I change my 2 micron filter in the Racor at the start of every season, and the engine filter every other year. I also have a vacuum gauge. One time, the gauge drag needle hadn't moved, so I didn't change the filter at the beginning of a season and sure enough a couple days into a trip across a bumpy Gulf Stream, the filter clogged. I changed it and did not have a problem the rest of the year. It's an annual thing for me, filters are inexpensive and it takes 5 minutes. I only have one Racor, another thing I do is always have one spare handy at the NAV at all times, that I can grab in a second and have it changed in less than 5 minutes ... as opposed to storing all my filters buried in a locker some place. Cheers, John