A displacement pump exhibiting an adjustable delivery volume, 1.1 which is intended for installation in a motor vehicle in order to supply an internal combustion engine which drives the motor vehicle with lubricating oil or to supply an automatic transmission with hydraulic fluid, wherein the displacement pump comprises: 1.2 a pump housing; 1.3 a delivery chamber which is formed in the pump housing and comprises an inlet for a fluid on a low-pressure side of the pump and an outlet for the fluid on a high-pressure side of the pump; 1.4 a delivery member which can be moved within the delivery chamber, for delivering the fluid; 1.5 an adjusting valve for adjusting the delivery volume, arranged in a flow of the fluid delivered by the delivery member and comprising: 1.5.1 a valve housing; 1.5.2 a valve piston which is mounted such that it can be moved in the valve housing, comprising an active surface for a valve-actuating pressure (P 20) of a fluid; and 1.5.3 a valve spring which counteracts a force exerted on the valve piston by the valve-actuating pressure (P 20), 1.5.4 wherein the valve piston comprises another active surface for the valve-actuating pressure (P 20), and the active surfaces (23, 24) are arranged to counteract each other and are different in size in order to generate a differential force which acts on the valve piston counter to the valve spring and corresponds to the difference in size of the active surfaces (23, 24); and 1.6 an adjusting device (27, 28), by means of which the valve piston can be adjusted in the direction of the force exerted by the valve-actuating pressure (P 20) or counter to this force, 1.7 characterised in that the adjusting valve comprises the adjusting device (27, 28), 1.8 the adjusting valve is controlled electrically, 1.9 the valve-actuating pressure (P 20) and a force exerted on the valve piston by the adjusting device (27, 28) act together counter to the force of the valve spring, and 1.10 the position of the valve piston can be adjusted relative to the valve housing independently of the valve-actuating pressure (P 20) acting on the active surfaces (23, 24). 1.2 a pump housing; 1.3 a delivery chamber which is formed in the pump housing and comprises an inlet for a fluid on a low-pressure side of the pump and an outlet for the fluid on a high-pressure side of the pump; 1.4 a delivery member which can be moved within the delivery chamber, for delivering the fluid; 1.5 an adjusting valve for adjusting the delivery volume, arranged in a flow of the fluid delivered by the delivery member and comprising: 1.5.1 a valve housing; 1.5.2 a valve piston which is mounted such that it can be moved in the valve housing, comprising an active surface for a valve-actuating pressure (P 20) of a fluid; and 1.5.3 a valve spring which counteracts a force exerted on the valve piston by the valve-actuating pressure (P 20), 1.5.4 wherein the valve piston comprises another active surface for the valve-actuating pressure (P 20), and the active surfaces (23, 24) are arranged to counteract each other and are different in size in order to generate a differential force which acts on the valve piston counter to the valve spring and corresponds to the difference in size of the active surfaces (23, 24); and 1.5.2 a valve piston which is mounted such that it can be moved in the valve housing, comprising an active surface for a valve-actuating pressure (P 20) of a fluid; and 1.5.3 a valve spring which counteracts a force exerted on the valve piston by the valve-actuating pressure (P 20), 1.5.4 wherein the valve piston comprises another active surface for the valve-actuating pressure (P 20), and the active surfaces (23, 24) are arranged to counteract each other and are different in size in order to generate a differential force which acts on the valve piston counter to the valve spring and corresponds to the difference in size of the active surfaces (23, 24); and 1.6 an adjusting device (27, 28), by means of which the valve piston can be adjusted in the direction of the force exerted by the valve-actuating pressure (P 20) or counter to this force, 1.7 characterised in that the adjusting valve comprises the adjusting device (27, 28), 1.8 the adjusting valve is controlled electrically, 1.9 the valve-actuating pressure (P 20) and a force exerted on the valve piston by the adjusting device (27, 28) act together counter to the force of the valve spring, and 1.10 the position of the valve piston can be adjusted relative to the valve housing independently of the valve-actuating pressure (P 20) acting on the active surfaces (23, 24).