This beam (4) is intended to be located between a shield skin (2) and a front end (6) of a motor vehicle front assembly (1), said beam (4) being designed to deform by absorbing energy in the event of an impact with the shield skin (2), said beam (4) having an approximately planar front face (8). The beam (4) comprises a rear fairing element (10) having a concavity (16) facing the front of the vehicle so as to promote a laminar flow of air from the front face (8) of the beam (4) toward the front end (6) of the front assembly (1) of the motor vehicle.