A test device for simulating motor vehicle crashes, wherein the test device has the following: - a carriage arrangement which is arranged so as to be displaceable along a rail arrangement; - a test setup which is arranged on the carriage arrangement and has at least one motor vehicle component to be tested; and - an acceleration unit by means of which a force can be transmitted to the carriage arrangement in order to accelerate the carriage arrangement, wherein the acceleration unit has a hydraulic drive cylinder with a piston and a piston rod which is connected to the carriage arrangement, wherein a control device is provided which is configured to set a quantity of hydraulic fluid which is fed into the piston-side region or the piston-rod-side region of the drive cylinder, or discharged therefrom, per time unit, in such a way that an acceleration force which is transmitted to the carriage arrangement assumes a value which is defined or can be defined in advance, characterized in that the drive cylinder is a hydraulic drive cylinder, with which a hydraulic fluid directly acts on the piston, in that a first measuring pickup is provided for sensing the pressure which acts in the piston-side region of the drive cylinder, and wherein a second measuring pickup is provided for sensing the pressure which acts in the piston-rod-side region of the drive cylinder; and wherein the control device is configured to set the quantity of hydraulic fluid which is fed into the piston-side region or the piston-rod-side region of the drive cylinder, or discharged therefrom, per time unit, as a function of the pressure (P1, P2) sensed in the drive cylinder, in such a way that the difference between the pressure which acts in the piston-side region and the pressure which acts in the piston-rod-side region assumes a value which is defined or can be defined in advance. - a carriage arrangement which is arranged so as to be displaceable along a rail arrangement; - a test setup which is arranged on the carriage arrangement and has at least one motor vehicle component to be tested; and - an acceleration unit by means of which a force can be transmitted to the carriage arrangement in order to accelerate the carriage arrangement, wherein the acceleration unit has a hydraulic drive cylinder with a piston and a piston rod which is connected to the carriage arrangement, wherein a control device is provided which is configured to set a quantity of hydraulic fluid which is fed into the piston-side region or the piston-rod-side region of the drive cylinder, or discharged therefrom, per time unit, in such a way that an acceleration force which is transmitted to the carriage arrangement assumes a value which is defined or can be defined in advance, characterized in that the drive cylinder is a hydraulic drive cylinder, with which a hydraulic fluid directly acts on the piston, in that a first measuring pickup is provided for sensing the pressure which acts in the piston-side region of the drive cylinder, and wherein a second measuring pickup is provided for sensing the pressure which acts in the piston-rod-side region of the drive cylinder; and wherein the control device is configured to set the quantity of hydraulic fluid which is fed into the piston-side region or the piston-rod-side region of the drive cylinder, or discharged therefrom, per time unit, as a function of the pressure (P1, P2) sensed in the drive cylinder, in such a way that the difference between the pressure which acts in the piston-side region and the pressure which acts in the piston-rod-side region assumes a value which is defined or can be defined in advance.