Battle of the Headlights: Halogen vs. Xenon vs. LED vs. Laser vs. Conversion Kits

The Electric Vehicle Company is credited with bringing the first electric headlights to market in 1898, obviously as an option. A decade later, Pockley Automobile Electric Lighting Syndicate rolled out a full set of electric lights, comprising the headlamps, sidelamps, and taillamps. Low beams were introduced in 1915 by the Guide Lamp Company, whereas Cadillac developed a system for dipping the light by means of a lever.

Once the standard in the United States, the sealed-beam headlamp was a bit odd because of the gas-filled glass housing. There's no bulb to replace, meaning that you had to purchase a new sealed-beam headlamp whenever the filament gave up the ghost. Fast forward to the early 1960s, and that's when the H1 halogen bulb was introduced to European vehicles. Granting a 1981 petition from the Ford Motor Company, headlamp regulations in the US of A were amended in 1983, allowing replaceable-bulb architectural headlamps with aerodynamic lenses.

It was big news for the US automotive industry, for the 1984 Lincoln Mark VII marked (pun intended) the return of replaceable-bulb headlights after a four-decade absence. Halogen lights would be bettered by high-intensity discharge systems in the early 1990s, with HIDs also known as xenon lights. Then came LEDs and matrix-style LED headlights, after which German automakers BMW and Volkswagen Group-controlled Audi started making the world's first production cars with laser lights in 2014.

Some prefer to call them headlights over headlamps; others use these terms interchangeably, but bear in mind that headlamp is the whole assembly while headlight is the beam of light produced by said assembly. Now's high time for us to dig deeper into each technology's intricacies, beginning with halogen lights.

Halogen headlamps

Still dominant in this industry, the halogen bulb has two main advantages, beginning with simplicity and cost. We also have to remember that changing a halogen bulb is also simple, with replacements costing less money compared to xenons and light-emitting diodes. The lifespan of a halogen bulb for automobiles? That depends on who you ask, with estimates ranging from as little as 400 hours to 1,500 hours.

Lifespan depends on plenty factors, beginning with the level of usage. Older vehicles that use the low beams as the daytime running light will obviously go through said bulbs more often. As far as modern electric vehicles are concerned, overvoltage and voltage spikes can wreak havoc on the tungsten filament.

Halogen bulbs are slowly but steadily becoming the second option for increasingly more automakers because halogen isn't synonymous with efficiency in this particular application. To better understand why, we have to understand how incandescent bulbs work.

As implied, the bulb is made of a glass envelope that's capable of handling very high temperatures. Iodine or bromine are mixed with an inert gas. Combined with tungsten for the filament, which receives electricity from the car's 12-volt battery, leads to a halogen-cycle reaction that redeposits evaporated tungsten on the filament.

The presence of halogen is what separates these bulbs from ordinary incandescent lamps, where tungsten deposits on the inner surface of the bulb, therefore weakening the filament with each hour of operation. Because halogens aren't miracle chemical elements, it shouldn't come as a surprise that halogen-bulb filaments also become weaker. A rupture renders the bulb unfunctional.

As for the single biggest issue with halogen bulbs compared to HID bulbs and light-emitting diodes, that would be wasted energy from heat. The second-largest problem with halogen bulbs is the way they react to various substances. For example, when replacing a faulty bulb, avoid touching the spare with your fingers because the grease from your fingers will cause the glass to heat unevenly, cutting the bulb's life.

If you do exactly that next time you change an automotive halogen bulb, gently rub the bulb with an alcohol-based substance, then clean off said substance using a clean cloth. Available in a wide variety of sizes and dimmable, halogen bulbs create decent forward illumination for the least amount of money. To sum it up, let's use a few bullet points and very concise terms.

ADVANTAGES

• Simple
• Inexpensive
• Many fittings to choose from
• Easy to replace

DISADVANTAGES

• Inefficient
• Not as bright as xenon bulbs or light-emitting diodes

HID headlamps (a.k.a. xenon headlamps)

The chemical element with the symbol Xe was discovered in 1898 by William Ramsay and Morris Travers. These lads are credited with discovering krypton and neon as well. The odorless noble gas is used as a starter gas in high-intensity discharge lamps.

