The 2017 Infiniti Q50 is available as a 4-door, 5-seat sedan. Starting at $33,950, the 2017 Infiniti Q50 2.0t Base RWD is powered by a 2.0L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 23-mpg in the city and 31-mpg on the highway. The top of the line 2017InfinitiQ503.0t Signature Edition AWD , priced at $ 40,700 , is powered by a 3.0L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 27-mpg on the highway.