Thx all for answers, i'll stay with 97 ron , i don't want to destroy my engine
!

I still have a question : there's octane booster sells in tunning shops for
exemple, it's like an additive, you don't have to do anything on your engine
management, just put in your fuel tank, what is it ?
And i don't speak about nitous oxyde kit, which are more and more expensive but
gives you a big kick in the ass when you press the magic button on the
dashboard.

Bruno.