A parametric study is carried out using the nonisothermal polymer electrolyte fuel cell (PEFC) model presented in Part I, which was experimentally validated against the current distribution data. The focus is placed on exploring the characteristics of low-humidity operation, including the effects of gas diffusion media tortuosity and thermal conductivity and membrane electrode assembly properties, such as ionomer fraction of the catalyst layer, the cathode kinetic parameter, and the membrane thickness. In addition, the effect of contact resistance is studied and co- and counterflow configurations between the anode and cathode streams are contrasted. The present work elucidates detailed effects of these important design and operating parameters on the current density distribution and assists in identifying optimal water and thermal management strategies for the low-humidity operation of PEFCs. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.2137655] All rights reserved.