Ethanol is an increasingly available gas alternative in the U.S. that can be mixed with gasoline, notably in concentrations of 10% (E10) and potentially 15% (E15) for flex fuel vehicles. This plant-based fuel reduces greenhouse emissions and supports local economies by decreasing reliance on foreign oil and creating jobs. However, its availability and cost-effectiveness vary across regions, and while it may operate less efficiently on traditional gasoline, many flex fuel vehicles perform better using higher ethanol blends.