This study investigates autothermal reforming of fuel cell-grade methanol as a method for producing hydrogen for transportation applications. A previous study on the effects of oxygen-to-carbon ratio on ATR reactor performance showed that the optimum of $O_2/CH_3OH=0.30$ found in the experimental tests is 30% higher than the theoretical optimum of 0.23. In this study, the influence of catalyst bed length is investigated to give insight into the reaction progression through the catalyst bed in methanol autothermal reformation. The effect of reaction progression through the catalyst bed is experimentally investigated in relation to reactor output parameters of fuel conversion, temperature profile, and reactor efficiency. The results from this study serve as a baseline for future research of autothermal reforming of hydrocarbon fuels as a method for producing hydrogen.