This paper presents the results of an analysis of 16 full-scale side impact crash tests that were conducted by the Japanese Automobile Manufacturers Association. The objective is to examine the influence of the major factors distinguishing the proposed U.S. and European passenger car side impact test procedures on the resulting injury measures. The factors addressed are the dummy, the moving deformable barrier, and the impact angle of the barrier.Each of the factors examined had substantial effects on the injury measures. For the front seat position, the design of the EEVC barrier face and the EUROSID rib structure combine to produce a Thoracic Trauma Index 80 percent higher than in the U.S. test. Conversely, the EEVC barrier face produces a resultant peak pelvic acceleration 131 g's (74 percent) lower than the U.S. test. These results underscore the importance of the differences in the proposed U.S. and European side impact tests and the obstacles to international harmonization.