I was searching and found on chevelles.com a PSI Test and PYB didn't do very well. 540 RAT did a test and it was less than I expected performance wise. However PP 5w30 was quite impressive on its PSI rating. Is PYB just not cut out for hard use and extended runs? I never had a reason to run dino but I guess I thought PYB would be a premier product like its synthetic alternative. It showed Havoline conventional even beating its syn counter-part. Man if that isnt awkward.