I ask this because I have a about 7 gallons of E30 I need to use up from my other race car. Ideally, I'd like to mix in 1 gallon E30 with 5 gallons of regular E10 (87 octane) if possible until all my E30 is gone. When I calculate it out the mixture would come out to somewhere around E13 - E13.5 and would be about 91 octane. Please let me know. thanks!