Mudflap in a wheel arrangement for a vehicle such as a truck or a utility vehicle or a trailer, the mudflap comprising a plate, arranged substantially in a vertical position, the plate being attached to a support in the vehicle, a front side being oriented toward the wheel, and a rear side oriented away from the wheel, the plate having a plurality of holes and closing member(s), wherein each closing member exhibits a rest position in which the closing member closes holes at the rear side thereof, and a deflected position in which a dynamic air pressure pushes the closing member away from its rest position, thereby allowing air to pass through the hole, and thereby reducing the aerodynamic drag of the mudflap.