In 2011 NHTSA made changes to the NCAP frontal full-width test rating that introduced a chest deflection metric. The dummy seating protocol did not specify routing procedures that consistently control shoulder belt positioning on the dummy. Thus, most NCAP tests were conducted with the D- ring in the fully up position, placing the shoulder belt far above the center chest potentiometer.

Sled and full-vehicle crash tests of a 2011 Dodge Caliber demonstrated that for the 5 th percentile small female passenger dummy, the high D-ring position causes the belt to cross the chest above the location of the deflection potentiometer. The ribeye gauges show that this belt configuration produces deflection measurements that are higher than those measured by the center potentiometer.

The differences in chest deflection measurement caused by variations in belt routing are not trivial. For the Caliber, the NHTSA NCAP test produced a chest deflection of 11.8 mm, corresponding to a risk of serious chest injury for older females of 0.6%. A crash test conducted by IIHS under the same conditions but with the belt routed across the deflection potentiometer produced a chest deflection of 34.5 mm, corresponding to a risk of serious chest injury for older females of 44.7%.