Manufacturer Profile
Cox Powertrain Ltd.
The purpose-built diesel V8 — the CXO300, a ground-up 300 hp marine diesel outboard from the UK.
Quick Facts
- Founded
- Project from 2007–2008; production 2020
- Headquarters
- Shoreham-by-Sea, United Kingdom
- Country
- United Kingdom
- Ownership
- Privately held (Cox Powertrain)
- HP Range
- 300 – 350 hp
- Fuel / Power
- Diesel (compression-ignition)
The Offer
Cox Powertrain builds the CXO300, a purpose-built 4.4-litre twin-turbo V8 diesel outboard — not a marinized car engine but a ground-up marine design. Developed with F1 engineering input and partner Ricardo over more than a decade (concept fired 2010, production 2020) in Shoreham-by-Sea, UK, it makes 300 hp (a 350 hp variant exists) with huge low-end torque. Cox targets military, commercial and high-end recreational users who need diesel range, single-fuel logistics and long service life.
Abridged History
- Roots trace to the late 1960s after co-founder Charles Good's boat fire drove a search for a safer diesel outboard; in 2007–2008 he partnered with F1 engineer David Cox.
- UK consultancy Ricardo joined as development partner; the first concept engine fired in 2010 after a program costing well over $160M.
- Production of the CXO300 began in 2020 at a purpose-built facility in Shoreham-by-Sea, using a “fewer, bigger, better” global distribution strategy.
Product Lines (2 families)
Signature Technology
- +Purpose-built 4.4L 60° V8 diesel with twin turbos and common-rail direct injection
- +Huge low-end torque (~1,052 Nm) for heavy loads
- +Built for commercial/military duty with long (250-hour) service intervals
Heritage
A ground-up British marine-diesel engineering project — over a decade of development with Formula One and Ricardo expertise to create the first purpose-designed high-power diesel outboard.
Company at a Glance
- Stock / Ticker
- Privately held
- Employees
- Not publicly disclosed
- Annual Revenue
- Not publicly disclosed (private company)
- Manufacturing
- One purpose-built manufacturing facility
- Key Plant Locations
- Shoreham-by-Sea, United Kingdom
- U.S. Presence
- Sold in North America through a selective (“fewer, bigger, better”) distributor network.
Cox Powertrain is privately held and does not publish detailed financials; development investment was reported to exceed $160–200M. Figures are point-in-time snapshots from company filings for the year shown; stock price and market value change daily — check the ticker for live pricing.
What Cox Marine Is Famous For
The world's first purpose-built high-power diesel outboard. Cox is famous for the CXO300 — a ground-up V8 diesel aimed at military and commercial operators, not a converted automotive engine.
Where Cox Marine Shines on the Water
Military & Commercial
Rugged diesel built for patrol, security and workboat duty with single-fuel logistics.
Long-Range & Efficiency
Diesel economy and torque suit heavy loads and extended range.
Superyacht Tenders
Diesel-tender option matching a mothership's fuel supply.
Dealers & Service
Cox uses a selective “fewer, bigger, better” distributor network across Europe, North America and beyond, with service through authorized partners. As a specialist diesel brand its network is far smaller than mass-market gasoline brands — confirm your nearest authorized service point. Cox does not publish technician head-counts.
Best For
Military, commercial and superyacht-tender operators needing a rugged, long-range diesel outboard and single-fuel logistics.
- ✓Purpose-built marine diesel (not an adapted car engine)
- ✓Diesel efficiency and range (claims of ~30% better economy)
- ✓Commercial/military durability and single-fuel logistics
Browse Cox Marine Outboards For Sale
Official Cox Marine Links
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