Mercury MerCruiser 4.5L 250hp

Mercury Marine

Mercury MerCruiser 4.5L 250hp

POA

Tax included.

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Trade-ins are available for engines, trailers and boats

Engine Type: V6 (2-valve pushrod)

Engine Specifications

250.0 hp

Power

4.5 litres

Displacement

343 kg

Dry Weight

Description

The Mercury MerCruiser 4.5L is the first sterndrive engine designed and built in-house specifically for marine use. By optimizing the design for the water, rather than adapting an automotive engine, Mercury achieved a lighter, more durable, and more fuel-efficient power source.

Key Features:

  • Purpose-Built Marine Block: Designed from the oil pan up for the marine environment, featuring cast-iron durability where it counts and weight-saving aluminum where it makes sense.
  • Aft-Facing Throttle Body: Directs intake noise away from the cockpit for a significantly quieter ride.
  • Adaptive Speed Control (ASC): Automatically maintains engine RPM as load or conditions change (like tight turns or tow sports), so you don't have to adjust the throttle.
  • Easy Maintenance: The conveniently located maintenance center puts all key service points—including the oil filter and fill—right at the front of the engine.
  • Corrosion Protection: Built with the MercFusion Paint System and SeaCore compatibility for the ultimate defense against saltwater.

Specifications:

  • 250hp (186kW)
  • 4.5L V6
  • Multi-Port Fuel Injection (MPI)
  • Alpha or Bravo Drive Compatible

Built for the Long Run

Every engine undergoes brutal testing (from log strikes to saltwater spray booths) to ensure it performs in the harshest environments.

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Adventures Backed By Expertise

Technical Details

Corrosion Defense

Constructed with Mercury's proprietary XK360 low-copper aluminium alloy and sealed with the MercFusion Paint Process. This system uses electro-deposition priming and a hard powder top coat to provide the industry’s best protection against saltwater intrusion.

Extreme Validation

Every engine design endures brutal testing protocols, including vicious log strikes, saltwater spray booths, high-humidity chambers, and thermal cycling between extreme hot and cold water temperatures. Powerheads are run at wide-open throttle for thousands of hours to prove long-term durability.

High-Displacement Power:

Mercury engines utilise large-displacement blocks to generate torque effortlessly. This "work smarter, not harder" approach ensures the engine is never stressed, even when pushing heavy loads.

SmartCraft Integration:

Engines are compatible with the SmartCraft digital suite. This provides access to Engine Guardian (which monitors sensors to protect the engine) and Active Trim (GPS-based automatic trim control) for optimized performance and fuel economy.