Toyota is actively investing in hydrogen internal combustion engine (ICE) technology as part of its 'multi-pathway' approach to decarbonizing the automotive industry. Alongside hydrogen fuel-cell electric vehicles (FCEVs), Toyota has been developing hydrogen ICE technology, which involves a combustion engine that produces sound unlike the silent FCEVs. While Toyota has showcased road-going prototypes, there are no production models with hydrogen combustion powertrains available to the public yet. Toyota Australia's vice president mentioned that hydrogen combustion technology will see further development over the next five years and could become more mainstream by 2035-2040. The carmaker conducted a pilot program with seven Hydrogen HiAce prototypes loaned to fleet operators, featuring a modified 3.4-litre V6 engine running on hydrogen. Despite the power and torque differences compared to petrol engines, Toyota continues to enhance hydrogen ICE technology. This commitment aligns with Toyota's vision for hydrogen as a significant part of the automotive industry's future, despite challenges such as the need for a widespread hydrogen refueling network. While Toyota leads in this area, other brands like BMW and Mazda have also explored hydrogen technology, highlighting a broader industry interest in alternative fuel sources.