This design works rather differently from halogen bulbs, for light is produced by an electric arc instead of a glowing filament. Better described as metal-halide lamps with xenon gas, xenon headlamps became a thing in the 1990s due to the E32-gen BMW 7 Series. The folks at Hella and Bosch produced the first low-beam HID headlamps for said 7er.

America followed suit with the 1996 model year Lincoln Mark VIII, whose high-intensity discharge lamps operate on direct current. Sylvania discontinued the DC system after Osram took over control of the company in 1997. Given the aforementioned, every single HID headlight in production today for OEMs and the aftermarket uses AC-operated bulbs and something called ballasts.

Because HID bulbs require a high voltage to ignite, the ballast is designed to provide a surge of higher voltage to the bulb. The ballast is also required to maintain the required flow of electrical current to the bulb. HID lights work pretty much like your usual neon tube.

You have an enclosed tube filled with gases, an electrode at each end, plus electric current passing through. In the automotive world, HID lamps feature a transparent quartz housing, tungsten electrodes, and a mix of gases that get stimulated by the high-voltage electric current passing between the two electrodes.

The process of lighting up xenon headlights? First is the ignition phase, when a high-voltage pulse produces a spark that ionizes the xenon gas and creates a tunnel of current between electrodes. The temperature in the bulb rises quickly, vaporizing the metallic salts, therefore lowering resistance between the electrodes. The ballast then switches to continuous operation, supplying a continuous amount of power so that the electric arc won’t flicker.

Automotive xenon bulbs produce more lumens and candela per square meter compared to their halogen counterparts, and these bulbs further sweeten the deal with a higher lifespan. Except for the start-up phase, xenons are more efficient than halogens as well. However, xenons do have a bad reputation for horrendous glare, namely low-beam xenons in a reflector.

ADVANTAGES

• Better visibility for the driver
• More efficient and brighter than halogen bulbs
• Higher life expectancy

DISADVANTAGES

• Pesky glare
• More expensive than halogens
• More complex
• Takes a few seconds to reach full brightness
• Xenon bulbs may contain toxic substances

LED headlamps

The four-ringed automaker from Ingolstadt gave us the world's first all-LED headlamps with the first generation of the R8. Prior to the V10-engined supercar, the Lexus LS 600h was the first production car with light-emitting diodes for the low beams. Thing is, what are light-emitting diodes and how do they work?

Invented by Russian scientist Oleg Vladimirovich Losev, the original LED used silicon carbide, whose light-producing properties leave much to be desired. Light-emitting diodes took a turn for the mainstream due to Monsanto and HP, which launched an LED indicator lamp and an LED numeric display in 1968. You can think of the diode as the simplest form of a semiconductor device. As for the working principle, that's kind of hard to explain.

If you insist, LEDs produce light by passing an electric current through a diode, thus emitting photons. The diode's material determines the LED's color, wavelength, and – of course – energy efficiency. This, in turn, means that light-emitting diodes work in a very different fashion from xenon and halogen bulbs. How different, though? By converting electrical energy into light rather than into heat and then into light.

The most important aspect when it comes to LED headlamps is the fact that said light-emitting diodes need low power to work compared to classic halogen bulbs. LEDs provide much focused rays, and – in stark contrast to automotive xenon and halogen bulbs – can be arranged in a matrix pattern for truly adaptive lighting.

Audi's Digital Matrix LED headlights take it up a notch due to digital micromirror device technology. Introduced by the e-tron Sportback (now known as the Q8 e-tron Sportback), the Digital Matrix LED headlights can project animations on the ground or on a wall. The predecessor of the Digital Matrix LED headlight technology is the Matrix LED headlight, which debuted in 2013 in the 2014 model year A8.

Clearly enough, the added complexity of matrix-style LEDs makes them prohibitively expensive to replace if anything goes wrong. Looking at the glass half full, aftermarket LED bulbs for automotive applications are fairly affordable. Other pros and cons? Glad you've asked!

ADVANTAGES

• Brighter than halogens
• Warmer than xenon headlights
• Small and easy to manipulate into various shapes
• Low energy consumption

DISADVANTAGES

• OEM replacement LED headlamps are expensive
• Complexity
• Certain LED solutions are louder than xenons and halogens due to cooling fans that dissipate heat away from the chips

Laser headlamps

BMW and rival automaker Audi both claim to be the first to launch laser headlights into series production. It so happens that the R8 LMX is a special edition while BMW's rather quirky i8 is a series-production vehicle. Although the i8 reached customers later than the R8 LMX did, bear in mind that more than 20,000 units were produced through 2020 as opposed to 99 examples of the breed for the R8 LMX.

