Misting and condensation in custom headlights

Some misting is normal in any headlight, custom or factory. A light mist that clears by itself is fine. Water droplets that form and run down the inside of the lens are condensation, and that isn't. Here's why misting happens, what makes it worse, how to reduce it and what to send us if you're not sure.

Misting or condensation?

As a rule of thumb, misting is fine and condensation isn't.

• Misting: a light haze on the inside of the lens that evaporates back into the headlight by itself.
• Condensation: water droplets that form on the inside of the lens and run down it.

We use BMW's dealer technical documents as our guide. What is and isn't excessive is set out in the guarantee and warranty for your custom headlights.

Why misting happens

Headlights are open units, so the weather and humidity outside affect them.

• When the car or the headlights are running, the inside of the headlight gets much warmer than the colder air outside.
• That heat makes the air circulate inside the headlight.
• When the car or some of its lights switch off, the heat goes and the air stops circulating.
• The warm air can't cool down or escape quickly. Still air next to the cold lens cools, and mist forms on the inside of the lens.
• The mist then evaporates back into the headlight by itself.

It's like breathing on a cold window.

What makes it worse

• Car washes, rain and cold weather, because humidity follows temperature. Misting is always more common in winter.
• Cars that produce more heat, such as V8, V10 and tuned engines.
• Upgrading from low-power, low-heat parts to higher-power ones. For example, changing a 501 (T10) sidelight bulb for BavGruppe Design angel eyes adds a lot of heat at the sidelights.

Misting happens in factory headlights that have never been modified, and BMW's handbook and dealer technical documents refer to it. It can look worse in custom headlights because areas that were chrome are often painted black. Mist that blended into chrome stands out against black.

Reducing misting

• Use silica gel packets. We recommend 10g in summer and 20g in winter.
• Extra breathers help the headlight cool down faster, before mist forms on the lens. We fit these for you, so ask us rather than adding them yourself.

Not sure which you have?

WhatsApp us on 0121 295 1900 with:

• your order number
• your vehicle's make
• its model and engine size
• photos of the headlights at their worst, with the weather at the time, covering 5 days in a row
• how often it happens, and in what conditions

Once we have all of this, we'll tell you what needs doing, if anything.

Common questions

Is misting in custom headlights normal?

Yes. Some misting is expected in any headlight, including factory ones that have never been modified. It can look worse in custom headlights because black paint shows mist that chrome would hide.

What's the difference between misting and condensation?

Misting is a light haze that clears by itself. Condensation is water droplets forming on the inside of the lens and running down it. Misting is fine, condensation isn't.

Will the mist go away on its own?

Yes. Misting evaporates back into the headlight by itself.

Why is misting worse in winter?

Humidity follows temperature. In cold weather the lens is colder, so warm air inside the headlight cools against it and mists more easily.

How can I reduce misting?

Use silica gel packets, 10g in summer and 20g in winter. We can also fit extra breathers so the headlight cools down faster.

Is misting covered by the warranty?

What is and isn't excessive is set out in the guarantee and warranty for your custom headlights. If you're not sure, WhatsApp us the photos and details listed above.

Need us to take a look?

WhatsApp us on 0121 295 1900 with your order number, vehicle details and 5 days of photos, and we'll tell you what needs doing, if anything.