Take your life on the water to new destinations with the Mercury Diesel 6.7L engine. This turbocharged workhouse redefines diesel performance for sport yachts and other large vessels, blending premium comforts and extended range with exceptional speed and acceleration.
Features may include:
Power & Torque
The high-displacement turbocharged engine spools up massive torque, generating instantly responsive power to get big boats out of the hole and deliver a midrange punch when you need it.
Smooth & Quiet
From vibration-dampening engine mounts to an air filter strategically positioned to also reduce turbo noise, the 6.7L engine is optimized for a smooth, quiet ride.
Grid Heater
The 6.7L engine is ready for all-season adventure, with a grid heater that makes cold weather starts easy.
Closed Cooling System
A thermostatically controlled closed-loop freshwater cooling system protects the engine in both fresh and saltwater.
HPCR Fuel Injection
The high-pressure common rail (HPCR) fuel injection system fine-tunes the air-to-fuel ratio to enhance acceleration, top speed and efficiency.
Photos
Highlights
Akron, Ohio
2025
Mercury Marine®
Mercury Diesel 550 Base
1, 642 lbs (745 kg)
Available
Specifications
2025
Mercury Marine®
Mercury Diesel 550
Base
General
550 HP (405 kW)
Inline 6
6.7 L
Peak: 1, 580 Nm (1, 165 lb-ft) @ 1, 900 rpm
WOT: 3200 RPM
Recommended: 15W40 ACEA C3 synthetic oil
EPA Tier 3 / RCD IMO 2
12 V 90 A / 24 V 70 A
Maintenance Interval: 250 hrs or annually | Sump Volume: 20 qt / 19.0 L