"You don't know what kind of crash you're going to get into, so you want a vehicle that affords the best protection in the most common kinds of crashes," Joe Nolan, the institute's senior vice president, said in a statement.
General Motors Corp.'s H3 was the only vehicle in the group that didn't get the top rating for frontal crash protection. Instead, it got the second-highest rating of "acceptable" because the test indicated high likelihood of injury to the driver's right leg. The H3 also got an "acceptable" rating in the side crash test and the worst rating of "poor" in the rear crash test.
"The Hummer H3 meets or exceeds all federal crash safety standards. The Insurance Institute tests represent one measurement of crash performance," GM spokesman Alan Adler said in a statement.
He also said the company designs its head rests to meet a variety of driver sizes, rather than the average-sized man used in the institute's tests.
The institute said it downgraded side crash results for the H3, Kia Motors Corp.'s Kia Sorento and Chrysler LLC's Jeep Liberty/Dodge Nitro which are built on the same platform because they lacked air bags that protected the torso. All three had curtain air bags that protected the head, but the tests indicated a likelihood of injuries to the driver's rib cage.
The Jeep Wrangler also got a low rating for side protection because its side air bags are optional and the institute tests vehicles without optional equipment. The Wrangler was the only vehicle in the group without standard side air bags.
In addition to the H3, the worst performers in the rear crash test were the Mitsubishi Endeavor and the Jeep Liberty/Dodge Nitro. The Jeep Wrangler, Suzuki XL7, Mazda CX-7 and Mazda CX-9 all got the second-lowest rating of "marginal" on the rear test.
The rear crash test measures the risk of injury from whiplash, which is the most serious injury reported in 2 million insurance claims each year. The institute said three vehicles the Mitsubishi Endeavor, Mazda CX-7 and Mazda CX-9 would have been top safety picks if they hadn't performed so poorly in the rear crash test.
The institute's frontal crash test simulates a 40 mph crash and its effect on the driver, while the rear test simulates a 20 mph test. The side crash simulates what would happen if the vehicle was struck in the side by a sport utility vehicle at 31 mph. The side crash test uses dummies in both the front and rear seats.
On the Net: Insurance Institute for Highway Safety: http://www.iihs.org