Ever since BMW introduced "halo" headlights to serve as daytime running lights on their 2001 5-series, rings of light encircling round headlamp bulb openings have caught on around the world as THE dramatic way to add visual Wow and stance to a vehicle's front profile. While composite headlamp assemblies became mainstream in the 1980s, it wasn't until the turn of the millennium that automakers began to style multi-faceted projector beam style bulbs within the housings. Because projector bulbs don't need the bulky parabolic reflectors required in earlier composite housings, the extra space stylists gained allowed them more freedom to create futuristic headlamp shapes and use halo rings to accentuate their handsome designs.
Whether you look at the headlamp assemblies of a 2002 Volkswagen Passat or a late model Chevrolet, you'll see stylish round cutouts for headlights, bright lights, turn signals, daytime running lights and more. All of which are highly visible and highly styled to look like lenses that a laser beam might radiate from.
Conventional halo rings most vehicle manufacturers use are illuminated by the same kind of incandescent bulbs found in turn signals or reverse lights. Because each conventional halo may be illuminated inside by only one or two bulbs, bright spots and dark spots develop inside the enclosed ring. Many feel the visual effect of a halo ring that's lit by underpowered bulbs is no more exciting than looking at a parking light that's been left on all night.
A strong upgrade to the underwhelming effect of dimly lit halo rings are Cold Cathode Fluorescent Lighting tubes (CCFLs). Unlike conventional halo lights, CCFL Halos are filled with gas (similar to a neon sign) ensuring the plastic halo shroud emits a solid and even light all the way around the ring. The light is brighter and whiter than incandescent bulbs, and the subtle yet high-tech blue hue allows the halo ring to match the look of projector headlight beams when they're on.
While CCFL halo lights do require an extra inverter component, the plug-n-play design modern kits are built with allows inverters to be connected directly to any vehicle's parking lights quickly and easily. Instead of extra switches and complicated wiring, CCFL lights can be controlled from the factory headlight switch.
Unlike conventional incandescent halo bulbs, CCFL tubes burn cool without creating hotspots and discoloration on their outer plastic ring housings or on headlamp assembly lens covers. When you consider that CCFLs enhance safety by making your vehicle visible to others from further away, use less power, and offer a greater lifespan, their slight price uptick compared to non-CCFL halos is seen as a great value.