Three Companies Innovate Internal Combustion Engines for Carbon Reduction
In a groundbreaking collaboration, Subaru, Mazda, and Toyota are working together to develop carbon-neutral fuel technologies. This partnership is set to revolutionize the automotive industry, as each company brings its unique approach to the table, culminating in innovative new engine technologies.
Subaru's Next-Generation e-BOXER
At the Multipathway Workshop on May 28, Subaru unveiled its next-generation engine, the e-BOXER. This horizontally-opposed engine hybrid system is a significant leap forward, combining a 2.5-litre petrol engine with a 90 kW electric motor and a 1.1 kWh lithium-ion battery. This setup delivers a total system output of 145 kW and features direct injection, DOHC with Dual AVCS, and an Atkinson cycle to improve efficiency.
The compact size of the new e-BOXER system is impressive, housing the differential, hybrid unit's twin motors and transmission, and transfer for rear wheels together. Subaru's engineers were able to mount the power control unit in the engine bay, allowing for larger fuel tanks.
Improved Fuel Economy and Cruising Range
The new Strong Hybrid e-Boxer is fitted in the 2026 Subaru Forester and represents a significant upgrade over the previous e-Boxer, which used a smaller 2.0-litre boxer engine paired with a much less powerful electric motor (12 kW) and a smaller battery. The new 2.5L Strong Hybrid improves fuel economy, achieving approximately 6.2 L/100 km on the Forester, a notable improvement reflecting the larger, more efficient hybrid setup. Both versions use the same 63L fuel tank, so the improved fuel economy directly translates to a longer cruising range for the next-generation e-BOXER.
Racing for Progress
The companies are constantly honing their technologies through competition on the racetrack. After the CEOs' presentations, the Chief Technology Officers (CTOs) of the companies discussed their new engine technologies. Subaru's CTO, Fujinuki, mentioned plans to introduce a new vehicle in Super Taikyu-the High Performance X Future Concept. The CTOs presented their engines with a sense of pride, reflecting their passion for their work.
A New Era of Engine Technology
The e-BOXER is not designed to extend the life of Internal Combustion Engines (ICEs), but to create a new engine for the age of decarbonization. Subaru is the only mass-market brand currently producing horizontally-opposed engines. The new e-BOXER employs a series-parallel hybrid arrangement, which promises better fuel economy. Production of the hybrid drive unit for the new e-BOXER will start at a plant in Kitamoto, Saitama, this fall.
Understanding the Engines
For those interested, a basic explanation of in-line, horizontally-opposed, and rotary engines can be found below:
- In-line engines, also known as straight engines, have their cylinders arranged in a single line.
- Horizontally-opposed engines, or boxer engines, have their cylinders arranged in pairs, facing each other horizontally.
- Rotary engines, or Wankel engines, have a rotor that rotates around an eccentric ellipse instead of pistons moving up and down in cylinders.
These new engine technologies are the culmination of each company's unique approach, marking a significant step towards a carbon-neutral future.
- Subaru is introducing its next-generation engine, the e-BOXER, which is a significant leap forward in the automotive industry, combining fuel efficiency and electric power in its hybrid system.
- The new e-BOXER system, fitted in the 2026 Subaru Forester, promises improved fuel economy, achieving approximately 6.2 L/100 km, and a longer cruising range due to the larger, more efficient hybrid setup.
- Companies like Subaru, Mazda, and Toyota are collaborating to develop carbon-neutral fuel technologies, a move that could revolutionize the transportation sector and contribute to a sustainable lifestyle with reduced carbon emissions.
- The new e-BOXER, a series-parallel hybrid arrangement, is not designed to extend the life of Internal Combustion Engines (ICEs), but to create a new engine for the age of decarbonization, marking a new era in engine technology and progress towards a cleaner, more sustainable future in the automotive industry.
