Coupling different subsystem simulators can be accomplished by a co-simulation [1, 2]. For this purpose, the subsystem solvers are coupled by appropriate input and output variables. In order to analyze the stability of the coupled simulation, not only the coupling technique must be taken into account, but also the subsystem integrators. On the one hand, the stability of the co-simulation is influenced by the extrapolation of the coupling variables and by the macro-step size. On the other hand, the numerical errors arising from the subsystem solvers may directly affect the coupled simulation. The focus of this paper lies on the question, how the subsystem solvers influence the co-simulation. Therefore, numerical studies regarding the numerical stability and the convergence order have been carried out by using a co-simulation test model. We restrict ourselves to explicit co-simulation techniques, based on a zero-stable applied-force coupling approach. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)