Headlights

High Intensity Discharge lamps

HID headlamps are popular as original equipment on new cars. They are a gas discharge lamp that produces light by means of an electric arc between two electrodes housed inside a transparent quartz envelope. They produce a higher light output compared to conventional incandescent lights because a greater proportion of their radiation is visible light as opposed to heat.  The light they emit may appear to have a blue tinge, particularly around the peripheries of the beam.  This is acceptable.

Due to their higher light output, HID lamps must comply with a specific set of Design Rules.  These include light colour, proportions of specified light wavelengths (including blue wavelengths) and ultra violet (UV) emissions.  Self-levelling systems and headlight washers are also mandatory for any headlamps producing over 2,000 lumens (a measure of light output).

Aftermarket HID conversions

Aftermarket HID conversions are available however their on-road use will generally contravene the relevant federal legislation. HID headlight conversions are not permitted under Queensland legislation either.

Nor do these simple retro conversions provide the necessary self-levelling system and headlight washers.

If the vehicle manufacturer offered optional HID lights on a particular model, then retrofitting the complete system, including the self-levelling system and headlight washers, to a similar model would be acceptable. But fitting a system to a different make or model is unlikely to be viable due to necessary certification requirements.

Queensland's Department of Transport and Main Roads (DTMR) advises that HID conversion of driving lights is acceptable.

Aftermarket lamp globes

A common question relates to the maximum wattage headlight that can be legally fitted.

A 'Watt' is a measure of electrical power, but the ADRs specify headlight output in Lumens or Candela and there is no correlation between Watts and Lumens or Candela. Simply, there is no maximum wattage for headlights defined in legislation.

Care should be exercised when choosing aftermarket bulbs that claim increased light output, as they may have a higher current draw than the vehicle's electrical system is designed for. In some cases, the increased current draw is disproportionate to the actual increase in light output, with much of the additional power consumption merely generating extra heat in the headlight.

Another thing to consider is that light colour is defined in the design rules in terms of chromaticity co-ordinates, while bulb manufacturers typically specify colour in terms of the Kelvin scale (there is no direct comparison that we are aware of).  This becomes important when trying to determine if a particular bulb from the 'bluer' range of aftermarket bulbs is legal. Many have mild blue colouring of the glass envelope, are marked as ADR compliant and are legal for road use. However, others emit significantly more blue spectrum light, and are not ADR compliant. These are usually marked for off-road use only.

Ultimately, given the complexity of the subject, we recommend that you either stick with what the vehicle manufacturer specified as original equipment or be guided by the bulb manufacturer. A bulb that isn’t branded as suitable for on-road use probably isn’t.

LED headlights

A small but increasing number of new vehicles are appearing with Light Emitting Diode headlights as original equipment. Their claimed benefits include reduced power consumption that translates into fuel savings and emission reductions.

However, there are also aftermarket LED conversions. We are not aware of any of these having been tested and certified as meeting Australian legal requirements. Without this certification they are not acceptable for on-road use.

We understand that some Queensland drivers have already been fined for using these unapproved conversions.

Headlight protectors

Headlight protectors are a popular accessory, however their value in protecting headlights from damage is questionable. Most modern cars now use polycarbonate plastic for headlamp lenses.  Polycarbonate is very strong and offers much greater shatter resistance than glass lenses or the acrylic used in lamp protectors.  Lamp protectors may offer some protection against scratching of the lens though.

Hazy/discoloured headlights

Polycarbonate lenses on older car’s headlights can go dull and cloudy due to naturally occurring UV radiation.  This can affect the vehicle’s roadworthiness as it reduces the light’s output.

Replacement with new or good second-hand lamps are options, however auto accessory/parts shops can provide special lens polishing kits to restore the lamp to an acceptable condition.  These kits are not suitable for removing discolouration from the inside of lenses caused by incorrect lamp globes. Reduced UV or ‘UV cut’ bulbs are specially designed to reduce this affect and should always be used with polycarbonate lenses. 

Headlight alignment

Incorrect headlight alignment is a prime cause of dazzle for drivers and is a common source of complaint. 

A quick test of headlight alignment can be made by parking the car on a level surface (a driveway will do) at right angles to a wall or garage door. Reverse back approximately 4 metres from the wall and with the lights switched to high beam the spread of the two beams should be at about equal heights and roughly straight in front of the vehicle.  When low beam is selected the light beams should drop and move slightly to the left.

