Vibrational energy transfer in van der Waals cluster predissociation and in collisions between aromatic molecules (pyrazine and methylpyrazine) and argon was investigated by means of quasiclassical trajectory calculations. The calculated results for cluster predissociation show that only a small fraction of the available vibrational energy is transferred to recoil energy, and the recoil energy distribution can be described by a smooth, roughly exponential function, in good agreement with experimental data [Yoder, L. M.; Barker, J. R. Phys. Chem. Chern. Phys. 2000, 2, 813]. The calculated collisional step-size distributions are almost independent of temperature for T less than or equal to 300 K, but change in a complicated way for T > 300 K. It is also found that the cluster dissociation energy transfer distributions resemble those of low-temperature collisions.