Medical complications such as sepsis or multiple organ system failure increase the morbidity and mortality associated with injuries due to car crashes. This study addresses the question of the association, if any, between crash characteristics and subsequent complications. Data were obtained as part of an in-depth, trauma center-based study of the biomechanics of vehicular trauma. Factors found to be predictive of the presence of complications included patient age, delta v≥30 mph, and lung injury. Those vehicle occupants involved in crashes with a delta v≥30 mph had a risk of complications 14 times greater than for those in the lower delta v group. Better knowledge of the dynamics and severity of the crash could help clinical staff with tertiary prevention efforts.