Motor vehicle forecarriage comprising - a forecarriage frame, - a pair of front wheels (10', 10") kinematically connected to the forecarriage frame by means of an articulated quadrilateral, - said articulated quadrilateral comprising a pair of cross members (24', 24"), hinged to the forecarriage frame in correspondence of middle hinges, - said cross members (24', 24") being connected together, in correspondence of opposite transverse ends (40, 44), by means of left and right uprights (48', 48'') pivoted to said transverse ends (40, 44) in correspondence of side hinges, - the cross members (24', 24'') and the uprights (48', 48") defining said articulated quadrilateral, wherein - each of the uprights ( 48', 48'') guides and supports a stub axle of a front wheel (10', 10''), each upright (48', 48") extending from an upper end to a lower end, - wherein each stub axle is mechanically connected to a rotation pin of the respective front wheel (10', 10") so as to rotatably support the front wheel (10', 10") around a rotation axis (R-R), and wherein each rotation pin of the respective front wheel (10', 10") is comprised between the upper end and the lower end of the corresponding upright (48', 48'') of the articulated quadrilateral, wherein each stub axle is mounted on a corresponding upright (48', 48") so as to have at least one degree of freedom with respect to the corresponding upright (48', 48"), said at least one degree of freedom comprising a translational movement of the stub axle with respect to the upright (48', 48") parallel to an axis of prevalent extension (T-T) of the upright (48' 48") and/or a rotational motion of the stub axle about said axis of prevalent extension (T-T) of the upright (48' 48"), characterized in that the coupling between each stub axle and the upright (48', 48") is of the prismatic type, so as to allow only one degree of freedom to the stub axle with respect to the upright (48', 48"), and a further element is arranged between the stub axle and the respective upright so as to enable the steering of the wheel. - a forecarriage frame, - a pair of front wheels (10', 10") kinematically connected to the forecarriage frame by means of an articulated quadrilateral, - said articulated quadrilateral comprising a pair of cross members (24', 24"), hinged to the forecarriage frame in correspondence of middle hinges, - said cross members (24', 24") being connected together, in correspondence of opposite transverse ends (40, 44), by means of left and right uprights (48', 48'') pivoted to said transverse ends (40, 44) in correspondence of side hinges, - the cross members (24', 24'') and the uprights (48', 48") defining said articulated quadrilateral, wherein - each of the uprights ( 48', 48'') guides and supports a stub axle of a front wheel (10', 10''), each upright (48', 48") extending from an upper end to a lower end, - wherein each stub axle is mechanically connected to a rotation pin of the respective front wheel (10', 10") so as to rotatably support the front wheel (10', 10") around a rotation axis (R-R), and wherein each rotation pin of the respective front wheel (10', 10") is comprised between the upper end and the lower end of the corresponding upright (48', 48'') of the articulated quadrilateral,