Never paid any attention to the filtering specs of inline fuel filters because honestly I didn't know there were different micron levels available or so it seems. The reason I said "or so it seems" is because I recently saw the filtering specs in a listing for a fuel filter and I can't think of any other reason why it would've specified the micron level if there weren't other options available. The only criteria I've always had when buying fuel filters was...will it fit the fuel line I have and does it look similar to what I'm replacing...but now I'm wondering if I've been overlooking important aspects. Aspects that could possibly play a vital role in performance or vital to the longevity of other components? So maybe someone can answer this. Is there a specific micron filter that should be used per the hp of an engine or size of fuel pump etc? What do you guys think? Thanks...Cup