I mentioned A5/B5 because that spec is the lower HTHS 30 grade, kind of like FA-4, whereas the CK-4 stuff is closer to the A3/B4 stuff by way of HTHS. Most of the A5/B5 oils are also ILSAC certified (at least in North America), but ours are all pretty much 5w-30 options. Other places get, I believe, 10w-30 A5/B5 options, so for those looking for an alternative in North America while insisting on a 10w-30 versus a 5w-30, might this be the answer?
I do wonder about what some of the additive packages would look like on these FA-4 oils. Of course, a $30 UOA has huge limitations, but that doesn't stop me from being curious about zinc, phosphorus, and the other elements.
I'm also wondering how much more "robust" an FA-4 10w-30 might be over a more ordinary ILSAC 10w-30 one might find out there. It's not a huge practical concern for me, given my climate and the value I place on a 5w-XX, but it is pretty interesting.