The technology group Wärtsilä’s successful and highly efficient Wärtsilä 31 diesel engine is being upgraded for higher power output than ever before. The upgraded version delivers an increased power to size ratio within the same physical footprint. The Wärtsilä 31 has the highest power per cylinder for engines of this bore size. Having fewer cylinders for the same power reduces the total cost of ownership, while maintenance costs are also lowered.

The Wärtsilä 31 was originally introduced in 2015 and was recognised by Guinness World Records as being the world’s most efficient 4-stroke diesel engine. In addition to its exceptionally high efficiency, the engine’s economic fuel consumption in turn results in lower levels of exhaust gas emissions.

“With this power upgrade we are delivering significant added value to our customers,” explained Lars Anderson, Director of Product Management at Wärtsilä. “The Wärtsilä 31 is already the best engine in its class, and this development widens its market advantage even further. By extending its performance, we are making a real contribution to greater sustainability and supporting our commitment to a decarbonised future.”

The first deliveries of the upgraded engine are taking place during the first half of 2023. Already, seven higher power output Wärtsilä 31 engines have been contracted.

Ronald Ervik, Managing Director of Herøyhav, a Norwegian fishing company and one of the first recipients of the upgraded engine said: “For our new vessel we opted for the Wärtsilä 31 engine because it is the most modern and most efficient medium-speed marine diesel engine on the market. Not only will it give us the power we need and with dimensions that fit our engine room design, but it will also lower fuel consumption.”

The power upgrade will result in the current output range of 4.9 to 9.8 MW, being increased to a range of 5.2 to 10.4 MW with 650 kW per cylinder. The power increase gives customers the option to select fewer cylinders, thereby reducing the required engine room space, as well as lessening maintenance requirements.

The Wärtsilä 31 has proven to be extremely popular for installation on a broad range of vessel types, including among others, fishing vessels, ice breakers, ferries, cruise vessels, cable layers, and catamarans.