Hybrid electric vehicles (HEV) have been recently attracting considerable attention from both car manufacturers and customers. This innovative concept is challenged by high expectations concerning the performance and comfort issues [6], whilst at the same time is required to fulfill strict restrictions with respect to the CO2 emissions. In order to achieve these goals, advanced control is applied at all levels of the vehicle, with the aim being to achieve a seamless torque transmission along the HEV powertrain. Whilst low level control is important from the perspective of achieving high performance of the various subsystems, it is essential to have an appropriate high level supervisory control over the entire system. To allow an extensive evaluation of different high level control approaches, a reliable and precise simulation model of a complete vehicle system is required. The main contribution of this paper is an evaluation of different frictional models for the application of a central coupling modelling approach for an all wheel drive HEV driveline system. A modification to an existing model is proposed and its effectiveness is demonstrated via simulation.