Will the naturally aspirated truck diesel engine survive the turn of the century ?

The worldwide increasing severity of exhaust emission standards promotes the employment of turbocharged and intercooled diesel engines. To assess the emission potential of naturally aspirated diesel engines, research and development work on both single and multicylinder engines - with emphasis on Europe and Japan - has been carried out. The achievable emission level - without the use of exhaust gas aftertreatment - is demonstrated and the necessary technologies are described. As a consequence, the market specific regions where the naturally aspirated diesel engine wiil survive the turn of the century are determined. (A)