NEW YORK (CNNMoney) -- The new all-aluminum Ford F-150 crew cab pickup did well in a tough new crash test, but the slightly smaller SuperCab version of the truck earned poor marks.
Both versions were subjected to the new small overlap front crash test. In that test, a vehicle hits a barrier at 40 miles per hour with just one-quarter of its front bumper. The impact occurs on the left side, just in front of the driver's seat.
The larger Ford F-150 SuperCrew version of the truck has additional structures that helped protect the passenger compartment during the test. It earned the Institute's top rating of "Good."
"Consumers who wondered whether the aluminum-body F-150 would be as crash-worthy as its steel-body predecessor can consider the question answered," said David Zuby, Insurance Institute for Highway Safety chief researcher, in a statement.
But lacking those additional protective structures, the passenger compartment on the smaller SuperCab truck got crushed. Parts of the footwell were pushed back about a foot, resulting in a risk of foot and leg injuries. The SuperCab truck earned the Insitute's second-worst rating of "Marginal."
The Insurance Institute was originally going to test only the larger SuperCrew truck because that's the most popular version of the truck. After learning of the structural differences from other versions of the truck, though, the Institute decided to test the smaller version as well. In the future, the Institute will test more than one version of large pickups like the F-150, the Institute said.
When this crash test was introduced in 2012, the new F-150 was already far into development, Ford spokesman Mike Levine said. Engineers weren't able to design the extra front-end protective measures quickly enough for all versions, he said, so a decision was made to add them first to the four-door SuperCrew truck, which accounts for a large majority of F-150 sales. The protective measures will be part of the vehicle's 2016 design.
About a quarter of the serious and fatal injuries in front crashes are caused by "small overlap" impacts similar to this, according to the Institute. These crashes can also cause severe foot and leg injuries as the car's front wheel is pushed back into the passenger compartment. These types of crashes happen in real life when vehicles leave the road and hit trees or utility poles.
Both these versions of the F-150 did well in all of the other IIHS tests including normal front and side impact crash tests.
Separately, the Insurance Institute also looked into body shop repair costs for the new F-150. Aluminum body parts can be more expensive to repair than steel body parts so there has been concern that the new F-150 would cost more to fix than other trucks after a crash.
The Institute ran low-speed crash tests with the new F-150 and older steel-bodied versions of the same truck. In these tests, the new aluminum truck had more damage and cost about 26% more to repair than the older steel truck. The results are roughly in-line with what the Institute has found for other vehicles with with high aluminum content, Rader said.
"We do not agree with the repairability costs and findings by IIHS," Ford said in a statement. "Real-world repair costs for the 2015 F-150 to date are comparable to or less than other full-size pickups and an average $869 more affordable to repair than last year's F-150 -- not the higher numbers released after crash stunts orchestrated by IIHS and others."
Higher repair costs would mean customers could expect to pay more in insurance premiums for the new F-150 than for a steel-bodied truck.
Editor's Note: The headline of this article has been changed from an earlier version to better reflect the report's findings.
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