Wärtsilä 46F marine engines English Wärtsilä portals Home Energy Marine Company Insights Home Marine Products and solutions Engines and generating sets Wärtsilä 46F Wärtsilä 46F marine engines Economical fuel flexibility with exceptional power-to-weight and power-to-space ratios. Get the facts: open the leaflet Adopt alternative fuels at your own pace with Wärtsilä 46F marine engines The Wärtsilä 46F is a four-stroke medium-speed engine series. These engines are ideal for many ship types because they offer the widest fuel flexibility in their power range, which is between 7.5 MW and 20 MW at 600 rpm. The engines are available in 6L to 16V-cylinder configurations. Choose Wärtsilä 46F when you want efficient and reliable performance for a demanding marine application. The Wärtsilä 46F engines are available in these fuel versions: Diesel:  HFO - LFO - liquid biofuel Dual-fuel:  LNG - LFO - HFO - liquid biofuel Methanol-ready:  MeOH - HFO - LFO - liquid biofuel Methanol:  MeOH - HFO - LFO - liquid biofuel All versions are suitable for both constant-speed diesel-electric operation and direct drive main engine propulsion. Who is Wärtsilä 46F for? The Wärtsilä 46F is your best choice when you are looking for the fastest possible uptake of alternative fuels as soon as this becomes viable for you. More than 18 years of operational history and 7,200,000 running hours are proof of its reliability and maximum uptime. Because the Wärtsilä 46F is flexible and cost-effective in operation, it works brilliantly for applications with high power needs. Such applications include the following, for example: Large ferries Ro-ro vessels Dredgers Key benefits of the Wärtsilä 46F engines Will adapt to alternative fuels  The Wärtsilä 46F engine series is flexible and can run on many types of fuel, from heavy fuel oil (HFO) to more sustainable alternatives such as bio-LNG and methanol. Because it is flexible, it can adapt to changing regulatory requirements without significant modifications. It is operationally viable for the long term with lower cost of conversion. Reliable with maximal uptime  The following figures prove that Wärtsilä 46F is rock-solid reliable: Over 18 years of operational history More than 300 engines sold 7,200,000 running hours The engines have extended overhaul intervals, which means better greater availability - and money saved. The modular design with fewer components cuts inventory costs, maintenance, and crew training time.  Cuts emissions and complies with regulations The engines are designed to meet stringent environmental regulations. IMO Tier III compliance is ensured with a selective catalytic reduction (SCR) system in diesel and methanol modes whereas the dual-fuel engine in gas mode is readily IMO Tier III compliant. Because the engines’ thermal efficiency ensures complete combustion which minimises exhaust gas emissions. Their noise levels are reduced. Methanol certifications speed up the adoption of green fuels, which further improves regulatory compliance. Efficient, with high power density The series delivers exceptional fuel economy with best-in-class power-to-weight and power-to-space ratios.  Delivers high performance consistently Delivers 100% of the engine's load – also in methanol mode, providing 1250 kW per cylinder. Achieves high-power output without compromising efficiency or reliability. Open the Wärtsilä 46F brochure One platform, four engines The Wärtsilä 46F engine series are based on a common platform. This allows ship owners and operators to decide their own pace of decarbonisation. The platform design leverages our extensive experience with the original Wärtsilä 46F engine since 2007 and with methanol as marine fuel since 2015. There are four engine versions for tailored pathways to a low-carbon future. Wärtsilä 46F diesel engine for conventional fuels including HFO. Can be converted to run on alternative fuels. Wärtsilä 46DF dual-fuel engine optimised for natural gas. Using natural gas as fuel cuts total greenhouse gas emissions. This engine can also run on conventional fuels. Wärtsilä 46F methanol-ready engine . Traditional diesel engine with readiness to easily convert to use methanol. Wärtsilä 46F Methanol engine . Start using green methanol from day one and enjoy the proven performance of the popular engine. This engine can also run on conventional fuels. Wärtsilä 46F and Wärtsilä 46DF Product guides and 3D models and drawings Get technical data and system proposals for designing Wärtsilä 46F and Wärtsilä 46DF marine engine installations. Download Product guides Access 3D models & drawings Find the right engine for you in a few easy steps with the engine configurator Use Engine configurator Adopting methanol as marine fuel If you are considering a switch to low-carbon fuel, methanol is an attractive option. Green methanol has the potential to be carbon free, and it meets current and future emissions targets in terms of NOx, SOx and particulates. Read more about Methanol as marine fuel Customer stories Discover the benefits others have already gained from Wärtsilä 46F engines. Finnlines' two RoPax vessels Two RoPax vessels: Integrated hybrid solution supports long-term decarbonisation goals Learn more about the solutions Related products and services 31 May 2022 Wärtsilä MethanolPac Wärtsilä MethanolPac is a complete fuel supply system for methanol-fuelled ships. It ensures the safe handling of methanol fuel. Wärtsilä Marine methanol conversion A solution for converting existing vessels to use methanol to fuel their engines. 26 Oct 2021 Managing vessel lifecycle Managing your vessels’ lifecycle helps you stay profitable and avoid downtime. Hand-picked press releases 7 Jul 2026 · Trade press release Wärtsilä propulsion solutions selected for Grimaldi Group’s major newbuild programme 15 May 2024 · Trade press release First Ro-Pax vessel receives DNV Silent(E) notation following successful sea trials with Wärtsilä propellers 5 Dec 2023 · Press release Wärtsilä enables acceleration of marine’s transition to sustainable fuels with introduction of four methanol engines Take advantage of Wärtsilä’s unique expertise. Get in touch and let’s discuss your needs!  Wärtsilä Marine. Let's connect. Contact us Energy Marine Insights About Careers Media Investors Sustainability Contact About Wärtsilä Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy industries. We emphasise innovation in sustainable technology and services to help our customers continuously improve their environmental and economic performance. © 2026 Wärtsilä Privacy notice Cookie notice Terms of Use Subscribe