Abstract A dynamic model is created for evaluating an electric variable transmission (EVT) developed by Allison Transmission Division of General Motors. The model is based on Kane's equations, and the concept of generalized velocity is used. Mechanical losses were considered. The performance of the EVT was simulated using the model. The capacities of the transmission output power and torque while the engine is running on the best fuel economy curve for a given two-mode EVT system are investigated. The operating behaviours of the electric units (motors/generators) are also studied. The results show an effective way to evaluate the EVT design concept.