AFTER TWO FULL DAYS at the wheel of Holden?s new 2010 VE (MY10) 3.0 litre SIDI V6 and the 3.6 litre SIDI V6, three things are apparent.
First, the new 3.0 litre and 3.6 litre direct injection V6 engines are significant advances over the old, not only in technology but also in refinement.
Second, with ADR combined cycle figures as low as 9.3 l/100km for the new 3.0 litre V6, fuel consumption and carbon emissions are also significantly advanced. Frugality of this order betters some four-cylinder contenders in the medium segment.
Third, the improved power outputs - 190kW produced by the 3.0 litre, and 210kW produced by the 3.6 litre ? show that efficiency and lowered emissions need not conflict with tractability and enjoyment at the wheel.
These are traditional big sixes with the power and responsiveness Australian buyers expect, but with the efficiency and emissions output that is a genuine match for some four-cylinder competitors. This point will not be lost on family and fleet buyers.
Also of significance to fleet and family buyers are the improvements to passive and active safety features right across the new Commodore range. Importantly, for the first time in the light commercial sector, six-airbags, including side and curtain airbags, are standard across the ute range.
But the ?ace in the deck? is Holden?s leading-edge SIDI (Spark Ignition Direct Injection) technology.
Holden?s drive-train engineers clocked up 1.1 million test kilometers and around 11,000 dyno hours in development of the new SIDI 3.0 litre and 3.6 litre V6s.
For efficiency, throttle response and refinement, the development effort shows. This is a real achievement for Australian engineering and for Holden?s global V6 engine manufacturing operations.
After our two days at the wheel - the first assessing performance over some winding and varied sections of foothill driving, the second an economy drive to the border and back - we?re convinced that Holden has something special under the bonnet with its SIDI technology.
The launch of the two locally-built Spark Ignition Direct Injection Technology (SIDI) engines is a first for Australian vehicle manufacturing.
SIDI works by injecting fuel directly into the combustion chamber. This process allows higher compression resulting in improved efficiency, greatly improved fuel economy, reduced CO2 emissions and improved output and performance.
Advanced multi-point injectors, a high-pressure engine-driven fuel pump and cam-phasing also improve both the environmental numbers and dynamic capabilities of Holden?s new V6s.
There is also a lower idle speed, now just 550rpm (down 50rpm), further reducing fuel waste and emissions when in heavy traffic or waiting at lights.
Holden claims that the Commodore Omega with the SIDI 3.0 litre V6 can travel from Melbourne to Sydney on just one tank of fuel. Such a claim for a large family car would have been a pipe-dream just a decade ago.
The 3.0 litre SIDI engine will power the Omega and Berlina Commodore sedans and Sportwagon. The 3.6 litre unit powers the premium Commodore range ? SV6, Calais, SV6 Ute and Statesman.
Both engines are all-alloy (with iron bore liners), DOHC and undersquare. Both run relatively high compression: the 3.0 litre at 11.7:1, the 3.6 litre, 11.3:1, but each are perfectly happy with 91 RON fuel.
Both engines are almost entirely new. The internal block architecture for the 3.6 litre SIDI V6 (essentially the same motor as used by the Cadillac CTS) may be the same as the engine it replaces, but external castings, mounts and heads are all-new.
The 3.6 litre continues to use an aluminium intake manifold, however the 3.0 litre SIDI has a composite (plastic) intake manifold with integrated intake runners in the head casting. The exhaust manifold is also integral to the cylinder heads.
Each is paired with the 6L50 automatic transmission. The six-speed manual can be specified for the SV6 models (the Aisin AY6 six-speed), but there is no manual option for the 3.0 litre.
The six-speed auto, for both engine variants, employs a ?turbine damper? which sits after the torque converter to reduce vibration through the drive-train, further improving refinement.
Bridgestone Turanza tyres come with the 16 and 17-inch tyre packages. These are designed to minimise flex through changes in the structure of the tyre and thus reduce rolling resistance at highway speeds. The rest of the range utilises Yokohamas.
Also improving efficiency is a low friction alternator and new energy management software. This draws power from the battery under certain conditions rather than continuously relying on the generator, thereby reducing mechanical drag on the engine.
The old 3.6 litre, without direct injection, carries over from the outgoing model for the base ute.
