I know this question is pretty common, but the curiosity for me is still there, maybe different engines build works well with different brands.
Well, I don't experience any knocking with 95, so far my car runs fine with any 95 but of course except Esso/Petron, I only tried the other brands once or twice. :) But one of our Mark X Club member reported issues (but not knocking) when using Petronas for some time, which was cured after he switched to other brands.most noticeable from the fuel different would be engine pinging or knocking rate and volume, this common problem happens after we changed from ron97 downgraded to ron95 :(