It is an interesting article, however, I have been using 2 micron racor filters in my boat for years. I change them annually and I have not had a problem. It seems to me that if the primary is 2 microns then the secondary can be as well. I note that the Yanmar primary filter is much smaller (less than half the size) and more expensive than the racor secondary filter. It would seem to me that, logically, the Yanmar would clog much more quickly if the racor let all the 2 - 10 micron garbage through. Changing the Yanmar also requires bleeding the engine and the racor doesn't.
I do see the issue with reduced
fuel flow, but since my
fuel tanks are above my engine, and provide a good deal of head pressure, that is not a problem for me. I guess a lot has to do with the location of the racor with respect to the
fuel tanks, and the ease of changing the racor filter.