The 2009 Maserati Quattroporte is available as a 4-door, 5-seat sedan. Starting at $119,750, the 2009 Maserati Quattroporte Base is powered by a 4.2L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 12-mpg in the city and 18-mpg on the highway. The top of the line 2009MaseratiQuattroporteSport GT S , priced at $ 133,700 , is powered by a 4.7L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 11-mpg in the city and 18-mpg on the highway.