P.S. I was running on standard unleaded 95 Ron - where you guys will probably use 97 Ron - I'm just a tight wad 
Maybe.
There's been a bit of a debate on that! 
Well - in my 6 cylinder beemer (with my driving style) - 95Ron lowest mpg =18mpg but 97 lowest was 26mpg
So 4 years ago with my beemer - it made a difference - Was using the Total stuff
With the diesel - the ultimate stuff makes a difference in the wifes Zafira - but non at all in the Golf!
So, it is very subjective, and I suppose it depends on how old the car is and how its tuned
