Holden looks at 'part-time' engines

HOLDEN is investigating the use of displacement-on-demand technology for use in the Commodore as a way of improving its fuel economy.

The company claims the technology will save "millions of litres" of petrol in Australia.

The technology closes off the induction of fuel and air into half the cylinders of V6 and V8 engines when the full power output of the engine is not required typically when idling or maintaining speed.

General Motors says displacement-on-demand will be fitted to two million engines in the US within a few years.

The strategy is part of a series of medium-term initiatives designed to improve the fuel efficiency and reduce emissions from GM vehicles as the company moves to its ultimate goal of being the world’s leader in fuel cell vehicles.

GM vice-president Asia Pacific Planning, Steve Carlisle, in a briefing on how GM planned to "take cars out of the environmental equation", said the company could not afford to concentrate on hydrogen fuel cells only because it "would be neglecting important opportunities to help the environment in the meantime".

GM, he said, was pursuing hybrids but heading in the opposite direction of the current players in the hybrid market.

Mr Carlisle, in what is effectively a swipe at the strategies of Honda and Toyota, said GM could not see the point of converting small cars to hybrid technology when there were far greater fuel savings from large vehicles – especially buses and large American SUVs.

Both the Japanese car-makers have focussed their hybrid technology on the Prius and Civic.

"We believe if you really want to help the environment, you don’t start by making the vehicles that use the least amount of fuel more efficient, you start by making vehicles that consume a lot of fuel more efficient," Mr Carlisle said.

He said GM was focussing on hybrid buses where fuel savings in stop-start traffic in large cities are massive.

"If you placed hybrid buses in the nine largest US cities, you’d save roughly 180 million litres of fuel a year. That’s the equivalent to 500,000 small hybrid cars or 10 years of hybrid sales based on today’s volumes," he said.

GM hybrid buses operate in about 12 US cities. They are 90 per cent cleaner (no black exhaust emissions), much quieter and require less maintenance than conventional buses.

Mr Carlisle said that in the US next year GM would introduce hybrid versions of the Saturn Vue and Chevy Malibu, followed by the Chevy Tahoe and GMC Yukon. He projected sales of a million units a year.