Took this sample at 9,100 miles on the oil through a Fumoto valve on my 07 6.0L F250 daily driver. I ran this Mobil One Delvac 5w40 ESP instead of my normal fill of Schaeffer's 5w40 at the last oil change; I was pressed for time and didn't have time to order the Schaeffer's. Bought the Delvac 1 at a truck stop in town, probably paid too much but man did it perform well. I didn't change the oil and I'm glad I didn't. I normally run this engine at 10K mile OCIs, this oil shows that it has more to give. I'll test again about 14K miles.