Yup one of the only real plus about the red-headed step child of the third gens. CLEAN OIL (no soot). I just changed my Valvoline 5w40 syn. and it was honey brown after ten thousand. Only time my oil went black was with the early 4.09 smarty software. It is just not the absence of the third injection event, but also the different cam lobe profile. Can we grasp the concept of the cummins in cylinder egr, ie valve overlap. Anyway not to brag you 325 guys still out perform on hp. When I get my oil analysis back I'll post the results.

 

I use AME 15W40 and EaO80. No bypass.............yet.

Last year sampled @ 10,500. Was over 3% soot, so I changed oil and filter.

I just sampled @ 5,800 and soot was 2.8%.

I guess I will need to change it again @ 7,500 and will add a BK-11 then.

 

Got the uoa back today. Soot level O ppm, what to say? Really happy with the silicone level 2ppm, same as always. Was wondering what it would be since I went from stock to AFE PG7.