I have been informed by the previous owner that my car's ecu is tuned by Feels to run on 102 ron as it was tuned in japan.

In the uk the highest we can get is 99 RON
BP did 100 for a while i'm sure but fazed it out.

However, this leads to me to a couple of things.

I've been told the ecu will retune its self to the fuel i use, being 99RON.
I have found an octane booster at a local parts place it is made by NOS and there are 2 types.
one states it is for street use and ups the octane by 3 octane numbers, and the other is for race use and ups the octane by 5 octane numbers.
Obviously the street one is the one i'd go for as it would make my fuel 102 RON.
but and this is a big BUT

DARE I PUT IT IN MY CAR......i've never used one and realy don't wanna **** this motor up as it cost me a bomb.....

What are your sugestions... i really wanna feel ( see what i did there ) what this engine can do with 102 ron

i will wait to hear from people on here before doing this. . . any help would be appreciated.