The eight vehicles tested, all mid-sized SUVs, were put through crashes that simulated the vehicles’ front corner hitting a tree, poll, or other vehicle at 40 miles per hour.

“Although some vehicles in this group offer very good protection, in other models, the airbags, safety belts and structure showed serious deficiencies,” IIHS chief research officer David Zuby said in a statement. “In those SUVs, a front-seat passenger would be at risk of injuries to the head, hip or leg in a right-side small overlap front crash.”

The test covered six criteria — impact of the crash on the car’s structure, effectiveness of passenger restraints and kinematics, head and neck injuries, chest injuries, hip and thigh injuries, and lower leg and foot injuries — to calculate an overall rating.

Ford Explorer received an overall “poor” rating for the passenger side due to structural damage caused in the accident, along with likely right hip injuries to the passenger and addition possible injuries to the passenger’s lower left leg. The Explorer got a “marginal” score for the driver’s side.

The Jeep Grand Cherokee’s “poor” rating in the passenger-side test was due to the possibility of right leg injuries and head injuries. In the test, the dummy’s head “hit the dashboard hard through the front airbag and then, because the side curtain airbag didn’t deploy and the door opened, it moved outside the vehicle during rebound,” IIHS said.

The Honda Pilot was given an “acceptable” score in the passenger-side front overlap test, although head injuries were also possible.

Ford defended the Explorer, referencing its score from the National Highway Traffic Safety Administration’s New Car Assessment Program (NCAB). The NCAP’s tests differ from the IIHS tests. For frontal crashes, the NCAP tests cars by ramming them at 35 miles per hour into object that is the full width of the vehicle. In this test the Ford Explorer received an overall five stars.

“Customer safety continues to be one of our highest priorities when we design any of our vehicles and we continually make improvements to our vehicles to help our customers stay safe on the road,” a Ford spokesperson told Fortune. “Explorer is a safe vehicle and has earned the highest 5-star overall NCAP ratings in the U.S. as well as ‘good’ ratings in front and side IIHS crash test modes. We fully expect next year’s all-new 2020 Explorer will perform well on both SORB test and other tests.”

Fiat Chrysler Automobiles, which makes the Jeep Grand Cherokee, pointed to federal regulations, and highlighted that in four other IIHS tests (moderate overlap front crashes, side crashes, roof strength, and tests for head restraints and seats) the Jeep Grand Cherokee received an overall “good” rating.

“All FCA US vehicles meet or exceed federal safety standards,” Fiat said in a statement. “FCA US vehicles are engineered to address real-world driving situations. No single test measures overall vehicle safety.”

Overall, the 2019 Kia Sorento was the only mid-sized SUV to earn the IIHS Top Safety Pick+ award (it was also the only 2019 model to be tested in this category). The Sorento, along with the 2018 GMC Acadia and 2018 Volkswagen Atlas were the three mid-sized SUVs to earn “good” ratings. The 2018 Toyota Highlander, Nissan Pathfinder, and Honda Pilot models all earned “acceptable” ratings.

The IIHS is an independent, non-profit organization founded in 1959 and funded by the auto-insurance industry. It tests differ from those performed by federal regulators, according to CNN.