Diesel dilemma

Measures to clean up our diesel fuel are underway, writes ALASTAIR SLOANE, but not soon enough to satisfy Peugeot

French carmaker Peugeot has abandoned plans to import its latest diesel model because it won't run on New Zealand fuel.

The Peugeot 607 uses the industry's latest clean-air device, an award-winning exhaust filter which traps and burns diesel particulates, a mix of combustion residue which includes the pollutant sulphur, a natural ingredient of crude oil.

But the high sulpher content in diesel from the Marsden Pt refinery clogs the silicon filter and prevents burn-off, Peugeot says.

Diesel in New Zealand is restricted to a maximum of 3000 parts a million of sulphur. On average it contains about 2000-2400 ppm. But the 607 will run only on diesel with a sulphur content of 350 ppm, the European limit.

Simply, a drum of New Zealand diesel can have nearly nine times as much sulphur in it than a drum of European diesel.

"The unavailability of the 607 diesel model is a twofold issue for us," said Andrew Bayliss, the general manager of Peugeot in New Zealand.

"As far as technology is concerned, New Zealand will fall behind unless it steps into line with developments overseas. Many here will be stuck with the perception of diesels being smelly and dirty.

"It harms us from an environmental point of view, too. We push this image of New Zealand being a clean, green country but in reality we are not. For a start, our diesel has far too much sulphur in it.

"The 607 filter technology would be fantastic here. Peugeot in France wants us to have it and so do we. But we will have to wait until New Zealand falls into line with international fuel and emissions regulations."

Carmakers are introducing clean-burn engines all the time and governments and the oil industry are working to ensure fuel quality improves with engine technology.

The filter in the Peugeot 607, for example, works in much the same way as a high-tech domestic oven. Just as accumulated gunk in the oven is burned off under a special high heat mode, the filter collects emission pollutants and, with the help of an additive, regularly fires up to 550 deg C to zap them.

European Union laws restrict sulphur in diesel to a maximum of 350 ppm. Until the mid-90s the limit in Britain and Europe was 3000 ppm, the same as New Zealand and Australia.

But the powerful green lobby helped to force it down almost overnight to 500 ppm. This year it has been lowered even further, to 350 ppm. By 2005 it will be cut to 50 ppm, 60 times lower than the New Zealand limit.

At the moment the New Zealand Refining Company produces diesel and petrol to legislative requirements - 3000 ppm of sulphur for diesel and 500 ppm for petrol.

Sulphur by itself isn't recognised by the oil industry as a lubricant, but it is when combined with other properties in fuel. So the refinery will have to install costly technology to ensure the new largely sulphur-less fuel maintains its lubricity.

The Marsden Pt refinery, a private company, has commissioned a study into the cost of making cleaner fuels and is talking with the Ministry of Economic Development about meeting new international standards. The first stage of the report is expected later this year.

Also expected towards Christmas is emissions legislation. Jenny Dickinson, the Ministry of Transport's assistant manager for safety and the environment, says an amendment to traffic regulations will allow police to pull over excessively smoky vehicles.

"At the moment police use the Ringelmann chart, which is like a paint chart with blobs in various shades of grey," Dickinson says.

"Police match up the grey blobs with exhaust emissions. You can imagine a police officer driving down the road trying to match up the paint chart with the colour of the smoke from the exhaust ... it's not very workable.

"So we are trying a test along the lines of the one they use in Australia, called the 10-second rule. A visible, continuous stream of smoke for 10 seconds or more is deemed to be excessive. Therefore the police can issue an infringement notice or take the vehicle off the road."

Emissions regulations for new and used vehicles will also be put in place, Dickinson says. "It will ensure that vehicles coming into New Zealand will have to meet the emissions standard they were manufactured to in the four major source markets of Japan, Australia, Europe and America. We are formalising what is a voluntary regime at the moment."