Corn is turned into ethanol, and is then blended with gasoline. The US consumes ~14B gallons of ethanol per year. It’s a net negative because it’s carbon and water intensive and farmers advocate for more ethanol than is necessary as a subsidy via government mandate.

https://www.theguardian.com/environment/2025/dec/03/environm...

https://ethanolrfa.org/media-and-news/category/news-releases...