There’s still life left for combustion engines. As the automotive world races toward lower emissions, many believe electric vehicles are the only path forward. But an exciting alternative is gaining momentum: hydrogen combustion engines.
While most focus has been on hydrogen fuel cells that produce electricity with zero emissions, another approach might prove more practical and cost-effective. These new engines burn hydrogen directly instead of gasoline or diesel, producing almost no pollution while leveraging existing manufacturing infrastructure.
The rise of hydrogen combustion technology
Several major automakers are investing in this technology. Toyota has been the most visible, even fielding prototype race cars powered by hydrogen engines. But impressive advances are also coming from South Korea.
Hyundai–Kia Motor Company (HMC) has partnered with the Korea Institute of Machinery and Materials (KIMM) to develop a 2.0-liter direct injection hydrogen engine. What makes this creation remarkable? It’s actually based on an existing production engine block, modified to burn hydrogen that gets injected directly into the combustion chamber at pressures exceeding 30 bar.
The development team incorporated a turbocharger that significantly boosts performance while maintaining high thermal efficiency across all operating conditions—from ignition to maximum load.
The direct injection breakthrough
What sets this engine apart from previous hydrogen combustion designs is its direct injection system. Earlier hydrogen engines typically injected hydrogen into a port where it mixed with air before entering the cylinder. The problem? Hydrogen’s gaseous state meant insufficient quantities entered the chamber, resulting in a fuel-lean mixture with lower energy efficiency.
By injecting hydrogen directly into the cylinder, the Korean team solved this fundamental limitation. The result is remarkably clean operation with 99% less CO2 and 90% fewer particulate emissions compared to gasoline engines. NOx emissions are minimal at just 15 ppm.
A practical bridge to carbon neutrality
Young Choi, the project’s lead researcher, noted: “The recently developed hydrogen engine technology offers an immediate and economical path to replace fossil fuels with carbon-free hydrogen fuel as the main energy source for vehicles.”
“Through our collaboration with HMC, we’ll verify the engine’s durability and expand this technology beyond passenger vehicles to commercial vehicles and electricity generation units,” Choi added.
The team believes continuous research and development of carbon-free fuel technologies will play a key role in achieving carbon neutrality across the transportation sector.
What does this mean for everyday drivers?
For car enthusiasts worried about the future of internal combustion, this represents a glimmer of hope. The familiar sounds and driving dynamics we love might survive the zero-emission transition. (I know I’m not ready to give up the rumble of an engine just yet!)
While full electrification continues at pace, hydrogen combustion offers an intriguing alternative that could preserve mechanical engineering jobs and utilize existing manufacturing plants. Have you considered what powertrain might be in your garage ten years from now?
This approach also addresses some practical limitations of battery electric vehicles. Refueling with hydrogen takes minutes rather than the longer charging times associated with EVs. The range anxiety that plagues some electric vehicle owners might become a thing of the past with hydrogen power.
The biggest hurdle? Building out hydrogen refueling infrastructure remains a significant challenge in most markets, along with establishing green hydrogen production at scale. These aren’t small obstacles to overcome.
The hydrogen ecosystem
For hydrogen engines to succeed, they need clean hydrogen. Today, most hydrogen comes from natural gas reforming—a process that still generates carbon emissions. The ultimate goal is “green hydrogen” produced using renewable electricity to split water molecules.
This project marks one more step toward diversifying our approach to clean transportation. Rather than a one-size-fits-all solution, the future likely includes a mix of technologies suited to different applications and regional needs.
As automakers race to meet increasingly strict emissions targets, hydrogen combustion engines might carve out their own niche alongside battery electric vehicles and hydrogen fuel cells. The road to zero emissions just got a little more interesting.
