Since the advent of the headlight, halogen bulbs have been used. They are cheap to manufacture and offer plenty of brightness. They work by sending an electric current via a filament. Halogen gas is then added to somewhat increase the brightness.
HID and LED headlights are relatively recent after-market replacement alternatives to regular halogen headlights that are standard on most vehicles.
The early 1990s saw the advent of HID headlights which were much brighter and able to highlight things usually within the peripheral vision of the driver.
With hazards from pedestrians and animals, and other traffic becoming more visible, accidents when driving after dark were reduced. The headlights are also capable of illuminating road signage, particularly useful when temporary, unexpected road signs are in place.
LED headlights are a recent invention and are rapidly growing in popularity, possibly due to their incredible brightness. However, they also have an exceptionally long life expectancy in comparison to standard halogen bulbs and require very little energy draw.
What are LED Headlights
LED stands for Light Emitting Diode and unlike conventional halogen bulbs, they don't require a filament for the current to pass through.
Instead, light is generated by the movement of electrons as the current passes through a semiconductor.
One particular advantage of this method is that the material properties of the semiconductor can be altered, thus changing the frequency of the emitted light and, in turn, the color of the light.
Due to their small nature, when used in headlights, LEDs consume little energy and generate minimal heat.
What are HID Headlights
HID stands for High-Intensity Discharge and is more commonly known as Xenon headlights, due to the gas's activity within the bulb.
The light is generated by an electric arc that is created between two tungsten electrodes.
HID headlights are up to three times more efficient than standard halogen lights which is why they are commonly used in street lighting and floodlit stadiums. Under normal usage, they have a life expectancy of approximately 2500 hours.
Car enthusiasts often opt for HID headlights as they are impressed by the blue-tinged light that they emit. However, they are available in a variety of colors.
Is it Easy to Upgrade to HID or LED Headlights?
Both types of headlights are available as a full headlight replacement or a plugin kit, with the latter being the less expensive option.
Some modifications are required:
Whether you opt for the full or replacement kit you will need to fit additional electronics as the lights require less voltage than the 12V the car supplies.
Require a small ballast to create a high-powered pulse that initiates the electric arc. It controls the flow of the current to ensure normal operation at all times.
Doing the upgrade yourself is a relatively simple task that requires a little know-how and some basic tools.
It should take around half an hour to fit either style of conversion kit.
How the Brightness of Headlights is Measured
The Kelvin Color Temperature Scale describes the way light temperatures appear visually.
It is measured in degrees and plotted on a scale numbered between 2700-5000 degrees Kelvin for interior lighting, for outdoor lighting the scale extends to 6500K.
The lower the K number the 'warmer' the color, the higher the K number the colder the light appears.
3000K ratings emit warm and cozy light, 5000K and beyond are not recommended for indoors as they are too bright and can damage eyesight.
All bulbs will have their Kelvin number referenced on the packaging.
How Bright are HID and LED Headlights
When you consider that traditional halogen headlights present on the Kelvin scale at 3500K, the illumination benefits of upgraded headlights become obvious.
HID headlights typically register around the 5000K mark.
LED headlights color higher on the scale, often registering around 6000K.
The most effective light output that garners the best response from the human eye is the color temperature that closest replicates the sun and natural daylight.
At noon, the color temperature of the sun is between 5500 and 6000K.
Advantages of HID Headlights
The light covers a larger spectrum and covers further throw distance providing natural light for comfortable night driving and during foggy conditions.
Although HID was once considered an expensive upgrade, in recent years costs have plummeted to make it much more affordable. A DIY conversion kit can be the cheapest way of creating a dramatic lighting improvement.
Minimal Energy Consumption
HID headlights typically use less than 25-30% energy to power. They use very little when running and require a short burst of energy upon startup. They are less of a drain on the battery and the vehicle's electrical system and, therefore, extend their life.
HID headlights have an expected service life up to 3 times longer than halogen bulbs.
They provide a high-end, classy look to most cars. They are a brilliant after-market upgrade that not only improves the overall look of the vehicle, but they also improve safety.
Disadvantages of HID Headlights
The brightness of HID lights is their biggest attraction. However, if you're sitting in the car in front or oncoming traffic, you may not feel the same.
Their supreme brightness can create a strong glare that can temporarily blind other drivers. The reflection in the rear-view mirror can be uncomfortable, although adjusting the mirror can help, however it isn't any less annoying.
HID headlights don't achieve full brightness instantly. They gradually increase until they reach their peak after around 30-seconds.
Although they are brighter than their LED counterparts, they are not as energy-efficient.
Advantages of LED Headlights
LED headlights supply a focused beam with incredible clarity. Compromised night vision is a hazard and LEDs provide natural lighting for 3x further down-road visibility and are much clearer than halogen bulbs. They reduce the demand on a driver's eyes and make driving in low light much more comfortable.
The illumination from an LED is more controlled and emits less glare. As a result, they are less bothersome to other road-users.
It can be as simple as swapping out the existing halogen bulb and replacing it with an LED bulb. Basic, if any, tools are required to fit the plug and play conversion kits.
Not only are LEDs the most energy-efficient types of headlight, they are also environmentally friendly. This is due to their low energy consumption that puts very minimal load on the car battery and alternator.
Long Life Expectancy
When you consider the average life expectancy of a halogen bulb is 500 - 1000 hours, the cost of an LED upgrade is justifiable; they can last up to 30,000 hours.
Thanks to the semi-conductor inside an LED bulb, color-changing bulbs are optional. If this appeals to you, ensure you stay within your State's legal requirements to remain road legal.
Disadvantages of LED Headlights
As the latest technology, LED headlights are still the most expensive type of headlight. However, as manufacturers learn new methods and more cost-effective manufacturing techniques, costs will undoubtedly go down.
As discussed above, LED bulbs have an exceptional life-expectancy, thus, over time they will pay for themselves.
If an LED blows it can't be repaired, rendering the whole unit useless and needing to be replaced.
Individually LEDs emit very little heat but when grouped in large clusters they may require additional cooling capacity.
Only 20% of halogen bulbs produce light, the remaining 80% presents as heat. LED bulbs are opposite, 80% of their energy is light with the remaining 20% presenting as heat energy.
The LED light can be switched to dim mode to provide instant energy reduction and faster cooling.
Upgrading from halogen headlights is worth serious consideration, particularly if you do a lot of your driving at night.
The wider spectrum of vision and natural bright light aids low-light driving conditions and improves safety.
HIDs provide the brightest lighting differences but can cause glare; LEDs are the most modern technology that requires minimal energy to run but are more expensive.