This may seem a stupid question but I am wondering if I need to strictly use 95 RON (PULP) if my fuel cap says I should be using this? I have been putting in 91 since I got the car a month ago but have realised maybe I should be using 95.

Also can I mix the 2 types if I start using 95 or should I try and use most of the 91 up then fill up with 95?

Sorry if this has already been discussed but I couldn't find anything on the topic.