The main differences between the procedure specified by the insurance institute for.
Roof strength test.
Roof crush testing of one side of the vehicle one sided testing was performed from april 2001 through march 2008 on 75 passenger vehicles.
The force applied relative to the vehicle s weight is known as the strength to weight ratio.
The model years of the tested vehicles ranged from 1997.
Roof strength the measure of roof strength was obtained from nhtsa s office of vehicle safety research roof crush test data.
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.
To earn a good rating the roof must withstand a force of 4 times the vehicle s weight.
In the institute s roof strength test a metal plate is pushed against 1 side of a roof at a constant speed.