I always use V Power in mine but i've been trying to get a grasp of how these detergents in fuel actually help (aside of keeping injectors clean).
Obviously, higher octane fuel will allow the timing to advance and run better. There is an article in Auto Express this week on buying a used GTI mkv and they very briefly mention cylinder head issues on some arising from using 95 ron fuel??? Unfortunately it doesn't elaborate.
The only cylinder head issues I can imagine is the coking of the valves which can affect some direct injection engines (FSI) (oil mist spraying on the valves i think). The thing is, if the fuel is directly injected, exactly what do the detergents clean anyway?
I'm personally a bit confused as to how 95 ron fuel could harm anything. Perhaps someone could advise in simple terms (I'm no mechanic but have basic engine understanding).