I changed out the German Castrol 0w30 in my Chrysler this afternoon. It had 5009 miles on it, and I'll be mailing off the sample to Blackstone on Monday for the UOA. One of the things the all-aluminum 3.2 and 3.5 Chrysler V6s are known for is a "weeping" rear main seal. This is something that you'll see on virtually every LH car you crawl under that has one of these engines. It's rare that the seal every seeps enough to actually cause an oil spot under the car, and that was the case with mine. The two bolts at the back of the engine where the transmission collar connects to the block are perpetually "wet," but never enough to drip. The first thing that jumped out at me today when I slid under the cars was they they were almost completely DRY. Given that esters are supposed to condition seals, it seems that GC has done just that to my weeping rear main.