Wärtsilä 20 is a compact, lightweight marine engine. It offers fuel flexibility and reliable performance in genset and main engine applications. It is available in diesel and dual-fuel versions, and the dual-fuel version will switch between different fuels during operation smoothly, without power interruption.
Wärtsilä 20 offers outstanding flexibility, which makes it a great choice for generating sets in larger vessels and as a main engine for both mechanical and electric propulsion. The dual-fuel version is a great choice for many vessel types, including hybrid installations.
Ideal applications for the Wärtsilä 20 engine include:
The Wärtsilä 20 has proven its robustness and reliability with over 7500 engines delivered since its introduction to the market in the early 1990s. The engine can switch from MDO to HFO and vice versa without power interruption at any engine operation load.
The engine is available in cylinder configurations 4L, 6L, 8L, 9L with the power output ranging between 740 and 1980 kW at 900, 1000 and 1200 rpm.
The Wärtsilä 20DF is based on the well proven and reliable Wärtsilä 20 diesel engine introduced in the early 1990s. Because of its fuel flexibility, the Wärtsilä 20DF can be optimized for constant speed generating sets, as well as variable speed mechanical drives, for main engine applications.
The engine is available in cylinder configurations 6L, 8L, 9L with the power output ranging between 870 and 1755 kW at 900, 1000 and 1200 rpm.
Get technical data and system proposals for designing marine engine installations with the Wärtsilä 20 and Wärtsilä 20DF.
The Wärtsilä 20 can operate on conventional liquid marine fuels (LFO, HFO or liquid biofuels) or LNG. Fuel switching takes place without loss of power or speed.
For vessel operators, a fuel-flexible engine means that it is possible to comply with the ever-tightening emission regulations. At the same time, operators will have the option to choose fuel according to cost and availability.
Adopting LNG as fuel can help you reduce greenhouse gas emissions significantly. To maximise the environmental benefits of LNG, it is important to minimise methane slip – the unburned methane that escapes into the atmosphere when LNG is burned as fuel.
Wärtsilä 20DF is a great choice because it cuts methane slip in two ways. Its combustion chambers are designed to reduce methane slip, and its combustion controls have been optimised.
Discover the benefits that others have gained from choosing Wärtsilä 20 marine engines.
The MS Helgoland ferry entered a new era of dual-fuel operations with the complete Wärtsilä LNG propulsion solution, featuring two Wärtsilä 20 engines. Watch the video to learn how they adopted a new fuel.
Wärtsilä Corporation, Press Release, 22 May 2025 at 12:00 UTC+2
Technology group Wärtsilä will supply its Wärtsilä 20 main engine and selective catalytic reduction (SCR) system for a new 40.9-metre long state-of-the-art fishing vessel, specifically designed for lobster fishing. The vessel, which will operate in North Atlantic waters, has been ordered by Canadian operator Clearwater Seafoods and will be built at the Hvide Sande Shipyard in Denmark. The order was booked by Wärtsilä in Q2 2025.
The operational profile of fishing vessels can vary significantly, depending on factors such as geographical location, fishing method and environmental conditions. As such, it was, Wärtsilä’s extensive experience - both globally and at a local level - in supplying solutions and services for the fishing sector that was cited as being a major factor in the award of this contract.
“We have worked closely with Wärtsilä before and trust their local service, equipment reliability, and respect their expertise. Understanding our needs is crucial for any supplier, and Wärtsilä has consistently demonstrated this,” says Tony Jabbour, VP Global Supply Chain, Clearwater Seafoods.
“This is a specially designed vessel that could well influence future designs for the fishing industry. Efficiency has been the priority not only for the design, but also for all the onboard equipment. The Wärtsilä engine and SCR system will clearly deliver the required propulsion efficiency,” adds David Birkwald Thorstensen, Head of Sales at Hvide Sande Shipyard.
With a strong focus on efficiency, safety, and sustainability, the vessel has been designed to excel in demanding North Atlantic conditions. The Wärtsilä 20 is a well-proven compact, lightweight marine engine, offering fuel flexibility and reliable performance in genset and main engine applications. The overall performance of the engine and exhaust aftertreatment will be optimised further with the SCR – improving emissions reduction, noise abatement, and engine efficiency.
“Delivering an optimal and highly reliable solution for a fishing vessel requires a deep understanding of its various operational modes. Wärtsilä has an extensive track record in supplying solutions and services for the fishing sector, and we are delighted to be supporting Clearwater Seafoods and Hvide Sande with their goal of ensuring that the vessel operates safely, reliably, efficiently and sustainably,” comments Stefan Nysjö, Vice President of Power Supply, Wärtsilä Marine.
The Wärtsilä equipment is scheduled for delivery during the first quarter of 2026.
Media contact for more information on this release:
Isabella Alder
Positioning and Strategic Communications Manager
Wärtsilä Marine
Tel: +44 (0) 7792 681 757
marine.media@wartsila.com
Image caption: Clearwater Seafoods’ new fishing vessel will operate with a Wärtsilä 20 main engine and selective catalytic reduction (SCR) system © Clearwater Seafoods
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Wärtsilä Marine in brief
Wärtsilä Marine is a global pioneer in power, propulsion and lifecycle solutions for the marine market. We develop industry-leading technologies, advancing maritime's transition to new fuels. We support building an end-to-end digital ecosystem where all vessels and ports are connected. Ultimately, Wärtsilä Marine is driving the shipping industry forward on its journey towards a decarbonised and sustainable future through our broad portfolio of engines, propulsion systems, hybrid technology, exhaust treatment, shaft line solutions and digital technologies, as well as integrated powertrain systems. Our offering, which is underpinned by our performance-based agreements, upgrades, lifecycle solutions, decarbonisation services, as well as an unrivalled global network of maritime expertise, delivers the efficiency, reliability, safety, and environmental performance needed to support a safe and sustainable future for our customers, our communities and our planet.
www.wartsila.com/marine
Wärtsilä in brief
Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy markets. We emphasise innovation in sustainable technology and services to help our customers continuously improve their environmental and economic performance. Our dedicated and passionate team of 18,300 professionals in more than 230 locations in 77 countries is shaping the decarbonisation of our industries across the globe. In 2024, Wärtsilä’s net sales totalled EUR 6.4 billion. Wärtsilä is listed on Nasdaq Helsinki.
www.wartsila.com
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