1, Advantages: It can adsorb some iron impurities in the engine oil, thus effectively cleaning the oil circuit. Prevent secondary pollution. The oil drain screw can be reused, but the washer of the oil drain screw cannot be reused. Because the gasket plays a sealing role, and the most commonly used gasket is aluminum gasket, because aluminum is softer than steel, when tightened, aluminum gasket will deform to fill the gap. However, the used gasket has been deformed during installation, and the internal structure has become dense, so it is difficult to compress and deform when it is used again, and it will not play a sealing role, so it is best to replace the gasket every time the oil is changed.
2. Disadvantages: If the oil is not changed for a long time, the engine will be worn. At this time, the magnetic oil drain screw will absorb a large amount of iron filings and accumulate at the bottom of the oil shell, which may block the oil pump in the oil pan, resulting in poor lubrication, thus wearing the engine. In addition, after the magnetic oil drain screw absorbs a large amount of iron filings, it is difficult to unscrew the oil drain screw when oil needs to be drained during oil change, which is very troublesome.