Pollution in four-wheel-drive

By SIMON COLLINS science reporter

Four-wheel-drive "Remuera tractors" are being blamed for much of the peak-hour air pollution which scientists say shortens the lives of 436 Aucklanders each year.

Registrations of large new and used four-wheel-drive vehicles have doubled in the past five years, from 16,067 in 1998 to 32,634 last year.

The director of Auckland University's energy and fuels research unit, Associate Professor Robert Raine, said yesterday that the growing use of cheap diesel in recreational vehicles was exacerbating the city's air pollution problems.

A report for the Ministry of Transport last year estimated that 436 people died prematurely in Auckland each year because of air pollution.

Of these, 253 deaths were due to vehicle pollution.

"The analysis done to quantify that was on particulates only, and they are only from diesel," Dr Raine said.

"There are particulates from petrol, but they are not measured in standard tests. The amount of diesel fuel being used in New Zealand is increasing dramatically."

The country's diesel consumption was constant from the mid-1970s until 1988.

In 1988, the tax on diesel was cut. Since then, consumption has almost doubled.

In the same period, petrol use has risen by only about 30 per cent.

Four-wheel-drive motorist Stephanie McCracken explained the difference yesterday as she filled up with 64.9c-a-litre diesel at a Remuera service station that was selling regular petrol at 104.9c.

"It costs me $39 to fill up to get 536km," she said. "My 318 BMW used to cost me $60.

"It's also a family thing, with the children. My husband is six-foot-five [196cm], and now there are no arguments about there being no room."

The McCrackens also pay road-user charges of $140 for every 5000km they travel. But the the big vehicle is still better value than the BMW.

Diesel is exempt from the tax of 36.5c a litre plus GST on petrol to pay for roads and general Government spending.

Diesel users contribute to roading costs through road-user charges, but do not pay anything towards general state spending except through GST.

Treasury Deputy Secretary Peter Mersi said diesel was exempt because it was used for boats, tractors and other uses as well as on roads.

"Petrol tends to be used on roads," he said.

"Therefore when you buy petrol and pay excise on it and a component of that goes to pay for the cost of the roads, it means there is a direct link between people using the road and paying for the roads.



"Because diesel is used for a whole lot of other stuff, you don't want your boat users paying an excise, a significant component of which is used to pay for the roads."

Automobile Association spokesman George Fairbairn said that policy was out of date.

"Historically, diesel was principally used for off-road services and there was a small number of vehicles using diesel," he said.

Today, there are 25,054 diesel tractors compared with 10,556 diesel buses, 159,654 diesel cars, including four-wheel drives, and 239,379 diesel trucks.

Diesel-powered cars now make up 7 per cent of all cars on the roads.

At a station in Remuera Rd yesterday, Dr Raine estimated that almost every second vehicle was filling up with diesel.

"The New Zealand diesel fuel price is very low by any international comparison," he said.



"In Europe, diesel is slightly more expensive than petrol."

Although diesel-power trucks outnumber diesel cars, Dr Raine said the major health impact came from peak-hour traffic.

"It's where those four-wheel-drives are in peak traffic, which the trucks obviously avoid because they can't afford to sit around in traffic jams," he said.

"I believe New Zealand is buying big problems by keeping diesel cheap and encouraging the use of large four-wheel-drive vehicles."

The Auckland Regional Council plans to measure emissions from up to 20,000 vehicles this month to test pollution levels from vehicles of different models and ages.

Cabinet ministers are due to receive a report in about a month on regulating emission standards.