Hybrid vehicle simulation methods combine physical test articles (vehicles, suspensions, etc.) with complementary virtual vehicle components and virtual road and driver inputs to simulate the actual vehicle operating environment. Using appropriate components, hybrid simulation offers the possibility to develop more accurate physical tests earlier, and at lower cost, than possible with conventional test methods. MTS Systems has developed Hybrid System Response Convergence (HSRC), a hybrid simulation method that can utilize existing durability test systems and detailed non-real-time virtual component models to create an accurate full-vehicle simulation test without requiring road load data acquisition.MTS Systems and Audi AG have recently completed a joint evaluation project for the HSRC hybrid simulation method using an MTS 329 road simulator at the Audi facility in Ingolstadt, Germany. The hybrid simulation consisted of an Audi A5 Coupé installed on laboratory road simulator, combined with virtual vehicle tires modeled using FTire™ and Audi digital roads running in the standard ADAMs simulation environment. The scope of the evaluation included the development of a complete set of 20-channel control signals for the 329 road simulator for 3 rough-road durability test profiles representing selected Audi proving ground roads.The physical spindle loads developed by the A5 + FTire hybrid simulation were compared to vehicle spindle loads obtained from three other methods: 1) a road load measurement for the A5, 2) a road measurement for a different but similar vehicle, and 3) analytically predicted loads from a complete virtual vehicle system model. The comparisons indicated that laboratory vehicle test loads created using accurate tire models and hybrid simulation closely correlate to fatigue-critical loads from a physical road measurement, and in overall result in more appropriate loads for the test vehicle than analytically predicted or "bookshelf" loads.This paper describes the HSRC hybrid simulation method, and its potential advantages for the vehicle durability testing and development process compared to other laboratory simulation methods. The paper describes the application of HSRC to create a full-vehicle laboratory test, and presents detailed simulation results for rough-road test events, along with comparison of the results to 3 alternate sources of vehicle loads.