The Wärtsilä 25 is a medium-speed 4-stroke marine engine with a future-proof, upgradeable modular structure that makes it easier than ever for you to target net-zero. Available in cylinder configurations from 6L to 9L and with a power output ranging from 1.7–3.4 MW, the Wärtsilä 25 provides reliable performance whether you are using it as a robust main propulsion engine or as a cost-efficient and flexible auxiliary engine. The engine is available in diesel and dual-fuel versions and now introducing ammonia.
Ammonia will play a big role in the decarbonisation of shipping. One major piece in the puzzle – dual fuel engine technology – has been missing until now. In 2020, Wärtsilä initiated the world’s first full-scale ammonia engine test, scaled it up and now an ammonia 4-stroke engine is ready to be introduced.
The Wärtsilä 25 is perfect for use as a main engine onboard smaller merchant vessels, fishing boats, tugs, dredgers, and offshore support vessels. Whether you are looking for a diesel, biofuel, or dual-fuel engine for your main or auxiliary
application, the Wärtsilä 25 is the answer. The Wärtsilä 25 Ammonia engine will help you immediately reduce greenhouse gas emissions by a minimum of 70% compared to a diesel engine.
All engine versions feature common rail, high-pressure fuel injection that enables cylinder-wise combustion control and fuel-injection settings for each operating point.
No matter what version of the engine you start with, the upgrade path is secured by the Wärtsilä 25’s outstanding modularity, which future-proofs your investment.
The modular, upgradable design allows you to reduce vessel fuel consumption and emissions from the first mile while providing the readiness to run on alternative fuels whenever viable – all without compromising performance. Whatever future fuel emerges as the most appropriate for your operations, the Wärtsilä 25 is ready for the challenge.
Get technical data and system proposals for designing W25, W25DF and W25 Ammonia marine engine installations.
Discover the benefits others have already gained from Wärtsilä 25 engine.