This may help in regards to NZ octane ratings....................
"The Regulations provide for two grades of petrol which are differentiated by their minimum octane, regular (91 RON/82 MON) and premium (95 RON/85 MON)."
(from
http://www.med.govt.nz/templates/Mul...____10382.aspx )
..........so based on this and using the US R/M system our octane ratings are regular
86.5 and premium
90.
Another thing to bear in mind is that most SVX in NZ are JDM and therefore tuned to where the fuel availiable is either
94 or
100 octane (which I assume is RON).