That's what I'm trying to find out because everyone DOES seem to be guessing...some of these people are saying they are changing their oil every THOUSAND miles...I want to know if anyone has any evidence that its beneficial....I've seen many references on the powerstoke boards to guys who log massive amounts of miles and DO sample their oil and most of those guys claim they will run 15-25k miles between oil changes because they HAVE watched it and logged the changes.




Chris