This paper presents the results of a study that examined the aerodynamic effects of two important ice-simulation features. It first examines two types of pressure-tap instrumentation, a pressure-slice configuration and a tapped-casting configuration, on streamwise and horn-ice simulations. It then examines the aerodynamic sensitivity of small changes in the geometry of horn-ice simulations. These experiments were carried out using ice simulations from icing-tunnel testing on 18-inch chord NACA 0012 and 23012 models. The subsequent aerodynamic testing was performed at the University of Illinois at Reynolds numbers of 1.0×10⁶ to 1.8×10⁶ and Mach numbers of 0.10 to 0.18. The results of the first part showed that there were no major differences in integrated aerodynamic performance between the pressure-slice and tapped-casting configurations. Therefore, either method is acceptable provided that care is taken in determining pressure tap placement. The results of the second part showed that small changes in upper-surface horn height and tip radius can significantly affect maximum lift. This is important as it has application to how ice accretions are traced in order to make two-dimensional ice simulations for aerodynamic testing.