The 2015 Porsche Cayenne is available as a 4-door, 5-seat sport utility. Starting at $61,700, the 2015 Porsche Cayenne Diesel is powered by a 3.0L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 29-mpg on the highway. The top of the line 2015PorscheCayenneTurbo , priced at $ 113,600 , is powered by a 4.8L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 21-mpg on the highway.