The aim of this work is to show a model approach capable of describing the SI engines cold start. The model bases upon a zero-dimensional thermodynamic description of the various gas components. A description of the combustion of homogeneous as well as stratified charges by a fractal approach for the fully established turbulent flame proved to be successful. The cylinder pressure is transferred via a mechanical model of the power train into a driving torque. Quantifying loss torques as well as inertias in addition to this driving torque enables the simulation of the engine run-up.
