This paper presents a mechatronic model of a powertrain with a half toroidal continuously variable transmission. In this model, the actuator, the load on the output shaft, and the mechanical, electrical, and control dynamics are simultaneously considered. A reduced mathematical model is stated for the half toroidal transmission, where a time-variant transmission ratio is considered to drive different input/output dynamic torques of the powertrain. The dynamic performance of the mechatronic model is shown through three case studies with different inertial/dynamic loads at the output shaft. Simulation results are performed for fixed and automatic transmission ratio changes. The model and simulation results presented in this article extend the options to design, control, and drive mechatronic systems that include a half toroidal continuously variable transmission.