Polymer electrolyte membrane (PEM) fuel cells are well suited for automotive applications compared to other types of fuel cells owing to their faster transient response and low-temperature operation. Due to rapid change in loads during automotive applications, study of dynamic behavior is of paramount importance. This study focuses on elucidating the transient response of a PEM fuel cell for specified changes in operating parameters, namely, voltage, pressure, and stoichiometry at the cathode and the anode. Transient numerical simulations are carried out for a single-channel PEM fuel cell to illustrate the response of power as the operating parameters are subjected to specified changes. These parameters are also optimized with an objective to match the power requirements of an automotive drive cycle over a certain period of time.