I haven't seen any or maybe I just haven't been looking but on the news they said it was ruffly 20-22 cents cheaper then normal fuel which I'm guessing they were talking about 91RON
But also said that it uses ruffly 25-40% more in consumption (another guess, but might be what you drive and how you drive it to what the consumption rate is). So whatever you may save at the pump when you fill up at first it'll cost just the same (maybe more) in the long run.
But in a years time, who know's might be better or they might have sorted something. We can only wait and see.