At some point you must have been driving along a motorway or main road at night when suddenly you see an intensely blue glow in your rear view mirror. No, it’s not an imminent alien abduction, but the piercing beam of a car that has been fitted with xenon headlights.
You might have wondered why they seem to have blue headlights. The light you see from these xenon headlights is generated by High Intensity Discharge (HID) xenon bulbs, which are special units that work differently to normal halogen headlight bulbs. These HID units are filled with xenon gas and use a very high voltage spark to ignite that gas, resulting in an intense and powerful light. Because these headlight units use very different technology to metal-coil halogen bulbs they are usually only available as an expensive option when ordering a new car.
The light itself is a brilliant white, and not the blue that you see as these cars approach. The blue tint is actually due to refraction of the light as it bounces around the reflectors and lens of the headlight unit. There are other colours generated but blue is the most prominent and gives cars that appearance of having blue headlights. So is there any way you can recreate that xenon look using ‘normal’ halogen bulbs and without resorting to an expensive aftermarket kit?
Yes, you can, by simply buying a set of upgraded headlight bulbs and fitting them yourself. You don’t need to worry about complicated wiring or changing fuses, just pop the old bulb out of your headlight unit and replace it with your new bulb.
There are a number of choices from different manufacturers but it is worth knowing that ECE regulations limit the amount of blue tint on the bulbs, as well as the maximum brightness, so in the end a lot of the blue headlight bulbs are very similar. Another point of note is that as the blue tint gets darker the bulb will get hotter, resulting in a shorter lifespan.
Two of the better known ranges of blue xenon bulbs are Osram Cool Blue and Philips Blue Vision. Both of these bulbs burn at 4000K, making them brighter than the typical 3200K you get on standard headlight bulbs. This means you get the benefits of making your car look more stylish as well as improving your night-time visibility with a brighter light.