New, more stringent crash test: 8 of 11 luxury cars perform poorly [Videos]

Only Volvo's S60 and Acura's TL earned the coveted "good" rating in the Insurance Institute's new crash test. Eight cars tested earned below-average "marginal" and "good" ratings.

A new crash test by the Insurance Institute for Highway Safety has proven challenging for two thirds of the entry-level luxury sedans the organization tested.

Only the Volvo S60 and the Acura TL earned a "good" rating in the new "small overlap" test, which IIHS says is designed to simulate "what happens when the front corner of a car collides with another vehicle or an object like a tree or utility pole."

While the traditional frontal offset test -- now called the "moderate overlap" test -- simulates a collision with another vehicle at 40 mph, the new small overlap test simulates a collision at the same speed with a solid, immovable barrier. The new test sees 25 percent of the tested vehicle's front end striking a 5-foot tall rigid barrier, compared with 40 percent of the front end striking a deformable barrier.

The video below gives a basic overview of the new crash test.

According to the institute's research, the new crash test simulates about a quarter of all real-world accidents. IIHS won't be abandoning the current crash test style, but it will use the new small overlap test as an additional measurement of vehicle safety and structural crashworthiness.

Frontal crash tests are used by other agencies across the globe, including the federally-funded National Highway Traffic Safety Administration's new car assessment program, as well as its counterparts in Europe, Japan and Australia. Unlike NHTSA, IIHS is not government-funded; the institute derives its running costs from the insurance industry.

The Infiniti G received an acceptable rating, while the Acura TSX, BMW 3-Series, Lincoln MKZ and Volkswagen CC all earned a marginal grade. The Audi A4, Lexus ES, Lexus IS and Mercedes-Benz C-Class ranked at the bottom of the segment with the agency's lowest rating: Poor. All 11 tested vehicles are 2012 models, although only the Lexus ES and Lincoln MKZ see significant changes for 2013.

Notably, the VW CC was the first vehicle to actually lose its door in an IIHS crash test. The Lexus IS suffered substantial structural failure of the passenger compartment, and the dummy in the Lincoln MKZ missed both the front airbag and the curtain bag.

IIHS has told Leftlane in the past that it considers marginal and poor to be essentially failing grades, and it is even critical of vehicles that achieve acceptable scores. The new test scores will be factored into its Top Safety Pick award, which requires vehicles to receive Good scores in every single test. Only the S60 and TL, among the 11 entry-luxury cars tested, will qualify for 2013.

IIHS will soon begin releasing crash test scores for other vehicles in different market segments.

"Nearly every new car performs well in other frontal crash tests conducted by the Institute and the federal government, but we still see more than 10,000 deaths in frontal crashes each year," IIHS President Adrian Lund says. "Small overlap crashes are a major source of these fatalities. This new test program is based on years of analyzing real-world frontal crashes and then replicating them in our crash test facility to determine how people are being seriously injured and how cars can be designed to protect them better. We think this is the next step in improving frontal crash protection."

Automakers nearly universally ace existing crash tests, something IIHS applauds. But the new small overlap test is designed to be much more difficult, a move that the institute hopes will lead to even safer cars in the future as automakers seek its Top Safety Pick rating.

As the images show, there are stark contrasts between the cars that performed well in the test and those that performed poorly. In particular, the difference between the way the cars' safety cages held up is staggering. The first two images in our gallery above are of the top-ranked Volvo S60, while the third and fourth are of the poor-performing Lexus IS. We also included a smattering of other vehicles to show the intensity of the test.