The latest trend in automotive lighting is headlights with light-emitting diodes, or LEDs. Available on only a handful of luxury models for now, pricey LED headlights are expected to trickle down to more moderately priced models in the coming years.
Manufacturers say that LEDs have the advantage of a brighter light than conventional bulbs, much like the now more common high-intensity discharge (HID) bulbs do. They also claim LEDs provide reduced energy consumption and a cooler operating temperature. Further, they claim that one set of LED lights has the potential to last the life of the vehicle.
Automotive designers like LEDs for the styling flexibility they provide and their intriguing, modern appearance. Current applications often have them arranged like a string of small holiday lights, although LEDs can be positioned in a variety of ways.
We've only tested one model equipped with LED headlights up to this point, the Audi A8 luxury sedan. They're a pricey option, adding $1,400 to the price of our test car. While the Audi's LED lights glowed with a bright intensity similar to that of HID lamps, their overall performance was unimpressive in our testing. We found a sharp cutoff at the top of their beam, and a shorter reach on both high and low beams than a good set of conventional halogen or HID bulbs. (Learn how we test headlights.)
Having only tested one vehicle with LED headlights, it's too early to pass judgment on the technology as a whole. But due to their limited availability, designs that are unique to each vehicle, and high initial cost, there is the potential that replacement may be quite costly. Even if the headlights have the potential to last indefinitely, they could still need replacement if damaged.
Like any other new technology, the cost of LED headlights is likely to come down as their use becomes more widespread. For now, the advice is, as always, to make sure you understand how any vehicle you're buying is equipped before you sign on the dotted line, in order to avoid expensive surprises down the road.
We'll report further as we gain more experience using and testing LEDs.