State-to-state branching ratios are reported for vibrational energy transfer in benzene and benzene-d6 due to collisions with D2 and with He in a supersonic free jet expansion. In both the benzene and benzene-d6 experiments the initial vibrational level pumped was 61. The state-to-state branching ratios are different for D2 compared with He in C6H6 and in C6D6. In particular, there is a significant increase in transfer to the 00 level for D2 compared with He. It is postulated that this may be due to the small moment of inertia of D2, which makes V→R transfer an important mechanism for this collision partner.