I thought that the E10's were about 95 RON and the good old unleaded standard was only 91 RON? Last time I bought ULP in Canberra it was a tad cheaper then the E10. I used to use E10 in most of my vehicles but having seen what it did to the rubber components inside a fuel tank, I now use either 95 or 98 RON, if that isn't available ULP, E10 only if none of the others are available.
After a couple of years of using E 10 in my Ford Exploder the fuel gauge stopped working, a few months after I switched to 95/98 RON the fuel gauge started working again, my theory is that the better fuel helped clean up the shite of the fuel gauge sender?