Toyota’s Sixth-Generation THS Hybrid System Moves Toward Wider Adoption With Lighter, Lower Design

Toyota’s sixth-generation THS hybrid system is designed to make its gasoline-electric vehicles feel more like electric cars. The company has reworked the electric motors, power electronics, battery and Hybrid Control system, while keeping the architecture that defines its hybrid lineup.

The front Hybrid Drive Unit now moves toward an e-Axle-style design. Toyota integrates the MG1 and MG2 motors, the Power Split Transaxle, the power-control unit and the transaxle into a single module. The changes cut about 10 kilograms from the system and reduce its height by 100 millimeters, helping lower the vehicle’s center of gravity.

The updated Lexus NX350h illustrates how Toyota has rearranged the motors and gears, simplified the cooling system and increased structural rigidity. The MG2 motor, which mainly drives the vehicle, has also gained strength. As a result, the system can rely on electric power in more situations, with stronger electric-motor involvement during starts and acceleration. Toyota says the changes benefit both performance and fuel economy.

The next stage will involve a new generation of battery packs. Toyota expects the batteries to improve hybrid performance and reduce costs, while allowing the electric motor to operate for longer periods. The company plans to convert existing hybrid-battery production lines in Japan between 2027 and 2028, creating capacity for the equivalent of 600,000 hybrid vehicles.

Recent Toyota patents also show a possible battery layout beneath the two front seats, similar to an electric vehicle. That arrangement could help handling and center-of-gravity performance. To preserve the existing gasoline-vehicle structure, engineers redesigned the exhaust route around the battery and retained space for the fuel tank and luggage compartment.