The 2017 Infiniti QX50 is available as a 4-door, 5-seat sport utility. Starting at $34,650, the 2017 Infiniti QX50 4x2 is powered by a 3.7L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 24-mpg on the highway. The top of the line 2017 Infiniti QX50 AWD, priced at $36,450, is powered by a 3.7L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 24-mpg on the highway.