The technology behind headlights has continued to advance since the introduction of the first automobile in the 1880s. From kerosene lamps to dynamo power headlights, the technology has continued to advance due to the introduction of more sophisticated systems. Today, modern carmakers are manufacturing their vehicles with various types of headlight bulbs in a bid to improve efficiency.
But, to those that are totally uninitiated, the world of headlight bulbs can be a bit of a minefield, especially, when words such as Xenon, Halogen, and LED float around. Now, with so many lighting options available, car headlights can sometimes seem like an optional extra or an aesthetic addition.
But, when it comes to driving at night, headlights are an absolute necessity as they illuminate the road ahead of you and keep you safe when driving on busy roads. So, what are the different types of headlight bulbs? Well, that’s exactly what we’ll be discussing in this guide.
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Types of Headlight Housings
Just before we get to our main topic, we would like to discuss just a little bit about the different types of headlight housings. When you think of the headlight, what comes to mind is the actual bulb. But, rather than the bulbs, the housing on which the bulbs reside has a huge influence on your overall lighting experience.
While the bulbs produce the actual light, the housing is responsible for dispersing the light to meet your lighting demands. Now, there are two main types of headlight housings available. These are the reflector and the projector headlights. Let’s examine each type in detail.
Reflector Housing
The reflector housing is the standard and most commonly used type of headlight housing by most vehicles. This headlight technology has stood since the invention of the electric headlight. This headlight housing consists of a steel bowl with mirrors placed all-around to help reflect light. At the center of the bowl is a holder that’s designed to hold the bulb.
The final piece of this headlight is a clear lens that rests outside to protect the bulb against damage. The older reflector housing had a sealed-beam design that made it entirely impossible to replace the bulb. So, in case the bulb was faulty, the only alternative was to replace the entire headlight.
However, in the 1980s, the sealed-beam headlight technology was improved with much simpler yet efficient technology. The modification involved placing mirrors inside the headlight itself instead of sealing the bulbs inside mirrored individual bowls.
Since the bulbs were placed directly on the headlight housing, it made it much easier to replace burnt-out bulbs. Some of the pros and cons of reflector housings include;
Pros
- They’re cheap to manufacture
- They’re smaller in size hence they take less space
Cons
- The beam of light produced is weak
- Light output is less intense
Projector Housing
The projector headlight housing was first used in the 1980s where it was installed on luxurious vehicles. This technology is very similar to reflector housing in myriad ways. Just like the reflector housing, the projector housing uses a mirrored steel bowl that has a bulb mounted in the middle.
The assembly is pretty much the same as that of the reflector headlight as it reflects light to the outside. The only difference with the projector assembly is that it has a magnifying lens at the front of the headlight to increase the brightness of the beam.
Besides the lens, projector housings have an inbuilt cutoff shield that angles the light beam produced downwards towards the road. By angling the light beam downwards, projector headlights are considered safer to use during the night, as they don’t blind oncoming motorists. Some of the pros and cons of these types of headlights include;
Pros
- They’re brighter than reflector housings
- Less likely to blind oncoming motorists
- The beam of light projected is strong without any weak spots
- Offer you the option to use HID bulbs
Cons
- Feel quite odd in case you were used to reflector headlights
What are the Different Types of Headlight Bulbs?
The reason why we discussed the different types of headlight housings is that the housing is the one responsible for disbursing the beam of light produced by the bulbs. Now that you’re well-aware of both the reflector and projector housings, we’ll now discuss the different types of headlight bulbs which are the Halogen, HID, and LED bulbs.
But, before we get to that, it’s good to note that bulbs are measured in three major ways. The first one is Lumens, which is used to measure the brightness/output of your bulbs. The second one is Kelvin, which measures the color temperature of a bulb while the third one is Hours, which is used to measure the lifespan. So, with that said, let’s now discuss the three main types of headlight bulbs.
Halogen Headlight Bulb
The halogen bulb is the oldest headlight technology that came as an improvement of the old sealed-beam headlight. Although this technology is old, most modern vehicles have comfortably continued to use it due to its efficiency, low cost of production, and ease of replacing the bulbs.
Now, similar to a normal household bulb, a halogen bulb consists of a tungsten filament that’s enclosed inside an air-tight tube pressurized with an inert gas. Just like its name, the tube is filled with halogen gas, which is a mixture of iodine and bromine.
For the halogen bulb to illuminate, an electric current is passed through the filament to heat the tungsten until it glows. Once it does, the halogen gas inside takes over to support the heating process to make it last longer. Besides, the halogen gas prevents the tungsten filament from burning up entirely and also blackening the tube.
Halogen bulbs are mostly the cheapest option available. They’re cheap to manufacture and very easy to replace. They come in different variations that include the H4, H17, H18, H8, H9, and H11. The H4 bulbs have double-filaments while the H17 and H18 are smaller and brighter. H8, H9, and H11 are self-sealing halogen bulbs that are mostly used as foglights.
