The dynamics of intramolecular energy transfer of large molecules has been the subject of a great deal of attention from both experimentalists and theorists. In recent years, collisions involving large molecules have been studied actively, revealing valuable information on the rates and the mechanism of vibrational energy transfer processes. The average energy transfer per collision between the vibrationally highly excited benzene and a noble gas atom is known to be about −30 cm, which is much smaller than benzene derivatives such as hexafluorobenzene and other hydrocarbons such as toluene and azulene. For example, the mean energy transfer per collision measured by the ultraviolet absorption method for hexafluorobenzene + Ar, is −330 cm, whereas the calculated value for the same system at 300 K using quasiclassical trajectory methods is −150 cm. For toluene + Ar, the amount of energy transfer is about −200 cm. These magnitudes are much larger than the results for benzene colliding with argon. Among large organic molecules, toluene is a particularly attractive molecule for the study of collision-induced intramolecular energy flow because of the presence of both methyl and ring CH bonds, presenting an intriguing competition between them. In elucidating this competition, it is particularly important to understand the direction of intramolecular energy flow in the interaction zone, i.e., from the ring CH to the methyl CH or the reverse. In this paper, an extension of the previous works in refs. 10 and 11, we study the collision-induced dynamics of vibrationally highly excited methyl CH bond or the ring CH bond of toluene interacting with argon using quasiclassical trajectory calculations with particular emphasis on the effect of the inner zone on the energy transfer which was not included in our previous works. Using the solutions of the equations of motion, we discuss the collision-induced energy transfer in the Ar-toluene system and intramolecular energy transfers among various stretches and bends of toluene, especially their time evolution. We then analyze the nature and mechanism of the competition in transferring energy to or from the incident atom and between the methyl CH mode and the ring CH mode. We set the initial vibrational energy of the highly excited methyl CH bond or the ring CH bond equal to the state just 0.10 eV below the dissociation threshold of each bond at 300 K. Interaction Model