My Busso engined cars have logged hundreds of thousands of miles on E10 fuel. At one time there were four Busso engined Euro 2 and Euro 3 cars in the family fleet doing daily driver work. No issues with E10. I dislike any type of mandate, esp the ethanol mandate. In the USA, non ethanol fuel has not been available in the cities. E10 burns leaner due to the different air/fuel ratio. Fuel economy falls off with E10, ethanol has less BTU than petrol.