Replacement headlight bulbs: a bright idea?(aerodynamic headlight)(high-intensity-discharge)

Premium replacement headlight bulbs are marketed as a functional and cosmetic improvement over the conventional bulbs found in most cars. The bulbs try to mimic the whiter, brighter light of the high-intensity-discharge (HID) lights found on some pricey vehicles. However, while these bulbs emit whiter-looking light, they don't provide a consistent performance improvement in our tests.

Changes in lighting regulations in the mid-1980s allowed automobile designers to create aerodynamic headlight assemblies. These assemblies use a replaceable halogen bulb rather than an entire replaceable assembly. Headlight performance varies considerably depending on the assembly's design, including reflector design and lens shape.

Expensive HID lights are a more recent innovation. CR's tests have shown that HID lights can be brighter, but illuminated distances are often comparable to those of halogen bulbs. Premium halogen replacement bulbs attempt to offer some of the benefits of HID lights while retaining the vehicle's original headlight assembly.

Bulb replacement is usually a simple task for most backyard mechanics.

MEASURING THE LIGHTS

CR tested five premium replacement bulbs, one from each of the top-selling brands: the APC Plasma Ultra White, GE Nighthawk, Philips Crystal-Vision, Sylvania SilverStar, and Wagner TruView. The bulbs are priced between $26 and $40 a pair (two to three times more than standard bulbs) and are sold in discount or auto-parts stores. All tested bulbs claim Department of Transportation-standard compliance; noncompliant bulbs may be marked as "for off-road use only."

Tests were both subjective, to determine how well distant objects could be seen by the human eye, and objective, measuring bulb illuminance, or brightness.