An inflatable restraint tailoring method has been developed which shows the effect of the passenger air bag module characteristics on occupant performance in the unbelted condition.The tailoring algorithm uses PASSIM-PLUS1 to predict dummy injury measures and kinematics. From these measures, restraint efficiency is evaluated from peak chest deceleration and relative displacement. This efficiency is them used to evaluate the occupant sensitivity to air bag characteristics and to design the module. The tailoring method evaluates a specified range of inflator outputs and bag sizes via the PASSIM-PLUS model. The venting is adjusted for each air bag module configuration to produce a constant bag penetration by the occupant. The results of these model runs are used to establish trends for passenger air bag module design based on a specific vehicle environment and crash pulse.