Good afternoon, I own Opel Astra sedane with petrol 1.4 turbo engine. In users manual, it states that recommended fuel is 95 RON octane unleaded, while 98 , and 91 octane are possible. I would like to know does it mean my car will run best on 95 RON? I know that lower octane is not an option, but will it make any difference if I put higher octane than recommended? I am asking this, because in my country, 98 or 100 RON petrols are higher in quality than 95. Thank you