In the Audi, we're dealing with two laser modules comprising four laser each. A phosphor converter is tasked with transforming the blue laser beam into white light for the road, with said light rocking a color temperature of 5,500 Kelvin. As you might have guessed by now, the laser spot supplements the LED-powered high beam.

BMW's first laser headlamps feature three blue laser beams per headlamp. The i8's lasers are said to produce an exceptionally bright light, with BMW claiming much greater luminous intensity than conventional automotive light sources. BMW further claims a 600-meter range with the laser boost feature, meaning 656 yards.

In both cases, the laser supplements the LED-powered high beams. Osram produced the laser-infused headlights of the R8 LMX and i8, with Osram highlighting that laser headlights offer the longest range of any current headlight technology. Laser headlamps became mainstream in 2015 with the G11-series 7 Series, which precedes the current-gen G70.

Back in February 2022, the National Highway Traffic Safety Administration issued a final rule on adaptive driving beam headlights for new vehicles. By adaptive driving beam, the federal watchdog refers to automatic headlight beam switching technology that provides more light on unoccupied areas of the road than on those occupied by vehicles or pedestrians.

At the moment of writing, laser headlights are limited in this part of the world due to antiquated regulations. Although nerfed to approximately 300 meters (328 yards), laser headlights do make sense in both Audis and BMWs due to the crisp light produced by the lasers and yellow phosphorus in combination with LEDs.

ADVANTAGES

• Around twice the high-beam range of LED headlights
• Energy efficient

DISADVANTAGES

• Ridiculously expensive
• Extremely complicated because laser lights combine LED and laser technologies
• US regulations still don't allow automakers to unlock the full potential of laser lights

Aftermarket conversion kits

If your car, sport utility vehicle, pickup truck, or van came with halogens from the factory, it would be best to replace any failed bulbs with similar halogens. Retrofitting xenons or light-emitting diodes to your originally halogen vehicle isn't exactly legal in the European Union, United Kingdom, and the United States of America.

Under Federal Motor Vehicle Safety Standard 108 requirements, one can't simply substitute a halogen bulb with a xenon bulb or a light-emitting diode. Diode Dynamics is a reputable seller of LED bulbs, with said company stating that there is no provision within FMVSS 108 to legally replace halogens with LED bulbs for vehicles intended for public roads.

The safety standard in question also makes it impossible to retrofit xenons where halogens used to be, even if the HID bulbs or kits feature DOT-approved labels on them. For off-road use, on the other hand, that would be totally fine.

Although xenon conversion kits used to be the norm in the 2000s and early 2010s, light-emitting diodes are all the range in the aftermarket automotive lighting industry. Keep in mind that xenon kits without projectors are not only illegal but also hazardous to other road participants.

Many kits feature plug-and-play designs, and they're not terribly expensive. The same can be said about replacement halogen bulbs. Replacement halogen headlamps won't cost an arm and a leg either, especially if you need something round à la the Jeep Wrangler's 7.0-inch units. There are plenty of aftermarket solutions for the Wrangler, including LED headlamps with laser modules.

OFFROAD GAMERS, for example, sell such lamps as a pair at $179.99 on Amazon. Similar to BMW and Audi, lasers assist the LED high beams. Over in China, you'll find projector-style LED units with laser modules. Considering that said technology still is relatively new, you are better off with LEDs than laser-assisted systems from companies with little name recognition.

ADVANTAGES

• HID and LED kits are reasonably priced
• HID and LED kits are reasonably easy to install
• High-quality xenon bulbs and light-emitting diodes can make a world of difference over the OEM halogen lights

DISADVANTAGES

• Upgrading from the stock halogen lights to HIDs or LEDs and from HIDs to LEDs is most certainly illegal
• Potentially dangerous for the recipient vehicle's driver, their vehicle, and oncoming traffic if installed incorrectly
• The recipient vehicle's electrical system can also be affected by aftermarket kits that feature low-quality parts