Vehicle Emissions in New Zealand Are Much Worse Than Thought

New Zealand cars are producing more harmful emissions than is currently believed, and this is costing both car owners and the country dearly, according to a study released today. The study also showed diesel powered vehicles are only a small part of the problem and petrol powered vehicles are a larger problem than previously thought.


The study involved 452 cars with petrol engines and 92 with diesel engines, and was conducted by Zero Emissions Limited, which has the only emissions testing system used throughout New Zealand.


“Our study shows that for petrol-powered cars, the emissions problem is much worse than the government thinks it is,” says Dr Ian Brooks, company chairman. “The government estimated that only 10% of the vehicles would fail an emissions test but our research shows that 16% of New Zealand cars with petrol engines, and 7% using diesel, would not be allowed on the road in Europe or most parts of North America.”


The government has underestimated the problem, according to Brooks, because they have only been looking at smoke emissions, whereas the Zero Emissions’ system measures hydrocarbons, carbon monoxide, carbon dioxide and oxygen in the car’s exhaust. Zero Emissions also measures a fuel-to-air ratio called Lambda, which indicates how efficiently an engine is burning fuel.


The new research suggests the problem is not just with old vehicles, which is where the government is currently focusing its attention. Approximately one-quarter of the vehicles in the Zero Emissions study were less than three years old.


“Of course, the failure rate was lower among newer cars,” says Brooks, “but it was still higher than you would think. Many of the owners of these newer

vehicles thought their cars would pass with flying colours and were amazed to find their vehicles were under-performing and costing them much more to drive than they realised. On the other hand, many owners of quite old vehicles were thrilled to discover how well their cars were running.”


According to Brooks these results suggest New Zealand faces a serious problem. “Not only do harmful emissions cause health problems and



contribute to global warming,” he says, “they cost people money. Engines producing high emissions are running poorly. They waste fuel and that could cost the owner anywhere from $500 to $2,000 a year in extra petrol. Engines with high emissions are also wearing themselves out prematurely,” he adds. “That can mean expensive repair bills in the future.”


The problem is not just with vehicles that fail. The Zero Emissions system, which is the only emissions standard used consistently throughout New Zealand, uses a two-tiered standard. The lower Zero e2 standard is adapted from Euro II and is the minimum level of emissions considered to be acceptable throughout most industrialised countries. The higher Zero e4 level is based on Euro IV and is the level at which most vehicles in Europe, North America and Japan are operating, according to Brooks.


The Zero Emissions’ study found 50% of the petrol cars and 15% of the diesel vehicles that passed, did so at the Zero e2 level and 50% of the petrol cars and 85% of the diesel, passed at Zero e4.


According to Brooks, most of the vehicles passing at the lower Zero e2 level are actually capable of meeting the higher Zero e4. He says that if they did operate at the higher level, they would save the owners money and make New Zealand’s air cleaner.


“Often it doesn’t take much to increase an engine’s fuel economy and reduce its harmful emissions,” says Ash Hames, a director of Zero Emissions who has been testing and repairing emissions systems at Anzac Automotive for more than three years. “In roughly 50 percent of the cases where a vehicle fails, the problem can be fixed for under $200 and another 30 percent need the oxygen sensor replaced which costs about $350.00. At $1.68 per litre for petrol, it doesn’t take long to get that money back.”


The 544 vehicles involved in this study were tested using the Zero Emissions system, which measures a vehicle’s exhaust emissions using a tail-pipe test employed extensively around the globe. In the majority of cases, these vehicles were brought into the workshops for their annual service. Zero Emissions believes these vehicles are a good cross-section of the New Zealand vehicle fleet.


“We were able to do this research,” says Brooks, “because we have a central IT system, developed entirely in New Zealand, that receives all test data and makes the decision whether to pass or fail a vehicle. This is the only emissions testing system in the world where the decision to pass or fail is made by a centralised system and not by an individual tester in a workshop.” Brooks says that as a result, they have consistent test results, data that can be trusted, and access to the test results for a wide range of vehicles being driven throughout New Zealand.




Zero Emissions Limited is a private New Zealand company which licenses workshops throughout New Zealand to use its system. It tests buses and trucks as well as passenger vehicles and vans. For more information, visit www.zeroe.co.nz.


New Zealand is one of the few countries in the developed world where emissions testing is not mandatory.