Global commercial vehicle powertrain giant, Cummins has revealed a revolutionary internal combustion 15-litre engine using hydrogen as its fuel source, paving the way for what it believes will be an ongoing future  for clean emissions-free  internal combustion heavy transport.

The CumminsX15H powerplant operates like a diesel engine but with clean hydrogen fuelling the combustion phase and will be built on the company’s new engine platform, which it dubs as ‘fuel-agnostic’, that will see engines share components below the head which ever fuel they use, with different combusiotn chambers and heads to match the fuel the engine  is using.

Cummins has indicated X15H hydrogen engine will enter production in 2027, along with a smaller 6.7-litre version.

Cummins, says hydrogen internal combustion engines such as the X15H will be more affordable than hydrogen fuel cell electric vehicles (FCEVs) and will be able to be installed into current trucks without major  modifications.

Jim Nebergall, the general manager of hydrogen engines for Cummins said engines designed to burn hydrogen will enable the transport industry to reduce greenhouse gas emissions within the decade without larger scale investment  in FCEV technology.

“Our customers are responding favourably to this practical technology. These engines look like engines, they sound like engines, and fit where engines normally fit,” Nebergall said.

The downside of burning hydrogen rather than using it in an FCEV system is that it is only about half as efficient and while it is free of carbon emissions, hydrogen ICE engines do emit harmful nitrogen oxides.

FCEV systems offer around 60 per cent efficiency, while hydrogen ICEs only operate at about 30 per cent efficiency which means it uses double thefuel consumption and requires double the fuel tank capacity to achieve the same range.

The forced induction required in hydrogen fuelled ICE powertrains is what leads to the production of the   nitrogen oxide. The only emission from FCEV systems however is clean water.

However the relatively easy integration that the hydrogen ICE concept offers could make a significant

positive impact on the environment given that after aviation and shipping, medium to heavy trucks account for most global transport emissions, so hydrogen engines such as the X15H could still be an easy option in the short term.

Cummins isn’t the only manufacturer investing in hydrogen ICE engineering and development with Japanese auto giant Toyota also well down the track of developing the technology for its future models.

Toyota revealed a hydrogen-powered version of its performance hot hatch the GR Yaris featuring the same powertrain as the experimental hydrogen-powered Corolla Sport it co-developed with Subaru, which Toyota holds a significant shareholding in. The Corolla has successfully competed in the Super Taikyu race series in Japan.

Toyota has adapted same fuel tanks and refuelling mechanism from its Mirai FCEV for use in the hydrogen GR Yaris concept, with the liquid hydrogen fed to a modified engine that Toyota says offers better responsiveness than a comparable petrol engine as a result of the quicker combustion rate offered by the diatomic gas.

Toyota and Yamaha have also collaborated on a hydrogen powered 335kW/540Nm 5.0-litre V8 engine based on the petrol V8 used in its Lexus RC F.

Mazda has also flagged it is developing a hydrogen version of its ‘thirsty’ but powerful rotary engine.