Diesel outboard influx to target commercial, defence markets

Dtorque, Oxe and Cox – they might not be familiar names on the Australian and New Zealand marine outboard landscape, but local marine and industrial power specialist Power Equipment Pty Ltd is hoping that's about the change, thanks to the benefits offered by these clever diesel products.

That's right, diesel… The concept of a diesel marine outboard isn't new, and in fact Yanmar (Power Equipment's flagship brand) produced models like its D18, D27, D36 and D40 models in significant volumes some years back. .

Now, the three innovative firms have plunged back into the local diesel outboard waters with some very high-tech offerings, and Power Equipment believes the outboards in question will hold plenty of appeal for commercial, government and military applications.

Market opportunity
Power Equipment recently invited Australian and New Zealand boating press to its headquarters in Melbourne's south-eastern suburbs this week to get acquainted with the three platforms. There we inspected the 50hp Dtorque 111 along with the Oxe 150 and 200, also learning about the looming Cox Powertrain CXO300.

The Dtorque and Oxe models are available now, while the importer says the high-power Cox outboard will go on sale in mid-2019.

According to Luke Foster (pictured), General Manager for Power Equipment, these diesel outboards represent a fresh opportunity for commercial marine operators.

"We are very pleased to have secured the distribution rights for these innovative outboards," he said.

"We are the only distributor in the world to have distribution agreements with all three of these brands.

"We're very excited about these new engines. We'd really like to get some penetration into the Navy and also the commercial marketspace, whether that be in fish farms or eco-tourism-type operations, among many others," Foster told boatsales.com.au.

Dtorque 111
The Dtorque 111 is produced by German engine specialist Neander Motors, and is distributed globally by Japanese giant, Yanmar.

The 804cc four-stroke turbo-diesel produces a claimed 50hp from 3500-4000rpm and an impressive 111Nm from 2000-3000rpm.

The engine adopts a horizontal parallel-twin format and utilises a common rail fuel injection system from Bosch.

According to Power Equipment, the unit offers fuel consumption two to two-and-a-half times better than that of an equivalent petrol outboard at wide open throttle, while offering torque that outperforms that of conventional 70hp petrol models.

With an aluminium head, block and base it weighs in at 175kg (dry), while Power Equipment says its reliability, durability, extended service intervals and safety (diesel being less flammable than petrol) will hold major appeal for a variety of commercial applications, along with use in superyacht tenders.

The engine uses dual counter-rotating crankshafts, its two conrods joined at the pistons with patented 'spaceball' technology. We won't go into the nitty gritty, but the tech is said to eliminate the vast majority of vibration and also minimises noise, leading to a very quiet, smooth ride.

Of course, all this upside comes at a cost and a significant initial one at that, with the Dtorque 111 attracting a retail price of $57,000.

Power Equipment went to pains to underline how, in addition to its long service intervals and fuel efficiency, the engine is essentially a clean-sheet design with low initial production volumes, hinting that prices could fall as sales momentum builds and production increases.

After the tech presentation boatsales was invited to take a spin on a Brig RIB fitted with the Dtorque outboard at the nearby National Watersports Centre.

While conditions on the enclosed waterway were perfect and the ride only brief, the engine certainly impressed with just how smooth and quiet it is in operation. At wide open throttle we were zipping along at just over 21kt (38.9km/h), with the Brig's dial indicating modest fuel usage of 11.9L/hr.

Oxe 150/200
Swedish firm Cimco Marine produces its Oxe diesel in two ratings: 150hp and 200hp. The 2.0-litre, in-line four-cylinder unit is based on a General Motors design, and adopts a horizontal cylinder format.

Of particular note is its use of belt drive instead of gears, which the company says allow a variable gear ratio and can permit rapid shifts without fear of damaging the transmission. This also allows a far slimmer lower leg housing to be used.

The belts deliver 200 hours between service intervals and an 800-hour life before replacement, while also neatly avoiding the timing issues inherent with a gear set-up. An overhaul is required at 2000 hours.

Weighing in at 350kg, the more powerful of the pair produces 200hp at 4100rpm and 415Nm at 2500rpm, while its sibling produces 150hp and 400Nm at the same points in the rev range.

