When considering upgrading a vehicles lighting system from halogen to xenon, one common question that arises is what type of xenon kit should be used – a “standard” xenon kit or a “Bi-xenon” kit. What’s the difference between the two and when should each be used?
Standard xenon kits utilize independent bulbs for the low beam and the high beam. One bulb turns on for the low beam, and then turns off as the other bulb is activated for the high beam. Believe it or not, on most new cars xenon headlights are only offered as the low beam bulb because the high beam bulbs are actually halogen bulbs.
Bi-xenon headlights use a single xenon lamp to produce both the high beam and the low beam. Instead of separate bulbs, two separate filaments are encapsulated in one single bulb – one for low beam and one for high beam. Typically bi-xenon bulbs have a shade or filter in front of the bulb obscuring the high beam filament during low beam operation. The shade then moves out of the way when the high beams are needed allowing the bulbs full output to be projected onto the road. So in either case you are getting true xenon lighting.
Bi-xenon kits with full time xenon lighting are thus the more popular choice if you have the option to use them on your vehicle. They also have the added benefit of a deeper and wider beam spread because they don’t have the halogen bulbs used in standard kits.
Then again some people actually prefer the standard kits because they have the option to angle each bulb separately thus obtaining differences in beam depths. Single filament bulbs are also less expensive than the two filament bi-xenon bulbs. If one of the bulbs burn out you only need to replace that one bulb. With bi-xenon bulbs, if one filament burns out you need to replace the entire bulb, even though the other filament is still working.
Also when upgrading from halogen to xenon bulbs you will need to install ballasts or power transformers. Simply exchanging one bulb for the other will not work. Halogen bulbs work with the standard 12 volt systems typical in most cars. Xenon bulbs on the other hand, require a much higher voltage to ignite (over 20 thousand volts) and 85 volts to keep operating. Therefore, ballasts are needed to transform and regulate the voltage supplied to the xenon bulbs. Without one, the xenon bulbs will simply not operate. Ballasts are normally included with xenon conversion kits.
Another thing to consider when upgrading from halogen to a bi-xenon kit, is that you may need to disable your daytime running lights. Check to see weather or not your daylight running lights (DRL) use the same bulb for the DRL and the low beam. If they do, you will have to disable your DRL because most DRL operate on reduced wattage or fluctuating current levels. This would cause the xenon bulb, and the ballast supplying power to it, to flicker and burn out prematurely.
Bi-xenon bulbs are available in H4, H13, 9004 and 9007 bulb type only. Color temperatures range from 3000K (Kelvin) to 12000K. 3000K bulbs are yellow in color and very similar to halogens bulbs. 12000K bulbs are very blue almost purplish in color. Typically xenon bulb retailers will recommend an 8000K bulb as it gives off a very white colored light with an exotic blue tint.
Bi-xenon headlights are the usual xenon light kits that come standard on luxury car brands such as Mercedes-Benz, BMW, Lexus and Audi.