The Ferrari FXX K is a high-performance track-only car and one of the fastest and most exclusive cars produced by Ferrari. The top speed of the Ferrari FXX K is around 349 km/h (217 mph).

However, it's important to note that the FXX K is not designed to achieve high top speeds, but rather to deliver exceptional performance on the track. The car's hybrid powertrain and aerodynamic design are optimized for maximum speed through corners and acceleration, rather than straight-line speed.

The FXX K is powered by a 6.3-liter V12 engine combined with an electric motor, which delivers a total power output of 1036 horsepower and 900 Nm of torque. The car can accelerate from 0 to 100 km/h (62 mph) in just 2.5 seconds, making it one of the fastest cars in the world in terms of acceleration.

Overall, the Ferrari FXX K is an exceptional and exclusive high-performance car that combines cutting-edge technology and engineering with the legendary Ferrari brand and racing heritage.