Managing motor vehicle noise

The EPA encourages members of the community to report vehicles with noisy exhaust. If the EPA finds a vehicle contravenes the noise pollution laws, they may require the owner to present it at an approved inspection station for noise testing and inspection.

If your vehicle exceeds relevant noise limits, you may be issued with a vehicle defect notice and/or a penalty notice and you will be required to rectify the problem.

More information: Avoid having noisy vehicle exhaust.

Buying your vehicle

Listen to the exhaust system when buying a vehicle. If it sounds noisier than you’d expect then someone may have:

• replaced the original system with a noisier one e.g. a sports system
• altered or removed baffles from the muffler.

If you think it’s been altered, ask the seller.

You could be fined for a noisy exhaust system, so get it checked by a qualified person (for example, a licensed muffler repairer, an EPA-approved mechanic or a licensed vehicle certifier).

Running your vehicle

How much noise an exhaust system is allowed to make depends on the vehicle’s age. See Allowed noise levels for vehicle exhaust systems for details.

Keep exhaust noise within limits by maintaining your vehicle’s muffler. Don’t fit non-standard components that make it noisier.

Modifying and repairing your vehicle

It is illegal to use temporary noise-reduction devices or packing in motor vehicle exhausts. For example, you must not  use, modify or repair an exhaust system to include:

• items (e.g. baffles) that are not welded or riveted into place
• valves or other adjustable items
• materials (e.g. steel wool).

Exceptions include:

• replacement items equivalent to the ones fitted by the manufacturer
• baffles bolted into a motorbike’s exhaust system.

Selling your vehicle

It’s illegal to sell a vehicle that has defective noise control equipment. This includes an exhaust system that makes more noise than the manufacturer’s original.

Allowed noise levels for vehicle exhaust systems

The maximum permitted noise levels for vehicle exhaust systems are prescribed under the Road Transport (Vehicle Registration) Regulation 2017 and referenced in the Protection of the Environment Operations (Noise Control) Regulation 2026. The allowed level for a vehicle depends on:

• whether the vehicle is certified to Australian Design Rule 83/00 (which came into force progressively from 2005) or to an earlier Australian Design Rule
• when the vehicle was built.

* Note: ADR 83/00 noise levels are on the Vehicle noise webpage of the Commonwealth Department of Infrastructure, Regional Development and Cities.

Engine components

Engine components are part of a vehicle’s noise control equipment. Aftermarket engine components can add noise. It is illegal to fit components that make more noise than the manufacturer’s original equipment.

Air filters

A pod-type air filter can increase noise from the air-intake system. Instead use a filter that is well encased or boxed in.

Blow-off valves

You must not fit blow-off valves that vent directly into the atmosphere or that can be adjusted to vent into the atmosphere. Blow-off valves that vent back into the induction system are much quieter.

You also must not fit turbo wastegates that vent directly into the atmosphere or which can be adjusted to vent into the atmosphere. Wastegates must vent gases into the exhaust system upstream of the muffler and/or catalytic converter. But beware! On late-model vehicles, waste exhaust gases that vent to the atmosphere upstream of the catalytic converter may also bypass control equipment and may be illegal too.

Gear drives and belts

Take care when you change engine gear drives, engine belts and auxiliary belts (e.g. alternator belts). Non-standard belts and drives can add noise.

Horns

Except on police and emergency vehicles, it’s illegal to install or use horns if they are louder than:

• 120dB(A) for noise made up of a single non-varying loudness and pitch
• 85dB(A) in any other case.

Refrigeration units

Refrigeration units on parked trucks can disturb neighbourhoods, especially at night. A resident should not be able to hear a vehicle refrigeration unit (even through open windows):

• before 8 am and after 8 pm on any Saturday, Sunday or public holiday
• before 7 am or after 8 pm any other day.

Drivers who break this rule may be issued a warning. If they break it again they may be fined.

