Originally Posted By: ToadU
Is there a point where fitting to smaller and smaller microns has no benefit for engine longevity? Is there any data on this??
The only practical way of achieving filtering efficiency much better than +/-95% of the 20 micron sized particles is a bypass setup.
You don't see these as factory equipment on any car or light truck, even cost no object high end ones.
Do smaller particle sizes contribute to engine wear?
Sure, as per the link provided above in this thread as well as links in a number of other threads on this very topic.
Does this actually matter in practice?
Probably not.
Ask yourself when you last retired an engine due to internal wear.
If we expected at least half a million miles out of an engine and maybe double that and the engines themselves were very expensive to buy or to rebuild, then we might be looking seriously at bypass filtration.
This is why bypass oil filtration is common on OTR trucks and virtually unheard of on light passenger vehicles, like the ones that almost everyone here operates.
We just don't put enough hours on our engines over the lives of the vehicles we operate to make better oil filtration a practical advantage.