The 2012 Mercedes-Benz C-Class, Audi A4 and two Lexus sedans — the IS 250/350 and the outgoing ES 350 — failed the latest round of IIHS frontal tests.
As we reported Monday, the Insurance Institute for Highway Safety’s new offset frontal-barrier test simulates a 40-mph collision with a rigid barrier that overlaps just 25% of the car. The test simulates a front-corner collision with a tree, a pole or another vehicle, a scenario that is responsible for almost 25% of front crashes that seriously injure or kill someone in front, IIHS says. The new test will augment the agency's existing frontal test, which crashes a car at 40 mph against a deformable barrier that overlaps 40% of the front.
"Outside of some automakers’ proving grounds, such a test isn’t currently conducted anywhere else in the United States or Europe," IIHS said in a statement, noting that despite an increasing number of cars that score well in frontal crash tests, some 10,000 highway deaths still come from frontal collisions each year.
Although a car’s main crumple zones protect the passenger compartment, so-called "small-overlap crashes" impact the front wheels, suspension and engine firewall, resulting in significant cabin intrusion. In some cases, the front wheel can end up crunching the footwell. The S60's passenger compartment resisted intrusion the best; see its photo versus the Lexus IS below.
Lexus wasn't the only automaker to fare poorly. IIHS says the crash test for Mercedes’ C-Class left the dummy's foot wedged beneath the brake pedal, while the driver's door opened on the A4 and the CC. The CC's door fell off entirely — the first instance of that ever happening, IIHS noted.
Widening the boundaries of the frontal crush structure and building safety cages that resist impact at their boundaries can help, IIHS said. Containing the occupant is important, too. Frontal airbag coverage proved difficult, though, as crash forces tended to move dummies toward the A-pillars. Side curtain airbag deployment could mitigate the situation, but just six of the 11 cars deployed them — and four of those didn't provide enough forward coverage. In the MKZ, for example, the crash-test dummy missed the steering-wheel airbag altogether. Compare it to the TL (below), whose dummy hit the bag.
See the full results below. IIHS expects to test family sedans like the Toyota Camry and Ford Fusion next. Top Safety Picks will continue for 2013, but IIHS will introduce a "higher award level that will be announced later this year" for cars that secure a top rating in the small-overlap test as well as the institute's existing tests.