Posted by Don in Missouri [172.68.38.43] on Thursday, February 23, 2017 at 12:45:20 :
In Reply to: Removing ethanol from gasoline posted by Dave in CA [108.162.215.73] on Thursday, February 23, 2017 at 11:28:06 :
In order to get the optimal performance from a higher blend of alcohol, the engine has to be designed to take advantage of ethanol's properties. When you do that, you can run a higher compression ratio than today's cars, and that makes them more efficient than it could be running straight gasoline. This could overcome the difference in potential energy in the two fuels. Theoretically, you would be wasting less energy in the engine.
Also, MPG is not the ideal metric. What you really care about is Miles per $. Alcohol is cheaper to produce than gasoline (even without subsidy). If there were a free market for E85, you should see that E85 is priced so cheap that even with a mpg penalty, E85 saves you money. The distributors have constrained the E85 market by holding prices even with gasoline on a per gallon basis, not on the basis of energy content or cost of production.