Originally Posted by pawoSD

My engine must make a lot of soot, because after running 5k on mobil 1 turbo diesel truck, it was what I would consider "too thick" when I was draining it. So, I switched to Rotella Synthetic and a 4k change....I'm thinking the 20% more often filter/full change on a slightly "lesser" (perhaps not even true) oil is better for the engine than extra miles on a "better" oil. Saves me a little bit of $$ too....and the engine likes it just fine....in fact I think it likes the rotella better than mobil. *flame suit on*