IIHS Introduces First New Frontal Crash Test Since 1995
The Insurance Institute for Highway Safety (IIHS) introduced its first new frontal crash test procedure since 1995. The new test is designed to test driver safety and vehicle structure in what the group calls small overlap frontal crashes. The IIHS also started this new test with a bang by utilizing cars in one of the most hotly-contested markets in midsize luxury and near-luxury cars.
Only the Acura TL and Volvo S60 earned the IIHS' highest ranking of "good" for the crash test, while the Infiniti G sedan line earned an "acceptable" rating. The Acura TSX, BMW 3 series, Lincoln MKZ, and 2012 Volkswagen CC earned "marginal" ratings, while luxury stalwarts like 2012 models of the popular Audi A4, Lexus ES, Lexus IS, and Mercedes-Benz C-Class earned "poor" ratings.
The test is designed to simulate an offset, frontal collision with a tree or utility pole. To do so, the IIHS crashed vehicles equipped with test dummies in the driver-seat into a 5-foot-tall rigid barrier at 40 mph. The cars struck the barrier approximately in-line with the driver-side front headlamp area. The area equaled approximately 25% of the car's front end.
After the data was compiled, the IIHS pointed out that the key to the test was the structural integrity of the vehicle. While certain parts of the vehicle are designed to crush and absorb as much of the impact as possible, the safety cage, or the area for the car directly surrounding its occupants, should experience little to no deformation. According to the IIHS, most modern vehicles have safety cages that can withstand head-on collisions and moderate overlap crashes. However, small overlap crashes translate crash energy directly into the front wheel, suspension systems, firewall, and A-pillar. This can cause severe deformation of the front passenger compartment on the side of the impact.
The Lexus IS had up to 10 times as much intrusion as the leading Volvo, causing the A-pillar to bend and collapse the left front footwell. The latter caused the dummy's left foot to become entrapped by intruding structure, while its right foot was wedged beneath the brake pedal. This also affected the Mercedes C-Class, as the dummy's right foot was also wedged under the brake pedal when the left front wheel was forced into the footwell during the crash. Other cars, like the Volkswagen CC and Audi A4, were docked points for the driver's door coming ajar during the test. In the case of the CC, the vehicle completely lost its driver door, making it the first car to ever do so in an IIHS test.
Safety belts and airbags also played an important role in testing, as they can become manipulated and lose effectiveness if the vehicle's safety cage is compromised. This is especially the case with real-world drivers, as their size, shape, and seating position can put them at greater risk of striking part of the vehicle's interior. While side curtain and torso airbags deployed in the Acura TL and Volvo S60, one or both of the airbags did not deploy in seven of the cars evaluated. Of the six curtain airbags that did deploy, four didn’t provide enough coverage. In the Lincoln MKZ, both the front and side curtain airbags deployed, but the dummy's head missed both entirely due to the deformation of the safety cage.