The 2015 Porsche Cayman is available as a 2-door, 2-seat coupe. Starting at $52,600, the 2015 Porsche Cayman Base is powered by a 2.7L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 20-mpg in the city and 30-mpg on the highway. The top of the line 2015PorscheCaymanGTS , priced at $ 75,200 , is powered by a 3.4L , 6 - cylinder engine mated to a manual transmission that returns an EPA estimated 19-mpg in the city and 26-mpg on the highway.