Halogen projector headlamps are standard on the Kenworth T660. Their low beams cast 40 percent more light down the road than sealed-beam lamps and last longer.
The simple sealed-beam headlamp, basically a bulb in a vacuum-sealed case, is heading the way of the dodo. Truck manufacturers and aftermarket shoppers are switching to newer technologies. One advance has been the composite reflector headlamp. It bounces the light off a diamond-shaped reflector on the back bounces the light off a diamond-shaped reflector on the back of the lamp, giving more output than a normal sealed-beam lamp. Other developments have been halogen and high-intensity discharge headlamps.
These newer technologies cost more, but generate more light, produce more even illumination and last longer than sealed-beam lighting. Wire Connections, for example, sells complex-reflector headlamps for $80 to $90. HID lamps can go for as high as $300.
The longest-life sealed-beam bulb commercially available is Truck-Lite’s halogen-based, 7-inch round replaceable headlamp, says Brad Van Riper, Truck-Lite vice president of research and development. It was designed for commercial trucks with a higher mounting height, enabling truckers to see farther. It retails between $50 and $60 and is rated to 1,200 hours on low beam, 250 hours on high beam.
“The common sealed-beam headlamps – 5 by 7 inches, 4 by 6 inches – were originally designed by passenger car companies,” Van Riper says. “Headlamps for passenger cars that are put on trucks reduce the amount of foreground lighting, and the beam often disappears quite early because it is projected further down the road.”
The light pattern is important, too, says Steve Howser, new product development manager for Grote Industries. Uneven patterns cause drivers’ eyes to focus on the brightest spots, he says. Grote headlamps uniformly provide “a smooth gradient in the pattern, not a bunch of bright spots,” Howser says.
The new technology is not limited to the aftermarket.
