Only three of 11 midsize luxury and near-luxury cars evaluated earn good or acceptable ratings in the Insurance Institute for Highway Safety’s new small overlap frontal crash test. This is the latest addition to a series of tests designed to force automakers to continue to develop safer vehicles that perform well beyond government mandated regulations.
The Virginia based Institute funded by the insurance industry said today that only the Acura TL and Volvo S60 earn good ratings. The Infiniti G was acceptable. The Acura TSX, BMW 3 series, Lincoln MKZ and Volkswagen CC were given marginal ratings. The Mercedes-Benz C-Class, Lexus IS 250/350, Audi A4 and Lexus ES 350 earned poor marks.
When the Volkswagen CC was tested, the driver door sheared off its hinges. The CC is the first vehicle the Institute has ever evaluated to lose its door completely. An open door results in an automatic downgrade to poor for restraints and kinematics, as also was the case with the Audi A4, whose door opened but remained attached to the car. Doors, of course, should stay closed in a crash to keep people from being partially or completely ejected from vehicles.
In the new test, 25% of a car’s front end on the driver side strikes a 5-foot-tall rigid barrier at 40 mph. A 50th percentile male Hybrid III dummy is belted in the driver seat. IIHS said the test is designed to replicate what happens when the front corner of a car collides with another vehicle, tree or utility pole. Outside of some automakers’ proving grounds, such a test isn’t currently conducted anywhere else in the United States or Europe.
“Nearly every new car performs well in other frontal crash tests conducted by the Institute and the federal government,” Institute President Adrian Lund says. However, small overlap crashes remain a major source of fatalities.
The new test program is based on years of analyzing real-world frontal crashes and then replicating them in the IIHS crash test to determine how people are being seriously injured and how cars can be designed to protect them better. All of the cars are 2012 models. (See these ratings in table format)
“We think this is the next step in improving frontal crash protection,” said Lund. According to the IIHS, Acura TL’s front and side curtain airbags worked well together to keep the head from coming close to any stiff structures or objects that could cause injury.
Virtually all cars have safety cages built to withstand head-on collisions and moderate overlap frontal crashes with little deformation. At the same time, crush zones help manage crash energy to reduce forces on the occupant compartment. The main crush-zone structures are concentrated in the middle 50% of the front end. When a crash involves these structures, the occupant compartment is protected from intrusion, and front airbags and safety belts can effectively restrain and protect occupants.
Every luxury car and near-luxury car IIHS evaluated earns good ratings for head, neck and chest injury risk based on measurements from the dummy’s sensors. This is true even though there are many cases of serious upper body injuries in real-world crashes with similar vehicle damage.
The number of drivers of zero- to three-year-old passenger vehicles involved in fatal frontal crashes has fallen 55% since 2001. Some of the success no doubt is due to consumer information testing like the New Car Assessment Program begun by the National Highway Traffic Safety Administration (NHTSA) in 1978 and crashworthiness evaluations the Institute started in 1995.
In NHTSA’s frontal test, passenger vehicles crash at 35 mph into a rigid barrier covering the full width of the vehicle. In the Institute’s new 40 mph offset frontal test, now called a moderate overlap frontal test, 40% of the total width of a vehicle strikes a deformable barrier on the driver side.
In a 2009 an IIHS study of vehicles with good ratings for frontal crash protection, small overlap crashes accounted for nearly a quarter of the frontal crashes involving serious or fatal injury to front seat occupants. Another 24% of the frontal crashes were moderate overlap crashes, although they likely occurred at much higher speeds than the Institute’s moderate overlap test. An additional 14% occurred when passenger vehicles under-rode large trucks, SUVs or other high-riding passenger vehicles.
The Institute says it is exploring countermeasures for large truck underride crashes and in other research has found that the problem of crash incompatibility between cars and SUVs is being reduced.