Abstract: A twist-beam rear axle for motor vehicles includes a flexurally stiff but torsionally compliant cross strut (2) which is combined with flexurally and torsionally stiff longitudinal arms (3) carrying an axle coupling (6) and a hub carrier (7). The cross strut (2) consists of an extruded aluminum channel section which determines the position of the roll center (RC) and of which the open-bottom U-shaped cross-section has closed chambers (25 and 26) at the free ends of its sides (21 and 22). At the ends of the cross strut (2) the sides (21 and 22) of the section are separated and are bent apart outwards to form portions of the longitudinal arms (3) which are closed by corresponding shaped members (8). Upper and lower chambers (23, 24 and 25, 26) are provided in each side (21 and 22) of the section allowing tuning of the torsional rigidity of the cross strut.