The Infiniti FX is a mid-size luxury crossover SUV produced by the Nissan-owned Infiniti luxury vehicle brand since the 2003 model year. The FX replaced the QX4 as Infiniti's mid-size luxury-type SUV, although the QX4 was smaller than the FX. It was released at the same time as its competitors, the Porsche Cayenne and Volvo XC90. It shares the same FM platform as the rear-wheel drive Nissan 370Z, whereas the similarly sized Nissan Murano is based on the same D platform as the front-wheel drive Nissan Altima. The FX and QX56, whose platform is shared with the Nissan Armada, are not sold in Japan.