Do LED & Xenon HID Headlights Fade Over Time?

• Do LED headlight bulbs fade?
• Why do LED headlights lose brightness?
• Extending the lifespan of LED bulbs
• Do Xenon HID headlight bulbs fade?
• Why do Xenon HID headlights lose brightness?
• Extending the lifespan of Xenon HID bulbs
• Hazy or dirty headlight assemblies
• Tips & Tricks
• FAQ

A common question we frequently get and a popular topic in automotive communities is Do LEDs and/or Xenon HIDs lose brightness over time?

The short answer is yes, they do. Both LED and Xenon HIDs will lose up to 70% of their original light output gradually over time.

Halogen bulbs, on the other hand, hardly fade over time. They simply stop working when they’ve run their course. They, however, only last a fraction of LEDs and HIDs lifespan.

For LED's and HID's, the degradation (dimming) of the light intensity is very slow and gradual, it’s like watching hair grow. For this reason, it can be tricky to know when it’s time to replace your LED or Xenon HID headlight and fog lights bulbs.

As a general rule of thumb, the higher the quality of the bulbs, the longer they will last, and the slower they will fade like our LED Headlights and Xenon HID kits that last up to 45,000 hours and 15,000 hours respectively backed by our lifetime warranty.

In this article, we’ll explore why LEDs and HIDs each fade over time and at what rate each should typically fade. We’ll discuss how to extend their maximum light output for as long as possible and conclude with some tips and tricks as well as some frequently asked questions.

Do LED headlights and fog lights fade?

Yes, LED headlights and fog light bulbs fade, however, very slowly. Various scientific studies have shown that high-quality LEDs last up 50,000 hours before they are no longer suited for their intended purpose.

In the context of a vehicle, this means that the LED bulbs will no longer produce enough light to illuminate the road ahead in a safe manner. They will still work and produce a faint light, but it won’t be able to perform its job.

Why do LED headlights and fog light bulbs lose brightness?

In simple terms, LED bulbs fade over time not because they are broken or defective but primarily because of heat and in part due to excessive shaking or vibrating.

LED chips are composed of many, many microscopic components that create the light. Excessive heat and vibrations cause threading dislocations, which essentially means the breaking of said components. As more and more components break due to heat, less and less light is produced.

The more heat and mechanical stress (vibrations) an LED chip is exposed to, the quicker the LED bulb will fade as threading dislocations accelerate.

Extending the lifespan of LED headlights and fog light bulbs

Now that we understand why LED bulbs fade over time, we can understand how to maximize their light output. As explained in the previous section, heat is the number one enemy of LED chips and bulbs. As such, keeping them cool should be the top priority.

Although most LED headlight bulbs come with cooling fans, not all of them work well. As such, a fantastic LED with great light output but a bad fan will not last you long, which defeats a big part of LEDs main selling point - a long lifespan.

What you’ll want to look for is LED bulbs with high powered, super cool fans such as the one found on our LED headlight bulbs. Spinning at 12,000 RPM and secured into our aluminum casing, our micro turbofan is powerful and quiet, keeping your bulbs cool and shining bright for a long time.

Lastly, you’ll want to make sure to find a bulb that fits nicely inside your housing. A loose bulb will be subjected more to vibrations, which can precipitate threading dislocations of your LED bulbs and in turn fade quicker than expected.

Do Xenon HID headlights and fog lights fade?

Yes, Xenon HID headlights and fog light bulbs also fade very slowly over time. Studies have estimated that high-quality Xenon HIDs last up 15,000 hours before they are no longer suited for their intended purpose.

In the context of vehicles, this means that the HID bulbs will no longer produce enough light to illuminate the road ahead in a safe manner. They will still work and produce a faint light, but it won’t be able to perform its job.

Common characteristics of faded Xenon HID bulbs are less intense light and/or a shift towards blue or purple-colored light.

Why do Xenon HID headlights and fog light bulbs lose brightness?

In simple terms, Xenon HID bulbs fade over time due to the gradual loss of the chemicals inside the bulb that create the light and the darkening of the inner tube where the chemicals react to create the light.

Scientifically, automotive HID bulbs work by passing electricity through xenon gas in a high-pressure environment which produces light from an electric arc.

As the bulbs are used, the xenon gas is depleted. Xenon depletion leads to rising pressure inside the arc tube, which in turn requires more power to sustain the light (arc discharge). Over time, the heat and chemicals stain the arc tube, which further dampens the light output.

Near the end of the HID bulbs’ life, they will begin to go on and off at an increasing rate, which is commonly referred to as cycling. Eventually, the power required to maintain the light will exceed the power supplied by the ballast indicating the end of the bulb’s life.

Extending the lifespan of Xenon HID headlights and fog light bulbs

Contrary to common belief, the lifespan of an HIDs is more affected by the frequency and the timing of on/off cycles than their total time on.

Turning your HID bulbs on and off in an attempt to preserve them longer will do the opposite and shorten their lifespan.

HID bulbs are worn down the most when they are turned on while they are still hot. So, if your lights have been on for a while and you shut them off, let them cool off for at least 1 to 5 minutes before turning them back on. Ideally, you let them cool off for 20 minutes.

Lastly, you want to make sure the other components of your Xenon HID kits are in good shape. A bad ballast or ignitor can shorten the lifespan of your bulbs significantly.

Hazy or dirty headlight assemblies

Sometimes, the issue does not lie with your bulbs but rather your headlight assemblies. Moisture, sunlight, and dirt can cause your headlights to become hazy and/or dirty over time.

Dirty headlights inhibit light from exiting the assembly, which can mislead some drivers into thinking that their bulbs have run their course when in fact they have not.

As we explain in our guide to making your headlights brighter, cleaning your assemblies with a headlight restoration kit can make a huge difference in your light output, even if you have halogen bulbs.

Tips & Tricks

If you’re not the type of person to pay close attention to detail, you might not notice that your lights are starting to fade or change colors, or you might forget when you installed the lights and for how long they’ve been running.

Not to worry, you’re not alone and as mentioned, the change is so gradual it’s difficult to catch. As such, we recommend taking a nice and clear picture of your lights right when you first install them at night. You can then compare the light output and any possible fading later on to the original light output!

Frequently Asked Questions (FAQ)

When should I change my LED headlights?

LED headlights and fog light bulbs should be changed when the light output has lost over 50% of its original brightness or when they completely stop working.

When should I change my Xenon HID headlights?

Xenon HID headlights and fog light bulbs should be replaced when the light output has dropped by over 30% of its original brightness or when they completely stop working.