ROAD TEST: LED headlights ready for prime time

truckinginfo.com

Thanks to:  Harry Rudolfs of trucknews.com 2013-05-21. Link provided below:

Truck-Lite's LED headlights in a Penske rental Cascadia light up the back roads around Mississauga, Halton

My trucking job mostly involves night driving between Toronto and Montreal, in all weather conditions. So I’m keenly aware of the importance of a good headlight system. And commercial drivers obsess about lights all the time – just leave your fog lights on after the mist has cleared and you’ll hear about it on the CB. Don’t get me wrong. The halogen bulbs in my dedicated Volvo do a pretty good job illuminating the road. But recently I’ve noticed that the clearest and brightest low beams belong to Freightliners, specifically Penske-owned Cascadias, as they slide past me on the Big Road.

I recalled seeing a news blurb somewhere about Penske outfitting its tractor fleet with LED headlights, and was genuinely thrilled when editor James Menzies asked me to test drive one of the retrofits. So one April night my godson Zak and I booked a newish 10-speed Freightliner Cascadia with a 425-horse Cummins ISX engine, and went looking for “the darkness on the edge of town.”

Truck lighting has come a long way since 1896 when Karl Benz mounted candles on his prototype truck. From lanterns to acetylene lamps to sealed beams, to halogen, HID-Xenon and finally LED headlights, it’s always been about seeing and being seen. Over the years, lighting solutions have paralleled – and sometimes lagged behind – other aspects of the automotive trade. But occasionally something new comes along that significantly moves the bar several notches.

The round two- and four-headlight sealed beam systems that we’re all familiar with were standard for 50 years or more, and rectangular headlights, mostly found on trucks, became more common after the 1970s. A major step forward came in the early 1980s when bulbs could be changed separately from the lens and reflector, followed in 1983 by the halogen bulb. By replacing the vacuum lamps with halogen (a combination of several gases) the tungsten filaments burned brighter.

Halogen remains the mainstay among trucking fleets but that could be changing. It tends to yellow with age and grow dimmer, and the bulb life is only about 1,000 hours. You often notice the difference when replacing a burned-out headlight. The new one burns much brighter. Depending on the manufacturer, halogen headlights can lose 20% of their luminosity in only 160 hours. Compare this to the “new generation” LED low beams which might eventually lose 7% of their output, but would take 20,000 hours to do so.

At 16 years of age, Zak is a physicist-in-training, and patiently explained to me the difference between candle power and lumens, photons, neutrons and electrons, as we spent several hours trundling the back roads between Toronto and Georgetown looking for dark stretches of highway. This is the time of year when a lot of animals are moving around and getting struck, so we were actually hoping to see some wildlife darting in front of the truck.

This didn’t happen, but the directional fluting of the beams onto the shoulders of the road was excellent. “Sixty degrees,” Zak announced when we stopped, measuring the sideways flaring of the headlights with his protractor.

This is an intentional design feature, according to Brad Van Riper, chief technology officer at Truck-Lite, which produces the LED headlights.

“We interviewed drivers during the development and they wanted more light on the shoulder of the road, more visibility of fog posts, pedestrians and animals.”

To accomplish the enhanced “road-shoulder” lighting, the design team went to computer simulation  technology to formulate the complex reflector-style beams of the Cascadia.  

“We used a computer-based optical design system to collect and direct the light to the area that we wanted,” says Van Riper.

Stellar is a word I would use for the overall performance, in more ways than one. Besides reaching further into the night than anything else I’d driven, the frequency and spectrum of the white light is meant to mimic that of sunlight or starlight. The only thing comparable right now might be the HID-Xenon system available on Kenworth and Peterbilt packages.

HID-Xenon lights are plenty bright, but tend to have a purple tint, swinging towards the blue, or cooler, end of the spectrum. I talked to one driver of a new Kenworth who thinks they are too bright. This is probably not the case, since all headlamp systems have to meet NHTSA standards. But this particular driver confided via CB radio, “I get flashed all the time.”

