Car Boss Wants To Kick Tyres

Sydney Morning Herald

Saturday August 16, 2008

Toby Hagon

Commodore may lose spare in the boot, reports Toby Hagon.

HOLDEN is considering removing the spare tyre from the Commodore and fitting controversial run-flat tyres as part of a broader plan to improve fuel efficiency and reduce carbon dioxide emissions.

Mark Reuss, General Motors Holden chairman and managing director, says the imminent move to tyres that can be kept rolling after a puncture is designed to reduce weight, part of a re-engineering program to give the V6 Commodore the efficiency of a four-cylinder.

He believes getting the basics of the Commodore design right is more important than expensive additions such as a hybrid powertrain, which he hints won't happen before 2010. This is in contrast to Nick Reilly, GM group vice-president, who said hybrid Commodores would arrive in a couple of years.

"There's a lot of things we can do in the near term and a lot of things we can do in the further term - there's a lot more to go [in efficiency improvements]," says Reuss, citing everything from weight reduction to more efficient tyres, engine improvements and better aerodynamics.

"It would be really stupid to make a sequential decision around a hybrid in a Commodore before we have efficiency in the base architecture done."

Reuss believes the fuel economy of a regular, petrol-engined Commodore can be reduced by 20 per cent or more. He says today's official average fuel consumption figure of 10.8 litres/100km could drop to 8.5L/100km. That would make the entry-level Commodore as efficient as many mid-sized four-cylinder cars. A Mazda6 uses a claimed 8.4L/100km while a Toyota Camry uses 9.9L/100km.

"We want to give what's important to the customers, which is the operating efficiency of a small car in a large car."

Key to the Commodore's fuel efficiency and carbon dioxide reductions is stripping weight.

"If we have a mindset that we have to go after every gram, the opportunity there is quite large. Mass begets mass, so the bigger the car is, the more massive the car is, the bigger the brakes are, the more you have to press the throttle. It just goes on and on."

He says the removal of the spare tyre and tools can save up to 16 kilograms. "There's plenty of things in the industry, like a Honda Odyssey minivan in the US, that uses a run-flat tyre. The technology is there, but we have to make sure the technology of a run-flat tyre is applicable to the car you're putting it in."

Reuss is acutely aware of the controversy surrounding cars fitted with run-flat tyres. The pioneer of the technology locally, BMW, staunchly defends run-flat tyres as safer and more convenient if you do get a puncture. Opponents have criticised the higher costs (no longer an issue), compromised ride quality and change in dynamics if you do get a puncture. Reuss plans to circumvent those concerns by giving buyers the choice between regular tyres or run-flat tyres. "[We'll] make it a free option and tell the customer how much fuel they're going to save by not carrying it around in the city.

"As long as we option it at no cost then who cares? If [a spare tyre] is what you want and you've got to have it then great, but don't penalise everybody [by adding weight]."

Reuss also says the increased use of lighter materials, such as aluminium, is also being considered. "How do you measure the cost of lost sales due to fuel economy and mass?" he says. "What it gets down to is you want to have a rule with everything you look at in a car on a cost per kilogram basis. [This is a] rule of thumb you apply to every single piece of the car."

He says the large car could get a smaller V6 and he has not ruled out a four-cylinder version. "If you look at technologies like direct injection you can decrease the engine size and actually increase the power and increase fuel economy."

The Commodore is also undergoing a complex analysis of its aerodynamics. Reuss plans to put it in a wind tunnel to verify proposed changes, which could encompass underbody updates, adjusted ride heights and revised tyre designs.

Holden and GM are embarking on a strategy to diversify the fuel options used in vehicles - including electric and hydrogen power, natural gas, LPG and ethanol.

What do you think: should Holden fit run-flat tyres to the Commodore? See www.drive.com.au/vote.

© 2008 Sydney Morning Herald

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