Rolls-Royce has officially begun testing for its mtu diesel engines in Friedrichshafen, Augsburg and Ruhstorf in Germany utilising solely hydrogenated vegetable oil (HVO).
As of the end of 2025, the company had successfully saved roughly 3,200 tonnes of CO2 as a result of the switch to the renewable diesel alternative, which is made up from vegetable oils and waste materials.
Rolls-Royce has been testing operations with HVO since 2021
© Rolls-Royce
Reports have also shown that the emissions of soot particles and nitrogen oxides fell ‘significantly’ since the switch first began with initial test runs in September 2024.
The following year, further facilities made the transition until, ultimately, the key diesel engines of the mtu Series 4000 for ships, trains and energy systems in Germany were all being trialled with HVO – with CO2 emissions from testing facilities (test benches) in Friedrichshafen reduced by around 25% in 2025 when compared to operations with fossil diesel.
Rolls-Royce has stated that it expects larger savings across 2026, as all test benches will now begin operating with sustainable fuel throughout the year.
Nicholas Templin, Executive Vice President of Production, Logistics and Quality Management at Rolls-Royce Power Systems, said:
Decarbonising our operations is a clear corporate priority for us. Through our solutions, we are also supporting our customers’ sustainability goals.
The switch to HVO is an important step towards even more sustainable manufacturing of our products. Our experience has been entirely positive: using HVO makes the production of our products even more sustainable and has proven its worth in operational use.
The company has been testing and approving its mtu engine series for HVO and other sustainable fuels since 2021, doing so due to the fuel’s ability to replace fossil diesel without the need for technical modifications to the engines themselves.
Thus far, a number of Rolls-Royce customers are already utilising HVO with mtu engines – including in trains, ships, mining machinery, data centres and energy systems. Deutsche Bahn (DB) has been using sustainable fuel in its vehicles since 2022, whilst data centres such as the Eco Datacenter in Sweden also run their emergency generators on HVO.