Rolls-Royce is continuing its drive towards becoming a lower carbon business with engine tests for its mtu diesel engines in Friedrichshafen, Augsburg and Ruhstorf in Germany now carried out on hydrogenated vegetable oil (HVO).
By the end of 2025, the company estimated it had saved around 3,200t of CO2 emissions as a result of switching to renewable diesel derived from vegetable oils and waste materials. Emissions of soot particles and NOx also fell significantly.
The switch began with initial test runs in September 2024, with further facilities switching over the following year until, finally, the key diesel engines of the mtu Series 4000 were all being tested with HVO in Germany. In Friedrichshafen, this reduced CO2 emissions from test benches by around 25% in 2025, compared to operation with fossil fuel. In 2026, Rolls-Royce expects even greater savings, as the test benches will be operated with sustainable fuel all year round.
Nicholas Templin, EVP Production, Logistics and Quality Management, 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.”
In 2025, the average price difference between HVO and B7 diesel was around 10c/litre.
Rolls-Royce has been testing and approving its key mtu engine series for HVO and other sustainable fuels compliant with DIN EN 15940, since 2021. The major advantage is that HVO can replace fossil diesel without the need for technical modifications to the engines. In addition to reducing CO2 emissions, HVO offers further environmental benefits. The fuel burns more cleanly, reducing particulate emissions by 40% or more and NOx emissions by up to 8%. Depending on the production process and raw materials used, CO2 emissions over the entire lifecycle can be reduced by up to 90% compared to fossil diesel. As HVO is produced from renewable raw materials and, in part, from waste, the greenhouse gases emitted across production, transport and use amount to no more than those previously sequestered during the growth of the biomass.
Numerous Rolls-Royce customers are already successfully using HVO with mtu engines. Rolls-Royce says it supports its customers in switching to HVO – from selecting suitable products to advising on technical and regulatory frameworks.
Image: mtu 4000 engine on the test bench in Friedrichshafen (credit: Rolls-Royce Power Systems)
