In the field of vehicle rollover, the quantification of occupant safety provided by a passenger car has, up until now, been quite difficult. As existing test procedures such as FMVSS 208 and FMVSS 216 mainly aim at the structural safety of vehicles, there is a lack of standardized injury criteria for the occupants. The results presented in this paper are based on the experience gained during the development of a rollover detection system. For this purpose a large number of rollover simulations using the modular vehicle modeling program Fasim_C++ have been conducted. This multi-body simulation tool has been developed at the Department of Mechatronics, and provides the possibility to model complex three dimensional vehicle models and include complex mechatronic elements like hydraulic systems, actuators, sensors and electronic controllers. Furthermore the occupant behavior during rollover has been studied. For this purpose the commercial occupant simulation toolset MADYMO is used. Various accident scenarios are modeled using FASIM_C++ and the subsequent occupant behavior is analyzed in MADYMO.By discussing the simulation results of various rollover maneuvers, this paper suggests requirements for a standardized rollover test procedure that focuses more on occupant safety than the existing regulations.