X40-B (legacy)

Marine low-speed engine providing excellent fuel consumption features and operational flexibility

Designed for vessels with shallow draught requirements, compact engine room dimensions and simple engine operation it is highly suited for both fixed pitch- and controllable pitch- propellers direct-drive propulsion of a wide range of small and medium-sized cargo vessels. Possible applications covers chemical and product tankers, bulk carriers, container feeders, reefers and gas carriers operating in deep sea, coastal and inland waters.

The X40-B is an electronically controlled, common rail marine low-speed engine which can be classed as one of the most efficient in its category and offers fuel consumption benefits up to 3% compared to a conventional mechanical main engine, depending on the sailing profile.


WinGD’s well proven electronically-controlled common-rail technology plays a key role in enabling ship owners to reduce fuel costs, mainly through the flexibility of the fuel injection and exhaust valve timing control. The X40-B and its predecessor X40 are even more flexible in shaping the injection pattern due to electronically controlled fuel injectors. In addition, different engine tunings (Delta By-Pass and Low Load) are available in order to meet specific customer requirements. The engines can be additionally equipped with Intelligent Combustion Control (ICC) system enabling further fuel savings and automatic balancing of each cylinder load.

The engine is fully compliant with IMO Tier III NOx emission levels when equipped with a SCR catalyst system. The introduction of the EEDI index also puts an emphasis on CO2 emissions and total vessel efficiency. The internal engine efficiency of X40-B, and the possibility to apply various Power Take-Off (PTO) arrangements for on board electricity production, make it easy for shipyards to meet these new requirements.


The X40-B is designed for exceptional reliability and for long periods of maintenance-free operation. It also allows extended Time Between Overhaul (TBO) of the critical components, to as much as 5 years. The service-friendly design will reduce downtime, maintain vessel operation and cut operating costs. Together with Condition Based Maintenance (CBM) and service agreements, the overhaul interval may be even further extended, thus minimising maintenance costs and maximising the revenue-earning capability of the vessel.

The Interactive Engine Room Simulator (W-Xpert) available for operators is based on the X40-B main engine and Wärtsilä auxiliary engines, allowing efficient training and self-education of the Crew.

 All data provided on this site is for information purposes only, explicitly non-binding and subject to changes without further notice.

Basic Engine Data


Extent of delivery


Marine installation manual

Installation instructions & concept guidance


Operation & Maintenance

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