10% etanol blend vs non ethanol blend 93 oct

[20psiofevil]

The way this was explained to me is that ethanol is added to increase fuel octane and to cut down on polution. I luckilly have a few stations local to me that sell the non ethanol blend 93oct that I'm thinking of switching to.

Curious to know what others would do in my situation. And if not ethanol, what is used to increase the octane number in the fuel?