The invention refers to a mechanical automotive vacuum pump (10) with a housing arrangement (9) enclosing a pumping chamber (11) and rotatably supporting a pump rotor (16) with a rotor body (22) with a bearing section (35) and a chamber section (36). The rotor body (22) is at the chamber section (36) provided with a radial vane slit (19) wherein a radially shiftable pump vane (18) is supported. The rotor body (22) is at the bearing section (35) provided with a cylindrical bearing surface (39) which defines together with a cylindrical bearing surface (37) of the housing arrangement (9) a friction bearing (38). The rotor body bearing section (36) is provided with a circular lubrication ring groove (60) and the housing bearing surface (37) is provided with a corresponding lubrication inlet opening (66) lying in the same transversal plane as the ring groove (60) and opposite to the ring groove (60). The inlet opening (64) is directly connected to a lubricant pump connector (70) at the housing arrangement (9) of the vacuum pump (10).
