QUOTE(polarisboy @ Jun 14 2008, 09:48 PM)

My engine builder for my 496 stroker recommends Rotella 15-40. He said it is the best oil you can buy. The high ash content really protects things.
I too asked about mobil 1, he said save your money and use this. I've used it and had no issues.
Rotella T is no longer high ash just like any other CJ-4 diesel oil. Since the CJ-4 specs came about to save the new diesel emissions systems the new oils have really been starved of the good protectors they once had.