Last Updated Jun 23, 2016 6:19 PM EDT
Drivers of small sport utility vehicles (SUVs) sold in the U.S. should feel pretty safe, but their front seat passenger better have the seat belt fastened, warned the Insurance Institute for Highway Safety (IIHS).
A frontal crackup test, conducted by the IIHS and aimed at the right side of the vehicle, resulted in the 2015 Toyota RAV4 receiving a "poor" rating and the 2014 Nissan Rogue and 2014 Subaru Forester measuring as "marginal." Three other 2015 SUVs, the Buick Encore, Honda CR-V and Mazda CX-5, were deemed "acceptable." The only model rated "good" was the 2016 Hyundai Tucson.
All of these cars rated "good" for driver's side collisions and performed well in other crash tests. But the IIHS upped the ante by simulating a 40-mile-per-hour crash that would likely occur if an SUV swerved into a telephone pole or tree with only the right corner hitting the fixed object. It is the only organization conducting this test.
"A poor rating indicates a high likelihood of serious or life-threatening injuries in a crash of this kind," said IIHS spokesman Russ Rader said. In fact, the "maximum intrusion" in a 40-mile-per-hour crash for the RAV4 was 13 inches more than the driver's side. It ripped the door hinge pillar off, which opened the door, likely ejecting a passenger who wasn't wearing a seat belt. The IIHS uses crash dummies in its tests.
Toyota told CNBC that these new crash tests were severe and beyond federal rating standards.
While it was clear that some of these vehicles had less protection on the passenger's side than on the driver's side, in other instances the vehicle looked symmetrical. This might have been an illusion, because the steering wheel and pedals could also add support to the car's structure on that side.
This problem could likely be solved by adding different material and a "few millimeters of thickness" to the passenger side - or to the whole compartment, said Becky Mueller, an IIHS research engineer.
The recent IIHS test shouldn't make anyone go out and trade in their car, said Rader. "But the next time you are looking for an SUV you may want to look for one with greater passenger protection."
Before the era of seat belts and air bags, the front passenger space was known as "the death seat" in the event of a crash and in some states children are still forbidden to sit there until they reach a certain age.
In 2014 more than 1,600 passengers in the front seat of vehicles were killed in accidents, according to IIHS officials.
CBS News reached out to various auto manufacturers for comments on the tests:
"At Hyundai, we continually strive to provide outstanding passenger safety to our customers, regardless of vehicle size or price," said Mike O'Brien, vice president, Corporate and Product Planning, Hyundai Motor America. "Our 2016 Tucson's good rating for both driver and passenger in the demanding IIHS small overlap crash test reflects our commitment to passenger safety at every level. We're certainly proud of our Tucson's industry-leading performance in the small SUV category."
We don't have anything to add to what IIHS has said at this time.
"The Mazda CX-5 remains a 2016 IIHS Top Safety Pick +. As IIHS notes, when comparing driver and passenger sides, vehicles are inherently asymmetrical due to the steering column, pedals, and supporting structures. Mazda will carefully review the IIHS test results."
Nissan is committed to the safety and security of our customers and their passengers. We are aware of the IIHS testing and we are currently reviewing the details to assess opportunities for improved performance.
Subaru Director of Corporate Communications Michael McHale says that they just received the results and are still studying them. He adds that their engineers are in Japan so they will not have a response today.
The IIHS small overlap test is severe, specialized and goes beyond federal vehicle safety requirements. After it was first introduced in 2012, Toyota took steps to improve the performance of its vehicle in the test. Rather than waiting to re-engineer both driver's and passenger's sides, we took immediate steps to enhance performance on the driver's side. Looking ahead, we've incorporated enhancements on both the driver's and passenger's side for vehicles built on Toyota's new TNGA platforms, beginning with the 2016 Prius. We continue to be transparent with IIHS throughout this process about the steps we have taken to improve the performance of Toyota vehicles on the small overlap test.
Also worth noting: Toyota leads the industry in third-party crash test ratings with more vehicles rated Top Safety Pick and Top Safety Pick + by the Insurance Institute for Highway Safety (IIHS) than any other manufacturer.