The World's Most Powerful Diesel Outboard

CXO300 Technical data

Engine Designation CXO300
Crankshaft power, kW (hp) 252 (338)
Propeller shaft power, kW (hp) 224 (300)
Engine propping speed, rpm 3700-4000
Displacement, L ( 4.4 (266)
Number of cylinders 8
Bore/stroke, mm (in.) 84 (3.3) / 98.5 (3.9)
Compression ratio 16
Ratio 1 (Propeller speed) 1.23:1 (3259)
Ratio 2 (Propeller speed) 1.46:1 (2739)
Peak torque, Nm ( 650 (479)
Aspiration Twin-turbo
Shaft Length, inch(mm) 25”(635) / 30”(762) / 35”(889)
Emission compliance EPA 3, IMO 2, RCD 2
Start assist Glow plugs
Rating Light-duty commercial
Trim range -4° to +16°
Tilt range 71°
Engine Oil Spec API CI-4 / SAE 5W40
Gear Oil Spec API GL-5 / SAE 75W140
Propeller spline spec 1.25” shaft / 19 tooth
Colour options Black / White


Technical description

Engine block and head

  • Aluminium alloy block and heads
  • 60 degree V8

Engine mounting

  • Standard outboard fitting layout
  • 6-bolt mounting with multi-hole adjustment

Fuel system

  • High pressure common rail fuel injection
  • Fine filter with water separator

Air inlet and exhaust system

  • Exhaust gas recirculation system
  • Twin turbochargers
  • Air filters with replaceable inserts
  • Closed crankcase ventilation


  • All outboards offer standard and counter rotating capability, programmable through the ECU

Cooling system

  • Thermostatically regulated raw water cooling
  • Tubular heat exchanger

Electric system

  • 12V/24V two-pole electrical system
  • 80A marine alternator


  • Electronic controls
  • Joystick to manage up to 6 engines
  • Keyless key fob
  • Wireless MOB and Key
  • NMEA 2000 CAN displays and controls
  • 4.8”/7”/10”/12” screen sizes
  • Compatible with the off the shelf Seastar and Ultraflex steering units, and 19t 1.25 propeller hub kits

Choose your CXO300

Less Fuel
Longer Life

View our brochure

Retrofit Compatibility

Although the first of its kind, as the most powerful diesel outboard brought to the market, the CXO300 has been developed to be compatible with existing industry standards – making it as easy to install on a wide range of vessels as any gasoline outboard.


Standard pump diesel


NMEA 2000 can bus


Transom same as current standard


Off the shelf


Compatible with all major brands

redefining standards

When purchasing a Cox diesel outboard you are buying more than an engine, you are acquiring a new level of service and care that comes standard with all our products. We have defined service standards to ensure you don’t lose a week’s worth of revenue, or that fishing weekend you have been planning for weeks because your engine is down. we offer an engine substitution programme and a true 24/7 customer service to ensure there is always somebody available to attend our customers no matter where in the world, no matter what time.