Because the existing oil filter, for example, can only filter out 60% impurities in the oil, and the other 40% impurities, including a large number of iron filings, are still circulating randomly, which can not be effectively filtered out at the first time. It is conceivable that the engine works at a speed of thousands or even tens of thousands of revolutions per minute.

The engine oil circulates at least thousands of times per minute, and the iron filings doped in the engine oil wear the engine thousands of times per minute. So how many minutes is the oil change and maintenance interval? The wear of iron filings on the engine cannot be calculated numerically. If this goes on for a long time, wear will change the original design parameters of the engine, relatively reduce the engine power, increase noise, increase fuel consumption, and shorten the service life of the engine and the service life of oil and paper filters.