Effect of the radial grid resolution on the arrival time and width of the shock of the CME. Left panel: arrival time of the CME shock (in hours after the CME insertion at 0.1 AU) vs. the radial grid resolution. Right panel: CME shock width (in hours) vs. the radial grid resolution for the low, middle, and high resolution simulations (blue, orange, and green, respectively). The points in red and purple represent the results of the middle and high resolution simulations with the original equidistant grid cells. The horizontal axis displays the number of cells in the radial direction in each resolution.