Side Impact Crashes: How Small Cars Stack Up

The tight economy has made tinier cars more appealing to some consumers, but not all small cars offer the protection they should, according to a report released Wednesday morning by the Insurance Institute for Highway Safety.

The group tested seven 2009 small car models and found that many of the vehicles would not fare well when side-swiped by an SUV or pickup truck. The disappointing crash test results came despite the fact that all of the cars have standard side airbags.

"We certainly don't think they should be performing this poorly," Adrian Lund, the president of Insurance Institute for Highway Safety, told ABC News.

"We've got some vehicles here that are lagging behind," he said.

VIDEO: A side impact crash test.Play

The IIHS says that side airbags, designed for head protection, are key because SUVs and pickup trucks crash into the side of those cars directly at passengers' head level.

In better news, all of the tested cars performed well on frontal crash tests, meaning they offer good protection when smashed into a barrier head-on at 40 miles an hour.

How Your Car Stacks Up

Good and Average Ratings: Only the Suzuki SX4 and Toyota Matrix, along with its twin, the Pontiac Vibe, offer good protection in side crashes, according to the IIHS report. The Ford Focus and Chevrolet HHR earned average ratings.

Marginal Ratings: Two vehicles that received marginal ratings on side crashes were the Hyundai Elantra and Saturn Astra.

Lund said a combination of factors can determine why some cars do better than others.

"Among the worst performers, what we see is that we get too much intrusion into the occupant compartment," Lund said. "That ends up causing high forces on the dummy, so we see a risk of rib fractures and internal organ injuries and even pelvic fractures and things like that."

Poor Ratings: The popular Chrysler PT Cruiser was the worst of the bunch in side impact crashes. When the barrier slammed into the vehicle at 31 miles per hour during the crash test, it dramatically crumpled the side of the vehicle. That meant that, even with the airbag, there was not enough protection for the driver. Further, there is no airbag at all for the rear passenger.

How Cars Rate in Safety

"The side structure was too weak," Lund said of the PT Cruiser. "We have much more intrusion than in the other vehicles there, and then the driver's side airbags didn't do a good job of protecting the chest and torso of the dummy. The air bags aren't doing their job, but they're also not being given much chance to do it because there is too much intrusion."

The PT Cruiser was also the only car in the group to receive poor ratings in both side impact and rear whiplash tests.

In a statement, Chrysler said the vehicle did well in government tests and said "no single test can determine a vehicle's overall safety performance.

"The Chrysler PT Cruiser received four stars in the government's frontal crash test (driver and front passenger), four stars for driver and five stars for rear occupant in the government's side-impact test, and four stars in the government's roll-over test," the company stated.

"Results from IIHS and other third-party test programs are reviewed by our engineers as part of our effort to continuously improve the overall performance of our vehicles," Chrysler added.

Overall, the IIHS has tested 21 current small car models. Eleven of them earned good ratings for side protection.