Plastics have become the material of choice for many designers and engineers in manufacturing high volume, high quality components at the lowest cost. Currently thousands of car parts, many intended for production in the New Millennium, are being designed. This design process, whether done on the computer or otherwise, is dependent on engineering property data availability.Historically plastic material properties are described by data sheets showing a set of values intended to represent typical characteristics of the plastic material. Often these properties are based on methods used in, for example, in the steel industry. Further, the designer and engineer need to relate material properties to specific end-use performance for the product being made. Discussion and examples on the relevance of plastic data for this purpose will follow.