Quote:
Originally Posted by aklim
I don't think they have higher compression. What happens when you DON'T have E85? It will detonate like there is no tomorrow.
I had a flex fuel vehicle once. In order to put a supercharger on it, I only needed a special program and a supercharger. However, if it wasn't flex fuel, you would need injectors. Why? Because FF has bigger injectors to make up for the lack of power. FF also has a sensor in the tank to detect E85 and then it can advance the timing and pulse width.
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http://www.popularmechanics.com/science/earth/2690341.html?page=2
The performance of E85 vehicles is potentially higher than that of gasoline vehicles because E85's high octane rating allows a much higher compression ratio, which translates into higher thermodynamic efficiency. However, FFVs that retain the capacity to run on gasoline alone can't really take advantage of this octane boost since they also need to be able to run on pump-grade gasoline.
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With turbo or supercharger more boost pressure can be used with E85.
More boost is like higher compression in a NA engine.
E85 also needs to run richer than gas, thus the poor mpg