Since Blackstone cut off the last bit of the oil description, this was QSUD 5w30 that was tested. I was quite impressed actually, even though my oil smelled like it had some gas in it, it still maintained TBN nicely. I had to use 1/2 qt. of PP (non-Pure Plus) 5w20 and 1/4 qt. of QSUD 5w30 for make-up over the amount of mileage. The 1/4 quart was added about 500 miles before the end of the OCI. Still thinking about giving PYB a try down the road, but I think I'll stick with this for at least one more OCI, given my sump already has a fresh change of QSUD 5w30.