Man driving car on illuminated street at night
Image: Car and Driver

Modern Headlights Guide: Illuminating How Your Vehicle’s Headlights Work

Although cars already had headlights from the beginning, lighting is one of the fields in which most progress has been made, especially in the last 15 years. This is how the technology of light in the car has evolved.

Almost 150 years have passed in which lighting has evolved a great deal. More specifically, two elements have progressed significantly: the headlamps and the light source. For the evolution of the first, the appearance of computers and design programs has been decisive.

Computers have allowed a much more accurate study of geometries and the headlight reflectors’ arrangement. Computers have also allowed the development of materials and molding machines that enable these increasingly complex shapes to be mass-produced.

As for the light source, there have been two enormous turning points in its evolution. The first was the use of electricity and the second was the development of high-brightness LEDs. So today, we’ll shed some light on how your vehicle’s headlights work, from the first oil lanterns to the current lasers and LEDs.

Old photo of a 1908 Ford Model T

Via Cars Guide

The Pioneers

The advancement of technology has allowed the lighting in cars to adapt to the needs of drivers. Current headlights have designs that favor greater range and visibility during the journey and illuminate specific points without damaging the driver’s eyesight. However, for vehicular lights to become what we know them today, they had to go through several processes.

It all started at the end of the late 19th century. Back then, cars mounted headlights that had an internal lantern or made use of the combustion of oil or acetylene gas to give the driver visibility of the road at night. However, effectively lighting the route was a complex task for those large lamps.

For this reason, the first incandescent light bulbs appeared at the beginning of the 20th century with the rise of electrification. These bulbs generated light by passing an electric current through a metallic filament that, when reaching high temperatures, emitted radiation perceptible to the human eye.

This form of lighting lasted several years until halogen headlamps appeared in the 1960s. This new headlight technology positioned itself on the market thanks to its range of up to 100 meters. Halogen light bulbs work under the same principle since they are made of a glass bulb that resists high temperatures and a metal filament.

Modern VW cars with halogen, xenon, and LED headlights

Via Autopista

Modern Headlights

The development of new lights continued, and in the 1990s, xenon headlights (Xe) were released. This new technology produced bluish light through a quartz bulb with two tungsten electrodes inside that led to a chamber filled with gas (Xe) and salts of sodium (Na) and mercury (Hg).

Shortly after, in the early 2000s, LED (Light Emitting Diode) lights began to be used in automobiles. They were adapted for automotive lighting due to their small size, long-range, superior duration, and low energy consumption. These characteristics have led it to be mandatory for some vehicles in Europe.

OLEDs (Organic Light Emitting Diode) were introduced in 2016 as a signaling strategy to warn motorists about the decisions made by other drivers, such as turning or braking.

Automakers like Audi and BMW have implemented technology based on laser lights. This new type of headlights offer a range of up to 600 meters, 30 percent more energy savings than LED, and longer life.

Likewise, Mazda has recently developed intelligent automobile lighting mechanisms that help increase safety. For example, Mercedes Benz introduced in 2018 its Digital Light technology. The lights can project from real-time guidance and navigation information, such as a HUD over the road, as well as details of road conditions, weather, and traffic warning symbols.

Hyundai Creta with daytime running lights

Via Kelley Blue Book

Types of Headlights Most Commonly Found in New Vehicles (5 Years or So)

LED. Compared to its predecessor, the light bulb, and its direct competitor, the xenon headlamp, the “Light Emitting Diode” (LED) has several advantages that both you, as a driver, and other road users will benefit from.

First, they are much more durable, with a useful life of ten thousand hours of operation. Second, they consume less electricity, thanks to their high efficiency, offering the same light output as conventional bulbs. Especially the oncoming traffic will thank you for the setup. Third, light distribution between various sources makes LED headlights glare much less. Even high beams will hardly bother road users.

LED headlights have become standard across the new vehicle range, and they are both bright/effective, and affordable. Pairs of 9005 LED bulbs range from $29 to $70 from SuncentAuto (online auto parts store), for example.

BMW M4 with laser headlights

Via Evo UK

Headlights In Modern Luxury Cars

Many modern high-end cars today are equipped with the latest technology in headlights. Of course, we are talking about laser headlights.

Introduced in 2014 by Audi, BMW laser headlights emit light with a brightness four times higher than a conventional LED. The lighting range is about 600 meters, compared to halogen lamps, which have a range of about 100 meters. In addition, laser lights don’t emit heat and propagate through special lenses that project the light almost in a straight line.

This light projection, together with a system of cameras and sensors, makes the vehicle adapt the light beam to driving and road conditions without relying on the driver.

Close up of HID headlight

Via Car and Driver

Headlight Types on Older Vehicles (5-15 Years)

Xenon. This type of headlight is also known as HID, an acronym that comes from the concept of high-intensity discharge. HID xenon lamps do not have a filament. Instead, the light is created by an electrical discharge between two electrodes in a small, airtight quartz capsule filled with xenon gas, mercury, and metal halide salts.

This improves durability on the road, as vibrations can cause damage to the filaments of lighting technologies. In addition, xenon headlights have a color temperature of 4000K-6000K, a bright blue-white light similar to natural daylight. On the other hand, halogen headlights have a color temperature of 3200-5000K, which is a warmer, yellowish-white light.

The light output increase of 35-watt HID xenon lamps is approximately 80% more light than a 55-watt halogen bulb. As a result, the HID Xenon system also consumes less power from your vehicle’s electrical system.

White Lotus Esprit with halogen pop up headlights

Via Evo UK

Headlight Types on Legacy/Classic Vehicles (15+)

Halogen. These are the most common headlights in legacy and classic vehicles. These lights work similarly to the light bulbs in your house. Light travels through a thin wire filament, and the bulb is filled with halogen gas to make it burn brightly. More expensive halogen bulbs will shine brighter while emitting a whiter colored light, which helps to improve visibility.

This headlight is very popular because it has a light power three times higher than halogen lights. They also allow a greater range and a clearer vision for the driver, in addition to their useful life, which can reach 2,500 hours.

Contrary to what many of us might think, likely, headlight technology in cars doesn’t need to evolve any further. It will no longer be the human eye that will have to see where to go but an electronic brain that will not need to illuminate objects. It will be enough to detect them with any other technology.