Fuel consumption in the 150 is claimed to 36L/hr at WOT, which Cimco says is well under that of equivalent petrol outboards and only marginally above that of a diesel inboard.

The Oxe also has readily accessible service points and a modular design, the latter allowing replacement of various components and, subsequently, lower maintenance costs.

Out on the water, the Oxe 200 fitted to our Naiad RIB looked thoroughly sinister in its black paint; it wouldn't look at all out of place behind a team of navy SEALs speeding toward their next target.

Like the Dtorque, the Oxe 200 also proved remarkably quiet underway. As the test unit was a pre-production engine, it is anticipated volume production units will be even quieter again.

On test, the Naiad was up and on the plane in no time, and we were streaking across the water at wide open throttle at 4100rpm and 28kt (51.9km/h), for an indicated fuel burn of 31.6L/hr.

Pricing for the Oxe? The 150hp unit will set you back $60,000, while the 200hp model comes in at $72,000.

Cox CXO300
That leaves the Cox Powertrain CXO300, which won't go on sale here for another 12 or so months.

This British design came about after the company won a contract from the British Ministry of Defence to develop a concept diesel outboard for a fast-response navy vessel.

The engine adopts a four-stroke V8 architecture which, like the Oxe, is based on an automotive engine (in this case a fresh design penned by major automotive engineering house, Ricardo).

Billed as "the world's highest power density diesel outboard engine", the 4.4-litre, twin-turbo engine is said to weigh the same as the Oxe outboards – 350kg – yet Cox says it produces 100 per cent more torque at the crank than leading 300hp petrol outboards, and 60 per cent more than leading 350hp petrol outboards.

On top of that, Cox says "users of the CXO300 could save up to 45 per cent over the lifespan of the outboard, based on heavy use of 6000 hours with an overhaul at 3000 hours".

Those are some big claims, but we'll just have to wait and see. Pricing for the CXO300 will be announced closer to its local release.

Commercial focus
While petrol dominates the outboard market, diesel obviously has several tricks up its sleeve. Producing broad spreads of torque from low in the rev range, diesel outboards are also more fuel efficient and more durable, the three manufacturers concerned say. Safety benefits are also claimed.

The engines are clean-running units, too. The Dtorque complies with Europe's RDC II, while the Oxe models meet EPA 3 and IMO 2 and RCD, and the CXO300 meets EPA 3, IMO 3 and RCD 2.

While Power Equipment's mainstays concern power solutions from Yanmar and John Deere (the latter's marine and industrial engines, added to the business in mid-2017), Foster is decidedly upbeat about these new players.

"I think they've all got unique features," he says.

"The DTorque, with its all-new engine design, is quite special for its smoothness and quietness. The Oxe is a standout for its innovative belt technology and the Cox, being in the high horsepower segment, is really exciting for us too."

Current pricing may exclude the recreational sector for now, but this trio of high-tech oilers looks well positioned to make a strong case for high-use commercial and military applications.

And who knows – in time, and with costs permitting, this diesel outboard technology could well flow on to the leisure industry. Diesel, it seems, has well and truly entered the 21st century…

Specifications: Dtorque 111
Format: Horizontal four-stroke twin-cylinder turbo-diesel
Capacity: 804cc
Power: 50hp at 3500-4000rpm
Torque: 111Nm at 2000-3000rpm
Weight: 175kg (dry)
Manufacturer: Neander Motors
Origin: Germany
RRP: $57,000

Specifications: Oxe 150/200
Format: In-line four-stroke four-cylinder turbo-diesel
Capacity: 2.0 litres
Power: 150/200hp at 4100rpm
Torque: 400/415Nm at 2500rpm
Weight: 350kg
Manufacturer: Cimco Marine
Origin: Sweden
Price: $60,000/$72,000

Specifications: Cox CXO300
Format: 60-degree four-stroke V8 twin-turbo-diesel
Capacity: 4.4 litres
Power: 300hp
Torque: 650Nm
Weight: 350kg
Manufacturer: Cox Powertrain
Origin: Britain
Price: TBA

Related reading:
300hp Cox diesel outboard arrives in Australia
Power Equipment wins platinum