If the beams are wildly out of alignment it may be necessary to temporarily cover each light in turn to determine in which direction they need to be adjusted.

Owner’s handbooks usually provide instructions on the desired beam pattern and the adjustment process. Alternatively, you may wish to have your local repairer do it for you.

HID lamps

HID headlamps are becoming increasingly popular as original equipment on new cars.

What are they?
  • Gas discharge lamps that produces light by means of an electric arc between two electrodes housed inside a transparent quartz envelope.
  • They are Eelectrically more efficient and have a higher light output compared to conventional incandescent lights because a greater proportion of their radiation is in visible light as opposed to heat.
The light they emit may appear to have a blue tinge, particularly around the peripheries of the beam, but it is actually whiter than that produced by a standard halogen lamp.
Australian standards
  • Due to their higher light output, HID lamps must comply with a specific set of Australian Design Rules. 
  • These include specifics around light colour, proportions of specified light wavelengths (including blue wavelengths) and ultra violet (UV) emissions.
  • Self-levelling systems and headlight washers are required to off-set the increased risk of dazzling other drivers. 
Vehicle manufacturers sometimes refer to HID lamps as Xenon or Bi-Xenon lamps, but these should not be confused with conventional incandescent bulbs that use xenon gas in their glass envelope.

Aftermarket HID conversions

Aftermarket HID conversions are available, but are unlikely to be legally acceptable so it’s important you do your research before buying and fitting them. Typically these ‘conversions’ comprise ballasts, wiring and HID globes that plug straight into the existing lamp.

Australian Standards
  • Halogen lamps and their globes must comply with ADRs 46 and 51, while HID lamps and their globes must comply with a different set of requirements within ADRs 77 and 78.
  • Interchanging globe types (putting HID globes into a lamp designed for a halogen globe) prevents continued compliance of the lamp/globe assembly.
  • All vehicles fitted with headlamps (including HID) producing over 2,000 lumens (a measure of light output) must have a self-levelling system and headlight washers. These simple retro conversions don’t provide these features and are therefore likely to be excessively glary to other road users.
If the vehicle manufacturer offers optional HID lights for a particular model, then retrofitting the complete system (including lamps, globes and the features required by ADR 13) to that model should be acceptable. But ‘grafting’ a full system between models or makes would impose performance certification requirements and is unlikely to meet the ADR. 
Queensland legislation
  • HID headlight conversions are not permitted under Queensland legislation.  If you’re  in another state or territory, you should check local requirements.

Aftermarket lamp globes

Replacement headlight bulbs often claim to offer improved light output and whiter light due to a higher wattage and higher light output.


When you’re choosing an aftermarket bulbs that claims to have an increased light output, care should be taken to ensure they don’t have a higher current draw than the vehicle's electrical system is designed for . In some cases the increased current draw is disproportionate to the actual increase in light output, with much of the additional power consumption merely generating extra heat in the headlight.
Maximum wattage
There is no maximum wattage for headlights defined in legislation. A 'Watt' is a measure of electrical power, not of light output, though it has been (incorrectly) used for this in the past. 
Light output
The Australian Design Rules (ADR) for Road Vehicles uses either Lumens or Candela to define light output (different parts of the standards use different units of measurement), but most bulb manufacturers use Watts, which cannot be compared to the design rule requirements. So there is no way to know what is acceptable unless the bulb manufacturer can provide the light output of the bulb when installed in the lamp in question - in terms that are consistent with those used in the ADRs.

High beam headlights – the total light output of all headlights is not permitted to exceed 225,000cd, though you need to read ADR13 to understand how this measurement is applied, as it isn't as straightforward as it appears.

Dipped beam headlights – there is no maximum specified, but anything over 2,000 lumens requires a self-levelling system and headlight washers. 

Light colour

Light colour is defined in the ADRs in terms of chromaticity co-ordinates, while bulb manufacturers typically specify colour in terms of the Kelvin scale (there is no direct comparison that we are aware of). This becomes important when trying to determine if a particular bulb from the 'bluer' range of aftermarket bulbs is legal. 

