When I switched on my 93, I ran a used oil analysis first (3k on dino juice), then ran 6000 miles on Mobil1 and did another UOA. Results came back about the same. I put in a fresh batch of Mobil1, and went another 5k. Results were a litte better than the first two. I attribute this to the fact that some of the contaminants were 'leftovers from dino juice' in my first Mobil1 oil change, and were purged out by the second.

Based on this, and the article I posted above, I do oil changes every 5-6k with a PREMIUM filter that is rated for this kind of use in independent tests (see article at www.bobistheoilguy.com ).

You may want to do the same thing I did, however there are a few of us now doing 5k change intervals with Mobil1. Just remember to keep an eye on oil consumption, and top off if needed.

I run Mobil 1 fully syn and a premium filter as well. I change it at 3,000 miles though.

i have run Mobil 1 fully syn(5/30) and a premium filter(Baldwin) for 140,000 miles.
i change it between 8K and 10K (10K if a lot of highway miles 75% / 25% are driven).
i use about 1/2 qt. of oil between each oil change.
i sent my old oil to(10k on the oil)
http://www.blackstone-labs.com/index.html
and it was still good to go, but at 10k i said what the hell and put fresh oil in.

ROD