Headlights: Guides by Make & Model

Bulb types, matrix LED considerations and fitment differ a lot between cars — find your specific model below.

Getting the Right Unit Matters More Than It Looks

A headlight that looks similar can use completely different bulbs, wiring, or coding requirements underneath. Pick your make and model below for the specifics.

Four Bulb Technologies, and Why They're Not Interchangeable

Halogen remains the most common type — a tungsten filament in a gas-filled bulb, cheap to replace and simple to swap yourself in most cars. HID (xenon) units use an electric arc through xenon gas rather than a filament, producing a brighter, whiter light and lasting considerably longer, but requiring a ballast to step up the voltage — a failing ballast produces symptoms (flickering, dimming) that are easy to mistake for a simple bulb fault. LED headlights use light-emitting diodes directly, either as a retrofit bulb or, more commonly on modern cars, as an integrated unit designed around LED from the factory — genuinely long-lived and efficient, though a full LED unit generally can't be "bulb-swapped" the way halogen or HID can if a segment fails. Matrix LED (adaptive) systems go further still, using an array of individually-controlled LED segments that can selectively dim sections of the beam to avoid dazzling oncoming traffic while keeping the rest of the road fully lit — genuinely clever, but also genuinely complex, with software coding tied to the specific car that makes generic aftermarket replacements risky.

UK Law on Headlight Aim and Modifications

Headlight aim is checked as part of every MOT, and a misaligned beam — whether from a knock, sagging suspension, or an incorrectly fitted replacement — is a common and avoidable failure point. Fitting HID or LED bulbs into a headlight unit that was designed for halogen is illegal for road use in the UK unless the whole unit was originally designed to accept them, since halogen reflector and lens designs aren't engineered to correctly focus the different light pattern these technologies produce — the result is typically a poorly focused beam that dazzles oncoming drivers, which is exactly the outcome the aim regulations exist to prevent. If your car came with HID or matrix LED from the factory, replacement bulbs or units need to match that same technology, not just fit physically.

Common Faults, DIY Difficulty & Aftermarket Advice

Dim or yellowing light output (often just an ageing halogen bulb, though a failing ballast on HID/xenon systems causes the same symptom), flickering (usually a poor electrical connection or failing ballast rather than the bulb itself), condensation inside the lens (a failed seal, worth addressing before it affects the bulb or wiring), and one side noticeably dimmer or misaligned (check headlight aim before assuming a bulb fault — a knock from a kerb can shift the unit) are all worth checking.

Bulb replacement varies significantly by design — some models offer straightforward access from the engine bay, while others require partial bumper or headlight unit removal to reach the bulb holder. Full headlight unit replacement typically involves removing the front bumper cover and is a moderate DIY job for an experienced home mechanic. Expect 15-45 minutes for a bulb swap depending on access, or 1-2 hours for a full unit replacement.

For standard halogen units, reputable aftermarket brands are a reliable, cost-effective alternative to OEM parts. For matrix LED or adaptive headlight systems, sticking with OEM or a directly compatible aftermarket equivalent is worth the extra cost, since coding and calibration issues are far more common with generic aftermarket units on these more complex systems.