In February 2004 I wrote this in the NZ Herald:
‘In the 1980s and 90s, Mazda pretty much went from one conservative passenger car to another, with the exception of the brilliant MX-5 sports car.
‘Its mainstream models were well built but largely lifeless. An outsider could be forgiven for thinking that Mazda executives wore cardigans, carried cut lunches and sat around formica tables talking shades of grey.
‘They certainly talked cost cutting back then. The company had 13 vehicle platforms on the go and couldn’t make enough of them work profitably. It had spread itself too thinly.
‘It knew it and set out to reinvent itself, to capture in its mainstream models the spirit of the MX-5 and breakaway technology of the original rotary-engined RX-7.
‘Less than two years into its new path, Mazda has reinvented its model line-up. Its executives have a new attitude, too. There’s an air of restless, non-conformity about them. No sign of cardigans and cut lunches.
‘They have apartments in the city, dabble in genealogy, carry coffee beans instead of worry beads, wear designer shirts outside trousers, and know the medicinal properties of native plants. That’s just the blokes.
‘It’s an image thing. It started 18 months ago with the Mazda6 medium sedan and picked up pace last year with the Mazda2 hatchback and RX-8 sports car. Now the transition has continued with the Mazda3, the replacement for the 323…’
Sixteen years on there’s a new transition – Skyactiv-X. It’s an engineering development of Skyactiv-G, a transition in itself introduced in Mazda engines early last decade to cut emissions and improve fuel use.
The first models to use Skyactiv-X in New Zealand are the updated Mazda3 ($51,995) and CX-30 ($54,990), pictured here and both running 2.0-litre four-cylinder units. The technology is expected to appear in a new mild-hybrid six-cylinder engine it is developing for the next Mazda 6 sedan and wagon and the CX-5 SUV.
Company president Akira Marumoto has already said it was planning a 48-volt Skyactiv-X powertrain for CX-5 models and above. The six-cylinder would therefore also be the premium offering in the next CX-7, CX-8 and CX-9.
Mazda has made much of Skyactiv-X as breakthrough petrol-power technology. It marries a variation of compression ignition – the way a diesel engine works – with a mild hybrid system comprising an electric motor and lithium-ion battery.
Energy recovered during deceleration powers the electric motor to assist the engine. Skyactiv-X offers as much as a 20 per cent saving on fuel use while boosting torque by between 10 and 30 per cent, says Mazda. It also says it cuts harmful exhaust emissions.
How does Skyactiv-X work? Briefly, petrol engines use sparkplugs to detonate the mixture of fuel and air in cylinders. Diesels instead compress the air inside cylinders to where it’s hot enough to detonate the fuel without a spark.
The higher compression ratio – diesels are typically around 16:1 – the more efficient the engine. Upside: better fuel economy. In petrol engines, fuel is injected earlier into the cylinder where the air is kept cooler with a lower compression ratio, typically around 9:1. The cooler air allows the air and fuel to mix better. Upside: a cleaner burn.
Skyactiv-X splits the difference with a compression ratio of 14:1 for more efficient combustion. The result is more of the power of petrol is used to drive the vehicle rather than being lost in the exhaust or cooling systems, or through mechanical resistance or friction.
But Mazda hasn’t reinvented the wheel exactly. Skyactiv-X uses what the carmaker calls “spark controlled compression ignition.” It means the engine has spark plugs but uses them only when necessary, like on cold starts.
The technology allows the engine to switch seamlessly between conventional spark ignition and compression ignition by using a spark to trigger both types of combustion in different ways.
It’s the next step in what Mazda says is its multi-solution approach to reducing emissions over the next 10 years, under the somewhat goofy phrase “Sustainable Zoom-Zoom 2030”.