Tres particulaire

Peugeot is aiming to take on the Germans with its new 607 executive sedan, which comes with everything that opens and shuts, including a clever filter in the diesel-powered model. ALASTAIR SLOANE reports.

Peugeot has gone a long way towards eliminating the unsightly product of diesel-powered cars - the sooty exhaust stuff called particulates.

The French carmaker will use the launch of its new executive 607 saloon - pictured today for the first time in New Zealand - to highlight a clever filtering device which traps particulates in the exhaust system.

The soot has been linked to cancer. It is one reason why diesel's image as a passenger car fuel in New Zealand remains somewhat tarnished.

Both petrol and diesel are comparatively cheap here. Diesel provides better economy than petrol and, overall, emits a less harmful exhaust mix. But grubby used and abused Japanese cars and vans, especially, don't help sales.

Things are different in Europe, where petrol and diesel versions of the new four-door Peugeot 607 will break cover this month at the Frankfurt Motor Show. The car is expected to come with everything that opens and shuts and go on sale in New Zealand later next year.

Peugeot and its French stablemate, Citroen, build 800,000 diesel engines a year, the highest output in the world. Eight years ago in Europe, diesel cars accounted for 15 per cent of all sales. This year diesels will account for 25 per cent of the new-car market.

In Austria, 55 per cent of new cars are diesel powered. In Spain it's 47 per cent; in France 41 per cent.

Dr Robert Buechelhofer, a member of the Volkswagen AG board and director of the carmaker's Asia-Pacific region, believes the diesel engine has a future in New Zealand, where its lazy pulling power is suited to twists and turns and hilly terrain.

"It might not be popular now," he said on a visit, "but wait until the luxury carmakers start to build sophisticated diesel engines for their top models. Then people will start to take notice. It will have a flow-on effect."

Mercedes-Benz, BMW, Audi and Jaguar have already confirmed the presence of multi-valve V8 diesel engines as an option in their premium models.

Now Peugeot has included a 98kW 2.2-litre "common rail" turbo diesel in its 607, an executive car aimed at pinching market share off the Germans and Swedes. Two petrol engines, a 116kW 2.2-litre four-cylinder and a 152kW 3-litre 24-valve six-cylinder, both equipped with the latest electronic technology, complete the powerplant range.

Common rail is a computerised fuel-injection system which lowers fuel consumption pollutant emissions, aids ride comfort and suppresses much of the noisy clatter associated with traditional diesel engines.

Briefly, conventional diesels use a mechanical pump to distribute fuel to each injector. But this is a complex process and the flow of fuel in the combustion process can't be precisely controlled. Mixing in a combustion chamber a large and irregular amount of fuel with compressed hot air is what made conventional diesels noisier than petrol engines.

Common rail does away with the mechanical pump and uses electronics to pre-heat and filter the fuel in a sealed metal tube called a "rail." The fuel is then electronically injected from the rail into each combustion chamber, using micro-second timing to regulate the combustion process to the point where the loud detonation is converted to a long roar. Subsequently, the engine runs much more quietly.

But Peugeot is keeping quiet details of exactly how its particulate-filtering device works until the car's launch. The device won't go as far as a prototype from Volvo, which was more an incinerator than a filter.

The 607 replaces the outgoing 605, which was, like almost all Peugeots, a delightful car to drive. But it was a sales disaster. Peugeot built just 225,000 over 10 years. Some luxury marques build that number in a year.

The 607 is expected to be equipped with the latest variable suspension and steering technology. Ride and handling has always been Peugeot's strong point.

But claims that its "nine parameters," or settings, in the suspension and its automatic illumination of hazard warning lights under hard braking aren't exactly ground-braking these days

Safety items include six airbags, Brembo anti-lock brakes, brake assist, anti-skid stability systems, an automatic gearbox that won't change up under acceleration if it senses lateral forces are too great ... pretty much everything that will help to prevent a careless driver from going backwards through a hedge.