Headlights
(more commonly known as headlamps) are available in three different
light-producing technologies: tungsten, HID, and LED. The technology
has come a long way and continues to improve.
Halogen technology makes tungsten filaments better producers of light.
Replaceable halogen bulbs were permitted in U.S. headlights in 1983.
Development of U.S. bulbs continue to favor long bulb life and low
power consumption, while European headlights design continue to prioritize
optical precision and maximum output.
HID (high intensity discharge) bulbs cause a high level of glare
to other motorists and, in the past, were made using the toxic heavy
metal mercury. Newer HID bulbs aren’t made with mercury, but
neither are they electrically or physically compatible with headlamps
designed for previous bulb types.
LED (light-emitting diode) bulbs have been undergoing active development
since 2004. Currently, they require large packaging and the strongest
emitter available. LED bulbs are still cost-prohibitive, but they
are meant to soon surpass HID headlights