A system for opening and closing a motor vehicle, the flap is swivalably mounted along one of its edge areas at a stationary structural component part about a horizontal swiveling axis. A first drive device and a second drive device act in parallel to more like flap from a closed position into an open position. The first drive device is a non-self-locking drive device, and the second drive device comprises a cylinder filled with a fluid under pressure. An interior of the second drive device is divided by a piston into a first work chamber and a second work chamber, wherein a piston rod of the piston is guided outward through the first work chamber. A valve arrangement in the piston closes a flow connection between the first work chamber and the second work chamber in a stationary operating state of the flap.