In this paper, a new semi-active magnetorheological (MR) engine mounting half car model is proposed for improving ride comfort. Such a model uses a dynamic sliding mode controller. It operates as a controller system for controlling the magnetic field strength of the engine mount coil. Controlling the magnetic field strength leads to change the magnetorheological liquid properties and thereby the generated force by the liquid. This controller system is simulated and the obtained numerical results are analyzed. It is shown that such a controller has the own great role in improving vehicle ride comfort in such a way that it can remove 60% of the engine’s vibration amplitude in the worst case as well as the its vibration frequency is tended toward zero. Finally, 25% of the total vibration transmitted from suspension system to vehicle body is reduced. Itisfoundthatusingthiscontroller, the undesirable vibrations imposed on the passengers can be diminished despite uncertainty of the load in the model.