If you’re a fan of off-road vehicles, you probably know about the Unimog. This versatile and rugged machine from Mercedes-Benz can tackle any terrain and perform any task, from plowing snow to fighting fires. But did you know that the Unimog is also going green? That’s right, Mercedes-Benz is testing a prototype Unimog with a hydrogen-powered combustion engine that could reduce its emissions and fuel consumption. In this article, I’ll tell you more about this innovative project and how it could change the future of the Unimog.
What is the WaVe project?
The WaVe project is a publicly funded initiative by Germany’s Federal Ministry for Economic Affairs and Climate Action, which aims to explore the potential of hydrogen as a fuel source for internal combustion engines. The project involves 18 partners from industry and science and is led by Mercedes-Benz Special Trucks, the division that produces the Unimog. The project started in July 2021 and is expected to run until June 2024.
The main goal of the WaVe project is to examine whether a hydrogen-powered combustion engine can perform the same tasks as a conventional diesel engine, especially as a multi-power distributor for the traction drive and all power take-offs (PTOs) of the Unimog. The Unimog uses its engine to power various attachments and implements, such as mowers, snowplows, cranes, and winches. These require high output, performance, and payload, which are not easy to achieve with battery-electric or fuel-cell drives due to space and weight limitations.
How does the hydrogen-powered Unimog work?
The prototype Unimog is based on the U 430 model, which has a 7.7-liter six-cylinder diesel engine that produces 299 hp and 1,200 Nm of torque. The diesel engine is supplemented by a hydrogen combustion engine from Keyou, a specialist company that develops hydrogen solutions for internal combustion engines. The hydrogen engine is equipped with H2PFI injectors from Hoerbiger, which deliver a precise and efficient hydrogen injection into the cylinders.
The hydrogen engine is installed in the front of the Unimog, next to the diesel engine, and is connected to the same transmission. The Unimog can switch between the two engines, depending on the driving situation and the power demand. The hydrogen engine can also run in parallel with the diesel engine, providing additional power and torque. The hydrogen is stored in a separate tank behind the cab, which has a capacity of 40 kg and a pressure of 350 bar. The tank is equipped with safety and monitoring systems to ensure safe operation.
The hydrogen-powered Unimog has several advantages over a conventional diesel Unimog. First, it can reduce carbon dioxide emissions by up to 40%, depending on the driving mode and the hydrogen source. Second, it can lower fuel consumption by up to 15%, thanks to the higher efficiency of the hydrogen engine. Third, it can improve the noise level by up to 10 dB, making it quieter and more comfortable for the driver and the environment. Fourth, it can offer more flexibility and range than a battery-electric or fuel-cell Unimog, as it can refuel faster and use existing infrastructure.
How is the hydrogen-powered Unimog tested?
The hydrogen-powered Unimog is currently undergoing intensive testing in various conditions and scenarios. The first test phase of the hydrogen engine was completed on a test stand in autumn 2022, where the engine was calibrated and optimized. The engine was then installed in the Unimog at the turn of the year, and initial tests in driving operation were carried out. The prototype Unimog was also presented at the demopark open-air exhibition in April 2023, attracting attention and curiosity.
In the second quarter of 2023, the prototype Unimog will be equipped with a body implement for mowing in order to gain further insights into work mode. The mowing implement consists of a front-mounted mower and a rear-mounted mulcher, which are used to cut and shred grass and vegetation along roadsides and embankments. The mowing implement requires a lot of power and torque from the engine and a high degree of maneuverability and stability from the Unimog. The mowing test will show how the hydrogen engine can cope with these demands and how it can improve the performance and efficiency of the Unimog.