Why I added Racor fuel polishing filters to ALL my diesel powered equipment, including my pickup truck. My International Eagle conventional road tractor (Cat 3406) came with one from the factory.
Most engine mounted fuel filters on filter down to 80 micron pass. The Racor spin on filters are at 30 micron pass plus, unlike OEM engine mount filters, they strip out any water entrained in the fuel. Always questioning fuel quality and how pure it is because end users haven't a clue where it's coming from in the first place.
You can buy Racor spin on filter cartridges with a 2 micron pass rate but I feel that 30 should be plenty. I believe 2 micron pass is overkill.
My other issue with fuel is, how many times it's transferred from one 'holding tank, vessel' to another. Every timer fuel is transferred, the chance of contamination increases, especially when filling a smaller tractor from a 5 gallon can you fill at a filling station. Lots of chances to get foreign crap in the fuel. I read on here about owners with plugged fuel lines, those lines get plugged from crap in the fuel when filling their tanks like small bugs or grass or whatever. Myself, I fill from my farm tank with a nozzle but believe it or not, I still get foreign crap collecting in my filler neck strainers I have in all my fuel tanks on my tractors. Stuff that could plug a fuel line easily. The Racor at least pre 'polishes' the fuel before it gets to the injection system and the filler pipe strainer get the big stuff.
I don't want fuel related issues and so far I haven't had any (knocking on wood)...lol