A new, full-dimensional potential energy surface has been constructed to describe the OH+CO<---->H+CO2 reactive system. The new surface modifies the existing many body expansion potential of Bradley and Schatz based on recent ab initio calculations and incorporates an entirely new hybrid surface to accurately describe the OH+CO entrance channel and two possible van der Waals complexes, OH-CO and OH-OC. Quasiclassical trajectory calculations have been performed for the reaction OH+CO-->H+CO2 using the new surface in order to examine the impact of the changes in the surface, to evaluate the accuracy of the surface by comparing to experimental results, and to investigate the reaction dynamics of this interesting complex-forming system. It is shown that the improvement in the description of the entrance channel has a rather large effect on overall reactivity and response to reagent rotational and vibrational excitation, but has little effect on various product properties such as angular and translational energy distributions, which still compare well to experiment. Also, although the reaction forms the intermediate complex HOCO, it is shown that energy is not completely equilibrated among all internal modes and, as a result, there is a strong correlation between reagent and product excitation. (C) 2003 American Institute of Physics.