By comparison, no one flashed their high beams at me while test driving the Penske Cascadia, but I personally think the intensity of both systems is about the same, though they have slightly different penumbras, and they are both brighter than that to which Joe Highway is accustomed. I was nervous about the amount of light the LEDs were emitting. But to the credit of the Truck-Lite engineers, the horizontal cut-off of the LED’s beam lined up just below a car’s trunk lid at a stop light. LEDs are monochromatic and narrowly focused. To fill out the rest of the light spectrum Truck-Lite used a blue chip that is coated with a phosphor.

“There are many ways of doing this,” says Van Riper, “but the most effective way is by coating the top surface of the LED with a phosphor and when the blue wave length light sees the phosphor, it releases photons that fill the rest of the spectrum, giving you white light.”

Like sunlight, Truck-Lite LED light is designed to be neutral, sitting midway between the cooler signature of the HIDs and the warmer halogen lights that we see on most of today’s trucks. Van Riper cites a study by the University of Michigan which suggests certain wavelengths of LED light suppress the release of melatonin, a naturally occurring hormone that factors into one’s sleep cycles.

“We’ve had feedback from a lot of drivers that they feel like they’re more alert,” he says.

Truck-Lite has never been that interested in halogen technology and they see LED systems as the way forward. In 2007 they were asked to design an LED system for the US Army which was field-tested on army trucks in Iraq and Afghanistan. They eventually sold 300,000 LED headlights to the US military. These days, the technology is available to anyone as seven-inch round beams and five-inch rectangular units.

But it is Truck-Lite’s application of LEDs to custom aerodynamic headlights like the Cascadia, which marks a new direction for the lighting manufacturer. According to Van Riper, LED headlights for several other truck makes and models should be available later this year.

After fumbling about on concession roads and secondary highways, Zak and I turned the Cascadia towards the industrial wilderness of Milton, Ont. Yes, lots more illumination in the dimly-lit truck yards. Then I remembered a grocery store in Brampton where I used to make night deliveries. This site featured a set of receiving docks that was separated from the nearby suburban townhouses by a wall. The area was always cluttered with debris, abandoned shopping carts and an overflow of garbage from the bulging refuse compressors. It was the loneliest feeling pounding on the steel doors at night and ringing the bell for an eternity with some kind of small creatures shuffling around my feet, anxious for the night receiver to open the door.  

Not to my surprise, the delivery docks were the same, with the same amount of refuse and cabbage leaves scattered on the ground – only now I could see better. And once again I came to realize why I don’t miss delivering to supermarket receiving docks, especially at night.

The last stop was the Husky Truck Stop off Dixie Road. There are always a number of tractors lined up in the parking lot and I was hoping to get a picture of the LED lights beside a conventional system. Nothing doing. Guys are in their bunks and sleeping. Oh, there are always a few drivers fuelling, and a couple in the coffee shop, but despite a full yard, like most truck stops on a Friday night it’s a quiet place. But I finally did sidle up beside a fuel hauler, old style halogen, and there’s no contest in terms of brightness between the two.

The remarkable thing, I suppose, is how a technology that’s so clear and precise could be so much more efficient. According to Van Riper, a rig and trailer completely outfitted in LEDs, as compared to a contemporary truck running on all incandescent lights, actually uses 33 less amps. This is significant, especially to an owner with a big bunk and lots of electrical gadgets, who might have to otherwise consider going to a bigger alternator. The power savings may result in a reduction in fuel consumption which is currently under study.

No question about the benefits and longevity of LED headlights, but the cost involved ($750)  is considerably more than halogen or HID-Xenon. But Van Riper estimates the price will come down as manufacturing and consumer demand heats up, and with Volvo and International coming online, that could happen sooner than later. Meanwhile, Truck-Lite’s offering interested Canadian fleets free one-week trials to see the difference for themselves.

http://www.trucknews.com/news/road-test-led-headlights-ready-for-prime-time/1002334482/