fuel ron rating in europe

[koh]

ive been reading up on the high comp engine tuning route through this forum
what fuel do you guys use in high comp 4age engines?
i run shell v power 98octane in my skyline as its the highest quality pump gas we have here
as my car is a japanese import im assuming even this 98 octane isnt great compared to jap fuel,i hear they have 110 pump gas?
are the standard fuel trims on the standard ecu able to cope with lower octane fuels?

should i be worried about it at all with my non turbo hachi?

any input welcome as im looking to use effective well thought out mods to improve my engine rather than spend a fortune or go 20v