Wärtsilä 31DF

Contact us

Wärtsilä 31DF dual fuel marine engine

Designed to set a new benchmark in efficiency and overall emissions performance

The Wärtsilä 31DF is the most powerful in its class and available in the range from 8 to 16 cylinder configurations. The power output ranging from 4.6 to 9.6 MW, at 720 and 750 rpm. The Wärtsilä 31DF introduces a 4-stroke engine having the best fuel economy of any engine in its class. At the same time, it maintains outstanding performance across the complete operating range. Through high power output per cylinder it enables a smaller footprint and cost efficient installation. W31DF is significantly also increasing the vessel availability through longer time between overhauls and also offering reduction in maintenance time and costs resulting in industry leading lifecycle operations.

Wärtsilä 31 is recognised by Guinness World Records as the world's most efficient 4-stroke diesel engine.

Key benefits

The Wärtsilä 31 retains its high efficiency and environmental values throughout the entire lifecycle of the vessel.

  • Lowest fuel consumption over a wide operating range.
  • Highest cylinder power in its segment, 610 kW/cylinder.
  • Available in Diesel, Dual Fuel (DF) and Pure Gas (SG) versions.
  • Meets the coming IMO Tier 3 regulations when operating on gas, and with an SCR when using diesel fuel. The SCR has a minimal effect on fuel consumption.
  • Reliability guaranteed through extensive validation and Wärtsilä’s vast manufacturing experience.
  • Supported by Wärtsilä’s extensive global service network.


The Wärtsilä 31 is designed to be suitable for a broad range of ship types and applications, both as a main propulsion engine and in diesel electric configurations, or as an auxiliary engine. It can be optimised for running either at constant speed or along a propeller curve. In the Offshore sector, the Wärtsilä 31 is a perfect solution for OSV´s and drilling or semi-submersible vessels, where operational flexibility, high power density, long intervals between overhauls, and high levels of safety are of paramount importance.

Wärtsilä 31DF Product guide and 3D models and drawings

Get technical data and system proposals for designing W31DF marine engine installations.

Wärtsilä 31 engine
  • Le Commandant Charcot

    Le Commandant Charcot, the world’s only luxury icebreaker, uses the Wärtsilä 31DF engines for sustainable polar exploration

    Read more


Modularisation hand in hand with manufacturability
29 MAY 2018 Article
5 min read

Modularisation hand in hand with manufacturability

The development of the new Wärtsilä 31 engine provided the perfect opportunity to exploit the...
Wärtsilä 31
1 JUN 2015 Article
7 min read

Wärtsilä 31 – the most efficient engine in the world

The Wärtsilä 31 marine engine sets the standard for energy efficiency. It has the lowest fuel...
Dual fuel engines hero image
26 APR 2017 Article
25 min read

Common rail fuel injection rules the waves

Very few marine engines are awarded a Guinness World Record. Thanks to Wärtsilä’s common rail injection...

Press releases

Wärtsilä Marine. Let's connect.