Maximum speed capability of a vehicle

Is the maximum speed that the vehicle and its components were designed for. If you were to modify any component to increase the speed (For example boost the engine performance) your car's top speed will increase, but the maximum speed will remain the same as all the other components will not be able to withstand the increased performance

Maximum speed capability = 150 km , Top speed = 150 km Boost engine (Performance increase) Maximum speed capability = 150 km , Top speed = 200 km all components need to be improved for the maximum speed capability to increase (Like axle support, better tyres, better brakes, etc)