So why are the protectors absent from the other 30 percent of F-150s?
"We optimize each cab structure based on many factors including cab style, mass, wheelbase, powertrain and driveline to meet regulatory requirements and achieve public domain ratings," the Ford safety spokeswoman said.
The different safety configurations among models puzzled some outside experts consulted by Automotive News. Third-party engineers said it was their opinion that the protectors were added to the SuperCrew model for the sake of passing the IIHS test.
That's no surprise, says Joe Nolan, senior vice president for vehicle research at IIHS and head of its crash lab. He said IIHS alerted automakers five years ago that it would begin conducting the small-overlap tests in 2012, and automakers have responded by striving to improve their test performance.
"We definitely can see -- certainly for the small-overlap test -- countermeasures that automakers have put in," Nolan said.
He said he was glad to see that Ford had installed the protectors for both front wheels on the SuperCrew F-150s because it indicated a genuine attempt to improve safety.
"If you were just trying to beat the test, [the protectors] could only be on the driver's side," Nolan explained, because that's the side where the small-overlap test is done.
Still, having safety equipment vary across the myriad configurations of the same model could be problematic for IIHS and the reliability of its safety ratings in the long run, Nolan said.
"We don't know what else is different," Nolan said. "It certainly is Pandora's box if we need to start testing every cab variant, box type [and] engine type." c
Ryan Beene and Nick Bunkley contributed to this report.