I've been experimenting with used oil analysis for about a year now. I've done a bunch of my own, and studied many dony by others. One of the things that has troubled me about UOAs as they commonly appear, is the vagueness as to just what the wear metal numbers indicate. Particularly, for example, is that "7 parts per million" of iron completely dissolved in the oil, does it form potentially damaging particles, or maybe some of both. So earlier this week when I sent in the latest sample from my VQ, I ordered the optional extra particle count from Blackstone. As background, the oil is German Castrol (the semi-fabled green stuff) and the filter was a Mobil-1. I'm very happy with the combo, as both the standard results are great, and the particle counts are on par with clean hydraulic fluid according to some other feedback I got, very good for a gas engine. GC with an M1 filter looks like a good combo. Also, I used both Lube Control and Fuel Power during this interval. Here's the report from Blackstone, particle size/number info appears in the "Comments" box:

EDIT: for now, we'll make it a link, since the image size is messed up. Here's the link to Blackstone report.