The 2012 Infiniti QX56 is available as a 4-door, 7-seat sport utility. Starting at $60,000, the 2012 Infiniti QX56 4x2 w/o Split Bench Seat Package (A7) is powered by a 5.6L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 20-mpg on the highway. The top of the line 2012InfinitiQX56AWD w/o Split Bench Seat Package , priced at $ 63,100 , is powered by a 5.6L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 20-mpg on the highway.