A method for determining the dynamic stiffness and damping of mounts in a powertrain mounting 〖HJ4.5p system (PMS) is developed based on the limitation requirements for the vibrations of a seat track, and the noise at the driver′s ear on the right side. A calculated model with 13 degrees of freedom (DOFs) is proposed that includes 6 DOFs for the powertrain, 3 DOFs for the car body and 4 DOFs for the four unsprung masses. In the model, the stiffness and damping of a mount are simplified as a function of excitation frequency. The vibration transfer function (VTF) or noise transfer function (NTF) from the connecting point of mount and body to the vibration of seat track, and the noise at the driver′s ear on the right side, can be measured and calculated. The vibration or noise of the interested points is estimated under different driving conditions.