Quick E85 question
 

With an EcuTek tune and appropriate flex fuel sensor will the ECU adjust for different fuel ratios automatically? Or do I have to run one or the other?

With the proper EcuTek tune and mapping set-up you can run 93 (or 91, whatever they tune for) and everything between up to E85. You will have to tap into your EVAP sensor wire to send the signal from the flex fuel sensor to the ECU; and based on what it tells the ECU, if set up properly, it will pull the map for your ethanol percentage.

Just had this done last week and it's worked well so far.

Aaahhhh okay. That clears things up. Thanks.