Ethanol actually provides a little more hp than regular fuel. It burns hotter - but that's besides the point
Jist remember, that this isn't every single car must avg. 35 mpg. It's a company-wide average. So look at it this way. say GM produces 70 percent of thier vehicle in 2020 with 40 mpg, witch is easily doable. This includes cars and crossovers and small SUV's. The other 30% is trucks, and Muscle Cars

...they average 28...which is underrating, they already get that...then the fleet average will be somewhere around 36.5 mpg...it's doable, and not as hard as most think. in the past Ten years we've seen dramatic increases in fuel economy. give another 13, we'll make it
All good news to me...(but) I just hope this includes Foriegn cars, too. They're not to smart in the inventing dept. only the improvment. They steal every on of our ideas and make them better, we could have done that!