Abstract: A differentiated intake system for multicylinder internal combustion engines in which the high-speed inlet pipes and the low-speed inlet pipes communicate with two separate high-speed and low-speed manifolds, respectively. Communication between the cylinders and the low-speed and high-speed pipes is controlled by a deflector valve, there being a single first butterfly valve at the inlet of the high-speed manifold and a plurality of second butterfly valves each in a respective low-speed inlet pipe. The first and second butterfly valves are operated simultaneously by means of a common actuator device.