Alright, another 15k miles and 2 UOA's since my last thread. Mazda forgot to pull a sample on the middle interval. Looks like I got some contamination in the engine 2 OCI's ago (06/07/08), possibly from driving through a lot of dusty construction areas along the interstate. In the most recent UOA below, I used a Wix Gold oil filter. Not sure if that contributed to the outstanding results or not, but very happy either way. Actually it's the best I've seen on this motor, although still shearing viscosity down to a 20W...