Thanks to growing environmental concerns and economic forces, 97% of fuel currently pumped in the U.S. is up to 10% ethanol. For a few reasons, ethanol in gas is a hot-button issue for some folks; search for an article on the topic and your chances of finding one that balances both sides of the aisle are pretty slim. But, while many drivers are familiar with Flex Fuel vehicles, which run on a fuel made of 85% ethanol, fewer realize that the gasoline they’re already putting in their cars is partially made from corn.