The 2012 Porsche 911 is available as a 2-door, 4-seat coupe. Starting at $103,100, the 2012 Porsche 911 Carrera GTS RWD Coupe is powered by a 3.8L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway. The top of the line 2012Porsche911Carrera S (M7) RWD Cabriolet , priced at $ 108,000 , is powered by a 3.8L , 6 - cylinder engine mated to a manual transmission that returns an EPA estimated 19-mpg in the city and 27-mpg on the highway.