Abstract For distributed drive electric vehicles (DDEVs), the influence of the power ratio between the front and rear motors on the energy efficiency characteristics is investigated. The power-train systems of the DDEVs in this study are divided into two different power-train configurations. The first is with its front axle driven by wheel-side motors and the rear axle driven by in-wheel motors, and the second is with both the front and rear axles driven by in-wheel motors. The energy consumption simulation and analysis platform of the DDEV is built with Matlab/Simulink. The parameters of the key components are determined by the experiments to ensure the validity of the data used in simulation. At the same time, the vehicle’s average energy efficiency coefficient is defined to describe the energy efficiency characteristics of the power-train strictly. Besides, the control strategies for driving and braking of the DDEV based on energy efficiency optimization are presented. Then, based on the existing energy efficiency MAPs of the power components including motor, inverter and reducer, the methods which calculate the energy efficiency MAPs of the power components with other sizes by calculating power losses related to the parameters and sizes are proposed. Thus, the energy efficiency MAPs of the power-train with different power ratios between the front and rear motors are acquired. Several simulations with different typical driving cycles are implemented to compare the energy efficiency characteristics of different power-train configurations. As a result, based on the energy efficiency optimization, we propose the best power ratio between the front and rear motors, which is about 1:2.5 for the power-train using front wheel-side motors and rear in-wheel motors, while about 2:1 for another configuration. Our works can provide recommendations for allocation of front motor power and rear motor power for DDEVs. Introduction In recent years, for DDEVs, the advantage that the torques of four wheels can be controlled independently brings much space to the optimization for performance of the power system. Thus, a lot of vehicle manufacturers and research institutions show much interest in the research of DDEVs. At the same time, the energy efficiency, which is closely related with the driving range for DDEVs, becomes a current research focus. The factors affecting the energy efficiency of electric vehicles include the topology of the drive system, the control strategies of driving and braking, the energy efficiency of the power components, the power allocation ratio between the front and rear motors and so on. According to the topological structure, electric vehicles can be divided into two types: centralized drive and distributed drive. Y u Zhuoping et al [ 1] concluded that the DDEV not only has the characteristic of independently controlled torques during driving and braking, but also can improve the energy efficiency by optimizing the torque allocation strategy which adjusts the torque ratio between the front and rear motors based on specific driving cycles. Wang Meng et al [2] compared the DDEV and the centralized drive electric vehicle, and presented that the DDEV has a better energy consumption performance than the centralized drive electric vehicle. For the DDEV with two driving motors, according to the motor’s energy efficiency MAP, the control strategy for optimized torque allocation between the front and rear motors was studied by ADAM BARÁK et al [3]. And by comparing the energy efficiency characteristics of DDEVs with many types of motors, the conclusion that the DDEV with both front and rear permanent magnet synchronous motors has the best energy efficiency has been drawn. Yan et al [ 4] came up with the global optimization control algorithm for power allocation based on the Karush-Kuhn-Tucker condition (KKT condition), for the DDEV with four in-wheel motors. And the validity of this