>>Kirby6+CM
But look at figure 8. At 40%, volumetric efficiency is at its peak. It's very important to note that these results are neither monotonic nor linear, so while the public only has access to E85 and E10/E15 (at least where I've been), those are almost ends of extremes and a middle ground can synergize. Yes some metrics always get worse the more ethanol you use, but hopefully you looked at the paper and saw that isn't nearly the full story.