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Although the superior properties of compacted graphite iron (CGI) are well known, its application to the series production of complex castings such as passenger car engine blocks has been precluded by the absence of a reliable foundry production technique. Despite the narrow chemistry range over which high quality CGI is stable, recent advances in cast iron foundry process control technology now serve as the starting point for a comprehensive CGI engine development programme at Adam Opel AG. The Opel CGI programme originated with the 2.5 litre V-6 DTM racing engine which now delivers 2.7 times more power and weighs 20% less than the standard grey iron production. Acoustical evaluations where then performed on identically designed 2.0 litre Family II engines to show that the audible noise level of the CGI engine was 1.1 to 1.5 dB(A) less than that of the grey iron engine.