Just bought an 02 WRX AWD turbo, my first turbo vehicle and wrx I have ever owned. I have been asking around about possible first mods, and everyone is talking about 93octane and E85. The gas station I currently fill up at only goes up to 91octane. Is this going to be a problem with upgrades, and what are the differences between 91, 93, and E85? Do I NEED to run a certain one of these for my upgrades to be safe and efficient? Lastly, does anyone know of any good tuners in the Dubuque Ia. or Davenport Ia. area? Any positive feedback would be appreciated.