Many aftermarket globes have mild blue colouring of the glass envelope, and are marked as ADR compliant and are legal for road use. Others globes emit significantly more blue spectrum light, and are not ADR compliant. These are usually marked for off-road use only and represent a potential hazard to other drivers if used on-road, it is also illegal to cause a glare hazard to other road users.

Given the complexity of the subject, we recommend you either stick with what the vehicle manufacturer specified as original equipment, or be guided by the bulb packaging or manufacturer. 

LED headlights

An increasing number of new vehicles are appearing with original equipment Light Emitting Diode (LED) headlights. These are acceptable under Australian Design Rule 46 and their claimed benefits include reduced power consumption that translates into fuel savings and emission reductions.

Aftermarket LED headlights 
There are also aftermarket LED conversions available that use an LED bulb in the vehicle's original headlight assembly. We are not aware of these having been tested and certified as meeting the requirements of ADR46, and without this certification they are not acceptable for on-road use.
Compliance issues
  • LEDs change colour slightly as they warm up, and the ability of such conversions to focus and direct their light output correctly.
  • LED bulbs are constructed differently and give off light in a different way to conventional filament or gas discharge bulbs, so there is a concern that the headlight's output could be affected, causing glare to other road users.
  • LED headlights also require a self-levelling system as defined in ADR 13.
Advice received from Queensland's Department of Transport and Main Roads is that due to differences in headlight design, these conversions would need to be certified for the particular application, rather than just as a blanket approval for the LED bulb.

We understand that some Queensland drivers have already been fined for using these unapproved conversions.

Common headlight complaints from road users

Glary headlights

Excessively glary headlights can dazzle other road users and create dangerous situations. Queensland’s road rules prohibit drivers from using lamps that distract or obstruct other road users. 

Blue coloured lights

Some drivers continue to raise concerns about the blue coloured headlights that appear to be becoming more common.

In Queensland, blue lights are reserved for the police and certain emergency services vehicles. Blue coloured lights on non-approved vehicles will quickly attract the attention of authorities, and drivers will incur hefty fine. 

These bluish headlights fall roughly into three groups:
  • High intensity discharge (HID)
  • Aftermarket HID conversions
  • Halogen lamps that have had aftermarket globes installed. 
Please note that headlights with a certain amount of blue colouration are permitted.

Headlight maintenance and accessories

UV cut globes

With polycarbonate plastics almost entirely replacing glass for headlight lenses, it is important to only use globes that are suitable for this application.

Globes with high UV output will rapidly discolour the inside of polycarbonate lenses. Reduced UV or ‘UV cut’ bulbs are specially designed to reduce this affect. 

Headlight protectors

Headlight protectors are a popular accessory, but their value in protecting headlights from damage is questionable. Most modern cars use polycarbonate plastic for headlamp lenses.  Polycarbonate is very strong and offers good shatter resistance, and for this reason, is superior to glass lenses and acrylic headlight protectors.

Queensland Safety Certificate requirements state that clear headlight protectors are acceptable, provided they don’t affect the light intensity on high or low beam. Tinted covers are also acceptable, but must be removed when the high or low beam headlights are operated.

Hazy and discoloured headlights

Polycarbonate lenses on older car’s headlights can go dull and cloudy due to the effects of naturally occurring UV radiation. This can affect the vehicle’s roadworthiness because it reduces the light’s output.

If this happens, you can replace your headlights with new or good quality second-hand lamps. There are also special lens polishing kits available from auto accessory and parts shops that can be used to restore the lamp to an acceptable condition. These kits are not suitable for removing discolouration from the inside of lenses caused by the use of incorrect lamp globes.

Headlight alignment

Incorrect headlight alignment can cause dazzle for other road users, and is a common complaint.

To test your vehicle’s headlight alignment, park your car on a level surface (a driveway will do) at right angles to a wall or garage door. Reverse back approximately 4 metres from the wall and with the lights switched to high beam, the spread of the two beams should be at about equal heights and roughly straight in front of the vehicle.  When you switch back to low beam, the light beams should drop and move slightly to the left.

If the beams are wildly out of alignment it may be necessary to temporarily cover each light in turn in order to determine in which direction they need to be adjusted.

Owner’s handbooks usually provide instructions on adjusting headlight alignment, or simply have your local repairer do it for you.

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