal! In the actual selection, it should be increased by 5 degrees as the safe value, and 10 degrees as the best selection value.

For example, 0w40 can withstand a minimum external temperature of -40. But by -40° the oil has solidified, so the safe value should be -35. , the optimal value should be -30.!

The number in front of w:

0W resistance to external low temperature limit value -40

5W resistance to external low temperature limit value -30°C

10W resistance to external low temperature limit value -25°C

15W resistance to external low temperature limit value -20°C

20W resistant to external low temperature limit value -15°C

The number after w:

30. Resistant to external high temperature 30°C

40. Resistant to external high temperature 40°C

50. Resistant to external high temperature 50°C

Most of the answers below are correct, but in the end. 5w-30 The difference between 5w-40 is not what oil is used at how many degrees of temperature. Rather, it is the kinematic viscosity of the oil at 100 degrees Celsius.

The kinematic viscosity of 5w-40 is slightly higher than that of 30, and it will not be too thin at high temperatures to cause an oil film (or a thick enough oil film) to form on the surface of the gear and cause wear. Therefore, generally new cars can use 5w-30 0w-30 engine oil; It is recommended to use 5W 40 for long-distance driving, urban areas in summer, long-distance highways, or with a certain mileage. In addition, the high viscosity of the oil can ensure adequate protection at high temperatures, and at the same time, it can better fill the gaps.

Of course, new cars can also use 5w-40, but it is generally recommended not to exceed this. Then the naturally aspirated new car is recommended * W-30 20. If you have a mileage, you can use *W-40 in general.

In general, 40 oils are more suitable for protection from higher temperatures of the engine under turbo and intense driving. The lower viscosity of the 20 30 saves fuel, but it is not suitable for intense driving and high-power turbo engines (as well as older engines). In addition to these parameters, it is also necessary to meet the specifications marked in the manual.

For example, Volkswagen will have requirements to meet the VW502 00 505 00 505 01 specification or 504 00 507 00. Each manufacturer has different names, and there will be relevant specifications on the back of the oil.

The W in front of the SAE of the motor oil indicates its low temperature tolerance level, and the latter indicates its SAE viscosity range, and the symbol W is the abbreviation of English Winter, which represents the meaning of winter.

The preceding digit indicates:

0 means that the oil can remain liquid at a low temperature of -40°C, and below -40°, the oil will solidify.

5 means that when the temperature is minus 35°, the oil can remain liquid, below -35°, the oil will solidify.

10 means that the oil can remain liquid at a low temperature of minus 30°, and below -30°, the oil will solidify.

15 means that the oil can remain liquid at a low temperature of minus 25°, and below -25°, the oil will solidify.

20 means that the oil can remain liquid at a low temperature of minus 20°, and below -20°, the oil will solidify.

That is to say, the smaller the previous number, the higher its cold resistance, in the northern winter, not close to high latitudes, it is generally recommended to use 0w oil.

The following number indicates the viscosity of the oil in the 100°C kinematic viscosity range (VISCOSITY AT 100OC).

w20 indicates that the viscosity is in between.

w30 indicates that the viscosity is in between.

w40 indicates that the viscosity is in between.

w50 indicates that the viscosity is in between.

W60 indicates that the viscosity is in between.

Some people replied that the number after W represents the performance of high temperature resistance in summer, saying that 5W40 is suitable for use in high temperatures of 40 degrees in summer, and 5W30 is suitable for use in summer temperatures of 30 degrees, which is the result of a lack of basic common sense and subjective assumptions of automobiles. In fact, the car engine has a cooling circulation system, and the temperature of the engine oil is always maintained at about 80 90 during normal operation. Where do you talk about high temperature resistance?

Viscosity is one of the most important characteristics of engine oil, and the characteristics of general "oil" are low-temperature thickening and high-temperature thinning, which is contrary to the actual engine working needs, and additives can be used to change the nature of the oil. The oil should have high fluidity (low viscosity) at the low temperature of the engine cold start, so as to quickly lubricate all the engine parts required, minimize the lubrication time before the oil completes the first cycle, and minimize the possible wear and tear of the engine. As the engine operating temperature rises, the viscosity of the oil will not be thinned and the strength of the oil film will not be attenuated, so as to provide complete lubrication.

The greater the viscosity of the oil, the more oil is consumed by the engine, and the noise is also greater, but the better the sealing performance, so the choice of oil viscosity must also consider the degree of new and old cars, and the gap between the engine parts of the new car is very small, so the oil with less viscosity should be selected, and the vehicle with serious engine wear should choose the oil with greater viscosity.

There are 6 types of winter oils, 4 types of summer oils, and 16 types of winter and summer general oils.

1.The oil grades used in winter 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;

2.The higher the number, the greater the viscosity, and the higher the applicable maximum temperature;

3.The general oil grades in winter and summer are: 5w w w w

The difference between 5w-40 and 5w-30 is only the difference between the following numbers, 40 can be used in summer temperatures below 40 degrees, and 30 can be used in temperatures below 30 degrees.

W is the expression of the fluidity of the oil at low temperatures. The lower the number, the better the low temperature flow, and 40 has a greater viscosity than 30.

W stands for winter, in 5w-40, 5w represents low temperature fluidity of the oil, the smaller the front of the w, the better, the back represents the high temperature viscosity, the bigger the number, the better.

The viscosity of 5w40 is greater than that of 5w30, w is the meaning of temperature, which can also be understood as the temperature of winter, 5w40 means that 5w temperature can be used at minus 30 degrees, and 40 means that the viscosity of the oil at 100% is 40.

w(w stands for winter w, 10w, the smaller the number in front of w, the better the low temperature operation, in addition to the low temperature viscosity grade, there is also a high temperature viscosity grade sae, the larger the number behind the horizontal bar, the higher the viscosity of the oil.

The standard for choosing engine oil is to choose according to the instruction manual of the original car.

Engine oil 5w-30 represents the number of engine oil, where 5w represents the minimum starting temperature of engine oil is -30, the more ** the number in front of w, the better the low temperature fluidity of the engine oil; The 30 represents the stability performance of the oil at high temperatures, and the higher the value, the better the stability performance of the oil at high temperatures.

SAE and API will be seen on the outer packaging of the oil. SAE is the abbreviation of the Society of Automotive Engineers, and API is the abbreviation of the American Petroleum Institute. The designation after the SAE indicates the viscosity value of the oil, while the designation after the API indicates the quality level of the oil.

Benefits of motor oil:

1. Lubricity. The ability of engine oil to reduce friction, slow down wear and prevent metal sintering under various conditions is called engine lubricity. The viscosity of engine oil is an important indicator of lubricity.

2. Low temperature operability. From the engine oil aspect, the engine oil is easy to start and reliable to supply oil at low temperatures, which is called the low-temperature operability of engine oil.

The low-temperature operability of engine lubricants includes two aspects: good for low temperature starting and reduced starting wear. The main indicators to evaluate the low-temperature operability of engine lubricants are low-temperature dynamic viscosity, boundary pumping temperature and pour point.