Mercury Marine Reveals Diesel 4.2L Engine with RCD II Emissions Certification

Published on: 17/01/2025

Mercury Marine®, a division of Brunswick Corporation (NYSE: BC), today revealed the latest evolution of its Mercury Diesel 4.2L marine engine, now fully compliant with the RCD II emissions standard and available for sale in the European Union and all markets that accept RCD II certification. Mercury unveiled the new engine at the Düsseldorf International Boat Show. The engine is offered at the 270hp (201kW) and 320hp (239kW) power nodes and is fully compatible with Mercury Marine Next Gen DTS control technology and JPS Precision Joystick control. Offered for sterndrive and inboard installation, the Mercury Diesel 4.2L with RCD II will be available for shipment beginning in March 2025.

“Mercury Marine is very excited to introduce the proven and reliable 4.2-liter RCD II emission compliant engine,” said Facundo Onni, President Mercury Marine EMEA. “With significant upgrades in design and technology, the Mercury Diesel 4.2L is an ideal solution for many new OEM applications and is the perfect repower option for the thousands of boats powered by prior generations of this engine.”

The Mercury Diesel 4.2L (RCD II) is a six-cylinder in-line engine displacing 4.2 liters (254 CI) and equipped with a power-boosting turbocharger and aftercooler. The engine utilizes a common-rail fuel system with digitally controlled injectors programmed to fine-tune the air-to-fuel ratio to enhance acceleration, top speed and efficiency and to suppress NVH (noise vibration harshness). RCD II compliance is achieved through use of revised fuel injectors and electronic engine management systems.

The engine is designed to operate on regular diesel fuel or HVO biofuel, an ecological and sustainable synthetic diesel which is produced mainly from renewable sources, such as oils and vegetable fats, granting reduction of PM, NOx and CO2 emissions and thanks to low gelling point (-32°C) it is also ideal for cold weathers.

Mercury Marine will continue to offer versions of the Mercury Diesel 4.2L engine with EPA Tier 2/IMO II emissions certification at 270hp, 320hp and 350hp nodes for sale in markets that accept a Tier 2 certification. The engine is not EPA Tier 3 certified for sale in the USA and Canada.

Performance Data

Mercury Diesel 4.2L (RCD II) 320 horsepower

• Peak Engine Torque 703 Nm (519 lb·ft) @ 2600 RPM
• WOT fuel consumption: 71.9 l/hr (19.0 gal/hr)

Mercury Diesel 4.2L (RCD II) 270 horsepower

• Peak Engine Torque 603 Nm (444 lb·ft) @ 2600 RPM
• WOT fuel consumption: 60.6 l/hr (16.0 gal/hr)

Key features of the Mercury Diesel 4.2L (RCD II) include:

Fresh water cooling with a fresh water/sea water heat exchanger for ease of maintenance and added durability. The cooling system also incorporates circuits for the turbocharger, engine oil, gear oil and power steering to enhance performance and reliability and to lower engine-room temperature.

Light weight enhances boat performance. Engine-only weight of 460 kg (1,014 lbs.) is 15 percent, or approximately 100 kg, lighter than the leading diesel competitor at this power node.

Next-Gen DTS rigging includes the intuitive control of SmartCraft® Digital Throttle and Shift (DTS) for smooth shifting and instant throttle response. The system also supports ActiveTrim, JPS Precision Joystick and JPS Precision Joystick with Thruster systems and a wide range of digital display options. For repower applications the Mercury Diesel 4.2L may also be rigged with previous-generation SmartCraft 2.2 architecture if that is in place on the vessel.

Corrosion resistance for long-term reliability and durability is enhanced by the thermostatically controlled closed water-cooled system and MerCathode® sterndrive protection system. Mercury SeaCore® corrosion-fighting technology is available for the ultimate in saltwater protection.

 Ample charging capacity to power onboard electronics, accessories and appliances is provided by an engine alternator delivering 110 amps of peak charging power.

Ease of ownership is supported by top-mounted fluid reservoirs, a self-draining oil filter and an easy-to-reach oil dipstick, each designed to keep maintenance and service simple.

Sterndrive or Inboard options to power a wide range of boat applications. The Mercury Diesel 4.2L is offered with MerCruiser Bravo I X/XR, Bravo II X/XR and Bravo III X/XR sterndrives or for inboard installation with ZF68 A, ZF68 IV and ZF68 transmissions.

For more information, visit mercurymarine.com

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