This paper will investigate the differences in results produced between FMVSS 214-D compliance testing and the recently implemented New Car Assessment Program (NCAP) High Speed Lateral Impact (HSLI) testing. NCAP HSLI testing is similar to the Frontal Impact NCAP program in that the tests are conducted with a higher impact velocity and the results are presented primarily for consumer information purpose. Readers of this paper will gain a broader understanding of side impact testing in general, as well as form estimates for expected differences for each test. Issues such as vehicle size, deformation, and occupant responses will be investigated and the results collected from tests on the same vehicle will be compared. The results of this study provide a general “rule of thumb” guideline for estimating HSLI test results from FMVSS 214-D test results. This general guideline provides safety engineers with a reasonable estimate of expected results for the HSLI evaluation.