Going through some different oils today at a local store and it seems that the ACEA 3 standard is more about viscosity than anything else. Looks like just about any 40 weight synthetic oil can pass that standard. I seen some of the old school Castrol Syntec 5w-50 oil and it meets the standard, but I wouldnt regard that oil to be very good based on some of the UOA's we've seen on it. I would say some of the better brand 30 weight oils would outperform the Syntec 5w-50 by a long shot if put to the test, despite the different ratings. I've contemplated going to a 5w-40 syn. oil thinking the ACEA 3 rating is all that, but now that I've seen Castrol 5w-50 with the rating endorsement makes me wonder why I should bother worrying about that standard/spec. any opinions on this ?