Bob:
Maybe I am missing something. If one uses two filters in parrallel with different filtration, won't the
oil simply tend to take the path of least resistance making the filter with the finer filtration surperflous? It would seem to me that the same type of filter should be used on both to assure equal flow. If there were in series it would be different, since the
oil would have to flow through both, but then that would increase, not decrease, the overall resistance. Just wondering.