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03/10/2011
REVIEW by EWAN KENNEDY
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Mazda has added a very important new model to its popular Mazda3 range, one of the biggest selling cars in Australia. Called SP20 SkyActiv, it features some all-new technology designed to significantly reduce fuel consumption and exhaust emissions.
Just as importantly, Mazda plan was to achieve this without any diminution of what the quirky Japanese marque calls it’s ‘Zoom-Zoom’ driving experience.
Early in 2011, we spent a full day with Mazda in Melbourne for a series of technical presentations by Japanese engineers about what the company calls its SkyActiv models. That was followed by test drives of a prototype of the SkyActiv diesel in a test ‘mule’ car.
SkyActiv covers not only engines, but also transmissions and body aerodynamics and special tyres.
The most startling features of the new SkyActiv petrol engines are the compression ratios. Typically a modern petrol engine runs somewhere between 9:1 and 10:1, with very-high performance units going up to as much as 12.5:1. Mazda engineers have managed to get their Skyactiv engine up to 14:1, a seemingly impossible figure until now. The higher the compression ratio, the greater the ability of the engine to extract the maximum amount of energy from petrol.
This ultra-high compression has been achieved in the new Mazda engines without creating ‘knocking’ within the engine by reshaping the piston tops and greatly extending the length of the exhaust extractors.
Unfortunately, the Mazda3 SkyActiv models we have just road tested have a detuned version of the engine, with a compression ratio of 12:1. That’s partly because many Australian drivers are reluctant to pay the extra for 95 high octane petrol, preferring instead the cheaper, lower grade 91 octane. Australian Mazda3 SkyActiv models suffer a performance loss of about five to six per cent according to the project’s program manager, Kenichiro Saruwatari, who travelled Downunder for the media launch.
However, this Mazda3 has an official fuel consumption rating of just 6.1 litres per hundred kilometres, an amazing reduction in consumption of 25 per cent compared with the standard engine.
During our 300 kilometre test drive out of Melbourne, along the Great Ocean Road and into the hills behind that scenic drive, we were recording figures in the low to mid sixes so the claimed number appears to transfer into the real world.
We have yet to test a Mazda3 SP20 SkyActiv in traffic conditions, but will do so soon and report on the car’s fuel consumption on a day-to-day basis that includes commuter running.
This Mazda uses a stop-start system that switches off the engine when the car is stationary. Though Mazda claims the engine restarts in about half the time taken by stop-start systems in other cars, we didn’t feel it was altogether different. Again, we can test it in full when we are back in our home area.
Part of the economy engineering in the SkyActiv is a new design of six-speed automatic transmission that features very tall gearing in fifth and sixth ratios. This sees the engine running at just over 2000 revs at 100 km/h. It used to take a big, thirsty V8 engine to produce numbers like that. The higher torque produced by the new engine means the torque converter can remained locked up for much longer than that of a conventional auto.
The new automatic transmission has semi-manual overrides, but these can only be used by way of the floor gear lever, we would prefer paddles on the steering wheel as well.
The overall package on the Mazda3 SP20 SkyActiv feels brilliant to sit behind. The engine has strong torque and is willing to rev, the transmission is generally in the right gear for most occasions and there’s a sporty feeling that keen drivers will enjoy.
Best of all, the SkyActiv achieves consumption that’s almost as low as that of a diesel engine, without the turbo lag and smell that are an unfortunate part of diesels.
Mazda3 SP20 SkyActiv is on sale now and has a recommended retail price of $27,990, which includes the mandatory automatic transmission.
As well as the introduction of the SP20 SkyActiv, Mazda has carried out minor revisions to the rest of the Mazda3 range. These include a slight facelift and added equipment being fitted as standard. Price reductions have been achieved in some versions, partly due to the strength of the Australian dollar against the Japanese yen, but also because this is a highly competitive segment of the car market and buyers are being wooed by many car makers.
The complete model range for the new Mazda3, with prices (excluding government and dealer delivery charges) is:
Neo: $20,330 (manual), $22,330 (automatic)
Maxx Sport: $24,490 (manual), $26,490 (automatic)
Diesel: $27,360 (manual)
SP20 SkyActiv: $27,990 (automatic)
SP20 SkyActiv Luxury: $30,990 (automatic)
SP25: $31,490 (manual), $33,670 (automatic)
MPS: $39,490 (manual) |
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