Those results are usually from over extending service between oil changes. Motor oil properties break down and carbon up from heat and use. I'd tell the owner to change his oil on time or more frequent for heavy use.
I bet if you pulled the intake off that Hemi the valley is caked with the black bits of carbon and it's just a matter of time the oil pickup screen will become clogged and you'll be dropping the oil pan to clean it. This is based on prior costomers vehicles that I had the pleasure.
I would like to agree with what you had to say, but from what I have heard and seen, this truck went in for service every 4000 miles.
Now we all now if you are not looking the service guys wont be working.
Maybe a few oil changes were skipped?
Maybe maybe not, In my experience doing many oil changes regular oil causes what you see in the picture.
out of ten random cars I do I say 4 will have dirty looking filters.
The Dodge Hemi that came off of I have done 2 AMSOIL oil changes and AMSOIL filters
First run 15,000 miles now on second run.
Engine used 3 quarts in 15,000 miles.
On another note I service another HEMI Dodge truck since 2006 and it has only 3 oil filter changes NO OIL CHANGE! It uses oil like crazy, I just add when ever the nice lady brings me the truck.
started at 67,000 miles and now the truck has over 150,000 with only 3 filter swaps and many gallons over the years.
Once I had to add 5 quarts to get her within range, WHY CHANGE THE OIL?
still runs great and she drives it very hard 90MPH speeding tickets regularly.
Javier