What is an objective noise test?

An objective noise test uses scientific procedures to measure noise levels. The equipment used will measure the vehicle’s exhaust noise levels against a pre-determined standard.

What is a subjective noise test?

A subjective noise test relies on the judgment and experience of the tester to assess whether the level of exhaust noise meets the legal requirements. The draft amendment Rule proposes changes to the wording of the subjective noise test for light vehicles to improve its application at WoF/CoF checks, and to align it with the objective noise test.

What are the current decibel limits for light vehicles?

The current decibel limit for exhaust noise for cars and light trucks (3500 kg or less) is 95 decibels (dBA). The limit for motorcycles is as follows:

What changes does the amendment Rule propose to the current decibel limits?

The Rule proposes that two years after the amendment Rule comes into force (ie, in 2010), the limit for new vehicles will be reduced to 90dBA with a 3dBA allowance given for wear and tear over the life of the vehicle. Used vehicles entering the New Zealand fleet after 2010 will need to meet a limit of 93dBA.

The current 95dBA limit will be retained for existing in-service vehicles already in the fleet before 2010. The 95dBA limit will also be retained for older vehicles (vehicles first registered in New Zealand or overseas before 1985), including those entering the New Zealand fleet after 2010.

The revised limits apply to cars, vans, light trucks and light omnibuses. Motorcycle and moped limits will remain the same.

What is the purpose of the amendment Rule?

The purpose of the amendment Rule is to reduce vehicle noise by targeting the noisiest vehicles in the fleet (the ‘gross emitters’), while minimising the impact on the majority of vehicle owners whose vehicles are not causing the problem. The ‘gross emitters’ tend to be vehicles purposefully fitted with modified exhausts that emit noise well above the legally allowable decibel limits. Although they make up a small percentage of the overall vehicle fleet, these vehicles cause a great deal of public annoyance.

How were the decibel limits reviewed?

A range of decibel limits were assessed using the following criteria:

The Ministry of Transport and Land Transport NZ have undertaken vehicle noise testing of over 250 vehicles and have sourced information on noise testing from overseas jurisdictions. This research has revealed that the vast majority of standard vehicles fitted with standard manufacturer’s exhaust systems, or exhausts similar to the original exhaust, would be well under the current 95dBA limit. As the majority of vehicles in the New Zealand fleet are standard, most vehicles in New Zealand would easily comply with the proposed changes.

What changes are being proposed that will affect the WoF/CoF tests?

A subjective noise test will still be a part of the WoF/CoF testing regime, however rather than being the only noise test for light vehicles, it will now be used to ‘filter out’ quieter vehicles that do not need an objective noise test. If a vehicle fails the subjective noise test the tester may refer the vehicle for an objective noise test to ensure that it meets the decibel limit, at the owner’s expense. The vehicle owner would have the option of repairing or replacing the exhaust and re-sitting the WoF/CoF test, should they not wish to proceed with an objective noise test.

The amended Vehicle Equipment Rule will introduce the objective noise test for light vehicles (those with a gross vehicle mass of 3500 kg or under, including mopeds, motorcycles, cars, and light trucks) undergoing in-service inspection and certification (WoF/CoF tests). The amended Rule will also provide for vehicles at entry inspection and certification to be referred to an objective noise test by vehicle inspectors. This is currently allowed under the provisions of the Traffic Regulations

Are the proposed changes needed?

Excessive vehicle noise is a significant public concern, particularly in some urban areas. Numerous public complaints are made about people operating their vehicles in an inconsiderate manner (eg, vehicle convoys, burn outs, drag racing, using loud stereos), and levels of exhaust noise.

The current limits have been reviewed to assess whether they are appropriate given advances in vehicle manufacturing technology over the last 20 years. The vast majority of new, standard vehicles are well under 90dBA whereas older vehicles (over 20 years old) were not designed to be so quiet.

