Flat-six makes a brief but triumphant return in Porsche’s hot-rodded 718 duo

Porsche unveiled a pair of 718-based sports cars that brazenly buck the industry’s downsizing trend. The 718 Cayman GT4 and the 718 Spyder ditch the turbocharged flat-four in favor of a naturally aspirated, 4.0-liter flat-six rated at 414 hp.