Originally Posted By: Vortec376
Originally Posted By: Swissdieselfan
It depends which Mobil 1 you are using, as they all have different add packs. In general terms M1 was designed for long OCI's, which means it has a fair amount of Calcium based detergent and dispersants and a high initial TBN, so it's a good cleaner. You don't get something for nothing, so a good oil with lots of detergents will chew up the anti wear layer more when changed too often for about the first 1K miles before it lays down a new layer.
Castrol Edge also comes in several different forms, but in general terms gives slightly lower wear figures but does not clean as well as M1, but to be honest I doubt if it will make a significant difference, as all the major brand full synthetics seem to give similar UOA results.
If it's an oil recommended for your specific engine type in a Mobil, Castrol or Shell web site, it will do a great job. Just look for a good special offer, as the oil and air filter quality will be more important, as will be your decision over when to change them.
So I've currently been changing it every 5,000 miles. Should I go further because of this? I also use the Mobil 1 EP Filter.
I'm often skeptical as I bet you are as well...and a little anal. I've been using M1 5-30 and had to do a few UOA to get me comfortable with the Armada in my sig. Sure enough, I'm doing 7500k with a valvetrain that can tear up oils and my UOA's have been stellar.
If I were you things here....I would go to 6k and send a sample in for analysis. Betcha with that engine even in PA winters and with those hills and the short 9m trip you will be more than good at 7k+. UOA will let you know for sure and give you confidence.