Yup. Ethanol bad.It takes one unit of energy to create 1.2 units of energy of corn ethanol. That is almost not worth bothering with.
Switch grass is a lot more efficient. From one unit of energy input to the process you can get 4 units out. But nobody is interested in growing that. No subsidies.
I used to get 25 mi/gal in my car. Now with 10% ethanol I get 23 mi/gal. So 10% ethanol in the gas makes my care 10% less efficient. Go figure.