Why You Should Upgrade Old Halogen Headlights to an LED or HID Kit

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Upgrade Old Halogen Headlights

Still running those dim Halogen headlights?

I still fondly remember the time when high-intensity discharge headlights, or HIDs, became standard on early modern cars. Better safety and enhanced visibility are the primary reasons why you should upgrade old halogen headlights to an LED or HID kit, but HIDs were way too expensive (back then) for my student budget.

Hi there! It’s me, Vince.

So, what’s a car-loving twenty-something young adult got to do? I tried searching for the next best thing: white halogen bulbs. You know, the type with blue-tinted bulbs that will mimic the look of a true HID light kit.

In all honesty, the white halogen bulbs were fine. They were cheap (cheaper than HID but more expensive than ordinary halogen bulbs), easy to install, and lasted quite a while. However, the whiter light was a curse on wet asphalt roads. I learned this the hard way by damaging my precious 17-inch rims on a water-filled pothole while driving fast on a rainy evening.

damaged rim
damaged rims are no fun….

I understand the reason why you are looking to upgrade the old halogen headlights in your car to a brighter and better set of HID or LED lights. It’s common sense! While HID and LED are two different systems, both of them will give your vehicle a wider and brighter spectrum of light to enhance safety and visibility on any type of weather and in any type of season.

However, it’s not that simple. Choosing between HID and LED is difficult enough since LED technology has grown exponentially over the years. I think it’s better to begin by learning the differences between halogen, HID, and LED along with the pros and cons of all three.

Best HID Headlight Kits Logo

What’s the difference between halogen, HID, and LED headlights?


Halogen bulbs consist of argon and nitrogen gasses that are electrically charged courtesy of a tungsten filament. The filament can heat up to 2,500 degrees Celsius as it ignites the gasses to produce light. Halogen bulbs can last from 450 to 1,000 hours on average before replacement.

halogen light
halogen lights are often yellowish and not as bright!


  • Low cost and cheaper to buy
  • Easy to install
  • Universal fit
  • Dimmable light beam


  • Produces excessive heat
  • Consumes a lot of power
  • Sensitive construction

HID or High-Intensity Discharge

HID is also known as Xenon bulbs. The first HID headlight was fitted to the production model of the 1991 BMW 7-Series. The bulb is a gas-filled tube with electrodes on both ends.

High voltage current passing between opposite electrodes will stimulate the Xenon gas and halide salts to produce the bright and dazzling light that HIDs are known for.


HID light from motorcycle
Img creds: motorbikeadventures – those HIDs look awesome on a streetbike!


  • Brighter beam of light
  • Lasts longer than halogen bulbs
  • Wider and farther-reaching light
  • Consumes less power


  • More expensive than halogen
  • Requires ballast and starter kit to be installed in the engine bay
  • Produces strong glare that may blind oncoming traffic
  • Cheaper kits have a flicker and suck

LED Headlights

LED headlights are standard equipment on expensive American and European luxury cars. It generates light courtesy of a light-emitting diode or LED that illuminates via the principle of electro-luminescence. Photon is released for thousands of times per second courtesy of negative electrons that run against the holes in a semiconductor.

led lights red yellow blue
LEDs… yeah close to what is in the headlight 🙂


  • Small and compact size
  • Brighter than halogen bulbs
  • Consumes less power


  • Higher cost
  • LED bulbs can heat up surrounding parts
  • Requires sufficient cooling
  • Higher Kelvin ratings of LED bulbs make them inferior in bad weather
  • Lots of cheap kits on the marke

So which one should I use?

before and after HID change RZR
Here’s a good side-by-side of Halogens vs HID. Sweet RZR there Bob – Check out his work on Flickr 🙂

Summing it all up, nothing beats the simplicity of an ordinary halogen bulb. HID bulbs are brighter and will theoretically last longer than halogen. However, it will require a bit of knowledge to correctly install and will cost more than halogen bulbs. LED bulbs are great if your car came fitted standard with LED lighting. If not, major modifications to the headlight assembly might be required to fit the LED bulbs properly. Also, modifying headlight components are illegal in some parts of the world.