But, despite their massive contribution to the headlights department, halogen bulbs have a number of flaws. One, they have the lowest amount of lumens that is around 1000 lumens. They also have the lowest color temperature that ranges from 2,500K to 5,000K.
Pros
- These bulbs are the cheapest to manufacture and the easiest to replace
- The beam of light produced is brighter
- Their small size allows them to take less space on the headlight unit
Cons
- They have a slight yellowish hue that has a color temperature of around 3,500K. This prevents these bulbs from casting light further ahead
- These bulbs produce a lot of heat when glowing. This makes them less energy efficient
- These bulbs have a shorter lifespan as compared to Xenon and LED bulbs
Xenon/HID Headlight Bulbs
HID bulbs use a completely different technology as compared to halogen bulbs. While halogen bulbs rely on a burning tungsten filament to glow, HID bulbs rely on an arc glowing between two electrodes. Halogen bulbs on their side contain a tube pressurized with a mixture of iodine and bromine gases.
When it comes to HID bulbs, the tubes are pressurized with a mixture of xenon gas, argon gas, and vaporized metals. Now, how do HID bulbs work? When current is passed through the arc between the two electrodes, the heat melts the gases and the vaporized metals (mercury and metal halides) to form plasma. The resulting plasma glows in a shade of white-blue hue to produce bright light.
This bluish-white light is what HID bulbs are famous for and are hence called plasma headlights. Other names you’re likely to hear with these car headlight bulbs include Xenon headlights (due to the use of xenon gas) and High-Intensity Discharge (HID) headlights.
When it comes to performance, HID bulbs are hailed for their typically higher lumen rating that ranges between 3000 to 5000 lumens. They also come in a wide range of color temperature that ranges from 3,500K to 8,000K.
Although HID bulbs are less efficient when compared to LEDs, they’re a much better pick when compared to Halogen bulbs. What makes them even better is the availability of aftermarket HID conversion kits in case you need your former halogen headlights to accommodate HID bulbs.
However, finding a road-legal conversion kit is very tricky. When buying a conversion kit, you must ensure it’s correctly E-marked. It must also be ECE R99 certified.
Pros
- These bulbs were invented by Philips Company thus making them authentic
- They use the plug-and-play technique making installation easy
- They’re energy-efficient
- They have a long life expectancy of around 10,000 hours
- They’re 350-450% brighter than halogen bulbs
- Their bluish-white hue (3,500K-8,000K) offers a greater range of illumination
Cons
- Sometimes you’ll need an aftermarket conversion kit which is quite hard to procure
- The strikingly bright hue produced can irritate oncoming traffic
- They’re slower in reaching full brightness
LED Headlight Bulbs
The last headlight technology we’ll be discussing in this guide is the LED technology. Since their discovery, LED bulbs have managed to overtake halogen and xenon bulbs but to some extent. The reason why I’ve said “to some extent” is that not all cars can manage to employ this technology.
You see, LED bulbs rely on completely different technology as compared to halogen and xenon bulbs. While halogen and xenon rely on heated filament and arc, LED bulbs rely on a very sophisticated technology known as electroluminescence.
In this technology, electricity is passed through a semiconductor to generate energy in form of photons. This energy appears in the form of tiny particles of light. To provide continuous illumination, this process is repeated many thousand times per sound to make the light stronger.
Although this technology is expensive and very sophisticated, the benefits are incredibly high. First, less heat is generated in the process making LED bulbs energy efficient. Secondly, less heat means that more energy is converted into light thus making these bulbs extremely bright than both halogen and xenon bulbs.
Another massive benefit with LED bulbs is the high lumen they offer (of around 4,000 Lumens) and the high color temperature of around 6,000K. Since they’re mostly used with projector headlight housings, these bulbs have a higher light intensity as well as a high degree of contrast that mimics daylight.
The only downside with this technology is that it’s still new. Since most aftermarket LED headlight upgrades are not road legal, these bulbs are offered other duties inside the headlights such as working as signal lights and DRLs (Daytime Running Lights).
Pros
- LEDs have the longest life expectancy of around 30,000 hours
- They’re energy-efficient hence they don’t strain your battery
- They can be customized to meet various aesthetic needs
- Small and compact hence take less space within the headlight unit
- They don’t irritate oncoming traffic
- The light generated mimics daylight
Cons
- Very expensive to produce
- Very expensive to replace. Remember you have to replace the entire light unit
- The majority of the aftermarket LED upgrades are not E marked hence not road legal
Conclusion
As you can see, the headlight technology has continued to flourish from the old oil-filled lamps to the newest LED bulbs. In fact, further technological advances are being evidenced with the likes of matrix and laser headlight technologies. The only problem with these newer technologies is that they’re still in their infancy meaning more tests will need to be conducted to guarantee driver safety.
Now, regardless of the headlight technology, you employ, the most important thing is driver safety. Thankfully, this guide has discussed three headlight light bulbs that are the most common in most vehicles on our roads.
Since each technology has its own share of positives and negatives, it’s highly recommended that you inspect each category keenly before making your final decision.
