Next-Gen Subaru Boxer Hybrid Motor Revealed With Proper Electrification

Subaru has shed some light into its next-generation boxer hybrid powertrain developed as part of its joint decarbonisation effort with rivals Toyota and Mazda.

Subaru unveiled its next-generation boxer hybrid powerplant, and it stands as the first developed by the marque as part of its joint ‘multi-pathway’ collaboration with rivals Toyota and Mazda. 

This innovative setup combines Subaru’s signature horizontally-opposed ‘boxer’ engine with hybrid technology, creating a series-parallel hybrid system similar to Honda’s e:HEV system.

The new powertrain marks a departure from Subaru’s current ‘e-boxer’ mild-hybrid (MHEV) system primed in the Forester and Crosstrek models marketed in Europe and North America. Key to this is its integration of the internal combustion engine, an electric motor, transfer case, and transmission at the front of the vehicle.

This configuration includes a drive shaft extending to a small rear diff, thus enabling all-wheel drive (AWD). The power control unit is positioned atop this setup, allowing for a traditionally-sized fuel tank to be positioned at the rear.

Subaru's CTO Tetsuo Fujinuki, emphasised the importance of the flat engine configuration and AWD system, which are key attractions - and signature elements - for Subaru customers. Though he acknowledged that horizontally-opposed engines may not be the most efficient option, they are integral to Subaru’s identity.

“If you were just going for efficiency, horizontally-opposed engines are not necessarily always the best option. But what would Subaru be without them? The basis of our focus is differentiation.” Fujinki said.

While specific details about the internal combustion component, such as capacity, power outputs, and fuel consumption, remain undisclosed, Fujinuki noted that the unit is smaller than Mazda’s prototype Rotary range-extender and will be compatible with carbon-neutral fuels starting next year. Additionally, plug-in hybrid applications are also planned for the future.

Unlike Subaru’s traditionally favored continuously variable transmission (CVT), the new system will transmit power to the wheels via a transaxle. Production of this advanced powertrain is set to commence later this year at Subaru’s recently renovated Kitamoto Plant. KR