regor -
Great post! I have read about Blackstone from saturnfans.com. Because I have 160K miles on my SW2, I wanted to do a "blood test" on the car, so to speak. My car came out squeeky clean :
Before this test, I was running heavier dino oil, 10W40. Not I am back the recommended dino oil, 5W30. However, I still have to check the oil, because she's a burner, like most S-Series.
CarloSW2