BMW luxury sedans fared worst in protecting their occupants from side-impact crashes, in tests conducted by the insurance industry.

After frontal impact crashes, side-impact incidents are the deadliest type of impact, according to the Insurance Institute for Highway Safety.

The insurance industry tested luxury sedans that had standard side airbags:

• Volvo S80
• Acura RL,
• Kia Amanti
• Cadillac STS
• Mercedes E-Class
• BMW 5 Series

All of the sedans tested were 2007 models except the 5 Series, which was redesigned for 2008.

The Acura RL, the Kia Amanti and the Volvo S80 all earned the highest safety rating in the study. The Volvo S80 fared particularly well and was rated the best performer in the study because of its good performance in rear and frontal crashes. It was also designated the Top Safety Pick by the Institute. The Cadillac STS and Mercedes E-Class earned the second-highest rating.

However, the worst performer in the study was the BMW 5 Series.

According to Russ Rader of the Insurance Institute for Highway Safety, this was an unexpected result.

"It was surprising in part because BMW was one of the leaders in side-impact protection in the 1990s," Rader told CTV's Canada AM. "They were the first to install head-protecting side air bags in a vehicle back in 1998."

BMW spokesman Thomas Plucinsky said the dummy in the 5 Series was injured when it was hit by the arm rest during the test.

Plucinsky said BMW conducts as many as 12 crash tests on all of its cars as well as computer simulations of crashes.

"The issue is that depending on the location of seat, the location of dummy, the location of the sled, the results could change," he told the Associated Press. "This was one test on one day on one car."

To determine the results in this study, the vehicles were struck by a barrier moving at approximately 50 kilometres an hour. The test was designed to emulate the impact of the sedan being hit by either an SUV or a pickup vehicle.

"It's severe in part because the top of the front-end of the barrier that's coming in is right at the head height of the crash test dummies in the car," said Rader.

The resistance of the vehicle to the impact and the injuries to the driver and passenger dummies were used to assess the performance of the vehicles in the study.

The luxury sedans were accorded ratings of either poor, marginal, acceptable or good. A good result determined that an occupant would have only suffered minor injuries in the event of a side impact crash.

A lack of protection for the lower body impacted the ratings of the vehicles that did not perform well in the study, as this is the area of the body that side impact air bags are designed to protect.

The study also indicated that the amount of money spent on the luxury sedan did not necessarily guarantee safety either. This was illustrated in the case of the Kia Amanti, which retails for around US$25,500 and the BMW 5 Series, which starts at $43,500.

"We had one of the most expensive cars, the BMW 5 Series earning the lowest rating in the group," Rader said. "And the Kia Amanti which costs almost half as much, was one of the top-rated vehicles. So it shows that consumers don't have to buy the most expensive car to get good safety."