Lighting
A brighter bulb in a reflector housing scatters light everywhere except where you need it. Here is what actually works, and what to spend the money on instead.
Almost every week somebody rolls in with a set of LED bulbs they bought online, complaining that the road looks worse than it did on halogen. They are not imagining it. The bulb is genuinely brighter, and the road genuinely is darker where it counts.
The reason is optics, not output. A halogen reflector housing is a mirror shaped around one very specific thing: a glowing filament of a known size, sitting at a known point in space. Every curve in that mirror is calculated to take light from that exact position and throw it at the road in a controlled pattern with a sharp horizontal cut-off.
What goes wrong
Drop in an LED whose emitters sit a few millimetres off from where the filament was, and the reflector no longer has the light source it was designed around. The mirror does what it was always going to do — it throws that light somewhere. Just not at the road.
The result is a lot of light in the trees, a lot of light in the eyes of the driver coming the other way, and a dim, patchy pool in front of your own bumper. You have made the total output higher and the useful output lower.
- Glare up into oncoming traffic, which is why you get flashed
- A washed-out foreground that hides potholes at exactly the wrong distance
- No usable cut-off line, so the beam ends in a vague smear
- Wet roads become worse, not better, because scattered light reflects back
What actually works
There are two honest answers. The cheaper one is a properly engineered LED where the chip geometry deliberately mimics a filament — chips mounted back to back on a thin substrate, positioned to within a fraction of a millimetre of where the filament sat. These exist, they cost real money, and they work in a reflector.
The better one is to stop fighting the housing and retrofit a projector. A projector does not rely on a mirror to shape the beam; it uses a lens and a physical shutter to cut the light off at a hard line. Put an LED behind a projector optic designed for it and you get the sharp cut-off, the wide foreground and the genuinely usable high beam.
Retrofitting means opening the headlight housing, which means baking the sealant, cutting, mounting, aiming and resealing. It is a workshop job, and it is the single most worthwhile lighting upgrade you can make to an older car.
Before you buy anything
Check whether your car has a projector already. Many cars sold here have projector low beams and reflector high beams, and the correct upgrade differs for each. Bring the car in and we will look with you — it takes two minutes and saves a lot of wasted money.
Want this done properly?
Bring the car to Wellawatte and we will look at it with you. No charge for an opinion.
