Engine oil is just like the gasoline we add every day. There are many standards according to the viscosity of engine oil. For example, engine oil with viscosity 20 is generally 0W-20, engine oil with viscosity 30 is generally 5W-30, and engine oil with viscosity 40 is generally 5W-40. Engine oils with different viscosity standards are suitable for different types of engines, and once improperly used, it may cause irreversible wear and tear of the engine. For example, an engine using 5W-40 engine oil must not use 5W-20 engine oil indiscriminately, otherwise it will burn the engine oil or even pull the cylinder, resulting in engine scrapping. This is why many masters often say that they can't use 0W-20 engine oil indiscriminately. This kind of oil has low viscosity and is not suitable for engines that need 40 viscosity oil.
But there are only three kinds of engine oil, one is mineral oil, the other is semi-synthetic oil and the other is fully synthetic oil. Among them, the mineral oil manufacturer marked the replacement every 5,000 kilometers, and the semi-synthetic oil can run to 7,500 kilometers, and the fully synthetic oil is even more amazing, directly 10000 kilometers. In fact, this is the rule of our country. In Germany, people have to run 20,000 to 30,000 kilometers to change their oil. The main reason is that our country's road conditions and oil quality are a little behind others. The maximum speed limit in our country is only 120, which is not available in foreign countries.
The 4S shop mainly changes the oil every 5,000 kilometers according to the standard of mineral oil. Changing the oil more frequently costs more money and won't damage the car. However, some 4S stores even weigh 5000 kilometers to change semi-synthetic oil and fully synthetic oil, which is really cheating and unkind. In order to reduce the maintenance cost of low-end cars, some 4S shops use cheap mineral oil, and the data of engine oil exceeding 5,000 kilometers drops sharply, which easily makes all kinds of sludge and impurities adhere to various parts of the engine, resulting in increased engine running resistance, decreased power and increased fuel consumption. So if you use cheap goods, it is no problem and necessary to change them every 5000 kilometers. But no matter what kind of car, it is recommended to use all synthetic engine oil.
Semi-synthetic engine oil is not cost-effective, although its unit price is very expensive in synthetic engine oil. Its production process is completely different from mineral oil, and it has better lubrication effect in synthetic engine oil. The replacement cycle reaches 10000 km. If there is no traffic jam in your car environment, 12000 doesn't matter if you change it again. It is better for the engine to change the real top with mineral oil twice. Wouldn't it save money if there were fewer engine problems in the future?
Unless you buy a fake, oil is really worth every penny. The way I avoid buying fakes is that the engine oil I use is a small brand of synthetic engine oil. Big brands sell well, and there are definitely many fakes. In addition, it is not that there are no fakes in 4S shops, and not all repair shops are untrustworthy. Conscience repair shops are often cheaper to maintain.