In the past there has been a concentration on performing LCAs of car components. Based on the increasing experience and know-how gained in the past by performing LCAs of car components truck designers get the chance to make a statement about the ecological impact of each alternative. The most significant difference between LCAs of car and truck components is the use phase.This paper describes a Life-Cycle-Assessment (LCA) of different air deflection systems made of composite materials. The actually used system is produced by Resin Transfer Molding (RTM) while a possible alternative could be made out of Sheet Molding Compound (SMC). The calculations have shown that there exists a potential to improve the ecological profiles of composite components by replacing glass fibers with natural fibers.