Cadillac's new vision for the future of luxury transportation is the innovative Provoq fuel cell concept. It features the latest example of E-Flex propulsion system, combining the fifth-generation fuel cell system and a lithium-ion battery to produce an electrically driven vehicle that uses no petroleum. The concept can drive 300 miles, with 280 miles from hydrogen and 20 miles on pure, battery electric energy. An active front grille features louvers that open when the fuel cell stack requires cooling. Incorporated in the left-and right front fender vents are charging ports. Michelin Green X energy-saving tires are wrapped around the 21-inch aluminum rims that have clear-covered space between the spokes.