This paper extends previous mechanistic rate information for catalytic oxidation into a more complex fuel system, methanol oxidation over platinum and rhodium. Rh and Pt have generally similar characteristics, but also show some significant differences owing to the high energy binding state of oxygen on the rhodium surface. On Pt, previous catalyzed methanol oxidation research is examined and a mechanism involving surface carbon formation is proposed. Data over Pt metal from room temperature up to 1600 K is discussed. In general, methanol conversion starts at temperatures as low as 400 K in large excess oxygen, but begins at temperatures up to 900 K for methanol decomposition (no oxygen) on Pt. Evidence for a transition from a carbon covered to a CO covered surface with increasing temperature is examined. This transition results in low catalyst activity for decomposition below 900 K. Also, oscillatory behavior is noted in this system under some conditions. None of these effects are noted on Rh. In contrast to Pt, where oxygen improves low temperature conversion, a large excess of oxygen appears to block surface sites and reduce activity on Ph. Otherwise, Rh decomposes and oxidizes methanol without dissociating the C-O bond, leaving the metal active for decomposition at temperatures as low as 500 K. On both Pt and Rh, a mechanistic model is developed. These models give excellent agreement with experimental results, suggesting that the proposed mechanisms are at least qualitatively correct. On Rh, the model assumes noncompetitive oxygen binding and assumes the C-O bond to be nondissociative. On Pt, the model allows the methanol C-O bond to break, forming surface carbon. Other differences between Pt and Rh results can be readily attributed to differing activation barriers to hyroxyl formation on these two metals.