Yes we should look into this further.Well about the octane rating, i just found out there is actually a difference between Europe and US in terms of octane rating for gasoline.
US are using "AKI" Anti-Knock Index and Europe is using "RON" Research Octane Number.
(thanks to Wikipedia; https://en.wikipedia.org/wiki/Octane_rating
in short, US Premium 91 is similar to our regular grade EUR95
Maybe it is interesting to start a new topic about fuel's, additives, octane? hmm..