The problem of excessive vehicle noise is caused by a number of factors outside the scope of the rule amendment (eg, enforcement practices, practical implementation of the subjective noise test, exhaust tampering, and illegal modification of exhausts). These wider factors are also being considered alongside decibel limits.

What are the advantages of the proposed change to decibel limits?

Which vehicles are likely to be affected by the draft amendment Rule?

Owners of vehicles fitted with excessively noisy exhausts will be affected. Vehicles may be referred to an objective noise test if they fail the subjective noise test at entry to New Zealand, at WoF/CoF testing, and as part of on-road policing. Under the draft Rule, vehicles fitted with modified exhausts that produce a noise output which is not “less than or similar to” the original manufacturer’s exhaust system, or, is not “clearly below the maximum decibel level”, would be required to undergo an objective noise test or have the exhaust repaired or replaced to make the vehicle compliant.

How will the change in decibel limits affect the owners of older vehicles?

There is no change in decibel limit for older vehicles. Vehicles in this category are light vehicles first registered in New Zealand or overseas before 1985, including classic and vintage cars. The current decibel limit of 95dBA is retained to reflect that older vehicles were subject to lesser noise control measures when new and can be harder to quieten down. Currently, there are approximately 45,000 vehicles over 20 years old in the fleet. While many of these are likely to be fitted with ‘similar to standard’ exhausts, many could fail a limit of 93dBA. These vehicles make up a very small percentage of the New Zealand fleet and are not considered to contribute significantly to the problem of excessive vehicle noise.

My car is fitted with a modified exhaust system – how will the changes in decibel limits affect me?

Not all vehicles fitted with modified exhausts will be affected by the change in decibel limits. This is because a modified exhaust system can operate with a similar noise output level as the vehicle’s original exhaust system, and comply with the decibel limits.

Under the draft Rule, vehicles fitted with modified exhausts would be required to undergo an objective noise test or have the exhaust repaired or replaced to make the vehicle compliant if they produce a noise output which is not “less than or similar to” the original manufacturer’s exhaust system or is not “clearly below the maximum decibel level”. It is estimated that up to 1.3 percent of the current fleet (maximum 50,000 vehicles) may fall into this category.

The vast majority of the vehicles tested that were fitted with modified exhaust systems emitted noise well in excess of the current decibel limit of 95dBA. These are the ‘gross emitters’ targeted by the draft Rule.

Not all vehicles referred to an objective noise test by WoF/CoF testers will undergo the test. The vehicle owner may decide to repair or replace the exhaust system to make it compliant, rather than undertaking the objective noise test.

If a vehicle owner chooses to undertake the objective noise test and the vehicle is within the decibel limit, the exhaust system will be certified. Provided the exhaust system remains unaltered, the vehicle will not have to undergo an objective noise test as a result of future WoF/CoF inspections.

How will the proposed changes affect the average motorist, who drives a standard vehicle without a modified exhaust?

Most vehicles in the New Zealand fleet are fitted with standard exhaust systems (ie, fitted with the manufacturer’s original exhaust or a ‘similar to standard’ replacement exhaust) and will comply with the reduced decibel limits. 94 percent of standard vehicles tested by the Ministry of Transport and Land Transport NZ were well under 90dBA.

It is estimated that five percent of standard vehicles (approximately 130,000 vehicles in the New Zealand fleet) tested are between 90-95dBA, so a proportion of these vehicles are likely to fail a limit of 93dBA. Therefore, these standard vehicles will continue to be allowed to enter, and operate within, the New Zealand fleet, provided they have passed a recognised overseas noise standard and have not since been modified.

How will the proposed changes affect owners of ‘scratch-built’ vehicles (eg, hot rods) and vehicles fitted with after-market exhaust systems?

The objective noise testing regime will apply to vehicles driven by car enthusiasts with modified exhausts fitted due to the nature of the vehicle (eg, hot rods), or to enhance performance output and sound effect (eg, after-market sports exhausts). Some of these vehicles may exceed the maximum decibel limit and would need to be made compliant.

How will the proposed changes affect vehicle importers?

