zlacker

>>thunde+(OP)
Is there a efficiency chart somewhere with multiple mixture ratios?

>>fooker+D6
The following link has some charts for just the ethanol. They look about as expected. Some things get better the more ethanol you use, some get diminishing returns, some have an inflection point and get worse, some are just worse as you increase ethanol percentage.

https://www.researchgate.net/profile/Aimen-Zeiny/publication...

>>Neywin+hL
Fundamentally, ethanol will always be less efficient per gallon than gasoline. It has significantly less specific energy compared to gasoline. This is a fact known by anyone that has tried e85 either for racing or for flex fuel compatible normal vehicles.

>>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.

>>Neywin+d91
I'm not sure what that proves? Volumetric efficiency is just about air efficiency. Higher VE is better, yes, but you need to compensate for higher VE by adding more fuel to utilize the air, otherwise you run lean, which is bad. Turbocharging a car, for instance, directly increases VE.

None of this directly equates to fuel efficiency although it can be related, which is what the GP was asking about presumably. You still need to content with the fact that ethanol has ~30% less specific energy per gallon.