Fuel type for mazdaspeed3 2012

Quick question, I have never ran anything but octane rating 93, now to my knowledge the greenies (EPA) wants to ruin our engines with ethanol gunking it up and lowering the life of the engine. From what I have heard ethanol free gas extends the life of gasoline engines. Now I don’t know about turbo powered cars but I have a gas station that has octane rating 90 non ethanol gas, would it hurt to run 90 non ethanol in my speed every now and then? I understand the ecu is programmed timing wise to the higher octane with ethanol but I’m a noob as is and still learning so I’m asking.

 

Anyone who thinks ethanol is bad for newer cars is wrong they are stuck in an 1987 mindset where ethanol would destroy fuel lines in older cars. Run 91 min octane and don't buy into the pure gas bullshit

 

My car was tuned by freektune under previous ownership, but it’s still pretty mild. I don’t think it’s breaking 300hp.

Am i also allowed to use 91 or due to the tune should i stick to 93?

 

no way to answer correctly without knowing the parameters of your tune.

 

Run whatever you're tuned for, 10% ethanol in the fuel isn't anything to worry about I'd be more worried about running a good oil than this.
Don't run 90, cars 91 min, if it's tuned for 93 just run that cycling fuels isn't great either