Models have a wide area of application in the automotive industry. They are used to test innovative control strategies in the development phase or to design more advanced engine management systems to reduce pollution and fuel consumption. A model can also be a useful tool for diagnosis, making possible the simulation of faults without affecting costs. Different kinds of models exist, describing engine performances at a very high level of detail. However with a limited set of experimental data, behavioral models are preferable for automotive companies, which benefits from their simplicity, their relatively accurate results and not being computationally demanding. This thesis aims to elaborate a model of an internal combustion engine for Hardware-In-The-Loop simulations.