Wärtsilä 20 marine engine
Wärtsilä 20 marine engine

Flexibility and reliability for a wide range of vessel applications

Get the facts: open the brochure

Wärtsilä 20 marine engines for a wide range of ships

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.

Who is it for?

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:

  • car carriers (PCTC)
  • merchant vessels
  • small cargo vessels
  • ferries
  • tugboats.

Wärtsilä 20 – proven in use

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.

Tug boat pulls a container vessel

Wärtsilä 20DF – small dual fuel engine

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.

3D rendering Wärtsilä 20 marine engine

Key benefits of the Wärtsilä 20 engine

  • Excellent fuel flexibility – capable of running on a variety of fuels (including diesel and LNG) and switching seamlessly between them.
  • Low fuel oil consumption over a wide load range.
  • Optimised power-to-weight and power-to-space ratios plus flexible engine support arrangements for a wide range of vessel applications.
  • Proven and reliable with over 6,000 engines delivered.
  • Long overhaul intervals.
  • Low exhaust gas emissions
  • Low gas feed pressure (DF)

Wärtsilä 20 and Wärtsilä 20DF product guides, 3D models and drawings

Get technical data and system proposals for designing marine engine installations with the Wärtsilä 20 and Wärtsilä 20DF.

Fuel flexibility and emission reduction

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.

Customer stories

Discover the benefits that others have gained from choosing Wärtsilä 20 marine engines.

  • a night-time image of a car carrier vessel
    Santoku Shipping

    Wärtsilä 20 dual-fuel engines enable Santoku Shipping to operate on LNG to cut CO2 and SOx emissions on its six new pure car and truck carrier (PCTC) vessels.

    Wärtsilä 20DF engines help to reduce SOx and CO2 emissions
  • Orion reference
    Offshore construction vessel Orion

    The world’s first LNG fuelled offshore construction vessel being built for DEME will be powered by Wärtsilä.

    Read more about the solutions
  • Viking Supply

    Hybrid upgrade for Viking Supply Ships sharpens competitive edge of LNG-powered PSVs

    Discover the hybrid upgrade solution
  • LNG vessel for Knutsen OAS Shipping reference
    LNG vessel for Knutsen OAS Shipping

    The latest development of the LNG infrastructure provides clear evidence of the increasing importance of LNG fuel to the marine industry. Wärtsilä has a lot of experience and know-how throughout the LNG value chain, and we are confident that their solutions are what we need for this latest expansion to our fleet.

    Discover the Wärtsilä equipment package

Case MS Helgoland

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.

Hand-picked press releases

First Ro-Pax vessel receives DNV Silent(E) notation following successful sea trials with Wärtsilä propellers

May 15, 2024, 11:00 by Wärtsilä Corporation

Technology group Wärtsilä has designed and delivered controllable pitch propellers for Stena’s new Ro-Pax vessel, Ala’suinu, which has successfully completed sea trials. Following these sea trials, Ala’suinu became the first Ro-Pax vessel to fulfil the DNV Silent(E) notation, satisfying the criteria in the operating conditions at 11 and 18 knots. This environment class notation from DNV was introduced to protect sensitive marine ecosystems, applying to vessels that demonstrate the ability to effectively reduce emissions of underwater radiated noise. 

The Ala’suinu, which was built at CMJL Shipyard (Weihai) in China, is under a 5-year lease to Marine Atlantic, a Canadian operator based in province of Newfoundland & Labrador. Environmental sustainability was a prime consideration in the design of the 203 metres-long ship, which will sail between Nova Scotia and the island of Newfoundland from June 2024. 

“The Ala’suinu is a specially designed vessel for Marine Atlantic. We are fully committed to reducing the environmental impact of our operations, and in this vessel another dimension of sustainability has been added. The dedicated Wärtsilä propeller design enables us to minimise underwater noise for the benefit of marine life off Canada's coasts,” says Captain Anderson Noel, Marine Atlantic’s Director of Fleet Operations. 

“With this notation, Stena and Wärtsilä are showcasing their commitment to taking proactive steps to reduce shipping's environmental footprint. Despite Ro-Pax being a challenging ship type from an underwater noise perspective, this innovative machinery configuration has enabled a propulsion plant with sufficiently low noise emissions to satisfy our voluntary class notation Silent(E),” adds Øystein Solheim Pettersen, Head of Section, Noise and Vibration - DNV. 

During the design process of the controllable pitch propeller, Wärtsilä’s industry-leading in-house design experts paid special attention to underwater radiated noise as a key design parameter. This was done without compromising on other important propeller design requirements, such as ensuring optimal performance and efficiency, for example. As well as reducing emissions of underwater radiated noise, Wärtsilä’s propeller ensures that owners and operators gain the benefits of lower operating costs and a reduced environmental footprint through less fuel consumption and fewer exhaust emissions.   

“For this project, we have designed and delivered propellers where vibrations and noise have been given the highest attention, in combination with the vessel design and operations. The vessel being awarded with the Silent(E) notation by DNV after successful testing at sea verifies the environmental benefits. We are proud to be the first on the market to deliver the dedicated propeller for a Silent(E) classed Ro-Pax vessel,” comments Bernd Bertram, Vice President, Propulsion - Wärtsilä Marine.  

In addition to the dedicated propeller, Wärtsilä has also supplied an integrated hybrid propulsion system for this vessel, consisting of Wärtsilä 46DF main enginesWärtsilä 20DF auxiliary engines, both of which are complimented with Wärtsilä NOx Exhaust gas cleaning system and Wärtsilä LNGPac™, as well as the reduction gear boxes and bow thrusters with motors. Also included in the scope are the Hybrid DC-link Shaft Generator system, Batteries and Energy & Power Management System, Integrated Automation System and Navigation & External Communication System. 

 Media contact for more information on this release: 

Isabella Alder  
Positioning and Strategic Communications Manager  
Wärtsilä Marine  
Tel: +44 (0) 7792 681 757 

Image caption: Wärtsilä has designed and delivered controllable pitch propellers for Stena’s new Ro-Pax vessel, Ala’suinu, which has successfully completed sea trials. © Stena RoRo   

All Wärtsilä releases are available at https://www.wartsila.com/media/news-releases and at http://news.cision.com/wartsila-corporation where also the images can be downloaded.  

Use of the image(s) is allowed only in connection with the contents of this press release. Wärtsilä images are available at https://www.wartsila.com/media/image-bank

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. 

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 environmental and economic performance. Our dedicated and passionate team of 17,800 professionals in more than 280 locations in 79 countries shape the decarbonisation transformation of our industries across the globe. In 2023, Wärtsilä’s net sales totalled EUR 6.0 billion. Wärtsilä is listed on Nasdaq Helsinki. 

Related products and services

Take advantage of Wärtsilä’s unique expertise. Get in touch and let’s discuss what you need! 

Wärtsilä Marine. Let's connect.