Hey guys im wondering if anyone knows the octane rating of japans premium? The 30M is supposed to have premium, but been japanese i want to know whether this equates to our 95 or 98. it has a knock sensor so would retard timing if 95 was too low, but i want all 199kw!

96ron is the Jap "Premium", so you want to be running 98 for full benefit.

cheers mate

98 is the norm for performance cars in japan so i'd say go with that.

? I thought they had 100 octane as their premium. Not sure if it's based on the same measurements though!

100RON fuel is readily available in japan, and since it is calculated as research octane number, it is comparable to au/nz standards. However for the OP, 100RON probably wasn't around when your aging MIVEC was new on the market so unsure it will be able to advance the timing enough to suit the fuel

i thought 100ron has been around for a while?

edit. in japan, i mean

my jdm evo6 (1999) has a factory sticker under the bonnet sayin "min ron 95"

cheers guys, yeah sounds like 95 is the go, although i have put in 98 a few times, no noticeable difference. It may be aging, but it goes like stink!