Inline diesel ‘six’ to meet Euro7 rules: Mazda

MAZDA says its newest inline six-cylinder turbo-diesel engine – which is set to debut in the Australian-bound CX-60 large SUV – will comply with more stringent Euro 7 emissions standards.

Despite demand for diesel-powered passenger vehicles falling by 34 per cent in Europe over the past year, Mazda Europe R&D centre senior manager of technical development Joachim Kunz said he was confident the engine would be Euro-7 compliant upon its release around the middle of this year – despite not fully knowing how strict the new rules will be.

“Mazda will fulfill the Euro 7 emission standards with the new diesel engine. This will be most likely be the last generation of internal combustion engines, so we will prepare for the toughest expected target and then adjust using after-treatment solutions,” Mr Kunz told Automotive News Europe.

Mr Kunz said that although Mazda’s engineers knew that they were facing a moving target (given EU policy makers have yet to settle on just how tough Euro 7 emission standards will be), he was confident that the Hiroshima-based brand would “invest more and forsake profits” to offer the engine – even if it meant the Euro-spec CX-60 would have a less powerful engine than forecast.

The inline six-cylinder engine’s large displacement of 3.3 litres (202ci) means Mazda can afford to detune the unit while still offering segment-competitive power and torque figures – and better the outputs of its current Skyactive-D four-cylinder turbo-diesel powerplants. Mazda previously said that 48-volt mild-hybrid technology was part of the plan to help keep its new-age engines compliant with tightening emissions regulations, but that design improvements, including outstanding combustion efficiency, would help minimise noxious oxide (NOx) emissions.

“Having a 3.3-litre engine means we want to be on the safe side for torque and power,” added Mr Kunz. 

“To get low NOx emissions we need low combustion temperatures (and) having a bigger engine keeps temperatures lower, which is good both for reducing the heat loss and for cutting the raw NOx emissions. This, in turn, will enable us to have a simpler after-treatment system.”

Mr Kunz said Mazda’s newest turbo-diesel mill would incorporate a selective catalytic reduction (SCR) system “to show the customers that we are making every effort to reduce NOx.”

The SCR, which converts NOx with the aid of a catalyst into diatomic nitrogen and water, will be smaller and require less frequent urea (AdBlue) refills by the operator.

The five-seat Mazda CX-60 is the brand’s first premium SUV and is slated to go on sale in Australia later this year. The Hiroshima-based brand says that at 4745mm in length, 1890mm in width and 1680mm in height, the model is notably longer and wider than the current CX-5 and will offer an eye-catching appearance that draws from its latest Kodo design language.

Inside, the CX-60 is said offer 44mm more front seat shoulder room than the CX-5 and 50mm more shoulder room across the rear bench. The rear seats are also said to offer “enough legroom for passengers to sit with their legs straight”, while the cargo area promises 570 litres of capacity in five-seat mode.

Mazda is yet to release power and torque specifications for its new inline six-cylinder engines – of which both a naturally aspirated 3.0-litre petrol and 3.3-litre turbo-diesel will be offered – but says both rear- and all-wheel drive configurations will be available.

Production of the CX-60 commenced earlier this month at Mazda’s Hofu Plant No.2 in the Yamaguchi prefecture with the Japanese-spec model to be introduced early next month (April).

Mazda Australia will release further details, including pricing and local specification, closer to the model’s local launch.

With Automotive News Europe