E15 is a type of fuel that contains 15% ethanol and 85% gasoline. Ethanol is a renewable fuel made from plant materials, which helps reduce greenhouse gas emissions compared to traditional gasoline. E15 is designed for use in many modern vehicles, providing a cleaner-burning alternative that can help improve air quality. This fuel is often promoted as a way to support American farmers and the biofuel industry, as it utilizes domestically produced crops like corn. However, not all vehicles are compatible with E15, so it's important for consumers to check their owner's manual before using this fuel type.