MAZDA IS AT IT AGAIN, STICKING DOGGEDLY TO THE INTERNAL COMBUSTION PETROL ENGINE.
Ignoring the downsizing, turbocharged trend of others (the days of which may be numbered anyway), and even the switch to hybrid powerplants, the Japanese carmaker has just given fans a preview of its next 'Skyactiv' efficiency technology.
Called Skyactiv-X, the latest version is the branding for the company’s breakthrough in compression ignition for a petrol engine.
Vehicle Style: Small Sedan - prototype
Price: $ N/A
Engine/trans: 2.0-litre 4cyl supercharged SPCCI petrol
Fuel Economy Claimed: N/A
Mazda believes there is still life in the internal combustion engine.
The company has released a new road map for its future, dubbed Sustainable Zoom-Zoom 2030, and has made a pledge to do all it can to stop global warming by reducing its CO2 emissions.
But while the popular choice is to go electric, Mazda believes that when you factor in the emissions generated by producing electricity, from burning coal, nuclear or even gas, an electric car is actually not as clean as we’re led to believe.
This so called well-to-wheel approach to reducing CO2 has driven Mazda to develop its next step in engines, dubbed Skyactiv-X.
HOW DOES IT WORK?
Traditional engines use a spark plug to ignite the fuel-air mixture inside the combustion chamber, but that isn’t as efficient as it could be.
So Mazda’s engineers have developed a system based on the principle of a diesel engine, which uses compression to ignite the fuel inside the combustion chamber, resulting in a cleaner, more efficient burning of the fuel and thus making the engine more efficient.
The problem is controlling that process without a spark plug, especially when the engine is cold. So Mazda’s solution was to include a spark plug as a control factor to allow the engine to work in every condition. Mazda calls the technology Spark Controlled Compression Ignition (SPCCI).
The spark plug is only used when it is needed, as the majority of the time the compression ignition process works on its own.
The results, Mazda claims, is a “drastic” improvement in fuel economy. As the technology is still being fine-tuned for production there aren’t any fuel economy figures being revealed but the company did say the fuel savings could be as much as 20 percent.
More than that though, in the face of impending real-world fuel economy testing, Mazda claims Skyactiv-X shows little difference in terms of fuel use between lab testing and real world driving conditions. That is a key point in the wake of the mistrust created by the Volkswagen emissions scandal and the continuing push by various bodies around the world - including Australia - for more real world fuel economy testing to help customers make clearer choices.
The company also says it creates better throttle response and acceleration continues at higher revs as a result of the more efficient fuel burn.
But Mazda isn’t just talking about this technology, as it invited TMR to its research and development centre near Frankfurt, Germany, to sample the prototype Mazda3 Skyactiv-X.
ON THE ROAD
The prototype sits upon Mazda's next-generation Mazda3 chassis, which features strengthened components to improve handling. But the packaged was covered in the bodywork of the current generation '3' in order to blend into traffic when we hit the public roads outside the centre.
The engine fitted to our car was 2.0-litres in capacity, but Skyactiv-X is expected to be offered in various capacities, as per Skyactiv-G. In order to ensure enough air is fed into the cylinders to ignite the fuel, the Skyactiv-X engines are fitted with a supercharger.
No official performance figures were provided by the Mazda engineers but they did reveal the target was for the engine to produce approximately 230-250Nm. For comparison, the current Skyactiv-G 2.0-litre engine produces 110kW and 200Nm while the 2.5-litre makes 138kW and 250Nm.
From behind the wheel, the Skyactiv-X engine feels immediately more responsive than the current units. There’s good pulling power lower in the rev range and the throttle performance does feel more urgent than the existing 3.
In terms of outright performance it doesn’t feel significantly more potent, with the same respectable acceleration that has made the Mazda3 one of Australia’s favourite small cars.
Because the cars we drove were prototypes there were some obvious issues that will need to be sorted out before Skyactiv-X reaches showrooms in 2019.
The most notable problem was a pinging from the engine under hard acceleration, which was explained as a byproduct of the switch between spark and compression ignition. There was also a slight stutter under throttle at times. But these are minor problems and should be rectified before Skyactiv-X becomes available to the public.
Of course the biggest question is: how much fuel does it actually save? The data provided by Mazda indicated that Skyactiv-X was up to 14.7 percent more efficient than Skyactiv-G, with its traditional spark ignition.
The data also showed just how little work the spark plug does in Skyactiv-X, with more than 90 percent of the test loop done using compression ignition.
As for the rest of the Mazda3 prototype and its upgraded underpinnings, it’s hard to make a definitive call on the changes due to the hand-made nature of the vehicles. The suspension tuning was also not the final calibration, so judgement on it will need to wait for another day.
The test drive showcased Skyactiv-X, which appeared to live up to most of Mazda’s claims.
While the technology is all-new, on the road it is seamlessly integrated into the existing package.
Mazda’s aim is to reduce CO2 emissions by producing an efficient car from well-to-wheel and sell it to a far wider audience by being more affordable than electric vehicles, at least in the short-term.
On that front, Mazda's decision to forge its own road could pay off - again.