Rolls-Royce is releasing mtu rail engines for use with sustainable fuels. With synthetic diesel fuels of the EN15940 standard, CO₂ emissions can be reduced by up to 100% compared to fossil diesel. Hydrotreated Vegetable Oil (HVO or renewable diesel), which is already commercially available today, reduces CO₂ emissions by up to 90%. If the fuels are produced with the help of renewable energy and green hydrogen—through what is termed a Power-to-X process—existing rail vehicles can be operated in a completely CO₂-neutral manner.

The mtu Series 1800 engines which are used in mtu PowerPacks, as well as Series 1300 and 1500 for locomotives and multi-purpose vehicles, are already approved for use with synthetic fuels such as HVO. Series 1600 and versions of Series 4000 engines will follow in the near future.

The release of engines for climate-friendly fuels requires a series of tests and trials and Rolls-Royce has found strong partners for this activity. DB Cargo and RDC Autozug Sylt have already tested or are currently testing mtu Series 4000 engines with HVO in their locomotives.

DB Series 294 locomotive with an 8V 4000 R41 mtu engine running on HVO.

HVO allows our customers to significantly reduce their greenhouse gas emissions with existing vehicles and engines and to make an important contribution to climate protection today. Emissions of soot and nitrogen oxide are also significantly reduced—without having to make any changes to the drive system or infrastructure. No significant changes in performance were observed and availability and service life of our engines remain unchanged, which is highly attractive for our customers.

In combination with our mtu Hybrid PowerPack, HVO allows not only low-CO₂, but also locally emission-free and almost silent operation. This makes it possible to achieve climate and environmental protection goals with existing vehicles and without the need for complex and expensive changes to infrastructure.

—Jürgen Blassmann, Director Rail Business at Rolls-Royce business unit Power Systems

Since mid-August 2021, DB Cargo, in coordination with Rolls-Royce, first conducted engine bench tests and then operational trials, for example with DB Series 294 locomotives with an 8V 4000 R41 mtu engine running on HVO. After more than 1,800 operating hours, the results are promising.

We were able to use HVO without any problems in our vehicles, without compromising performance and reliability.

—Ali Dogru, Head of Assets and Maintenance at DB Cargo

The evaluation of one of the engines after completion of the field test is scheduled to take place in September 2022, after which Rolls-Royce will promptly release the widely used mtu rail engines of the types 4000 R01 and R03 for synthetic diesel fuels of the EN15940 standard, including HVO. DB Cargo also uses HVO in other locomotives in its fleet.

RDC Autozug Sylt and Rolls-Royce recently started HVO field trials with a Vectron DE diesel-electric locomotive equipped with an mtu engine of type 4000 R04, which meets the strict EU Stage IIIB emission regulations for rail drives.

Vectron DE diesel-electric locomotive equipped with an mtu Series 4000 engine.

Following the successful completion of the tests with RDC, Rolls-Royce also intends to generally release the Series 4000 R04 engines for use with HVO and other EN15940 synthetic diesel fuels, as early as 2023. RDC is already using HVO in other services since July 2022.

Rolls-Royce announced in 2021, as part of its sustainability program “Net Zero at Power Systems”, that it would realign its product portfolio so that by 2030, new fuels and mtu technologies can reduce greenhouse gas emissions by 35% compared to 2019.