A very small number of vehicles imported from Japan already fitted with modified exhausts could be affected once the reduced limit of 93dBA for used vehicles is introduced, as the exhaust noise limit in Japan is 96dBA. The impact of this will be minimised by allowing a two year lead-in time before reducing decibel limits; this will give time for the market and vehicle owners to adjust.

Will reducing decibel limits be sufficient to address the problem of excessive vehicle noise?

A wide range of issues contribute to the problem of excessive vehicle noise (eg, enforcement practices, practical implementation of the subjective noise test, exhaust tampering, and illegal modification of exhausts). Reducing decibel limits alone will not be sufficient in addressing the problem if these wider issues are not addressed – this is why a package of complementary initiatives is being proposed to support the implementation of the draft Rule amendment.

These initiatives will be further developed over the next few months, and include:

If the Police already have the power to deal with noisy vehicles, why does objective noise testing need to be brought into the WoF/CoF testing system?

The New Zealand Police have a wide range of powers to deal with the noisy operation of vehicles, including the power to refer a vehicle for an objective noise test. However, there is public concern about excessively noisy exhaust equipment being fitted to vehicles, and that this problem requires additional controls.

Bringing the objective noise test into the WoF/CoF regime will help to target the noisiest vehicles in the fleet (the ‘gross emitters’) and ensure these vehicles are made to comply with the law. These vehicles tend to be purposefully fitted with excessively noisy modified exhausts and are well above the current decibel limits. These vehicles make up a small percentage of the overall vehicle fleet, and cause a great deal of public annoyance.

Why are motorcycles (having an engine capacity of more than 125 cm3) allowed a higher limit than cars?

The objective noise test method for measuring exhaust noise allows a higher decibel limit for motorcycles compared to cars, in order to account for engine noise registering as part of the exhaust noise measurement (ie, the engine is situated much closer to the exhaust system in a motorcycle than a car). This is standard practice in overseas jurisdictions.

When will the proposed changes come into force?

Subject to government approval, it is proposed that the Rule will be signed in February 2008 and come into force by May 2008. The extension of objective noise testing to in-service inspections would come into force in May 2008, while the proposed reduced decibel limits for vehicles entering the fleet will take effect two years after the Rule comes into force (ie, in 2010). The reduced limits will apply to new and used vehicles entering the fleet after 2010. Older vehicles (vehicles first registered overseas before 1985) entering the fleet after 2010 will need to comply with the current 95dBA limit.

Where can I get details of the proposals in the draft amendment Rule?

Details of the proposals are contained in the Overview to the yellow (public consultation) draft of Land Transport Rule: Vehicle Equipment Amendment 2007 (Objective Noise Testing). Copies of the yellow draft or further information about the proposed amendment Rule may be obtained by contacting the Land Transport NZ helpdesk on 0800 699 000 or by emailing info@landtransport.govt.nz.

The draft Rule, its overview and accompanying information material, together with an on-line submissions form, are also available on Land Transport NZ’s website at www.landtransport.govt.nz/consultation/vehicle-equipment

Does the draft Rule and accompanying Overview document give me all the information I need to fully understand what is proposed?

Because it is an amendment Rule, the draft Rule only sets out the changes that are proposed to the Vehicle Equipment Rule. To see how these proposed changes fit in with the current Rule you will need to refer to the Vehicle Equipment Rule.

How can I get a copy of the Vehicle Equipment Rule?

All published Land Transport Rules are available on the Land Transport NZ website at www.landtransport.govt.nz/rules or can be purchased at selected bookshops throughout New Zealand that sell government legislation.

If you access the yellow draft amendment on the website you will see that it has been linked to the Vehicle Equipment Rule.

You can also download the Low Volume Vehicle Standard 90-20 (Exhaust Noise Emissions) from the Low Volume Vehicle Technical Association website at
www.lvvta.org.nz/Noise%20Emissions%20Std030706.pdf

How long do I have to make a submission?

Submissions on the draft amendment Rule close on 19 April 2007.