Our infrastructure on the chassis dynamometer and engine test stand enables in-the-loop operation of the test specimen. Simulation with the assistance of a real-time capable vehicle model enables real driving situations and operating strategies to be modelled on the test bench at an early stage and their development and evaluation to be carried out. The methodology used enables in-the-loop operation of individual system components (hardware-in-the-loop) through to complete vehicle simulations on the chassis dynamometer (vehicle-in-the-loop).