Torque Shop: Seeing better with high-tech lights for an old car

How are the lights on the current generation of cars different from what they used to be? Is it possible to upgrade the lights of a classic car to the latest technology?

Exterior lighting has always been an integral part of the automobile. From simply illuminating the road ahead at night, motor vehicles are today required by international design regulations and local laws to comply with clearly defined specifications for every exterior light, including those for signalling to other road users.

For the headlamps, the technology has progressed beyond the basic tungsten filament lamps through halogen-filled bulbs and gas-discharge lamps to the current standard, which is LED (light emitting diode) technology.

Filament-type lamps, including the halogen variety, require specially patterned lenses to achieve the desired spread, defined cut-off and distance range, with a small degree of directional adjustments possible mechanically. This is why, for older cars, headlamp alignment is necessary in order to pass the illumination test during periodic inspections.

Initially, LED lamps were used only for tail and indicator lights, due to their limited illumination range. The technology progressed, and modern LED lamps are now also widely used for headlamps because of their high level of illumination, spread and range.

LED lamps are far more energy-efficient than any filament-type bulbs, and also less complex than xenon-gas discharge bulbs, making them ideal for daytime running lights.

Laser headlights are currently top of the range in automotive lighting technology. They provide the longest range of illumination, compared with any other light system used in headlamps.

Very few cars today are specified with laser headlights, which are meant for long-range illumination during very high-speed driving when the driver needs to be able to see as far as possible.

Like LED, laser lights incorporate electronic controls and sensors to adapt the lighting output according to road conditions ahead. For instance, during night driving, these lights can automatically switch from high- to low-beam in response to an oncoming vehicle.

Although seemingly simple and straightforward, retro-fitting with non-standard light units or just the bulbs is not recommended.

For example, there are various after-market LED replacement bulbs mostly for the halogen headlamp units. Even though they may fit into the original headlamp sockets, they do not always light up. As LEDs consume significantly less current than filament bulbs, this can trigger the car’s sensors to cut power to the sockets because the energy reading is different from the original setting.

Two other issues make switching to LEDs an objectionable modification.

First, traffic rules do not allow modifications to the original headlights.

Second, headlamps are designed to work with specific technologies to illuminate the road ahead with sufficient pattern, spread and range, while minimising glare to oncoming vehicles. Swopping a conventional bulb with an LED may not always result in improved lighting.

Just as with LED replacement bulbs, retro-fitting with an after-market lamp unit would result in failing the periodic vehicle inspection.