Originally posted by brtecson
my bro says that there is two ways of measuring octane, motor octane number and research octane number. American gas stations use the a.k.i., the anti knock index, which is just an average of the m.o.n. and the r.o.n.. Japan only uses one of those two, so their octane rating system is slightly different.
That's correct, I can check with some friends of mine that just got back from japan to verify, but I was trying to give the US equivalent grade, but as I said, I can verify if everyone's in dire need to know.