ShinerBock wrote:
Oh and another thing.  Here is some good reading material for those that think that sulfur is a main lubricant in diesel.  It is not.  The reason why ULSD has lower lubricity is because the process used to remove sulfur from crude also destroys other compounds that give diesel its lubricity. However, many additives are usually added to diesel to bring the lubricity back up before it is even transported to your local fuel station.  
TAKING THE MYSTERY OUT OF LUBRICITY
Thanks for some reading material.  
My fuel filter is 2 micron.  (Have no idea what level my water filter is) I often wonder if I'm trapping some additives when going through the fuel filter? Present time I change fuel filter when fuel pressure gauge loses one or two PSI.  
Cummins engineers are an interesting bunch. (I like)  Last one I meet convinced me to back up my maint schedule 10% from OEM spec.