ABSTRACT: The paper presents the latest developments of a methodology for simulation of tilting vehicles, related specially to the holistic modelling of the hydraulic actuation system. After a few notes on the physical principles and past experiences on modelling and simulation of tilting vehicles, the explanation of the need for a complete closed-loop model for the design and optimization of the tilting system is given. The development in object has gone through several phases, the last of which, here presented and discussed, consists in the physical modeling of hydraulic actuation system. The new model takes into account the physical properties of components like power generation unit, safety valves, and the pipes, with concentrated and distributed losses. Consequently more flexible modelling capabilities and accurate simulation results are obtained, both in nominal and in degraded modes of operation. The paper closes with an overview of the results of the methodology’s validation process.