Royal Caribbean Cruises’ latest Oasis class cruise ship, Utopia of the Seas, will be the first ship powered by Wärtsilä 46TS-DF engines. Designed with a focus on efficiency, environmental performance, and fuel flexibility, the 460 mm bore x 580 mm stroke 46TS-DF is the latest addition to the Wärtsilä multi-fuel engine portfolio. Wärtsilä says that it signals a new era of medium-speed marine engines and, In gas fuel mode, the highest efficiency thus far achieved in the medium-speed engine market.