Why Do Headlights Turn Yellow and How to Prevent It?
Yellowed headlights have a terrible effect on any car’s appearance. On top of that, your visibility decreases at night or during adverse weather conditions, which is a safety issue.
The question is: Why do headlights turn yellow?
It’s not a problem that only the owners of older vehicles have to deal with. I see many modern cars suffer from it because they come from the factory, not with glass but plastic headlights.
The headlight material isn’t the only reason. So, let’s get to the root of the problem, and then we’ll talk about what measures you can take to prevent it.
In case your headlights are already yellow, see how to clean them at home.
What Makes Your Car’s Headlights Turning Yellow?
From UV rays and oxidation to road debris and scratches, there are many reasons that cause headlights not to be as bright and crystal clear as they once were. Let me dive a bit deeper.
Plastic Lenses
As I mentioned, most modern car headlights are made from polycarbonate plastic. While this material is durable and resistant to impact, it’s not immune to environmental factors.
Over time, UV rays break down the outermost layer of the plastic, causing headlight oxidation. You know how the sun damages our skin – similarly, it degrades your headlights’ clarity and color.
Wear and Tear
Road salt, chemicals, and even your car wash soap also contribute to the discoloration. These elements strip away the clear coating on your headlights, leaving them vulnerable to oxidation.
The physical abrasion from sand, dust, and debris kicked up by other vehicles can scratch the surface of your headlights and make them appear foggy after a while.
Light Bulbs
While most older vehicles have glass lenses, they’re fitted with less efficient light bulbs that generate significantly more heat. This factor accelerates aging and leads to foggy yellow headlamps that are dangerously dim.
Alright, moving on to the more important part: What stops headlights from yellowing?
How to Prevent Headlights from Yellowing?
As an owner of two 20 year-old BMWs, I can tell you that keeping your car’s headlights shining bright isn’t as hard. The Bimmers are modified cars I enjoy on weekends, but I apply the same methods to our daily driven Tesla Model 3.
Be Smart When Parking Your Vehicle
You see, the sun is your headlights’ biggest enemy. Obviously, the best you can do to protect them is to keep your car in a garage. But during your daily commutes or road trips, parking in direct sunlight is a surefire way to speed up the yellowing process.
Every time I take any of my cars out, I make it a point to look for a shaded or covered spot. Avoiding direct exposure to UV rays is a simple yet effective strategy to keep your headlights from turning yellow.
Be smart when parking. It will have a major impact on the long-term health of your car’s headlamps!
Clean Your Headlights Regularly
Being your eyes on the road, the headlights deserve regular treatment. If dirt, salt, insects, etc., stick on a lens for a while, these contribute to the clear coat and surface degradation.
Don’t use harsh chemicals when washing your vehicle. These damage the paint, trim, and headlights.
What I do first is give each headlight a good rinse. Then, I wash the lenses using gentle automotive soap and soft cloth. At the end, I dry them with microfiber or a paper towel to make sure there are no water spots.
Polish and Wax the Headlights
Next, let’s talk about the dynamic duo favorite to car DIY’ers – headlight polish and wax. While some folks think these two serve the same purpose, that’s not the case.
Polishing your headlights is a process you can do periodically to buff out minor imperfections and restore the smooth surface. I’m talking about those fine scratches that make your headlights vulnerable to yellowing.
Waxing the lights comes after the polishing. By applying a thin layer, you create a barrier that blocks the UV rays and fights headlight oxidation.
Polishing and waxing the car headlights regularly is a very effective maintenance routine that can significantly extend their crystal clear look.
Apply Headlight Protection Film
For those looking for a more “set-it-and-forget-it” approach, applying a headlight protection tint film is the way to go. As opposed to regular polishing and waxing, this is a more permanent solution, which is why I’ve been using it on all my cars lately.
The film works not only as UV protection but also as a shield from sand and small rocks. The high-quality options are even self-healing and will last for years.
My favorite part is that they come in different levels of darkness, an effective way to customize the exterior while fighting headlight oxidation.
Last Thoughts
The bottom line is that it doesn’t matter if your car has glass or plastic headlights.
To keep them looking and working like new, you have to do regular maintenance or opt-in for permanent solutions.
After all, even if you’re not into car modding, clear headlamps aren’t just about appearance – they’re also important for your safety.
