If you’re considering upgrading your dull halogen lights to brilliant white HID lights, you should be aware of the difference between factory HID bulbs and after-market bulbs.
Factory bulbs are installed by the car manufacturers during the production stage.
It all started in the 1990s when BMW introduced HID headlights on the 7 Series. This new type of headlight no longer used bulbs with filaments but instead used xenon gas-powered bulbs that produce a high intensity light.
The bulbs work by sending an electrical charge into a bulb which is filled with xenon gas and metals. This charge creates an arc between two electrodes. The charge triggers a mass of plasma and it’s the movement of this plasma that generates a brilliant white light.
The result is a much brighter and whiter headlight that makes driving in the dark safer while also looking far cooler than a halogen bulb. HIDs draw down less power and last 5 times as long, too.
When HID bulbs are factory-made, they start with a D. It’s way more expensive to buy a car with factory-made HID bulbs.
With HID headlight bulbs, there are 3 main components that combine to deliver that brilliant white light:
- The ballast (delivers and controls the electrical current)
- The igniter (starts the arc)
- The bulb capsule
With factory bulbs, these components can be configured in different ways.
You’ll need to be aware of the different types of bulbs, their features and the type of ballasts they require. That way you can ensure that you make the right purchase for your particular make and model of vehicle and type of headlight housing.
Types of Headlight Housing
Manufacturers developed HID bulbs to make them more effective with reflective or projector housings.
Reflective housings direct the bulb inside so it bounces the light out in different directions. As this produces more glare, the R bulbs are encased in opaque glass to dissipate the strong light.
Projector housings on the other hand are fine with HID bulbs. Around 5% of headlights have projector housings and they seem fine with HID bulbs. If you have a projector housing, you might find it easier to maintain as it’s easy to replace the bulb.
D1 and D2 Bulb
The first factory bulb to come on the market was the D1 in the late 1990s. The D1 consists of a bulb and an igniter.
The D2 bulb was introduced not long after the D1. The D2 is much smaller than the D1 as it lacks the igniter, which makes it more economical as this can be expensive to replace.
The D2 is more common due to the economy factor and is found in car models from year 2000 to 2015.
Due to its popularity, many variants of the D2 bulb have been developed, the most common being the D2S and the D2R. Any bulbs with an S designation are made for projector headlights, and bulbs with an R designation are made for reflective headlights.
D2R and D1R bulbs have an extra shield of glass over the bulb itself. This is to prevent over-magnifying the intense light beam in the reflective headlight and produces the cut-off line necessary to prevent HID headlights from dazzling other drivers.
There are also some after-market variants of the D2R and D2S.
You may come across a D2C bulb which is an after-market design. The D2C has notches that allow it to be fitted in both a projector and reflective headlight. However, it’s still always best to install the appropriate bulb for reflective or projector headlight.
A D2H bulb is also available. Like the D2C, this bulb has notches on both sides to make it compatible with both types of headlights, the only difference is that it connects with amp connection wires rather than a socket type connection. The amp connection wires connect to a ballast, which is ideal if you don’t have much space inside the headlight.
D3 and D4 Bulbs
D3 and D4 bulbs are newer inventions that came after the D2 bulbs. These work and connect just like the D1 and D2 bulbs, only these ones are more environmentally-friendly as they don’t contain mercury.
D5, D6, D7 and D8 Bulbs
Manufacturers decided that the raw power that the earlier bulbs emit was unnecessary so they developed these bulbs with less power. As optic technology has progressed, it has become possible to produce as much light with a bulb that has only 25 watts.
Connecting Factory HID Bulbs
These various factory HID bulbs are configured slightly differently and so connect to the car’s power source differently. Some use a socket type connection and others require a ballast.
D2 and D4 Bulbs
D2 and D4 bulbs always require a socket although you can get a ballast that converts amp style connectors.
D1 and D3 Bulbs
These bulbs require factory ballasts to connect D1 and D3 bulbs. However, there are after-market replacements available.
D5 and D8 Bulbs
D5 and D8 bulbs use the same style of connection, although these can be more expensive. If you’re still in any doubt as to which factory HID bulbs to choose, reach out to our friendly team here at LED Light Street.