Here’s a riddle for you—if it’s said that diesel has traditionally been the fuel of the
maritime industry, why aren’t there more diesel outboards out there? As New Atlas
shares, now with the production of the 50hp Yanmar Dtorque 111 turbo-diesel getting
underway, arguably the first widespread diesel outboard engine will be hitting the market.
Diesel outboard predecessors have hazarded tried their luck in the past, including
attempts by Yanmar itself, but that was a time in the past. With the stack of benefits that
come with the new German-designed Neander-Shark engine, pitting this to traditional gas
outboard engines is nothing if not cause for excitement.
Here’s how they compare: the Yanmar Dtorque 111 is lighter and more densely
constructed than similar capacity gas engines. A lack of vibration in the two-counter-
rotating crankshaft design means it doesn’t need the heavier vibration-absorbing clout of
a traditional diesel. It runs smoother, has double the engine life at an expected lifespan of
over 10,000 hours, and puts out less toxic emissions. At full throttle and full loading, it
typically burns less than 3.2 gallons of fuel per hour—which is half the amount of
gasoline in similar-performing outboards. And the Dtorque 111, incidentally named for
its remarkable low rpm torque (with 111 Nm on offer at 2,500 rpm), can bring a boat up
to plane even faster. This is before bringing the safety and availability benefits of diesel
fuel into the discussion.
Granted, it’s not all fun and games. Pioneering non-traditional technology can be an edgy
business, but it’s a path already walked by Germany's Kiel-based Neander Motors in
several markets due to its two-conrods- per-piston, small-capacity diesel engines. And it’s
something that Austria’s Stevr Motors is ready to jump onboard with when it comes to
taking on production of these new outboards. It was officially announced at the Monaco
Yacht Show that Yanmar would begin global distribution of the Dtorque 111 outboard
engine. This is after two years of promising pre-series trails conducted by both Yanmar
and Neander across six European countries—including testing in Sweden at temperatures
of 5 degrees Fahrenheit. In a port area that had been freed from ice, this engine ran
perfectly in all speed and load ranges, starting and idling so reliably that the Swedish
coast guard directly expressed interest in the technology.
"We invited a wide cross-section of our customers around Europe to performance-test the
outboards in differing sea states and loading conditions gathering as many opinions as
possible," explained Floris Lettinga, Yanmar Global Sales Manager. "Our research has
confirmed that this product is ideally placed for the light duty commercial market…We
are confident that the combination of long range, low running costs, durability and low
emissions delivered by this unique diesel outboard will appeal to operators across a wide
range of applications.”

Photos credited to Yanmar/Neander-Moto