Yanmar Marine International (YMI) has announced the official launch of its twin-cylinder 50hp diesel outboard engine, the Dtorque 111.

Described as a ‘game-changer’, the compact unit was designed to revolutionise the small workboat market where its expected lifespan is well over 10,000 hours – at least double that of any comparable outboard gasoline engine, Yanmar claims.

It is also said to be the world’s smallest diesel engine with common-rail fuel injection. This allows it to deliver 50hp at the propeller, with a torque output of 111Nm at just 2,500rpm. According to Yanmar, this is considerably better than the latest 70hp four-stroke gasoline models and more than enough to quickly accelerate most small craft onto the plane with plenty of low-down lugging power for heavy displacement duty.

The Dtorque 111 is also well within the latest EU RCD 2 limits for exhaust emissions. At full throttle and lading it typically burns under 12lt of fuel per hour – two times less than most 70hp gasoline outboards of similar performance, Yanmar claims. The Dtorque 111 ensures fewer refuelling stops and lower running costs.

To create the Dtorque 111, Germany's Neander Shark deconstructed conventional small-diesel engineering to first principles. The result is a two-cylinder common-rail turbo charged diesel engine, using a unique system of dual counter-rotating crankshafts in an aluminum block, which dramatically reduces the vibration levels that a conventional small two-cylinder diesel engine would normally generate. This technology with a patented 'Spaceball' design not only achieves less vibration but also less noise, lighter boat handling and less stress on the engine.

For the past two years, both Yanmar and Neander have been trialling pre-series outboards in six EU pilot countries. The Dtorque 111 turbo diesel outboard is SOLAS (MOB) certified and now in full production with customer deliveries in the last quarter of 2017.