Gasoline is around $3 not $4. Where I live it’s $3.24
Ethanol has tons of other problems. It likes water, it has less energy content, it will damage older vehicles and small engines, and when corrected for energy efficiency, there’s no price advantage at all...
Ethanol contains energy that may have a market. For example a tractor may be designed to run on ethanol, or a water heater, space heater. This will make some consumers independent from the world oil prices. But to mandate it was a mistake.
Every thing likes water. Right now 14% of your exhaust is water. I have yet to see an unvarnished breakdown on the cost of producing ethanol. I have seen costs on producing ethanol blended gas. And imo it's full of politics and spin. The blender gets ~$2 a gallon while the producer gets a ~$0.10 credit. And the farmer is painted as a gouger.