Forgive me if this is covered elsewhere but searched fuel type and 95 , 98 ron and cant find anything so need to know asap as am off to petrol station ...

The manual sends mixed messages , indicating engine needs 95 RON then says it runs better on 98 ... which is it? And if 98, i have a quarter tank with 95 in , so do i use 95 til i am ready to refill fully with 98, or will 95 and 98 mix ok?