A question regarding mixing E85 and 93 Premium. Would it be a good idea to mix e85 and straight 93 premium. Where I live I can straight 93 which contains no ethanol. I would like to try to fill up with about 30% E85 and 70% straight 93. Would this increase the octane to 98 give or take a point? What would I need to adjust from a tuning stand-point?