The 2008 Porsche 911 is available as a 2-door, 4-seat coupe. Starting at $89,700, the 2008 Porsche 911 Carrera 4 AWD Cabriolet is powered by a 3.6L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 18-mpg in the city and 26-mpg on the highway. The top of the line 2008Porsche911GT2 RWD Coupe , priced at $ 191,700 , is powered by a 3.6L , 6 - cylinder engine mated to a manual transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.