theres a huge thread on fuels on here somewhere, it was a top topic for a couple weeks a few months back,something which pops up from time to time is where you buy your petrol from.
Often the quality of the fuel from petrol stations like Shell or BP is much better than from a supermarket filling stations.
I remember someone once telling me that supermarkets put additivies into their fuel the "cheapen" it....don't know if that is true, but i find my mpi runs a lot sweeter on fuel from big name filling stations, rather than from a supermarket.
i think it started as someone trying to fight the fuel price increases, lots of info on fuel if you can find it.
thers ya key words right there lol
I was filling up in a TOTAL garage......I never ever ever use supermarket fuel