Headlights are a necessity on any car, and apart from making a car look good, are often overlooked as safety features. So in terms of what headlight bulb you need – well, if you want the safest car, you need the best you can get.
The purpose of a headlight
Obviously, the primary purpose of a headlight is to illuminate the road ahead when driving in the dark. There are various options to consider when selecting the best bulb to fulfill this purpose.
The second, more obscure reason for headlights, is to show other users of the road where you are – to make yourself visible. Again, when selecting the best headlight bulb for this task you need to be aware of some things.
Seeing in the dark
The general perception is that the brighter the light, the easier it will be to see things in the dark. The Xenon and LED bulbs give much better results than the older halogen bulbs. For comparison, halogen bulbs give around 1400 lumens in light intensity, whereas Xenon and LED bulbs give around 3000 lumens (with some LED bulbs emitting up to 4800 lumens).
Although brighter lights do make it easier to see, there are some other aspects that play into creating great visibility.
The light not only needs to be bright, but also needs to be illuminating where it is needed. What is meant by this is that a bright light that is dispersed into areas where one does not need it, loses its effectiveness.
The term used in the motoring industry is “cut-off” – in other words, the side of the road that you are travelling on is illuminated, as opposed to the opposite travelling lane or next to the road.
What is important for cut-off is the color temperature. The higher the color temperature the more contrast there is in the beam. This, along with the type of housing and how the beam is thrown, all play into the cut-off.
Most LEDs and some Xenon bulbs have higher color temperature, pure white (6000K), as opposed to the more yellow tinged halogen lights. They therefore should give better cut off.
The reach of the beam is also important – it is no good only seeing 5 meters in front of the car. The further along the road you can see the safer it is to react to potential hazards.
Because of the higher light intensity, the general rule is that the reach of the beam for the Xenon and LED bulbs are greater – however, this also depends on the angle at which the beam is set and the housing type.
Consider your fellow traveller
Having a pure white beam that reaches far, making your night into day, is one thing, but it needs to be balanced with not blinding oncoming traffic.
The less intense halogen bulbs, although not as defined in terms of beam pattern, were not usually a problem. The newer Xenon and LED bulbs, with their higher light output, also need to have their beam controlled. As already pointed out, the color temperature allows easier control over the cut-off – thus keeping the beam from wandering into the oncoming traffic lane.
You also need to consider what type of housing your car has as this will affect the beam going out. The older reflective housing, used for halogen bulbs, will not work with Xenon or LED bulbs as oncoming traffic will be blinded silly.
The projector housing is designed to take these high output bulbs and ensure the light is projected to where it should be and not dispersed into oncoming traffic lanes.
Taking all these factors into consideration, the first thing to establish is if you have a car with a reflective housing. If you do, then halogen is the only option. Halogen bulbs have been around for a long time – they still work absolutely fine.
If you have projector type housing in your headlights, then Xenon and LED bulbs are options. You then need to consider things such as price, lifespan, and ease of installation.
As it stands currently, both Xenon bulbs and LEDs have advantages and disadvantages – with LEDs possibly just sneaking ahead in the race for best bulb. It does, however, come down to personal preference as to which to choose.