Actually any modern car with
Actually any modern car with a turbo is tuned for a specific octane rating or octane rating range. Usually the other turbo subaru models do require 91 octane as a recommended fuel. Not necessarily required. This is apparently a new engine although I would bet it's the exact same short block as the current wrx, sti or FXT. Usually subarus have a weak/mild tune to get the highest mpg rating. this would be amazing on a E85 tune.