How often to you guys replace your fuel filters? Diesels have primary and secondary filters on them as opposed to gas with one lonely filter/water separator. I have been replacing the primaries on both engines and generator every end of season (Racor cartridge) however this year I am questioning if this is simply an overkill/waste. Draining any water from the primary units is will be done every season however is a filter change really required? I am guessing I went through about 1,500L (400g) of fuel this season which is probably my seasonal average.

I should mention the secondary filter was the original when I purchased the boat with 1000hrs on the engines. They do have electronic water sensing built into them which will alert me if there is any water in them which has never occurred. I have been replacing those every other year since I got the boat, overkill?