Abstract
The design and development of an advanced turbocharger incorporating a variable nozzle turbine (VNT), intended for highly rated, medium duty highway truck Diesel engines in the 6-8 L displacement range is reviewed and important accomplishments discussed. Further development to production release is planned. Interactive engine and turbocharger control, always critical, was found to be especially so for more highly rated engines, particularly during transient operation and decompression engine braking for vehicle retardation.