With 210kW @ 6400rpm and 350Nm @ 2900rpm, the 3.6 litre feels very strong. Those figures have it encroaching on V8 territory, and the extra power is apparent underfoot.
With a six-speed auto transmission (or six-speed manual available), the 3.6 litre will capture some buyers who might otherwise have leaned to the V8. It is a responsive, tractable and free-spinning unit and can really hustle when pressed.
Importantly, from 60km/h to 100km/h, those critical speeds for overtaking safely, it can really pick up its skirts and bolt.
The 3.0 litre, while it?s the smallest Commodore power-train in more than 20 years (you?ve got to go back to the gasping ?Starfire? four to find a smaller unit) produces a commendable 190kW @ 6700rpm and 290Nm @ 2900rpm.
It's a willing unit and not at all overawed by the task. And, though shaded for power and torque by the bigger 3.6, is also a spirited drive.
While on paper the smaller 3.0 litre does not seem over-endowed with torque, paired with the six-speed transmission it can be kept nicely in the ?sweet spot? of its torque curve.
In the hills, new incline sensing (inclinometer) technology has the transmission shifting down early which pre-empts loads and stops speed from washing off. It also drops down a ratio on declines too, using engine braking to maintain vehicle speed.
Most importantly, it doesn?t ?hunt? (as some do, annoyingly) and impresses as a very well-matched drivetrain-powertrain package. As a piece of technology, the 6L50 is worlds apart from the four-speed slushbox it replaces.
As an integrated system, the shift mapping and well-spaced ratios work nicely with the 3.0's torque and 190kW power output. It won't excite the senses in the same way the 3.6 might, but very few commuters or family buyers would fault it.
Otherwise, for the drive, little else has changed with the new model.
On the road, both variants are typically well-balanced, with sharp turn-in and the right damping and isolation from coarse and broken surfaces for Australian roads.
A new spherical bearing has been fitted to the rear lower control arms, replacing the squishy rubber bushing used by the outgoing model and improving suspension performance under load.
Thicker rear swaybars on models fitted with 18 and 19-inch wheels help rein in body roll and understeer, but otherwise the VE's suspension hardware carries over unchanged.
The Commodore ? like the Falcon incidentally - has always been a benchmark for handling and versatility for the affordable large car sector.
Quiet at highway speeds, and with a robust and durable feel, the new Commodore performs as well or better than its imported direct competition.
For value and the totality of the product, score ?one up? to Australian design and engineering for the Commodore.
Score another point for real-world fuel economy too. The first stage of Holden's drive program focused on performance driving, but despite both engines being thoroughly spanked through some of Central Victoria's more challenging roads, the 3.0 and 3.6 litre SIDI V6s each delivered fuel economy around the 10.0 l/100km mark.
The second stage involved a long-distance economy challenge from the outskirts of Melbourne all the way up to the NSW/Victoria border.
Ignoring the spirit of the challenge somewhat, we drove the first three legs without paying much attention to attaining the lowest fuel economy. However, although frugal driving methods often took a backseat, the worst average fuel economy figure reached was 8.3 litres per 100km.
During the final leg - which TMR decided to take a little more seriously - our 3.6 litre SV6 automatic netted a 7.2 l/100km fuel consumption figure. Not bad for a sports-oriented V6-powered large car.
Safety-wise, each model in the Commodore sedan and Sportwagon range score a full 5-Stars in ANCAP testing. The new ute range now receives ESC and front, side and curtain airbags as standard, and is due to be tested by ANCAP later this month.
Each come with a steering shroud energy absorber, seat-belt reminder, ESC, ABS, electronic brake-force distribution, electronic brake assist and traction control.
With the new SIDI-equipped Commodore range, GM Holden is responding to the challenges in the market, and those of the environment, with a car for the times.
The new powertrains offer a technological refinement that makes an already good car an excellent one.
Commodore sales took a bit of a battering last month, but, once word gets out, these new models should return the natural order of things - as well as throw down the gauntlet on large-car fuel economy.
With Commodore?s traditionally strong resale values, and with a willing 3.0 litre offering fuel efficiency that some ?fours? struggle to better, family and fleet buyers who may have moved away from the bigger sixes are well advised take another look.
A longer test drive will tell, but the SIDI-equipped Commodore might just be the best buy of the moment.