You can add more filtering area by adding more pleats and larger pleats. Also, the acutal filtering media isn't all the same.
Regardless, if theres some crud small enough to fit through the filter media then it will continue to stay in the oil. Some particles will also break down in the filter, and then work through the filter continuing back on through the engine. Oil isn't just black because of sludge or the filter being clogged.
If oil only became black because the filter is clogged then why would I not change the filter on my dirt bike with every oil change? Because it isn't clogged but I don't trust old oil to lubricate an engine spinning 10,000 rpms on the face of a 50' double.
I can't think of what, but I know it's not just common practice on dirt bikes.
think you missed what i said, or i just said it wrong.
regardless of filter, the surface area, add in the microns it can filter. if a filter minimum is lets say 50 micron's right but a factory is 100 microns, surface area is still the same, due to same enclosure, they dont make the filter bigger.
now factory is 100, which gives it a life of 5000 miles, now this is done for a reason, which is tested on the engine for best life. now you add a 50micron, same surface area it will catch more, but clog faster, which means what? stops actually working faster or later?
you can do this with city water mains and sink tests, if you have concrete mains. (nyc) and heck they even dont last the time frame printed on them, due to fine micron's they filter to.
my sink will never clog with the w/e mesh thing on the end of it, add a filter, to filter the water, that strainer on the sink gets shrunk more, and the filter will clog, my sink regular tap never will.
anyway, we can disagree, w/e i'm tired and going to sleep, but its always better to maintenance more then less. end of the store really. the money you spend is yours i'm not going to tell you how, but its not how much you spend its how often you do maintenance, which honestly is a pain the ass and most people are too busy to do.
oil filters, microns etc all work the same, the more you catch of finer stuff they quicker it just clogs up.