mobile 1 5w30 synth... nearly 2 months after the oil change and the oil is pretty much as clear as the day i pored it into the crank case. even though with the lack of oil i pulled out, was black as hell.. i am shocked i am getting no gunk or anything in my current oil on the stick and i check it with a white rag all the time as i am trying to gauge its usage... ok yeah i only have about 600 miles on the oil change.
pretty damn clean engine and good oil as far as i can tell
return line from the valve cover to the intake tube down by the turbo barely has any residue in it either,, again twisted a white rage and pushed it through it..