Arlington, Virginia -- June 22, 2017 -- The US-based Insurance Institute for Highway Safety (IIHS) has released results that indicate headlights are improving overall, but many are still not performing adequately.
The latest tests conducted by IIHS focused on midsize SUVs. This is the fourth group of vehicles IIHS has evaluated since launching headlight ratings in 2016. Collision Repair magazine reported on earlier testing conducted by IIHS that show the headlights on many pickup trucks were not up to the job. For more on this, please see “Report: Most pickup headlights not performing adequately.”
According to IIHS tests, the 2017 Hyundai Santa Fe and the 2017 Volvo XC60 are the only models available with “good” rated headlights among the 19 midsize SUVs and 18 midsize luxury SUVs evaluated in this new round of tests. Twelve SUVs are available with headlights rated “acceptable.” The majority, a total of 23 vehicle models, aren't available with anything other than headlights rated as “marginal” or “poor.”
"As a group, midsize SUV headlights perform slightly better than the other SUVs and pickups we evaluated last year, and that's encouraging," says IIHS Senior Research Engineer Matt Brumbelow. "Still, we continue to see headlights that compromise safety because they only provide a short view down the road at night."
Nighttime visibility is critical to highway safety as about half of traffic deaths occur either in the dark or at dawn or dusk, according to IIHS. Differences in bulb type, headlight technology and even something as basic as how the lights are aimed all affect the amount of useful light supplied.
During the IIHS tests, engineers measure how far light is projected from a vehicle's low and high beams as the vehicle travels straight and on curves. Glare for oncoming vehicles is also measured from low beams in each scenario to make sure it isn't excessive.
Headlights can vary by trim line, so vehicles often come with multiple headlight variants. The 37 SUVs that IIHS evaluated have 79 possible headlight combinations.
Most headlights use one of three different light sources: halogen, high-intensity discharge (HID) or LED. Each of these can be paired with either reflectors or projector lenses. Projector headlights use one lens to spread the light out, while reflectors have multiple surfaces that bounce the light forward. All the good- and acceptable-rated headlight variants in this group of midsize SUVs have projector lenses, and the three good-rated headlight variants are HID. However, having HIDs and/or projector lenses doesn't guarantee good or acceptable performance in IIHS evaluations.
The XC60 is available with optional curve-adaptive HID projector headlights, which earn the top rating. Curve-adaptive headlights swivel with the steering wheel to better illuminate bends in the road. The XC60's HID headlights also can be purchased with optional high-beam assist, which helps increase high-beam use by automatically switching between high beams and low beams depending on the presence of other vehicles. Models equipped with high-beam assist earn extra credit in IIHS ratings.
According to IIHS, one of the worst midsize SUVs for visibility is the Kia Sorento, despite using curve-adaptive HID projector low beams. On the right side of the straightaway, for example, the Sorento's low beams only illuminated 148 feet, compared with 315 feet for the XC60's low beams.
More than half of the 79 headlight variants evaluated have too much glare. In 17 of those cases, the headlights would be rated poor based on glare alone.
"Managing glare can be more challenging for taller vehicles like SUVs and pickups because their headlights are mounted higher than on cars," Brumbelow says. "Better aim at the factory can minimize glare."