By the early 1980s, regulations were changed to allow replaceable bulbs in headlights and this allowed the auto manufacturers to style the headlamps as part of the body’s overall design. There are now many companies marketing Hid Xenon or Bi-xenon light conversion kits. Bi-xenon lights are Xenon bulbs that are used for both high and low beam operation. A small electric motor moves a shield in the bulb to redirect the light for the desired beam pattern.

In the past decade, we have taken another giant step forward in headlamps, with High Intensity. Older vehicles that use sealed beam headlamps can be converted to hid lights that use replaceable hid bulbs. There are several manufacturers of these lights and each has lenses that provide a distinctive lighting pattern on the road so be sure to compare them before buying. Newer vehicles already have Hid headlamps with replaceable bulbs, so you don’t have to change the complete assemblies, only the bulbs.

There are many headlight bulbs on the market. There are standards for headlight bulbs, but these typically pertain only to mounting design, connector configuration and the colour temperature of the light the bulb produces. OEM car manufacturers typically equip their vehicles with bulbs in the 4100 to 4300 Kelvin range. This produces light most like daylight in colour. You may have seen some headlights with bluish or purple tints. These lights operate in the 5000 to 6000 Kelvin range. A higher colour temperature doesn’t mean there is more light on the road – it only changes the colour the bulb produces. Whatever
Beware of cheap headlight bulbs. They may not be built to the same quality and can position the filament of the bulb in a slightly different position. This can create a dramatic decrease in illumination.

Hid Headlamps get their focus and pattern either by directing the light through a projector lens, or by bouncing it off of a reflector. In either case, the bulb filament must be positioned correctly so the light beams are focused by the lens or reflector in the correct spot. There are premium halogen headlight bulbs on the market. I recently installed a set of General Electric Nighthawk bulbs in one of my vehicles and the difference over the existing halogen bulbs was amazing. GE claims the Nighthawk bulbs produce up to 90 per cent more light on the road. While I can’t confirm this, they do provide a lot more light.