DEMAND FOR HIGHER SPECIFIC OUTPUT FROM DIESEL ENGINES has resulted in virtually all heavy duty engines being turbocharged. To obtain further increases in specific output, turbocharged engines can be coupled with a charge air cooling system. All major engine manufacturers now offer at least some models employing charge air coolers. The favorable impacts of charge air cooling on fuel consumption, emissions, altitude performance, thermal loading of engine components and the capability for higher specific output have encouraged several investigators to undertake in-depth studies of optimum charge air cooling system.This paper reviews the evolution and trends in charge air cooling systems. The advantages and concerns connected with the various methods are discussed. Some test and analytical results of the effect of charge air cooling on various engine performance parameters are presented.