The synchronization of a classic internal combustion engine, traction electric motor and battery pack traditionally costs valuable luggage compartment space or limits functionality when folding the rear row of seats. In the standard configuration, the battery pack with a capacity of between 1 and 2 kWh and the accompanying control electronics are positioned in the spare tire niche or behind the backrests.
The brand's engineers choose a completely different vector. A new patent application reveals a concept in which the battery module is moved directly under the front two seats - an area that in classic electric vehicles (BEV) is used for the main battery pack. The move lowers the center of gravity and positions it centrally between the two axles, improving mass balance and cornering dynamics, while maintaining full trunk volume.
The key issue with this configuration is the general redesign of the exhaust system. The central tunnel under the floor, where the exhaust tract normally passes, is now occupied by the battery. To overcome this, the designers rerouted the generation: after leaving the engine compartment, it makes a sharp 90-degree turn towards the side sill and continues along the bodywork all the way to the final tailgate at the rear.
Thus, the underfloor space accommodates both the battery pack and the fuel tank, without requiring modification of the cargo compartment. Such a solution is extremely practical for modular platforms designed to support simultaneously gasoline, self-charging hybrid and fully electric drivetrains.
However, redesigning the platform brings its own technical challenges. The new exhaust system route requires a specific geometric shape of the tank, more serious thermal insulation of the sills and repositioning of the catalytic converter and resonator. Due to the installation of the catalyst under the floor in the passenger area, a minimal structural protrusion in the interior is possible.
A challenge also arises with mechanical four-wheel drive systems, since the centrally located battery pack prevents the passage of a traditional cardan shaft. For Toyota's hybrid range, this does not pose a significant problem due to the mass implementation of E-Four technology, in which the rear axle is driven by an independent electric motor without a physical connection to the front axle.
The patented architecture manages to simultaneously preserve the useful volume in the passenger compartment and optimize the vehicle's weight distribution. At this stage, the development remains a patent-protected engineering solution, and it remains to be seen when and in which serially produced models it will find practical application.