The 2015 Infiniti QX80 is available as a 4-door, 7-seat sport utility. Starting at $63,250, the 2015 Infiniti QX80 4x2 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 2015 Infiniti QX80 Limited AWD, priced at $88,850, 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.