Toyota, Mazda, and Subaru Working on Next-Gen Combustion Engines

Since the first-generation Toyota Prius and Honda Insight models arrived in the late 1990s, Japanese automakers have become leaders in offering gasoline-electric hybrid vehicles. Japan's early success with hybrids inspired others, like Tesla, to electrify the automobile further, to the point where we now have hybrids, plug-in hybrids (PHEVs), and pure-electric cars as viable alternatives to gas-only vehicles.

However, while automakers such as General Motors, Ford, Volkswagen, and others have invested billions of dollars in recent years to develop battery-electric vehicles (BEVs) that don't require gas-powered engines, Toyota, Mazda, and Subaru have trailed. But now, not without irony, as the initial excitement about BEVs wanes, the three Japanese automakers have come together to develop next-generation gas combustion engines suited to electrification and the goal of carbon neutrality. Toyota is leading, branding the new strategy as "Engine Reborn." With these new engines, each of the three companies will aim to optimize the integration of motors, batteries, and electric drive units.

Decarbonizing Engines to Lower Life Cycle Emissions

When tracking emissions over a vehicle's entire life, from production to recycling, Toyota says the original electricity energy source and the emissions caused by battery production should also be factored into a BEV's overall environmental impact. Toyota claims that BEVs may require energy from coal power plants to recharge their bigger batteries, and manufacturing BEVs and their batteries can emit more carbon than a comparable combustion engine. According to Toyota, hybrid vehicles — like its iconic Prius, which is among the most fuel-efficient, gas-powered cars you can buy — generate more emissions in operation but less in production and energy supply than BEVs.

That said, no matter how big the battery and electric motor are, hybrid setups will always emit carbon as long as they are attached to gasoline-burning engines. With a shared goal of reducing carbon dioxide (CO2) emissions, Toyota, Mazda, and Subaru plan for these new Engine Reborn gas units to be more efficient, perform better, and burn all sorts of carbon-neutral fuels, including biofuels, liquid hydrogen, and synthetic fuels (also known as e-fuel).

New Engines will Revolutionize Vehicle Packaging

Car designers love the flexibility compact BEV drivetrains provide for their creative minds, compared to the more cumbersome internal combustion hardware. With that in mind, the Japanese trio also hopes these new engines will give designers more freedom by making them more compact. These smaller engines could allow for lower hoods and improved aerodynamics, supporting the overall goal of improving fuel economy and complying with stricter emissions regulations.

Each Brand will Focus on its Own Signature Engine

Even though ​​Toyota, Mazda, and Subaru compete for car buyers' wallets, Subaru's horizontally opposed "boxer," Mazda's rotary-based range-extender, and Toyota's inline four will continue to be offered. That competition will continue with the Engine Reborn strategy, with each automaker developing a "signature" engine.

Toyota plans a 1.5-litre engine that will be 20 per cent smaller in volume and 15 per cent lower in height than its turbocharged counterpart. Meanwhile, Mazda is working on rotary-electric powertrains with either one or two rotors. Subaru's next generation of boxer engines will feature a hybrid system previewed with a Crosstrek prototype.

"The three companies, which share the same aspirations, will refine engine technologies through friendly competition," said Toyota CEO Koji Sato, who was joined on stage during the Engine Reborn media event by Subaru CEO Atsushi Osaki and Masahiro Moro, Mazda's CEO, in which Toyota owns minority financial stakes.

Maybe the Gas Engine isn't Dead Yet

While the Japanese automakers' strategy towards carbon neutrality is interesting, there are still plenty of questions. Investment figures, time frames, costs, efficiency gains, and plans for corporate synergies between Toyota, Subaru, and Mazda have yet to be presented. While Toyota is a hybrid leader, its expertise should benefit the other two companies.

And now, the Japanese may have company trying to save the combustion engine.

One week after the Engine Reborn event, France's Renault Group and China's Geely announced a new company called "HORSE Powertrain Limited." Located in London, England, the partnership will focus on creating hybrids, internal combustion engines, synthetic fuels, and hydrogen.

Renault Group and Geely said that a combination of highly efficient internal combustion engines, lower carbon e-fuels, and hydrogen can achieve "successful decarbonization in a world where more than half of vehicles produced are expected to still rely on combustion engines by 2040."