Since 1998, during my activity at the FKFS and IVK University of Stuttgart an innovative fast-response 3D-CFD tool has been developed. This tool aims for a better integration in the development process of internal combustion engines and represents a step towards virtual engine development. A more reliable calculation of the engine processes for engineering purposes and a clear representation of the results allow a more comprehensive analysis of the engine behavior. In addition comparisons with experimental data or results from other simulation tools can be easily and efficiently performed. The 3D-CFD-domain is not, as usually, limited to the simulation of the cylinder alone, but can be extended up to the full engine. This allows a more predictive simulation by reducing the effects of the boundary conditions on the results. The simulation run is always performed over many operating cycles so that the convergence of the results can also be proofed.