Mazda plots cleaner diesels, rotaries, stop-start

By Richard Aucock

Motoring Issues

19 September 2008 07:00

Mazda has opened its R&D department up to CAR, in a demonstration of how it's tackling a changing world. It's spilled the beans on its future engine tech, how it's going to continue stripping weight out of its cars, when stop-start is coming – and more besides. Read on for the lowdown on Mazda's eco tech future.

And it's not all boring. Zoom-zooming in a ‘green’ black Mazda 6 is a tasty way of demonstrating the firm’s environmental plans. No stuffy hand-wringing lectures here. Rather, a grounded, realistically ‘eco’ philosophy, that presses all the right buttons with car guys like us. An engineer’s sense, rather than head-in-clouds idealism, generating guaranteed savings today, not theoretical ones tomorrow. And among the first fruits of the ‘sustainable zoom-zoom’ mantra (yes, they really do call it that), is that 183bhp diesel…

A fast and green Mazda diesel? Tell me more…It’s coming to the 6 early in 2009. Higher-pressure injectors, an enhanced variable-geometry turbo and stronger aluminum pistons equal 295lb ft of effervescence on the road. CAR had no problem harassing BMWs on Frankfurt’s autobahns.

It’s responsive, has a broad rev range, and is smooth, too, courtesy of a balancer shaft and stiffer block, albeit not quite as other-worldly-refined as Mazda reckoned. Traces of in-town rattle remain. This isn't a new engine but a heavily revised version of the existing 2.0-litre diesel; the upshot is that the 183bhp diesel is cost-effective and will fit wherever the current one does.

I’m not seeing much that’s green there Well, it’s fast and sleek enough to be a genuine alternative to the 2.5-litre petrol. There’s a 15mpg advantage in your pocket right away. Indeed, it’s as economical as the 2.0-litre – 50.4mpg combined – and a new type of particulate trap gets rid of soot more efficiently. That means faster DPF regeneration, fewer cycles, and more economy.

But we have to wait until 2011 for the real ‘green’ diesel. Mazda's all-new engine will be ten percent more economical, even more powerful, higher-revving, with weight similar to a petrol unit. There will be a two-stage turbo, expensive Piezo injectors and a petrol-like feel thanks to lower internal resistance. Apparently.

Sounds like Mazda’s busy!You bet. CAR was briefed on what’s coming and there are new direct-injection petrol engines coming in 2010, said to be 20 percent faster and more economical. Mazda's fabled rotary engine will get direct injection too, and grow in capacity (to 800cc x 2), which will yield more torque, power and (phew) economy.

The oddball rotary's future is secured, as it’s key to Mazda’s plans for clean-fuel hydrogen-IC hybrids (which can also use regular unleaded), as a step towards hydrogen-electric fuel cells. A rotary-electric hybrid Mazda 5 is already running, as rotarys thrive on somewhat volatile H2. There is also a canny new ‘SISS’ stop-start, much more advanced than current systems, albeit limited to those direct-injection petrols for now.

Click 'Next' to read about more future tech in store at Mazda

By Richard Aucock