If you have an engine that ingests air from the atmosphere, you are inducing solid microscopic matter constantly. Does the furniture in your house get dusty, mine does. That stuff will pass through any air filter made for an automobile, eventually it ends up in the oil. In a dirt track car (which I'm very familiar with) the process is accelerated by the sheer numbers of particulate in the air.
You need to do more research about how filtering down to 5 microns extends the life of any engine roughly 7 fold over a conventional oil filter. The only way you can keep the microscopic dirt accumulation in check is the flush the crankcase with fresh oil repeatedly. The price of oil is rising constantly, but you can keep flushing the engine with it if you choose to. Or you can remove it with a filter designed to remove it, OEM filters are designed to keep flushing the system with fresh oil, they don't remove the fine matter from the oil.
I really don't want to get further off topic here, since it isn't my thread. I'd be glad to speak about by pass filters in a thread devoted to that subject.
