FRIEDRICHSHAFEN, Germany - Rolls-Royce has converted MTU diesel engine testing at three German facilities to hydrogenated vegetable oil, eliminating approximately 3,200 tonnes (3,527 US tons).of CO2 by the end of 2025. The phased transition began in September 2024 at sites in Friedrichshafen, Augsburg and Ruhstorf and ultimately encompassed the full MTU Series 4000 line used in ships, trains and energy systems.
Test bench CO2 emissions at Friedrichshafen fell roughly 25% in 2025 compared to fossil diesel, with steeper reductions expected in 2026 as facilities run on HVO year-round. The fuel also cut particulate emissions by 40% or more and reduced nitrogen oxides by up to 8%, with no engine modifications required.The HVO push reflects a broader Rolls-Royce sustainability strategy that extends well beyond ground power.
The company has completed compatibility tests for 100% sustainable aviation fuel on its full range of in-production civil aerospace engines, including the Trent 700, 1000 and XWB series, finding no technical barriers to adoption. Like HVO for diesel engines, SAF is chemically similar enough to conventional jet fuel to require no hardware changes, positioning both fuels as near-term, drop-in solutions while longer-term alternatives such as hydrogen mature.
Unlike first-generation biofuels (like Ethanol or FAME biodiesel), HVO and SAF are "paraffinic." This means they are almost chemically identical to the fossil fuels they replace, allowing them to be used in existing engines without the rubber seals perishing or the fuel "gunking up" during storage.
