A diffusor system for a motor vehicle, including a diffuser duct, which extends along a virtual duct path and is traversable by flow in a flow direction, having at least one duct bounding surface which is curved about a diffuser curvature axis, the diffuser curvature axis forming an angle with the duct path, and including a downforce-generating body, which can pivot between two operating positions about a pivot axis, which is orthogonal to the duct path; in a cross-sectional plane, which is orthogonal to the pivot axis, the downforce-generating body having a profile that generates downforce in response to approach flow; in an activation operating position, a leading edge of the downforce-generating body, which is more proximate to the upstream longitudinal end of the diffuser duct, being at a greater distance from the curved duct bounding surface than in an inactivation operating position, which differs from the activation operating position; the pivot axis extends outside of the downforce-generating body.