Car maintenance： oil knowledge and replacement precautions

Its grade represents its performance standard and quality grade, and it can reflect the key indexes such as fluidity, lubricity and cleanliness of engine oil at different temperatures. To judge the performance of engine oil, there are usually the following aspects:

Engine oil is generally divided into:, semi-synthetic oil,. The characteristics of these three oils are:

Mineral oil: low cost, although imported additives are added to mineral oil now, the service life is generally about half a year.

Semi-synthetic oil: It has good oxidation resistance, and it is a very good long-lasting engine oil, with a service life of about one year.

Synthetic oil: long service life, stable performance, but high price.

The "grade" of engine oil can be classified according to the standards of different international organizations and the attributes of engine oil.：

1. SAE (American Society of Automotive Engineers) classifies oil according to its viscosity value.

For example, SAE 5W-30, where W stands for winter, and the number before W stands for flow viscosity at low temperature. The smaller the value, the better the fluidity and the better the protection of the vehicle during cold start. The number after W represents the viscosity at 100 degrees, and the higher the number, the better the viscosity.

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According to the quality grade of engine oil, the higher the number, the higher the grade of engine oil.

A/B series: generally suitable for light-duty diesel engines.

C series: suitable for catalyst engines, C1-C4, and C3 or above are generally used for engines.

E series: heavy duty diesel engine.

3. API and ILSAC(& International Lubricating Oil Standards and Approval Committee) are classified according to the environmental protection grade of engine oil.

The series beginning with A and S represents gasoline engine oil, and the specifications are: API SA … Sn.

The series beginning with B and C represents diesel engine oil, with specifications of API CA……, CG-4, CH-4 and CI-4.

C, when S and C exist at the same time, it means that it is a universal type of gasoline and diesel.

D, the letters after S and C mean: from SA to SN. The farther back, the higher the environmental protection level. In-cylinder direct injection should be at least SN.

E, ILSAC adopts a higher engine oil quality grade evaluation standard, which requires further GF-5 specification evaluation of SN-grade engine oil passed by API. It is required to improve fuel economy, compatibility with exhaust system and prolong engine service life, so GF-5 standard is higher than SN.

Is the performance of engine oil good? How to judge?

It mainly depends on the recommendation of the vehicle manufacturer and the specific requirements of the engine. The following are some factors that are usually considered when choosing family car oil.

1. According to the user’s manual or maintenance guide of the vehicle, the engine oil type and annual grade suitable for this model are usually recommended, and it is most important to follow the manufacturer’s recommendation.

2. Different types of engines may require different types of engine oil. For example, high performance requires higher viscosity engine oil to provide better lubrication protection.

3, climatic conditions, according to the climatic conditions of your location, choose the appropriate viscosity, vehicles in cold areas need lower viscosity engine oil 0W-20, so as to be easy to start at low temperature and protect the engine. Vehicles in hot areas may need higher viscosity oils such as 10W-40 and 15W-50 to maintain lubricity at high temperatures.

4, environmental protection, some places with environmental protection requirements require the use of low-flow or low-phosphorus engine oil to reduce the environmental impact.

5, personal driving habits, often driving at high speed or heavy load, may need more advanced engine oil to provide additional protection.

6. With the increase of vehicle age, engine wear will increase. At this time, engine oil with higher viscosity or specific formula is needed to provide better protection.

Generally speaking, domestic users usually use 5W-30 or 10 or 10W-40 engine oil, but it is better to decide the appropriate engine oil according to the manufacturer’s recommendation and personal actual situation.

The above is my previous knowledge about engine oil.

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The following are the precautions for oil change

1, be sure to buy genuine engine oil, machine filter.

2, it is not impossible to change yourself, the key is to save those wages and ignore them compared with their own safety. Except for those who like to do it.

3, don’t listen to those bloggers who make you, 20,000 kilometers of maintenance all right, according to the maintenance manual, it’s right, if they are so powerful, what do they need the factory’s auto engineers for?

4. Some fans asked whether the oil was put away or pumped well. Is it necessary to open another article on this?

5, the oil must be quantified, and it is not good to have more or less.

6, record the oil change mileage, in order to grasp the oil change time next time. Generally, there are some in the store, but some are lazy or forget, so you should remember to remind them.