The insurance institute for highway safety iihs is.
Iihs roof strength test.
The head restraints seats rating is based on a sled test of the vehicle s seat and head restraint.
Roof strength test overview.
The force applied relative to the vehicle s weight is known as the strength to weight ratio.
In order to earn a good rating a vehicle s roof must withstand a.
This rating only applies to the specific seat head restraint combination tested indicated on the.
Document revision history a history of revisions to this document is provided in appendix b.
In the test the strength of the roof is determined by pushing an angled metal plate down on one side of the roof at a slow but constant speed and measuring the force required to crush the roof.