Is it illegal to install HID headlights?

It depends on the laws in your state or locale. According to the rules of the US Federal Motor Vehicle Safety Standards or FMVSS 108, the replacement headlight capsules must match the dimensions and electrical specifications of the factory equipment. But there’s a slight problem. You know that HID systems require a ballast, right? While the HID bulbs may match the exact size and specs of the halogen bulb, installing the two will require a different process altogether.

If your came standard with HID headlights from the factory with bluish-white light, you’re in the clear. They are perfectly legal. If not, auto manufacturers would not equip your vehicle with HID in the first place.

But when it comes to the legality of installing HID headlights, you’re completely on your own. Again, this will all depend on state laws. You can get pulled over for simply fitting blue-coated halogen bulbs that look similar to the bluish-white beam of HID bulbs and I’ve heard many horror stories regarding this matter.

What about HID kits with a DOT logo? Forget it. The logo doesn’t mean anything rather than the company that manufactured the kit has self-certified the product to meet federal requirements. And while the HID kit may conform to DOT standards, the idea of a DOT-approved headlight simply doesn’t exist.

Which is better: HID or LED headlights?

From a personal perspective, I simply prefer HID because they are proven to work on any vehicle, even on vintage or older cars. It is easy to find an HID conversion kit for any type of vehicle. The bulb itself can be fitted with no further modifications to the stock headlight housing. You only need a little bit of wiring knowledge to successfully complete the installation. However, the legality of changing halogen to HID bulbs will depend on the laws where you live.

On the other hand, I personally like the energy-efficient nature of LED headlights. The problem is compatibility. Most LED lighting systems are integrated and designed to work with specifically-designed headlight housings that can command a higher price tag. On some cases, it is possible to retrofit LED bulbs to an older car, but certain modifications will need to be performed in order for the system to work properly.

LED headlights will require sufficient cooling to prevent heat build-up on the surrounding components. The LED bulbs themselves are not producing heat, but the components that produce the repeated flashes of photon beam will produce tremendous amounts of heat. The heat may be high enough to damage the headlight housing and the LED bulbs in general.

If your car is fitted with stock halogen bulbs, the next worthy upgrade would be to install HID. But if you can buy a brand new after market headlight housing for your vehicle that is designed to accommodate LED lighting, you can give it a shot as long as you don’t mind the added cost. Also make sure you are not breaking the law in the process.

Make sure you check out our two guides for more info:

What is the brightest headlight on the market today?

The distinction of the brightest headlight belongs to the laser headlight. Depending on the specifications, laser lights can produce 1,000 times brighter light than comparable LED headlights. Despite this glaring intensity, laser lights only consume half as much power than HID and LED bulbs.

Laser lights consist of three or more blue lasers that fire the laser beam through small mirrors. The mirrors will point the energy to a lens or phosphor plate. The phosphor will generate a white light as it interacts with the laser light. The light is beamed to a reflector that points on the road ahead. It all sounds complicated and unsafe especially if you consider the presence of powerful and piercing lasers on the front of your car.

Laser light is also more far reaching than HID or halogen bulbs. LED lights can only produce around 100 lumens per watt while laser lights can generate 170 lumens per watt on average. Laser lights are the brightest headlights in the market today, but they are also the most expensive to buy at the moment. Examples of production vehicles fitted with laser headlights are the BMW i8 and the Audi R8 LMX.

Are HID headlights legal in the UK?

I’m afraid I don’t have a direct answer to that. But if you consult the Guidance to Aftermarket HID Headlamps published by the UK Department for Transport, it clearly states that it is not legal to sell or use after-market HID lighting kits for the purpose of converting conventional halogen headlamps to HID Xenon.

If you still insist in converting halogen to HID in your vehicle, you must purchase a new set of HID headlamps. The reasoning behind this is that the stock lens and reflector are only designed to work with halogen bulbs. Installing a more powerful and brighter HID bulb in the same reflector will negatively affect the beam pattern and blind oncoming traffic.

But if your car came fitted with HID headlamps from the factory, you don’t need to worry. Your car is legal to drive in the UK.

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