Toyota has been at the forefront of alternative fuel innovation for a long time, pioneering hybrid technology, hydrogen fuel cells, and internal combustion hydrogen engines. While most automakers are gearing towards battery-electric vehicles (BEVs), Toyota is taking a different path that could redefine the future of combustion engines.
Toyota is working on liquid hydrocarbon combustion engines, which is a new engine technology that could offer an alternative to both traditional gasoline and hydrogen fuel cells. The Japanese automaker plans to make the liquid hydrocarbon combustion engine available for use in car production in 2026.
What is a Liquid Hydrocarbon Combustion Engine and How Does it Work?
A liquid hydrocarbon combustion engine is a new type of internal combustion engine that runs on synthetic, carbon-neutral liquid fuels. Unlike hydrogen internal combustion engines (HICEs) which burn gaseous or liquid hydrogen, or battery-electric vehicles (BEVs) that run on lithium-ion batteries, this engine uses synthetic fuels that mimic gasoline but emit fewer emissions.
Liquid hydrocarbon fuel is injected into the combustion chamber where it mixes with air and ignites under controlled conditions producing energy to power the vehicle. Unlike hydrogen internal combustion engines (HICEs) which require complex high-pressure storage systems, liquid hydrocarbons can be stored and transported at ambient temperatures making them more practical for commercial use.
Through this technology, Toyota will finally bridge the gap between internal combustion engines and zero-emission alternatives by providing a low-carbon solution that utilizes existing fuel infrastructure while providing performance and other benefits found in traditional ICE vehicles.
Real-World Testing of the Liquid Hydrocarbon Combustion Engine
Toyota carried out a major test of the liquid hydrogen and other alternative combustion technologies during the Super Taikyu Fuji 24-Hour Race using the liquid hydrogen-powered GR Corolla.
After a similar test in 2023, Toyota learned that liquid hydrogen reduced refueling times by 40% allowing the car to achieve 30-lap stints between refueling. This also improved performance and efficiency.
However, some challenges encountered in 2023 were recurrent in 2024 such as pump failures that required multiple replacements during the race. Since then Toyota has revised the design of the fuel pump but intermittent issues with fuel sloshing inside the tank affected performance. The ABS module also failed in 2024 sidelining the car for five hours.
Challenges of Liquid Hydrocarbon Combustion
Toyota’s liquid hydrocarbon combustion engine still faces challenges such as fuel production costs. Synthetic carbon-neutral hydrocarbons are still expensive to produce on a large Scale. Infrastructure is also an issue because there are no stations to distribute liquid carbon fuel. However, this issue will likely be solved if this engine is ready for commercial use.
Why Toyota is so Invested in a Multi-Pathway Approach
While most automakers are abandoning combustion engines in favor of BEVs, Toyota continues to pursue a diversified fuel strategy. This strategy is a mult-pathway that has seen the company focus on hydrogen internal combustion engines, fuel cell electric vehicles, ammonia combustion engines, solid-state batteries, and liquid hydrocarbon combustion engines. Toyota’s strategy to focus on all these technologies instead of one enables it to adapt to the global market where fuel availability, consumer needs, and infrastructure vary significantly.
How Liquid Hydrocarbon Combustion Engine Compares to Other Technologies
Liquid Hydrocarbon vs Hydrogen Internal Combustion Engine (HICE)
A liquid hydrocarbon combustion engine burns synthetic carbon-neutral liquid fuels making it compatible with existing fuel infrastructure and ICE technology. It also offers higher density than hydrogen thus eliminating the need for complex high-pressure storage tanks.
Liquid Hydrocarbon vs Hydrogen Fuel Cell Electric Vehicles FCEVs
A liquid hydrocarbon offers instant refueling and seamless integration with existing fuel systems. On the other hand, FCEVs, require hydrogen refueling stations which are expensive to develop. Therefore liquid hydrocarbon engines are easier to adopt and integrate with existing infrastructure.
Liquid Hydrocarbon vs Ammonia Combustion Engine
Ammonia combustion engine burns liquified ammonia producing high nitrogen oxides which require complex after-treatment systems. Additionally, although ammonia is cheaper and easier to store the hydrogen it burns slowly thus reducing its efficiency.
Liquid Hydrocarbon vs Solid-State Batteries (SSBs)
While liquid hydrocarbon provides high performance, quick refueling, and range similar to traditional gasoline engines, it produces some emissions. On the other hand, SSBs promise higher energy densities, faster charging, and longer lifespan. Therefore they are more viable than liquid hydrocarbons once their production challenges are solved.
Toyota’s liquid hydrocarbon combustion engines offer a bridge between fossil fuels and full electrification and developing them could provide a viable alternative solution in the future.