The official line from the company is that turbocharging will only be used where it can replace cylinder count – in the case of the CX-9 that means the previous model’s V6 engine makes way for a turbocharged four-cylinder.
The reason, according to Mazda’s North American Vehicle Development Engineer, Dave Coleman, is because the efficiency gains through removing friction losses by removing cylinders, are greater than simply downsizing an engine’s capacity.
Stands to reason then that future generations of Mazda’s mainstream range could be seen with a two- or three-cylinder turbocharged engine stepping in for the naturally aspirated four-cylinder engines, right? Not so according to Mr. Coleman.
“You get into other issues like NVH challenges and stuff like that,” Mr. Coleman said. “Like, ‘what are the knock-on effects of having to deal with a three-cylinder or two-cylinder engine?’”
Admitting that Fiat’s Twin Air two-cylinder engine proves the concept can work, Mr Coleman hinted that Mazda’s corporate size might be the biggest limiting factor.
“At our size, we need to keep things pretty common across the platform, and not go with too many wildly different directions at once,” he said.
That doesn’t mean that Mazda is trying to limit its engineering resources though.
Development work on a new SkyActiv 2 range of engines, chassis, and transmissions is already underway, but like the current range, expect to see the new technology spread company-wide to help amortise development costs.