Jack the car up, set the throttle at 2,000 RPM and let it burn one gallon of each against a stop watch while powering a 1,000W boom box and get back to me after you’ve tested all 15 blends.
I don’t think I need to, that’s kind of the whole point of the study I cited.
I posted the link to their report, you’re more than welcome to rip it apart.