Originally Published: 03 JUN 22 13:50 ET

By Peter Valdes-Dapena, CNN Business

(CNN) -- A Jeep Wrangler tipped over onto its side during a crash test by the Insurance Institute for Highway Safety. This is the second time a Wrangler flipped onto its side during this type of crash test by the IIHS, and it comes after engineers said they had worked to fix the issue with this test following a similar result in 2019.

The 2022 model year four-door Jeep Wrangler tipped over onto its side during a so-called "small overlap crash test." In the test, a vehicle is thrust into a crash test barrier at 40 miles per hour with just the outermost part of the bumper on the driver's side hitting the barrier. The test replicates a relatively rare but particularly dangerous type of crash that concentrates impact forces into a small area, according to the Insurance Institute.

The IIHS has run the small overlap crash test since 2012. The IIHS gave the Wrangler a rating of "Marginal" for its performance in the test, the second lowest of four possible ratings

In this case, the Wrangler spun to one side then tipped over onto its passenger side, just as it had during the 2019 test. It is the only vehicle model ever to tip over during this test, Insurance Institute spokesman Joe Young said.

Ordinarily, automakers perform crash tests themselves following detailed instructions provided by the Insurance Institute. The IIHS then separately performs tests on some of the vehicles itself to check the results provided by the automakers.

Prior to the 2019 Wrangler crash test, Fiat Chrysler Automobiles, Jeep's parent company at the time, had tested the SUV and it didn't tip over. It did when the IIHS performed the test itself, though.

After the first tip-over, Jeep engineers made changes to a suspension component to address the issue, a spokesman for Stellantis, Jeep's current parent company, said in a statement after the most recent result. Fiat Chrysler insisted at the time that vehicle was safe and that the company was unaware of similar real-world incidents in which the Jeep tipped over like this.

Stellantis pointed out, again, that the company is aware of no real-world instances of this happening.

"Stellantis is reviewing this latest result," the company said in its latest statement. "We routinely consider third-party testing and factor it into our product-development process, as appropriate. But we engineer our vehicles for real-world performance."

"By conservative estimate, [Jeep Wranglers] have accounted for 105 billion on-road travel miles. And we are unaware any of field reports that correspond with the IIHS test results," the company added.

The Wrangler did a generally good job of protecting occupants from ordinary impact forces, according to the Insurance Institute. But tipping over is a major potential problem because it could lead to occupants being partially or even fully thrown from the vehicle, according to the Insurance Institute. This is particularly a concern with the Wrangler, the IIHS said, because it is a convertible. Wranglers are sold with cloth tops or removable hard tops. Even the doors can be removed, leaving occupants without much to keep them inside the vehicle except their seatbelts. (The Wrangler's owner's manual says that door removal is intended for "off road operation only.")

The IIHS is a private auto safety group financed by auto insurance companies. It conducts a variety of crash tests that are different from those performed by the federal government's National Highway Traffic Safety Administration.

The Wrangler earned the top rating of Good in four other IIHS crash tests.