Diesel outboards are just a sliver of the recreational market and used primarily by government agencies and the military, which has made it a mandate to get gasoline off its ships. That’s one of the reasons why diesel outboards are gaining popularity on the commercial side.
Like their automotive counterparts, diesel outboards are workhorses offering longer service intervals compared to gasoline counterparts, better range and are far less smelly and smoky than previous generations. The military prefers the less combustible diesel fuel over the gasoline counterparts.
Here’s a roundup of some of the diesel outboards on the market.
Oxe Marine AB
OXE Marine long viewed itself as disrupting the industry with its high-horsepower diesel outboards. The Swedish builder says its outboards have better torque, range, fuel economy and a longer shelf life than its gasoline counterparts.
OXE Marine offers four models from 150 to 300 horsepower. The diesel OXE300 25-inch version weighs 947 pounds, while the comparable horsepower gasoline-fuelled Mercury Verado 300 weighs 600 pounds.
OXE Marine rates the 300-hp outboard at 10,000 hours with the company marine-izing a BMW diesel automotive engine. The diesel outboard situates the engine horizontally (on most outboards it’s vertical) and transfers the power through a belt system to a transmission and belt that drives the lower shaft. The proprietary belt system eliminates vibration common to diesel engines and can absorb the torque.
OXE Cox Marine diesel models available include the OXE150, OXE175, OXE200 and OXE300. The company introduced a new ultra-high-performance water jet for its diesel outboards. The unit is a bolt-on replacement to the standard lower unit on the company’s outboards.
Cox Marine’s only offering is the CXO300 diesel outboard for the commercial and recreational markets. The 300-hp Cox Marine outboard reportedly offers 30 percent better fuel efficiency compared to its 300-hp gasoline counterpart.
Delivering 479 foot-pounds of torque at 2,250 to 3,000 rpm, the CXO300 reportedly produces 25 to 35 percent less C02 emissions than a gasoline outboard. Cox Marine’s CXO300 achieved the stringent BSO-II Bodensee emission standard for both single, and more recently, twin installations operating on the protected waters of Lake Constance.
Cox Marine was founded in 2010 and raised over $130 million in private investment before bringing the CXO300 to full production in May 2020.
Cox Marine backs the CXO300 with a five-year or 1,500 hours warranty for the recreational market, while the commercial outboard comes with a one-year or 1,000 hours warranty.
When it comes to diesel outboards, Mercury Marine has just one choice and it’s designed for patrol boat applications. While most center consoles run outboards, some of the sport fishers opt for inboards, Mercury Marine offers multiple diesel engine options.
Mercury’s 6.7-liter, 480-, 500- or 550-hp engine package is designed specifically for sport yachts. It’s compatible with Mercury Zeus pod drives and Mercury Joystick Piloting for inboards. The 550 produces a sizeable 1,580 foot-pounds of torque at 1,900 rpm.
Mercury’s 2.0-liter diesel engine is available in 115-, 130-, 150- and 170-horsepower iterations. Take the 170-hp version, it weighs under 600 pounds and burns a measly 9.6 gallons an hour.
The 3.0-liter platform offers a 150-hp sterndrive, 230-hp inboard, 230-hp sterndrive, 270-hp sterndrive and 270-hp inboard. An air filter on the 3.0L doubles as a silencer that eliminates the turbo whine that is typical with diesel engines. The motor mounts are designed to minimize vibration.
Mercury’s diesel outboard is a two-stage direct fuel injection that produces 175 horsepower. Mercury says, “an on-board Propulsion Control Module (PCM) microprocessor optimizes fuel and spark timing for improved running quality and performance throughout the engine’s operating range.” The 3.0-liter diesel outboard is available in 25” and 30” shaft lengths.Boating, boatlife, BoatLifeStyle, BoatMaintenance, BoatOwners, BoatPower, BoatUpgrades, DieselEngines, EngineMaintenance, EnginePerformance, FuelEfficiency, FuelManagement, MarineEngines, MarineMechanics, MarineTechnology, NavigatingWaters, OceanAdventures, sailing, Seafaring, Yachting Boating, boatlife, BoatLifeStyle, BoatMaintenance, BoatOwners, BoatPower, BoatUpgrades, DieselEngines, EngineMaintenance, EnginePerformance, FuelEfficiency, FuelManagement, MarineEngines, MarineMechanics, MarineTechnology, NavigatingWaters, OceanAdventures, sailing, Seafaring, Yachting