An engineering thermoplastic from GE Plastics—ULTEM polyetherimide resin—has replaced aluminum under the hood in a throttle body application. Compared to other amorphous resins, ULTEM resin performs better in aggressive environments, at higher temperatures and stress levels, for longer periods of time. Its use for ETP throttle bodies is expected to be a critical breakthrough for the integration of the air management system. Throttle bodies were one of the last components in the system to be accepted as a thermoplastic application. Now that the entire system can be made of thermoplastic, automakers can begin incorporating complete air management modules rather than individual system components.