Citroen Racing's engineers have taken all their multi WRC winning expertise and applied it to the DS4, which represents a significant evolution from the DS3 Racing limited edition. The concept features new carbon-fiber components including an air diffuser, front splitter and wheel arch extensions. While the Citroen Racing-developed 1.6-liter turbo gasoline engine provides up to 256hp, a record for a Citroen series production car, and an equally impressive CO2 emissions of just 155g/km.