Fully quantal scattering calculations are carried out for H 3 5 Cl in Ar, using both close-coupling and coupled-states calculations on the Ar-HCl H6(4,3,0) potential surface of Hutson, which was obtained by fitting to extensive spectroscopic data on the Ar-HCl and Ar-DCl Van der Waals complexes. Line width and shift cross sections are calculated for the pure rotational and infrared fundamental and first overtone bands of HCl. Both widths and shifts are found to be in reasonable agreement with existing measurements. However, there is considerable scatter between the different sets of experimental results, and more precise measurements are needed to provide a sensitive test of the quality of the potential.