Tristram Marine and Mercruiser have been working closely together to develop economical and unrivalled sterndrive packages. The most recent Tristram/Mercruiser combination tested is the Tristram 741 Offshore, equipped with the incredible Mercruiser 4.5L petrol engine.


Built for Marine

Designing a V-6 block solely for marine use allows Mercury to build the 4.5L with the ultimate protection system, using cast-iron componentry where the engine intersects with seawater, and using corrosion-resistant aluminum and composites everywhere else.

Next Generation Technology

Featuring a host of engineering innovations, the 4.5L series establishes new standards for power-to-weight ratio, driver experience, acceleration, durability, and ease of maintenance. This engine is a powerful performer thanks to its new, long-runner scroll intake manifold which draws in more air and converts it into additional torque.

Smooth & Quiet

The 4.5L’s newly designed rear-facing throttle body, anti-whistle throttle plate, engine cover and mounts, lightweight flywheel, fuel-supply module, and structural oil pan all work together to deliver a superior idle, smoothness and low vibration. Resulting in an exceptional driving experience.

Electronic Throttle Body with Adaptive Speed Control (ASC)

The new refined throttle turns boating exhilaration up a notch. Holding RPM during hard turns allows the operator to keep both hands on the wheel, which is not only safer, but makes for a more exciting and “sportier” driving experience. Holding a boat on the plane at slow speeds is useful when navigating in following seas or in windy conditions, during tow sport activities, or whenever precision boat control is needed without a lot of speed. With the electronic throttle body, acceleration is significantly more responsive and exciting.

Performance Test Figures

Mercury have completed a comprehensive performance test. The results of this test are published below.

Performance Data

Test Date: 24 August 2016
Boat Weight: 2450 kgs
Air Temperature: 10 c

Sea State: Smooth
Wind Velocity: 12 knots
Fresh/Salt Water: Salt

Fuel Level at Testing: 200 ltr
Top Speed: 35.55 knts @ 4820 rpm
Best Fuel Economy: 0.7nm/l @ 3500 rpm

Fuel Consumption
Fuel Consumption

Mercury® MerCruiser®: 4.5L

  • HP / kW
    250 / 186
  • Maximum RPM (WOT)
  • Engine type
    V6, 2-valve/cylinder pushrod
  • Displacement (L)
  • Bore and stroke
    4.0 x 3.6" / 102 x 92 mm
  • Fuel requirement
    90 RON 10% Ethanol Maximum Unleaded Regular 87 Octane Minimum (R+M/2)
  • Fuel delivery system
    Computer controlled Multi-Port Electronic Fuel Injection (MPI)
  • Air induction
    Performance-Tuned Scroll Intake Manifold
  • Ignition
    SmartCraft PCM 112 Digital Inductive
  • Alternator amp / Watt
    70 amp / 882 watt (Belt-Driven)
  • Water drain system
    Air Actuated "Season Extender"
  • Exhaust system
    Through prop
  • Cooling system
    Water cooled with thermostat and packaged with SeaCore Drive (Bravo)
  • Lubrication system
    Integrated wet sump
  • Recommended oil
    NMMA Certified FCW 25W-40 Synthetic Blend
  • Dimensions (L x W x H)
    28 x 30 x 22" / 696 x 740 x 559 mm
  • Weight (engine only)
    756 lbs / 343 kg
  • Tristram’s chosen drive (since 2003)
    Bravo Three

Demonstrator Updates