Wärtsilä Enhances Ammonia Engine Power Rating for Marine Applications
Wärtsilä has announced an upgrade to its ammonia-fueled engine solution, increasing the power rating of the Wärtsilä 25 Ammonia engine. The engine now offers 315 kW per cylinder at 900 rpm and 345 kW per cylinder at 1000 rpm, aligning with the power level of the LNG-fueled Wärtsilä 25DF engine. This enhancement reduces the number of cylinders needed for specific power demands, simplifying installation and maintenance. The increased power supports engine conversion between LNG and ammonia fuel operation, offering flexibility for shipowners. The upgrade was demonstrated during type approval tests in autumn 2025, under classification society supervision. 
