To meet tighter performance requirements of the customers and the future emissions regulation, car manufacturers need to adopt innovative technologies to boost powertrain efficiency. Among these, the engine turbocharging, especially when combined with downsizing, represents a mature technology and a well-established solution, offering a cost-effective path towards the simultaneous fulfillment of both higher power output and lower CO2 emissions. In particular, the development of variable nozzle turbine (VGS – Variable Geometry System) for gasoline engines is gaining consensus thanks to its high aerodynamic efficiency levels and to the possible synergies with other engine technologies (e.g. Miller Cycles). On the contrary, this concept typically operates in much more critical conditions with respect to its diesel counterpart (e.g.