It is very interesting item that was raise by Prabhakar Agrawal. This problem excites a blood. Many years we are told that it is needed to change oil, it is needed to change oil frequently and routinely. And suddenly…
I understand that it is needed to change oil not because it requires OEMs (except for warranty period), but it requires the condition of oil. During of job oil build up water, unburned fuel, oxidation and wear products, soot. It loses viscosity, TBN, additives level… And so on.
Well, to put the case that we have any filter that can separate all solids with size up to 1 micron. It will be wear debris, solid oxidation products (sludge), nonsuspension soot, external contaminations (dirt, sand). Maybe it can separate the water that not dilute in oil. But how it can separate the organic acids which no react with TBN additives and dissolves in oil? How filter can take away the fuel? How it can renew low viscosity from behind VI improver shear? Phabarat says about 2-4 % topping-up. Maybe it can renew TBN and additives level partially. But we're talking about diesel engines (loko, dozers, dumps…) which generate high levels of soot. Sooner or later the dispersants will be depleting. The soot will be agglomerate and block up the fine filter whatever it large may be. How control this filter state?
But on the other hand Prabhakar Agrawal says about its experience in large fleet. And I have not beyond reason not to believe to him. He saw not only Used Oil Analysis Reports, but condition of engine parts after dismantling. Some time ago I was read the article on very long oil life without change. I do not remember exactly but sound like maybe 9 years, maybe 1,600,000 miles. But it was single case. In our case we read about 200 engines. I can hardly believe it!
If I had such filter I run sample of very contaminated oil through it and then compare two Analysis Reports - before and after - and then make any conclusion. It is very interesting, once again!