Okay, this has probably been discussed a million times, but searching I couldn't find anything...
I need to go fill up, but before I do, is it worth spending the extra 5p / litre on the premium fuel from Tesco, or the extra 8p / litre for BP or 9p / litre for Shell? This is based on my local Tesco's current standard fuel price. I have a MK5 GTi. I am more concerned about economy than 'go' in this case.
Thanks