Xenon Headlight vs. Bi-Xenon Headlight: Which is Better for You?

Which is the right headlight for your car? Which one offers you the most value? Xenon or bi-Xenon headlights?

For many drivers, the Xenon technology is relatively new, and so bringing bi-Xenon bulbs into the pictures makes things more complicated.

Both technologies use Xenon bulbs in the car headlights, but the way the headlights get manufactured and how they function are both different.

The following side by side comparison takes a look at both headlight technologies and provides you with all the necessary information that you'll need when making a buying decision.

Xenon Headlights

Photo: autocar.co.uk

Xenon bulbs, which are also called High-Intensity Discharge bulbs or HID, produce the whitest and brightest lights that get used in car headlights.

They first came to use in a 1991 7-Series BMW and have continued gaining popularity since then. Xenon bulbs take a few seconds to power up and this has limited their use in certain applications.

In addition to a delayed power-up, Xenon bulbs also get so bright that they'll immediately blind the drivers in oncoming vehicles when used as a high beam.

These reasons led to the use of Xenon bulbs as low beams and halogen bulbs as high beams. So most so-called Xenon headlights use a combination of halogen and Xenon bulbs to work.

It also makes sense because switching a Xenon high beam Off and On to avoid blinding an oncoming driver can get dangerous, since the Xenon bulb will need a few seconds to power back on, and many things could happen in this period.

With a halogen high beam, the danger of blinding oncoming motorists gets reduced and you get instant long-range vision once you switch on the high beam.

Although this solution is very helpful and welcomed by most drivers, it still uses halogen for the high beam, which creates a rather yellowish light that many find inferior to Xenon's day-like light.

Pros

• No moving parts. The first advantage of a standard Xenon headlight over a bi-Xenon system is that there are no moving parts in a Xenon system. Bi-Xenon bulbs use different methods to physically change the direction of a bulb's beam, and these physical movements create a possible weak point. This means that a standard Xenon headlight is less prone to failure because it has no moving parts.
• Beautiful low beam. Although the high beam comes from a halogen bulb, there are many situations where using the low beam is enough for driving. In these situations, the driver gets to enjoy the daylight brightness and cool look of the Xenon bulbs.Also worth noting is that Xenon light has a longer and wider reach than halogen lights. So with a low beam Xenon light, you can see more of your surroundings in the bright-white beauty of a Xenon beam.
• Less blinding of motorists. Halogen bulbs may not produce light as bright as Xenon bulbs, but their lights are still potentially blinding to an oncoming motorist. The small advantage here is that halogen light is less blinding than Xenon light.

Cons

• Yellowish high beam. One downside of this system is that although a more modern technology like Xenon exists, and which produces bright white light, one still has to settle for a yellowish high beam from halogen bulbs. Some drivers may not care, but for those who find the bluish-white light of Xenon bulbs fascinating, it's a little of a letdown.
• Costlier than Bi-Xenon. With a standard Xenon system, there are 2 bulbs per headlight, making 4 bulbs in total. With a bi-Xenon system, there is only one bulb per headlight, making 2 bulbs in total. The math is simple, the Xenon and halogen combination costs more.
• Halogen bulbs have shorter lives. Xenon bulbs typically last over twice as long as halogen bulbs. This means that there'll be more frequent bulb changes once a halogen bulb gets involved.

Bi-Xenon Headlights

Trying to solve the problems associated with Xenon bulbs as part of car headlights led to the bi-Xenon headlight system development.

With the bi-Xenon headlight system, a single Xenon bulb is used to carry out both high beam and low beams. This results in long-term cost savings, although a mechanical system is introduced into the headlight system.

The mechanical system can either be used to point the bulb upwards and downwards, or it can work to partially block and unblock it.

Each bulb's reflector can also be moved and this includes both vertically and sideways. Some cars even go further and automatically move the reflector sideways when the car is making a turn in that direction, allowing you to see better.

What this means is that there are no down times, once the Xenon bulb gets switched on. You flick a switch and the bulb's beam is immediately redirected in full brightness.

These features make the bi-Xenon technology interesting and with lots of potential for the future. One major downside though is the reliance on mechanical systems, which theoretically fail with time.

Pros

• Lower cost. The first obvious advantage of having a bi-Xenon system is the cost savings since you use just one bulb per headlight. When the time to change the bulb comes, there is only one bulb to change. Xenon bulbs generally last longer than halogen bulbs, and this brings the extra advantage of less frequent bulb changes than a Xenon system.
• Improved visibility. Xenon bulbs create more illumination than halogen bulbs. When driving with a high beam powered by a Xenon bulb, then the difference is clear. You see further ahead of you, you see further to your right and left sides, plus you see tiny details more clearly than is possible with a halogen beam.
• Convenience. Although the beam change is mechanical, it's still controlled by the car's electronic system, so all you need to do is flip a switch or lever and it's done.
• Blueish-white light is cool. In addition to providing more illumination and safety, the bluish-white light of Xenon bulbs is nice, trendy, and modern. It's cool.

Cons

• Possible mechanical failure. One thing about mechanical systems with moving parts is that they are bound to develop issues. Although this is also true with bi-Xenon systems, these moving parts are usually properly engineered to make it highly unlikely to develop any problem for decades to come.
• The issue with fogs. Bi-Xenon headlights may be powerful, but they are still no match for fogs. You'll need extra fog lights if you often drive through fogs.

Making the Right Choice for Xenon Headlight vs. Bi-Xenon Headlight

Xenon and bi-Xenon systems each offer their unique advantages and disadvantages. It's left for you to make a choice from their features, based on what you need and what you don't need. Following is a quick overview of these features.

Bi-Xenon headlights are the more modern, efficient, and cheaper to manage systems. It would seem that the bi-Xenon is the sensible and correct choice, but then, people are different.

You may prefer the warm, yellowish glow of halogen bulbs and not mind making more bulb changes. In such a case, the Xenon/halogen headlight could be ideal.

On the other hand, if you do like the bright, energy-efficient, and modern look of Xenon bulbs, then you should definitely consider the bi-Xenon.