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VZ Commodore: Fuel economy doubt for V6

A load off: The Alloytec engine's weight has been confirmed at 168kg – around 10kg less than the current Ecotec V6.

Holden's new Alloytec engine may chew as much fuel as the engine it replaces

Holden logo23 Jul 2004


HOLDEN has conceded the all-new $400 million Global V6 that will power Commodore from next month’s facelifted VZ is unlikely to be any more fuel efficient than the Buick-based 3.8-litre cast-iron pushrod V6 employed by Commodore since 1988.

Officially, the Global V6 press blurb states that "Alloytec produces significant increases in torque and power with a lower capacity engine that delivers fuel efficiency on par with the outgoing 3800 engine – historically recognised as a very efficient V6 powerplant".

Specific fuel consumption figures for the new all-alloy DOHC V6 – in either 175kW/320Nm Alloytec or 190kW/340Nm Alloytec 190 guise – will not be released until all VZ Commodore variants are weighed and compared with their 3.8-litre predecessors.

However it seems the new 3.6-litre engine is unlikely to be more efficient than its forebear, with Holden executives refusing to confirm whether the new engine, which features four valves per cylinder compared to just two in the current engine, would be more economical.

The outgoing Ecotec 3.8 delivers ADR81/01 combined fuel consumption of 11.3 litres per 100km in base Commodore form. Its closest rival, Ford’s Falcon, consumes fuel at 11.5L/100km – just 200ml more per 100km – and was roundly criticised at launch for its excessive fuel consumption.

Meantime, Alloytec’s weight has been confirmed at 168kg – around 10kg less than the current Ecotec V6 – which Holden claims is "fairly competitive" with other new V6s. It is believed the weight savings realised by aluminium construction are largely offset by the extra weight of Alloytec’s more complex 12-valve cylinder heads and three more camshafts.

Holden also confirmed at the Global V6 launch that a turbocharged version of the engine would be produced "within the next 12 months", but it is unlikely to power any Commodore variants in the short term.

And while Holden is confident the reduction in displacement over the previous engine will not be perceived by consumers as a retrograde step, it has been quick to point out that capacities of up to 3.8 litres are possible with Alloytec.

It also admits that 3.6 litres is the "safe range" and that developments with linerless cylinder blocks would need to occur before Alloytec grew any larger.

Holden is currently ramping down assembly of Ecotec V6 while it ramps up production of Alloytec V6, shipments of which are already heading to Mexico for fitment in Buick models.

Built at the rate of 586 per day as of last week, Alloytec will be built in numbers of 960 per day by the third quarter of 2005, with a total of 2500 VZ Commodore engines being 18 ahead of target.

Available to manufacturers in 2.8, 3.2 and 3.6-litre displacements via a combination of two cylinder stroke lengths and two cylinder bore widths, Global V6 will power models as diverse as Saab, Alfa Romeo and Cadillac.

According to one Holden insider, it has also attracted interest from many non-General Motors car-makers – including "some that might surprise" – and that by the end of the decade it will power vehicles from a "surprising number" of manufacturers globally.

Holden plans hybrid

By BRUCE NEWTON HOLDEN boss Denny Mooney has confirmed the new Alloytec V6 engine will form part of a petrol-electric hybrid powertrain that could be on sale in Australia in five years.

Speaking at last week’s Alloytec launch in Melbourne, Mr Mooney also confirmed that a V8 hybrid was on the cards, no doubt based on the forthcoming LS2 6.0-litre unit which has only just been launched in the US in the C6 Corvette.

"We’re working on some alternatives," Mr Mooney said. "I really hope that ultimately we have a hybrid Holden product.

"It would be one that we would develop. I’m sure it would use General Motors technology – we can’t afford to develop that ourselves, but we’re working on enough different V6, V8 alternatives that we could package ourselves." Mr Mooney’s comments are in contrast to his predecessor Peter Hanenberger, who was a fan of fuel cells rather than hybrids, although he recognised the latter would have to be employed as a bridging technology.

"As time goes on it looks like there are a lot of infrastructure issues with fuel cell," Mr Mooney said.

"I mean, I think that fuel cell may be the ultimate solution to get over this oil dependency, but the reality is that things are looking further and further out." Whichever alternate powertrain comes in vogue, it should not affect Holden's co-operation with the CSIRO on super-capacitor technology, as it is applicable to both hybrid and fuel cells.

* For the full Denny Mooney interview, go to www.professional.goauto.com.au

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