The development process in the field of automotive engineering is more and more characterized by virtual developing methods. This approach increasingly potentiates the scientific insights of real world testing procedures or even replaces those methods. Particularly in the area of driver assistance systems, testings in virtual reality - primarily in early development phases - become an essential strategy for assuring product quality while minimizing development expenses. Driving simulation represents one of these virtual tools. In this article, the application of the truck driving simulator at the institute of automotive engineering (FTM) at the Technical University of Munich is shown on the exemplary use for testing and optimizing the driver assistance system ACC Stop and Go.