A gasket for the cylinder head of a motor-vehicle engine includes a body including a polymeric matrix containing a reinforcement material including a dispersion of nanofibers or nanotubes of electrically conductive material. Each nanotube or nanofiber has a substantially elongated shape. A uniform distribution of electrodes is associated to the body. Two layers of electrically insulating material are arranged on the top and bottom surfaces of the body, one on top of and one underneath the polymeric matrix, and designed to insulate electrically the dispersion of nanofibers or nanotubes contained therein. Control and processing means are designed to be connected to any pair of electrodes of the distribution for determining any variation of load applied in an axial direction to the gasket.