Outboards

Advanced diesel outboard engines designed for commercial, governmental and recreational use.

300HP & 350HP Models

High torque at low RPM

Designed with sustainable innovation in mind, the V8 diesel outboard is a fuel efficient, eco-friendly outboard designed for maximum speed. Explore the careful engineering and flawless details our designers put into this powerful outboard motor.

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Driving cleaner marine propulsion with sustainable design

At Cox Marine, sustainability is engineered into every outboard we build. From emissions compliance to alternative fuel compatibility and future-focused innovation, we are committed to reducing environmental impact without compromising performance.

Certified clean

The Cox Marine V8 diesel outboard is certified to the world’s leading emissions standards, including EPA Tier 3, IMO II, and RCD II. These certifications confirm our engines meet strict limits for NOx, hydrocarbons and particulate matter, supporting cleaner operations in regulated waterways and emissions-controlled zones around the globe.

Ready for renewable fuels

Cox outboards are fully compatible with HVO (Hydrotreated Vegetable Oil) – a sustainable diesel alternative derived from renewable feedstocks. When used with HVO, operators can significantly reduce lifecycle CO₂ emissions compared to conventional diesel, without requiring any engine modification.

Recent trials – including the 350 V8 launch demonstrations and the Pegasus programme – have proven the outboard’s robust performance on HVO, showcasing our commitment to cleaner fuel integration. This compatibility allows fleet operators, governments and private users to make an immediate switch to a more sustainable propulsion solution.

Powering future fuels

Cox Marine is actively investing in next-generation propulsion technologies, including hydrogen-diesel hybrid prototypes. These projects are already in development, supporting the marine industry’s transition to zero-emission alternatives over the long term. By combining hydrogen energy systems with our proven diesel platform, we aim to deliver scalable, flexible propulsion that meets future emissions targets and operational needs.

Build Features

1. Twin Turbo Engine

The V8 has twin turbos that generate significantly more torque at lower RPM and maintain power across engine speeds.

2. Vertical Crankshaft

The vertical design allows for efficient packaging and direct drive of the transmission, providing closer transom spacing for multiple installations.

3. Power Distribution Module

Equipped with self-resetting fuses, this module allows for active power management of the outboard power systems.

4. Electronic Controls & Steering

The Optimus steering enhances control of your vessel. Compatibility with the NMEA200 makes it easy to install on a wide range of vessels.

5. Power Tilt -Trim

Designed in-house, the V8’s PTT bracket is built to withstand the toughest conditions and has undergone extensive durability testing.

6. Universal Transom Bolting Pattern

Allows easy installation to a wide range of vessels, making re-powering easier than ever.

7. Transmission

The transmission has been specifically designed to withstand high torque, even in the most challenging sea conditions.

8. Standard Propeller Spline

1.25 “19-tooth spline output ensures both durability and compatibility with a range of industry-standard hub kits and propellers.

Technical Specifications 60° V8

Power Output	300 HP (224 kW)
Emissions Certifications	EPA 3, IMO II, RCD II, BSO-II
Max RPM	4,000
Displacement	4.4L (266 cu.in)
Dry Weight	393 kg (866 lbs)*
Aspiration	Twin-turbo
Gear Ratio	1.46:1
Shaft Lengths	25", 30" & 35"

Power Output	350 HP (260 kW)
Emissions Certifications	EPA 3, IMO II, RCD II, BSO-II
Max RPM	4,000
Displacement	4.4L (266 cu.in)
Dry Weight	393 kg (866 lbs)*
Aspiration	Twin-turbo
Gear Ratio	1.46:1
Shaft Lengths	25", 30" & 35"