Gasoline is 10% ethanol. E88 is 15% ethanol. The EIA estimates that we use 376 million gallons of gasoline per day in the USA. That’s 37 million gallons of ethanol, minimum, per day.
I’m going to paste from a comment I made the other day:
There was a good discussion of this on Reddit recently. Sorry to link to Reddit, but it’s a good, topical post worth perusal.
https://www.reddit.com/r/Agriculture/comments/1dv7fw9/how_much_good_land_is_used_to_grow_food_for/
Hmm. I forgot about the admixture into fossil fuels, good point. It makes me wonder if there really is no good alternate use for the byproducts, other than animal feed. Biodiesel is one possibility, although I’d have to research the economics of it at this point in technological development.
The top reply there is “it’s mixed”, which is fair. Some places you have farmers growing alfalfa on good food land, which I personally see. Other places you have livestock grazing on semidesert - there really is no obvious alternate use there, until we run short on actual desert to build solar in.