More Power For Wärtsilä’s 31DF Engine
By Jack Burke07 December 2020

Wärtsilä has increased the power output of its 31DF dual-fuel engine line that was introduced in 2015.
The 4-stroke engine is popular on a broad range of vessel types, including among others, cruise ships, ferries, tankers, and fishing vessels. The power upgrade will result in the current output range of 4.2 to 11 MW being increased to a range of 4.6 to 12 MW with 600 kW/cylinder at 750 rpm, and 580 kW/cylinder at 720 rpm. The new development also lowers the level of greenhouse gas emissions to a point where a typical ferry can reduce its emissions by as much as 750 tons per annum, the company said.
“This power upgrade to the Wärtsilä 31DF represents significant added value to our customers,” said Janne Klemola, general manager, Product Management Small and Medium bore, Wärtsilä Marine. “Getting more power from an engine that already delivers exceptional efficiency, low emissions, and fuel flexibility is a real benefit. Regardless of whether the engine is installed on ships for propulsion or in land-based power plants for electricity generation, achieving this upgrade with fewer cylinders lowers the lifecycle costs, while at the same time reducing both the installation and maintenance costs.”
Since its introduction, more than 100 Wärtsilä 31 engines have been sold, and in excess of 60 000 field operating hours have been accumulated.
“Sustainable power production is at the heart of Wärtsilä’s product development strategy, and with all sectors of the global economy looking for ways to combat climate change, optimizing efficiency and lowering emissions is of critical importance. Internal combustion engines will play a crucial role in balancing the future energy mix, and hence we are focusing strongly on continuously developing our engines to achieve better power generation performance, greater cost-efficiency, and to accept new fuels. Powering up the W31DF is one good example,” said Jukka Lehtonen, vice president, Technology & Product Management, Wärtsilä Energy.