Sound systems

The biggest problem with sound systems is low-pitched (bass) noise. This travels further than high-pitched noise. It also travels more easily into buildings and other vehicles.
It’s illegal for a vehicle sound system to make ‘offensive noise’. Sound is more likely to be offensive if:

• it can be heard clearly outside the vehicle, and
• it contains low-pitched noise
• the vehicle is being driven in a residential area or other areas where people want to enjoy reasonable noise amenity.

If your vehicle sound system makes offensive noise you could:

• lose 2 demerit points
• be fined $270 by the EPA or police.

If you get a penalty notice and you weren’t driving the vehicle at the time, you can say who was. 

Off-road motorcycles and other vehicles often have mufflers that are not as effective as those on road vehicles. The noise from off-road vehicles can annoy pedestrians and residents where trails pass near residential areas. Trail bikes and four-wheel drive vehicles must therefore operate quietly when near properties.

The Road Transport (Vehicle Registration) Regulation 2017 specifies a noise limit of 100 decibels for motorcycles.

Unregistered trail bikes should never be used on:

• roads
• footpaths
• nature strips
• areas open to the public and designated for use by cyclists or animals
• road shoulders
• areas that are not roads that are open to the public for driving, riding and parking of vehicles

Owners of offending vehicles who receive a penalty notice in the mail will need to nominate the driver in control of the vehicle at the time of the alleged offence. Under the Regulation a property owner or occupier may be held liable for offensive noise generated by vehicles being used on their property.

If an enforcing authority is unable to identify the person or persons responsible for the offending vehicle noise, it may issue a warning to the owner or occupier of the property. If the offensive noise occurs again after a warning has been issued, the owner or occupier may be subject to a penalty.

The Regulation  defines the types of private property to which these provisions apply.
These requirements do not apply to vehicles being used for agricultural purposes.

Noise from engine or compression brakes can be intrusive, especially at night. Heavy vehicle drivers should avoid using exhaust brakes, engine compression or 'jake' brakes near residential areas and noise-sensitive areas such as hospitals and schools, unless they are necessary for safety reasons.

Transport for NSW has more information on reducing heavy vehicle noise.

• Keep your exhaust system maintained.
• Only use exhaust systems the same as the vehicle’s original one.
• Ask a reputable supplier for advice before you buy aftermarket components.
• Don’t fit your engine with:
  • non-standard belt drives or gears
  • pod-type air cleaners
  • waste gates or blow-off valves that vent to the atmosphere.
• Only use your horn to avoid a collision.
• Think about places you drive past and if noise will bother people there.
• Don’t speed off or slam on the brakes except in an emergency.
• Don’t use your off-road vehicle where its noise will be offensive.
• In residential and noise-sensitive areas (e.g. schools and hospitals):
  • avoid exhaust and compression braking
  • limit the use of truck refrigeration units. 
• Use your vehicle’s sound system responsibly.

Table 5 lists different kinds of motor vehicle noise and who to contact about them.

Kinds of motor vehicle noise and who to contact about them

*These times are when noise from residential premises should not be heard in a ‘residential room’ in a neighbour’s residence, whether or not a door or window to the residential room is open.. A residential room means any room that is not used as  a garage, storage area, bathroom, laundry, toilet or pantry.

'Offensive noise’ is defined in the dictionary at the end of the Protection of the Environment Operations Act 1997 (POEO Act). It is noise:

1. that by reason of its level, nature, character or quality, or the time at which it was made or any other circumstance
   1. is harmful to (or is likely to be harmful to) a person who is outside the premises from which it is emitted, or
   2. interferes unreasonably with (or is likely to interfere unreasonably with) the comfort or repose of a person who is outside the premises from which it is emitted, or
2. that is of a level, nature, character or quality prescribed by the regulations or that is made at a time, or in other circumstances, prescribed by the regulations.

Authorised officers decide if noise is offensive by considering:

• its loudness
• its character
• the time of day it’s heard
• how long it lasts
• how often it occurs
• whether it’s typical for the area
• how many people it affects.

For more about offensive noise see section 2.1 of the EPA’s Noise guide for local government.