Triple OptiMax 300XS Donzi is capable of speeds over 70 MPH fully loaded.

We were invited to Mercury’s Media X-Cursion – a media event held at Duck Key, Florida, where members of the press are given the opportunity to examine and test these new products firsthand.  Located at Hawk’s Cay Resort, it was the perfect location for such hands-on testing and evaluation.  Of particular interest to our readers were a triple 300XS-powered Donzi and a quad-Verado powered Yellow Fin, which was a perfect platform for experiencing quad-engine Shadow Technology. 

Other products present were the new 700SCi high performance stern drive package with the new NXT out drive down to the 25 horsepower EFI as well as the light and portable 2.5 and 3.5 horsepower 4-stroke models.

The 300XS OptiMax has many unique features that allow it to develop its refined power cleanly while living up to its Mercury Racing heritage. Some key features of these new engines are as follows:

• 3.2-liter V-6 powerhead features stroked and balanced crankshaft for maximum displacement and performance.
• Extensive research and development result in a Formula 1 race-based exhaust porting and reed block fuel induction design for top power.
• New combustion chamber design results in the engine producing peak power longer at the upper end of the operating RPM range.
• A unique two-stage direct-injection system atomizes fuel into small, uniform particles, resulting in complete and instantaneous combustion.
• Fuel/air mixture is injected into the combustion chamber at 95 psi (a 15 psi higher differential than standard DFI or OptiMax products) for enhanced high RPM running quality.
• New PCM 07 microprocessor features a 14-pin Deutsch connector harness, incorporating both engine ignition and SmartCraft CAN wiring in one connector.
• The SmartCraft Engine Guardian system monitors engine functions for early indications of problems that could lead to engine damage.
  The 60-amp, belt-driven alternator is the most powerful in its class.
• Electronic multipoint lubrication system delivers precise amounts of oil where and when it’s needed.
• Acoustically-tuned foam cowling wrap and new exhaust bucket design result in quieter engine sound throughout the operating range
• Through-hull Noise Vibration Harshness (NVH) levels are further reduced on 25” and 30” models thanks to the use of softer upper and lower engine mounts.
• A new exhaust system, along with a foam-lined cowl and attenuator for the compressor, greatly reduces the operating sound levels.
• Torque Master, Sport Master and new Heavy-Duty Fleet Master gearcases enhance the versatility of the world’s most powerful outboard.

Mercury's OptiMax 300XS engines disprove the myth that environmentally-friendly engines cannot achieve traditional 2-stroke engine performance.

The 300XS tips the scales at a relatively lightweight 505 pounds, and is available with integrated trim system or the heavy duty transom bracket assembly.  The new pistons and piston rings feature a composite coating for extra durability and the XS-exclusive heavy-duty fuel injection compressor that can withstand extended high-RPM use.  The unique two-stage fuel system incorporates a higher air-fuel pressure delivery than production engines, and Mercury states a 45-percent increase in fuel economy compared to traditional 2-stroke engines. Full-throttle RPM range is stated at 5800-6300 RPM for the 20-inch model, and 5500-5800 for the 25 and 30-inch model.

Our first ride was aboard the 300XS-powered Donzi.  This was the same boat we experienced at Miami, and again, its 70-MPH performance was very impressive.  Acceleration is extremely brisk, and noise levels were comparatively low for engines of this pedigree.  While power delivery is very smooth, there is no mistaking the fact that these engines are high performance beasts – but with a tamed attitude.  Mercury Racing implemented advanced acoustic tuning to bring the noise levels down, however, the characteristic Mercury V6 tone is still there, and with the 300XS’ tuned exhaust it’s quite pleasant to listen to at wide open throttle. 

I’m glad to see the option for the heavy duty transom assembly available, and this engine is light enough for a very wide array of performance boats.  I like to think of the 300XS as a 300X that is more refined with much better fuel economy.  The 300XS is a win-win situation for performance boaters for sure.