Xenon headlamps: a different type of headlamp bulb

Xenon headlamps were introduced in 1991 as an option on the BMW 7-series and are essentially the same technology as your common-or-garden street lamp – they produce light using an “arc” rather than a “filament” as in your normal household bulb.

But whereas streetlamps are filled with a gas called Argon, Xenon bulbs are filled with a gas called, er, Xenon. Might seem a bit geeky but Xenon allows the bulbs to produce light instantly, but an Argon bulb takes a minute or so to achieve maximum brightness. You might have seen this outside your house at dusk.

This would be embarrassing in a tunnel on the M25 when you turned your headlights on and nothing happened until after you’d crashed.

In a nutshell, Xenon lights are brighter than normal headlamps. On dipped beam you’ll see further and more clearly than with normal bulbs, and as he price continues to drop they’re a technology that’s really worth investing in.