Abstract: Effects upon the overall characteristics of a torque converter having lock-up match with an engine are studied when the engine employs an all-speed governor and a two-speed govemor respectively. For this purpose, calculations and analyses have been carried out, taking into consideration the dynamic behavior, the economic factors, characteristics in automatic lock-up and gear shifting of the vehicle. Conclusins resulting from the study are that the two-speed governor works well with the on-road transport vehickes while more factors must be considered for the off-road vehicles in the choice of governors.