Correct me if I'm wrong but SP95 is E5 and most (in fact all as far as I know) supermarket outlets have SP95 E10. In my experience they are spread about 50/50 so you can give E10 pumps a miss and find E5 not far away.
E10 is cheaper than E5. I can't say I've noticed comsumption difference between the two, maybe E15 would be different.
I don't recall seeing E15 pumps, certainly not common. Was that just in Spain?
Over dramatic conclusion there I think.