Basing on its well-known “M” combustion system for truck Diesel engines, M.A.N. has developed the Controlled Direct Injection (CDI) System to meet the requirements of passenger car Diesels. A variable-area injection nozzle permits mixture preparation in the combustion chamber to be matched to speed and load. This varies the injection pattern with wall deposition of the fuel predominating at high load and speed, whereas air distribution prevails at low load and speed. Apart from the established advantages of direct injection in respect of fuel economy, the system also enables low emission and noise levels to be obtained.