Thanks guys for replying. I am aware of the issue of potential ring coking, and injector coking from oil usage. Phydeaux88- your reply seems to be talking about the "coking" issue I read about elsewhere. That is definately a concern to me. However, from what I have read, it takes so long for a failure to occur from this process that repairs would be covered by the money saved in fuel. My truck is old and not worth much, plus I have backup vehicles in case a failure does occur. So If I blow my engine or lose an IP, that sucks, but its not the end of the world. Do you have any input on how long it would take for these submicronic particles to build up and cause problems?

One thing to consider is how much junk is potentially getting into ulsd or #2Diesel from its journey from the refinery to your fuel tank. Who is to say that the stuff from the pump is cleaner than what I can make in my shed?

You mentioned the particles filling the submicronic gap around piston rings. I have rebuilt many diesel engines, and never have I seen a space around a piston ring that was submicronic. That clearance is measured with feeler guages in thousandths of an inch during a rebuild. During normal engine operation, the piston ring will move to the top of the ring groove and back to the bottom as the piston travels up and down. I can't see these particles clogging up that space quickly, but if they did, I agree a siezed piston or seriously excessive wear would rapidly occur.

I read about many people using high concentrations of wmo that has been filtered similar to my setup (or in many cases with much less filtering) and running through summers and winters for years. So far I haven't read about anyone having a wmo-for-fuel-related failure (other than clogged filters). But I continue to read every new post I can come across in hopes of finding new info or valuable experience from others.

BTW any input from experienced wmo users is highly appreciated.