A high performance direct methanol fuel cell is achieved with thin electrolyte membrane. 320 mW cm(-2) of peak power density and over 260 mW cm(-2) at 0.4 V are obtained when working at 90 degrees C with normal pressure air supply. It is revealed that the increased anode half-cell performance with temperature contributes primarily to the enhanced performance at elevated temperature. From the comparison of iRcompensated cathode potential of methanol/air with that of H-2/air fuel cell, the impact of methanol crossover on cathode performance decreases with current density and becomes negligible at high current density. Current density is found to influence fuel efficiency and methanol crossover significantly from the measurement of fuel efficiency at different current density. At high current density, high fuel efficiency can be achieved even at high temperature, indicating decreased methanol crossover. (C) 2017 Elsevier B.V. All rights reserved.