HOUSTON -

They may be some of the most luxurious models on the road, but for all the bells and whistles, many luxury sedans are scoring low marks in a new front-end crash test.

For years, car manufacturers have known what to expect. Federal crash tests have tested the same areas on each vehicle, but new crash tests are focusing on a different type head-on collision and used some of the safest cars available, because the Insurance Institute For Highway Safety was baffled by a question: Why do so many people still die in frontal crashes despite the fact the vehicles are performing well in our crash tests and they're performing well in government crash tests?

The institute then modified its tests to address what they said is happening in about a fourth of these head-on collisions.

Instead of full frontal-impact, only a corner of the car slammed into a structure. What they found was greater risk of serious injury to those inside because it's the part of the car that offers the least but needs more protection. 

Eleven 2012 midsize cars were tested. Only three, the Acura TL, Volvo S60 and Infiniti G, earned a good or acceptable rating.

The Lexus IS and ES models, along with Audi's A4 and Mercedes C-Class, all were rated poor.

Toyota/Lexus and Audi said they will keep these tests in mind when designing new vehicles.

Mercedes said it disagrees with the tests and strongly believes its C-Class is safe.