The 2002 Explorer sustained $5,432 worth of damage in four tests conducted at 5 miles per hour, earning the institute's lowest rating for bumper performance.
The tests are designed to imitate the kind of impact that often occurs in commuter traffic and parking lots.
In a statement, Ford said it designs its bumper systems to meet government standards, company requirements and customer expectations, not the tests of the institute.
"These tests by the Insurance Institute for Highway Safety are conducted to determine cost estimates to repair damage incurred in low-speed bumper impact tests and are not related to safety," the company said. "In addition, these tests may not be representative of the type of damage that occurs in real world situations."
The Chevrolet TrailBlazer was given the best rating of the four vehicles tested after suffering $2,445 in damage. All the damage was to the bumper, which protected the vehicle body.
Like the Explorer, the 2002 Jeep Liberty earned the lowest, "poor" rating after sustaining $5,667 in damage. The worst result - more than $1,700 in damage - occurred when the vehicle was backed into a flat barrier, shattering the rear window and damaging the rear windshield wiper motor and the tailgate.
Adrian Lund, the institute's chief operating officer, said the Jeep Liberty performed so poorly because it has a spare tire mounted on the back. The spare extends beyond the bumper, so the bumper doesn't absorb any of the impact.
Another vehicle made by DaimlerChrysler Corp., the 2002 Dodge Ram 1500, improved in the tests. It sustained $3,843 in damage in the four tests, compared to $8,438 for the 2001 model.
"The Ram used to have the worst bumpers among the large pickup trucks the institute tested, but now it has the best bumpers," Lund said.
DaimlerChrysler spokeswoman Angela Ford said the company was pleased with the Ram test results.
"But it's important to remember this test measures insurance claims cost and is in no way a reflection of vehicle safety," she said. "Although we attempt to keep repair costs low on all of our products, our primary focus is safety, both in terms of government testing and real-world safety parameters."
By Nedra Pickler © MMI The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed