You could always splash in your own ethanol with E85 to raise the octane a few points.
There is a calculator online at http://www.intercepteft.com/calc.html
to determine the octane/percentage blending your own.
The stock fuel system can handle a 1:1 blend (E47) but you need a tune for anything over around 30% ethanol to keep from popping a CEL for excessive positive fuel trims. The fuel trims adjust for the extra fuel needed after driving a few miles and the fueling carries over into the WOT fueling for positive fuel trims also. I ran 30% E with no issues when I was stock.
Avoid leaded race fuel as it will destroy your O2 sensors over a short time.