Gone is the 2.5-liter flat-four that motivated the previous-gen 718 Boxster and Cayman GTS.The new 718 duo adds the 4.0 badge and with it, a naturally-aspirated flat-six mill thats bound to tickle the fancy for a lot of Porsche purists. Whats more, the 4.0-liter engine is the exact same one currently found in the Porsche 718 Boxster Spyder and 718 Cayman GT4, but its been detuned a little. Oh, and according to Autoblog3, the four-cylinder-powered models will be retired after the 2019 model year.