A vehicle has an engine driving an alternator. The electrical energy supplied by the alternator feeds an electric traction motor, via a rectifier, an electric line, and an inverter. The electric traction motor is mechanically coupled to a wheel. A super-capacitor is connected to the electric line by a voltage-matching circuit. A unit for controlling the torque applied to the vehicle wheel manages the circulation of the electrical energy in the drivetrain so as always to discharge the super-capacitor as a priority, in order to be able to be ready to recover the energy at the next braking.