Are you talking about adding Ethanol into your gas tank or have it sprayed(mist) into your Intake?

If sprayed into your intake check this site out:

Ethanal+Water Injection System

I used a system like this on my '93 Eclipse NA 4G63 and loved the extra HP I had gained from it.

As for Adding to Pump Gas, Dont know, never tried. But did some research before about it, that it will affect your AFR. but ya, I really dont know much about it.