This study presents the challenges arising during the numerical design and simulation of surface-microtextured piston rings. The evaluation of performance is based on the values of asperity and hydrodynamic friction, as well as the lubricant film thickness. The simulation tool AVL Excite Piston & Rings is used to perform the calculations. The aim of this study is to understand how selected surface pre-processing (pre-treatment) steps affect the calculations. Two methods are presented to achieve a realistic surface topography representative of a state after running-in. Pre-treatment is performed through metrological filtering and thresholding of the topography, and Gaussian smoothing of the virtually applied micro-texture array is carried out. The results show the anticipated behavior of decreasing asperity and hydrodynamic friction losses with the concurrent application of both techniques.