[dannyhilton]

Having driven a fair few MK7 Fiesta models, from CL to Zetec, all I can say is that 91RON does not do the car any favors. The test Fiesta I drove was on E91, and a friend who has a Black CL puts only E91 in her car, guess what, it pings, and the pickup isn't there not to mention fuel economy isn't as good as mine, and I rev my car. I've tried 98RON in my Fiesta, and every four tanks put some in, but I personally don't find any massive advantage (perhaps over time I would), but using a constant supply of 95RON seems to work a treat. Even if 95RON sky rockets in price, the convenience of having more pickup, along with better economy (wether it be better in comparison to the cost doesn't worry me, I don't pay for my fuel my work does) makes 95RON the better choice for me. 98RON could again be better, it was in the WP Fiesta. Everyone has different needs in life, different financial situations, different influential factors, all I can say is what I think and know, and 91RON or E91 just doesn't cut it for me.