Change every 5000 kilometers. The oil must be replaced together with the oil filter element when changing the oil. Changing the oil without changing the oil filter element has the same effect as not changing the oil.
Generally, the engine oil and filter should be changed once every 5000 km or half a year. The two indicators should be the first one. For example, if your car has only been driven for three months and the mileage has reached 5000 kilometers, you should go for maintenance and change the oil in time. If the mileage has not reached 5000 kilometers within half a year, you should also change the oil, because the oil also has a warranty period. The engine oil should be changed once after the new car has driven 3000 km. It can be appropriately extended or shortened according to different driving environment, driving habits and other factors.
Auto oil is the lubricating oil for the internal components of the engine. In addition, it has the function of cooling the engine. It can absorb the heat generated in the engine combustion chamber and the piston crown. It can also be used as the cylinder sealant to fill the gap between the piston and the cylinder wall. Therefore, older vehicles need to add more viscous oil.
According to the chemical composition of the engine oil, the engine oil can be divided into mineral oil, semi-synthetic oil and fully synthetic oil. It is better to change the ordinary mineral oil every 3500-4000 km; Semi-synthetic oil can be changed every 5500-6000 km; Full synthetic oil can be changed every 7500-8000 km.

What to do if the oil screw leaks
The oil screw leaks oil, which should be handled according to different situations. If there is only a slight oil leakage, it is likely that the gasket of the screw is aging and the sealing is not tight.
You can try to put a circle of glue around the screw first, which can generally solve the problem. If the problem still cannot be solved after a circle of glue is applied, the gasket of the screw can be replaced.
If the oil pan has been deformed, the seal between the oil drain and the oil drain screw will be lost, and the oil will also leak in this case.
Solution: replace the oil pan. In addition, if the screws are slipping, the oil pan can only be replaced.
There is also a more extreme method, that is, to weld the screw hole and replace the oil with a circulator instead of gravity.
The oil screw is generally at the bottom of the oil pan, because it is outside, you can see it at a glance. The advantage of this design is that it is beneficial to clean the oil drain and clean the oil sump.