Daimler showcases Unimog U 430 offroad truck on hydrogen

At the European Demopark open-air exhibition for the green industry, Daimler Truck showcased a demonstrator prototype of its offroad truck, the Unimog, with a hydrogen combustion engine. This hydrogen Unimog based on the U 430 is part of the WaVe project funded by the German Federal Ministry for Economic Affairs and Climate Action.

This project with 18 partners from industry and science started in July 2021, and is set up “to find out the extent to which the tasks of a conventional diesel engine as a multi-power distributor for the traction drive and all power take-offs can also be performed by hydrogen-powered combustion engine in the future”. In the Unimog case, the U 430 has a body implement for mowing.

Keyoun engine

The hydrogen engine is provided by Keyoun, a Münich-based company specializing in converting existing diesel commercial vehicles to zero-CO2 hydrogen vehicles, and is equipped with H2PFI injectors made by Hoerbiger. The latter joined forces with Keyoun in early 2021 to produce and commercialize injectors for hydrogen engines targeted for the heavy-duty sector.

The first tests of the H2 engine were completed on the test stand in autumn 2022. In late 2022, the engine was built into the Unimog, and initial tests in driving operation were carried out.

Replacing 7.7-liter diesel

Daimler Truck doesn’t specify the specs of the hydrogen ICE engine. Still, it says it’s the better solution to provide the power for its heavy off-road truck developed explicitly for implementation use. The regular U 430 features a Euro VIe six-cylinder diesel engine of 7 698 cm³ delivering 220 kW/299 hp and 1 200 Nm of torque.

That engine must also deliver power to all kinds of machinery the Unimog can be equipped with. According to Daimler Truck, a battery-electric version or a fuel cell system on hydrogen would be challenging to implement in the compact off-roader. Hence the choice for hydrogen combustion.

Only climate-neutral trucks by 2039

By 2039, Daimler Truck intends to offer only climate-neutral new vehicles in driving operations in its core global markets (EU30, USA, and Japan). For its e-trucks, it holds on to a dual strategy with battery and hydrogen-based propulsion.

By the end of June 2024, for research purposes, complementary drive systems such as hot hydrogen combustion in the piston engine for the Unimog will be investigated as part of the WaVe joint venture, the company says.