A safety institute recently tested 30 brand new (2016) mid-sized vehicles for their headlight output performance.
The results are eye opening, as a vehicle’s price tag is no guarantee of a good headlight and many of the poor rated lights are found on brand-new luxury vehicles. If you’re having trouble seeing behind the wheel at night, it could very well be your headlights and not your eyes that are to blame.
The ability to see the road ahead, along with any pedestrians or obstacles, is an obvious essential for drivers, but government standards for headlights allow for a huge variation in the amount of illumination that headlights provide in actual on-road driving. Statistics show that about half of traffic deaths occur either in the dark, dawn, or dusk conditions, so improved headlights have the potential to bring about substantial reductions in fatalities.
Recent advances in headlight technology make it a good time to focus on the issue. In many vehicles, high-intensity discharge (HID) or LED lamps have replaced typical Halogen ones. Curve-adaptive headlights, which swivel according to steering input, are also becoming more widespread. Research has shown advantages for the new headlight types, but they don’t guarantee good performance. This headlight rating system used doesn’t favor one lighting technology over the other, but simply rewards systems that produce ample illumination without excessive glare for drivers of oncoming vehicles.
Vehicles were evaluated on a test track after dark with a special device that measures the light from the low and the high beams as the vehicle is driven on five different approaches. Traveling straight, a sharp curve from the left and from the right and gradual curves in each direction as well. Additionally, the glare is tested for each scenario to make sure it isn’t excessive.
Results were then compared to those of a hypothetically ideal headlight system and rated in contrast. The low-beam results were weighted more heavily, since they are used more often and straightaway more important than curved, because more crashes occur on straight sections of road. According to this test, the optimal low-beam distance should be roughly 330 feet, with the high-beam optimal illumination reaching just under 500 feet on a straight section of road.
Since many of the vehicles are available with multiple headlight options, they tested a total of 82 headlights across the selected vehicle models to cover every possible combination that could be available from a dealership.
They found that only one vehicle had a ‘Good’ rating. The Prius v, when purchased with the Advanced Technology Package, is equipped with LED lights and high-beam assist. This LED low-beam headlight will reach nearly 400 feet on a straightaway; however, the halogen version was only lighting the road about 230 feet ahead.
The ‘Acceptable’ list included the Audi A3, Honda Accord, Infiniti Q50, Lexus ES and IS, Mazda 6, Nissan Maxima, Subaru Outback, Volkswagen CC and Jetta, and the Volvo S60.
Interestingly, even on a vehicle by vehicle basis, the newer technology is not always the better technology. For instance, the A3 low-beams were illuminating about 350 feet ahead with the HID option, but only 240 feet when equipped with LEDs. It is important to note that not all LED options are offered with projectors, which typically outperform reflectors. In the case of this Audi, the LEDs were placed in a reflector housing.
One of the best headlight systems evaluated has none of the new technology. The Honda Accord, when equipped with the basic Halogen projector was reaching over 300 feet and put the Accord into the Acceptable list; however, the LED projector was lighting less than 250 feet ahead and rated only Marginal.
Some vehicles are offered with curve-adaptive ability. The headlights will turn slightly with the steering wheel. The Q50 is only available with an LED projector, but the vehicle is offered the option to have the curve-adaptive or without. The curve-adaptive option on those headlights will give the driver a view of about 20 feet further when taking a long sweeping turn.
Curve-adaptive systems don’t always lead to better ratings. The Cadillac ATS, Kia Optima and Mercedes-Benz C-Class all earned poor ratings even when equipped with adaptive low and high beams. In the case of the Mercedes-Benz C-Class, the LED projector high/low-beam option found on their Lighting Package produced an excessive glare to oncoming traffic and still didn’t meet the optimal illumination standards. While the LED projector low-beam coupled with a LED reflector high-beam option preformed a bit better (still not optimal) with no glare.
Many vehicles offer options for their high-beams. From the data that they collected, the Halogen reflector high-beam can often far outperform the LED high-beam. The Lexus ES350 is offered with a low-beam LED projector and the option of a high-beam LED projector or Halogen reflector. With this particular vehicle, the Halogen reflector would light up the road nearly 100 feet further than the LED counterpart.
In the case of Lexus’ IS250/350, the headlight options include HID or LED. The HID low-beam was found to reach a distance of about 350 feet, while the LED low-beams were only good for about 280 feet.
Unfortunately, buying an expensive luxury vehicle doesn’t necessarily mean you have the best technology lighting the road ahead of you. The Acura TLX is equipped with only one option, an LED projector. That headlight was only able to light up a distance of 250 feet with the low-beams and came about 50 feet short of the optimal distance with the high-beams reaching roughly 440 feet. And the BMW 3 series, when equipped with the base model Halogen option, saw its low-beams lighting up only about 130 feet ahead!
From this study, it is clear to see here that styling often takes precedence over function and that new technology doesn’t always mean better technology.