i agree with bill the mobil1 is crap now and i have seen the same thing. i went to redline or purple for roller cam engines. the rotella did the same thing with the add package this yr so now i would stay away from them to. this oil changing all the time is pissing me off. i have my oil analized to find the best oil so far the purple is the best i have run in roller cam engine but i have never ran the stuff bill is talking about from joe gibbs racing. i will be trying it thou just to see how it holds up in testing.