Cool...I don't doubt that a bit....The Subaru factory rep told me there was no need in changing my Castrol more often than 5k and could easily go 7.5K, depending on how much around town driving, as opposed to highway, and getting the engine really warmed up for at least 30+ minutes. When I do the next change, I switching to Mobil 1 in the car, so will definitely stretch it to 7.5K then. My friend who is the Oil guru, recommends changing every 3 to 5k on my Ducati, but that's because it has straight cut tranny gears, and it's in the same sump as the engine, so bits of it wear off and get pumped through the engine...he recommends having the oil analysis when I near 6K to get a baseline for comparison, then another at 10K to compare and see if I can stretch it out. The oil itself does not break down...it's the particles that are suspended that you have to worry about...the good news is the syn oils do a great job of suspending, so if you change oil when the temp is hot, you can be sure to get all the suspended paricles out, instead of them laying in the bottom of the crankcase, like the old days. In HD motors, he says 5k is no problem at all, if you use a group IV or V syn oil, and 7.5K would be no worry either. It's hard for me to break old habits, as I changed at 3K all my life, but I'm realizing that now days, I'm wasting the resource.