If your engine is designed to run on 95RON, run it on 95RON because 98/99RON will
never pay for itself and makes absolutely no sense whatsoever. If your car is tuned to use 98RON then use 98RON. Simples.
There was a big thread about this recently with lots of real, factual info in it rather than "I use posh because I have a nice car"
