Drive

Drivers ‘see the light’ with HID bulbs

If the road has seemed a little brighter these days, it’s not your eyes playing tricks on you. Many automakers, especially the premium brands, use high-intensity discharge headlights, or HID, which produce a bright white light.

“The light intensity is closer to a natural light,” says Hayato Mori, manager of product planning at Honda Canada. “HIDs put out light that is much more intense than a halogen headlight. They also use less electricity.”

A conventional halogen headlight is an incandescent bulb. It uses a filament that heats up to create light, while the halogen gas inside the bulb increases the light’s intensity and helps to lengthen the filament’s lifespan.

HID headlights don’t use filaments. Instead, they contain a gas, most commonly xenon, which lights up when electricity flows into a diode in the headlight. This is similar to the way a fluorescent light works, but the xenon gas lights up much faster. Even so, HID headlights still need to warm up, and if your car has them, you’ll notice that it takes a few seconds before they reach their full brightness.

On many cars with HID headlights, only the low-beam lights use the xenon bulbs; the high-beam lights are halogen bulbs. Some use “bi-xenon,” meaning that both the low and high beams are HID, but there aren’t two bulbs. Instead, there’s a single HID bulb with a shutter in front of it. When the driver has the low-beam headlights on, the shutter flips down, reducing the amount of light shining out.

“When you want high-beam, the shutter flips up,” Mori says. “It’s a more expensive setup, because it requires switches to flip the shutter up and down, but you achieve low and high beams with one bulb.”

A third headlight type, light-emitting diode or LED, is available on a few premium models and will be coming to Acura and possibly Honda, Mori says. Many cars already use them as taillights.

“Instead of a gas, the diodes react to electricity. They don’t consume as much electricity. The lamps don’t get hot, but the device that powers them does, and the difficulty is in keeping that cool. It requires fans and cooling mechanisms, and it’s difficult to make, so that’s why you don’t see a lot of these right now. As more manufacturers use it and the technology gets better, it will bring the cost down, and you’ll see it on more conventional cars in the future.”

Keep it clean

  • Dirt and grease on halogen or HID bulbs can affect the performance, and can even cause halogen bulbs to break. Always use gloves when changing them to avoid touching the glass bulb.

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