Control of sound levels in vehicles is becoming an integral part of the design criteria used by vehicle and equipment designers. Standards are in place which require noise control and the consumers are demanding the control for the safety and productivity of their workers.Molded fiber glass offers solutions to the noise control problems as well as providing many other product benefits. The fiber glass can be easily molded into parts of various shapes and densities that provide both acoustical and thermal control for the service life of the system.The fiber glass parts offer consistent performance with minimum variation from part to part. This effective and consistent performance allows a designer to be more confident that a given design will perform as intended.Molded fiber glass parts can be an extremely cost effective way for vehicle and equipment designers to address concerns with thermal and acoustical energy. With the emphasis on performance, reliability and comfort which exists in todays cost competitive business environment, designers have a monumental task to choose materials which can handle a variety of concerns at the lowest possible total installed cost.Fiber glass can be molded into many different shapes and densities. It can also be easily incorporated as part of a composite design to address specific physical property or aesthetic application requirements. When used as part of a well designed system, fiber glass can perform as intended for the full service life of the system.This paper will address some of the physical performance characteristics which make fiber glass molded parts an attractive choice for equipment and vehicle designers.