LED vs HID Headlights: Pros/Cons
When it comes to car headlights, LED and HID are the two names that stand out and continue to gain popularity over the now fast aging halogen technology.
If you are like most car owners and drivers, the words LED and HID might seem confusing, since they both describe modern headlights, which are both very similar to one another.
These two headlight technologies might seem similar, but they are very different. They also each have their advantages and disadvantages.
The following side by side comparison will take a closer look at these similarities and differences.
LED is an acronym for Light Emitting Diode. It is a technology which produces light by exciting a semiconductor and forcing it to release light particles.
This technology has been around for many decades, but it was restricted to green, blue, and mostly red-colored LEDs. It was in the 1990s that white LEDs got developed and their use began to spread.
LEDs are popular because of their energy efficiency and flexibility of design. They are also cool to the touch and brighter than halogen bulbs.
Although HID or Xenon lamps are brighter than LED bulbs, both produce bright white beams that are typical of modern cars.
For an aftermarket LED installation, you can either buy a drop-in LED replacement kit or an entire headlight kit, which is usually more expensive. These LED replacement kits are more popular.
How LEDs Work
The functioning principle of the light emitting diode is that of electroluminescence. This happens when photons, which are also known as light particles escape as a result of electron movement through a semiconductor.
A LED is a kind of diode, which is 2 semiconductors that are attached together. One side must always be positively charged, while the other must always be negatively charged.
When an electric charge gets applied to this semiconductor junction on both poles, electrons tend to move in one direction only. This leads to the diodes functioning as controllers of electricity flow direction.
With LEDs though, electrons from the current recombine with positively charged atoms through the p-n junction (Positive-Negative junction). But, before recombining, these electrons release their photons, which are the light particles that create light.
This release of light particles is known as electroluminescence and the coating of the p-n junction with the right filter materials will produce any desired color of light.
- Energy efficient. LED bulbs need very little electric current to work. They also don't need the initial energy surge that HID bulbs need to start up. They produce a near equally bright light as HID bulbs, but with less power. In fact, LEDs beat Xenon HID bulbs hands down when it comes to overall energy efficiency.
- Dimmable. Given their unique semiconductor nature, LED bulbs can get dimmed. By reducing the flow of electric current to the p-n junctions, the rate of light emission gets controlled. The decision to dim the light and the type of dimming depends on the car manufacturer though and on what they want to do.
- Flexible. Single LED lights are small, so you need to connect an array of these small LEDs to create a full LED bulb. This opens opportunities for creative LED design where different light forms or stylish lighting gets created.
- No glares. Unlike Xenon lamps, LEDs do not create strong glares that blind the drivers of oncoming vehicles.
- Durable. LED lights can last longer than HID bulbs. They are usually rated at over 5,000 hours, with some manufacturers rating theirs at over 25,000 hours.
- Installation requires cooling. The LED lights themselves stay cool but the surrounding components often heat up when there is an LED array. To counter this problem, LED headlights are often fitted with a cooling fan or heat sink.
- Expensive. The upfront cost of LED headlights is higher than that of HID lights, but since there'll be hardly any bulb changes, LEDs provide long-term cost savings.
HID stands for High-Intensity Discharge lamp and is a technology that produces light by passing current between 2 electrodes that are sealed inside a bulb with an ionized gas.
There are different variations of HID bulbs, including those which use Mercury, Sodium, and Metal Halide, but when it comes to car headlights, Xenon is the most popular choice. HID bulbs are also named for the gas they contain.
Xenon HID headlights produce the brightest and whitest light beams that get used in cars today and they have slowly and almost surely, replaced halogen lights in most cars.
They are more than twice brighter than halogen lights but only slightly brighter than LEDs. HID bulbs are also more energy-efficient than halogen bulbs but they are less energy-efficient than LED lights.
Although LEDs have a longer lifespan than HIDs, they both cost roughly the same, with LED headlights being costlier upfront but HID headlights requiring more maintenance in the long run.
How HIDs Work
High-intensity discharge bulbs work in a similar fashion to neon lights. Electric current passes
through a gas-filled tube with electrodes at both ends of it, and the high voltage of this current ionizes the gas and creates a glow.
There is no filament here and the heating up of the Xenon gas needs lots of energy. It is necessary to keep exciting this Xenon gas with high voltages over 20 kV until the tube reaches its working temperature.
Once it reaches this temperature, the metallic salts also contained inside the bulb melt and vaporize as well. This is when resistance reduces, more current flows between the 2 electrodes, and the HID bulb reaches its maximum brightness.
- Brightest and whitest light. Xenon HID headlights produce the most intense, whitest, and brightest lights for cars. The lights are so bright that they actually produce glares which are a problem for oncoming vehicles.
- Farther reach. In addition to its brightness, the light from HID headlamps is also farther reaching than LED lights. This makes HID bulbs ideal for fog lights and other applications.
- Energy efficient. Although they need lots of energy at first, HID lamps usually cut down on energy consumption after starting up and so produce very bright light with little energy. This makes them more efficient than halogen bulbs, although they are slightly less efficient than LEDs.
- Cheaper than LEDs. HID bulbs are cheaper than LED bulbs, but this gap is closing and LEDs are getting cheaper every day.
- Fewer color options than LED. The technology behind HID bulbs makes it difficult to produce differently colored lights like is possible with LEDs.
- Strong blinding glare. HID bulbs are very bright and this helps for improved visibility, but their intense beams create strong glares which are blinding to oncoming motorists. LEDs do produce such glares as well, but they are not as intense and blinding.
- Warm up time. Another disadvantage of HID bulbs is that they need some time to heat up before reaching their ideal brightness. This delay can last for up to 30 seconds depending on the exact bulb, whereby you can switch on LEDs almost instantaneously.
Making the Right Choice
HID and LED bulbs each have their different advantages and disadvantages. So, for you to make the best buying decision, you'll have to consider their features. Following is a list of these features.
Takes up to 30 seconds
Above 2,000 Lumens
Around 3,000 Lumens
Over 5,000 hours
2,000 - 5,000 hours
Shockproof & vibration resistant
LED and HID headlights are both based on 2 different but impressive technologies. They are both equally impressive and modern technologies, and you'll be well served to choose any of them.
Depending on your needs though, HID lamps will serve you better if you need the most illumination possible, especially if you are speeding.
If however, you just need a great lighting solution, which is affordable, stylish, and has a future, then you'll be best served with an LED headlight.