The auto safety group, which is financed by the insurance industry, recently tested a group of new family sedans, including the Camry, Honda Accord and Ford Fusion.
The cars, 18 different models in all, were subjected to a new type of front crash test in which a car, going at 40 miles an hour, strikes a crash barrier with just a small part of the front bumper on the driver's side. It's a tough test, since it concentrates impact forces into a small area. When the IIHS put a group of luxury cars through the same test in August, only two cars out of 11 got top marks.
In the latest test, the two cars that did the worst, earning ratings of "Poor," were the Toyota Camry and the Toyota Prius v hybrid wagon. In the test, the Camry's front wheel was pushed back, bending the passenger compartment footwell inward.
The steering was also pushed far to the right so that airbag, which is mounted in the steering wheel, did little to protect the crash test dummy's head. Side curtain airbags also didn't extend far enough forward to provide needed additional protection.
The Prius v's passenger compartment was also crushed inward and that car's airbags deployed too late to offer protection.
"Toyota engineers have a lot of work to do to match the performance of their competitors," said Institute president Adrian Lund in a statement.
Two of the moderately priced cars got the Insurance Institute's top rating of "Good." Those were the four-door Honda Accord sedan and the Suzuki Kizashi. The Accord often ranks second to the Camry U.S. in car sales. Suzuki, on the other hand, recently announced it was pulling out of the U.S. auto market after years of poor sales here. Suzuki sold 500 Kizashi's in November compared to the over 26,000 Accords Honda and 29,000 Camrys sold.
"With this new test, the Institute has raised the bar again and we will respond to this challenge as we design new vehicles," Toyota said in a statement.
While the so-called "small overlap test" may seem extreme, it mimics a type of crash that, according to the Insurance Institute's research, accounts for nearly a quarter of frontal crashes that seriously injure or kill front seat occupants.
Most cars in the test, including the two-door Accord coupe and the Ford Fusion sedan, were rated as "Acceptable.'" Other cars earning the "Acceptable" rating were the Kia Optima, Nissan Altima and Maxima, Subaru Legacy and Outback, Dodge Avenger, Chrysler 200, Mazda6 and Volkswagen Passat.
Three other cars -- the Hyundai Sonata, Chevrolet Malibu and Volkswagen Jetta sedan -- earned the second-worst possible rating, "Marginal."
Since introducing the new crash test, the Insurance Institute now gives two different awards for auto safety. They are the Top Safety Pick award, for vehicles that do well on all the Institute's other front, side and rear impact safety tests, and the Top Safety Pick Plus award for vehicles that do reasonably well in all the tests including the new "small overlap test."
The Institute still gives both the Prius v and Camry its Top Safety Pick designation but not the Top Safety Pick Plus award.