By Veeno Dewan
Mazda’s radical new technology for its next generation of cars is called SKYACTIV and is all about efficiency; efficient engines, efficient transmissions, efficient chassis and efficient car body technology.
The benchmark car for SKYACTIV engine development, when it came to responsiveness to driver input, was the iconic MX-5. It’s a car that offers race car-like response rates and delivers one of the world’s best ‘behind the wheel’ experiences outside that of a supercar from Italy.
Kiyoshi Fujiwara, Mazda’s Executive Officer for Product Planning and Powertrain Development said, “the “most important thing was to make it more fun to drive. That’s harder to measure. It’s something you feel”.
Fujiwara went on to say, “Oneness between car and driver is our goal. That’s more important to us than absolute power. It’s that response and linearity that make driving fun.”
Mazda’s vision is to make “cars that always excite, look inviting to drive, are fun to drive, and make you want to drive them again”, but at the very same time, delivering a greener footprint on the environment. What that means for drivers is more torque, more power, greater response, and at the same time, the ability to deliver 30 percent better fuel economy by 2015 compared with 2008 consumption levels.
In SKYACTIV-D form, Mazda engineers have broken new technological ground in creating the world’s lowest diesel-engine compression ratio of 14.0:1, is lighter and achieves 20 percent better fuel economy than the current diesel engine.
SKYACTIV-G is what Mazda’s next generation petrol engines are called, and just like the diesel versions, is a product of breakthrough technology. This is a highly-efficient direct injection 2.0-litre engine with an extremely high compression ratio (14.0:1) that develops 15 percent more low- and mid-range torque than the Mazda’s current 2.0-litre petrol powertrain. Not only that; remarkably, fuel consumption falls 15 percent to around the same rate the current diesel engine uses.
The big surprise in a comparison test driving current Mazda6 sedans with prototype SKYACTIV-equipped Mazda6’s on a few test runs was how smooth and torquey the new cars are when accelerating out of a low speed corner. That’s a product of SKYACTIV-DRIVE; the all-new six-speed automatic transmission, that’s not only quick shifting, but Mazda believes is a product of the best features of all three types of auto boxes; meaning Step Automatic, Continuously Variable (CVT) and Dual clutch (DCT).
In order to achieve such sharp characteristics, Mazda engineers have reduced the weight of the new gearbox by 16 percent. The transmission uses a triple-shafted gear train for the ‘large’ version, which allows for a common gear for 2nd and 3rd gear ratios. This has meant a 20 percent shortening of the secondary shaft.
It’s a complex system in theory; suffice to say that the number of components and the weight of the gear train have been reduced by three kilograms.
As much work that has gone into SKYACTIV engines has also been applied to weight reduction and strength of the body and chassis, and those remarkable effects of SKYACTIV-Body and SKYACTIV-Chassis were more than evident and clearly demonstrated on the test runs as the prototype Mazda6 felt immediately lighter and considerably more agile than the current model cars.
Even though the weight of the body has been reduced, rigidity is up by 30 percent through the use of more high-tensile steel in the construction process. You can feel increase in stiffness in the prototype cars and are able to speed faster through the corners than the current model.
There are more spot welds, thinner gauge steel, but stronger framework has been applied for not only a lighter and stronger body but for an altogether safer body through multi-load paths. And there are likely to be further weight reductions under the SKYACTIV regime, as Mazda engineers point out that many car companies are using up to 60 percent high tensile steel, whereas they are using just 40 percent of the lighter gauge metal.
Big reductions have also been made with the chassis, too, with no less than a 14 percent drop in weight over the current model. The front and rear suspension systems and the electric power steering unit have all been newly developed to provide that “oneness between car and driver”.
Mazda said SKYACTIV technology will be seen in production cars later this year, with SKYACTIV engines and transmissions to begin with, with the complete technology introduced on new models in time. Best news is that Mazda say that vehicles fitted with the new SKYACTIV technology are not anticipated to be more expensive than current models. The Mazda boffins seem to have been very busy of late!