Mazda says that the trend of downsizing with turbochargers is coming to an end, with real-world emissions and fuel economy favouring larger-capacity engines with more cylinders.
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The Japanese company believes that it was right to invest heavily in naturally aspirated internal combustion engines (ICE) as part of its SkyActiv technologies, helping bring fuel economy gains and better emissions from a technology that many other manufacturers thought had hit its peak.

The SkyActiv technologies, fundamentally, are about getting the very best out of an ICE with higher compression ratios and other tweaks. Now, though, it’s looking to go even bigger with capacity and cylinder count for future generations.

Speaking to the Australian media at today’s Los Angeles motor show, the company’s head of research and development, Kiyoshi Fujiwara, said the trend to downsize is now going in the opposite direction.


“Most of the European manufacturers have begun to speak downsizing to right sizing or upsizing. That was announced by us five years ago, back then everybody said downsizing is better or a trend but we said right-sizing or upsizing. Now it has completely changed in the wind [in our direction],” Fujiwara said.

He said that means further turbo-charging of its engines is “not so important for future technologies”, but admitted that it will still be needed for some of the brand’s engines.

Mazda recently launched a 2.5-litre four-cylinder petrol turbo with the new CX-9.

“Of course I know i4 (four cylinder) can be a replacement for V6 engines with turbocharger, therefore CX-9 engine is quite suited for that kind of technology, but if we have some money or enough to invest in more cylinder, it's better suited for future technology.”


According to Fujiwara, turbochargers are not the answer for real-world fuel economy gains.

“A wide range of capabilities is required to reduce emission gas or CO2. In that case, more cylinder or upsizing bigger displacement is suited for all of the models. Bigger displacement size is much better for us, much better for us, and real world emission systems. A 3.0-litre or 4.0-litre we cannot do with i4 engine, which means more cylinder is required, requires a higher-displacement engine.

"[It is] better for us, better for [the] future.”

Every single BMW and Mercedes-Benz engine on sale today is now turbocharged, but Mazda seems to be going in an entirely different direction with its larger and naturally aspirated future engines.

“Bigger [capacity] to smaller turbocharged [engines], that is the last 10 or 20 years trend, but now, it’s time to change to a different direction. As you know, Audi and other manufacturers are all the same, now rightsizing or upsizing, now to change trend,” Fujiwara said.

Although not admitting it outright, it appears Fujiwara is stating that while turbocharged engines are good at getting low fuel economy ratings in regulated testing cycles, in the real world, the use of the technology results in ultimately a higher fuel usage than a larger capacity, high compression ratio, naturally aspirated unit.


“Five or six years ago we said higher displacement is a lot better, because we care about real-world emissions, therefore customer satisfaction with fuel economy is the best way.

"We have to do that for the customer first, therefore real world fuel economy is most important for us.”

The recently launched 2017 Mazda CX-5 makes use of the company’s existing range of engines, a 2.0L, 2.5L petrol and a 2.2-litre turbodiesel.

As for how soon we will see a range of new V6 engines with higher capacity from Mazda? That remains to be seen, with Fujiwara admitting that the company only recently came out of financial debt and that “now again we are standing on the starting point, so we have go save the money to invest”.