Mercury Marine New Engine Line-up
Launched at the Miami Boat Show, Mercury’s new line-up of outboard engines looks to be setting a new benchmark for middle-capacity V6 motors in terms of power to weight. The range of outboards is based on a new 3.4L V6 engine block, with power outputs of 175hp, 200hp and 225hp, each with an all-up weight of just 215kg. This makes them the lightest in their class, some 5kg lighter than the closest 4-cylinder competition. This is quite an impressive feat for a 4-stroke V6 this size, especially considering the engine’s capacity.
The range uses a naturally aspirated, double-overhead-cam, four-valve-per-cylinder powerhead, mated to an existing Mercury midsection and gearbox, with a single propeller. They are offered with either digital or mechanical controls, making them ideal for repowering older boats. Hydraulic or electrical power steering is available, and unusually Mercury are offering these engines in black or white, with a variety of accent panel colours for white engines.
Mercury are claiming these engines to be class leaders in terms of low-down power delivery, producing ‘20% more torque than the closest 4-cylinder competitor at cruise’. From this one can suppose that this V6 produces maximum torque somewhere between 3200 and 3500 rpm, which will be the sweet spot in torque and efficiency terms. Without wanting to appear cynical, you would expect a 3.4L V6 motor to produce more mid-range power than, say, Yamaha’s 2.8L straight-4 F200, or Suzuki’s 2.9L DF200A. It would be great to actually know crankshaft torque figures, but as with every outboard producer, such information is never published.
It is also stated that the new range is ‘calibrated to maximise fuel economy at cruise, yielding a 15% improvement over the competition’. From this you can deduce that when not powering hard under load, the ECU weakens the fuel mixture slightly to have a ‘lean burn’ effect. Mercury refer to this as ‘Advanced Range Optimisation’ (ARO), which is said to work to varying degrees across the power spectrum. Battery management is enhanced by a high-charge alternator putting out an impressive 20 amps at just 650rpm – ideal if trolling or using a large suite of electronics at low speed, especially radar. A handy feature known as ‘Adaptive Speed Control’ maintains RPM regardless of loading or sea conditions, so you could set the engine at its eco sweet spot on long passages for maximum efficiency.
Noise and vibration have been reduced by the design of the multi-chamber air intake, special fuel injector covers and a specially constructed and insulated engine cowl. One feature that certainly is unique is the top cowl service door, which enables easy oil checks without having to lift off the whole engine cowl. Why somebody hasn’t thought of this before defeats me. All engines are available in 20in, 25in and 30in shaft lengths. Prices are yet to be confirmed. All engines will be available from June this year.
200hp V6 SeaPro
A specific mention needs to be made of the 200hp SeaPro. This is a 200hp commercial version based on the same 3.4L V6 engine block. Like all Mercury’s SeaPro engines, it is built for commercial use, with durability and reliability being top of the list of its priorities. It has all of the features of the engine range, including ARO.