تلخیص
For the past several decades automobiles have been a major source of ground level emissions of
various pollutants like CO, HC, NOx, SOx, CO2, etc. Due to their dangerous effects on human health,
vegetation and on climate, various pre-combustion, in-cylinder and post combustion techniques have
been tried for their abatement. This paper reviews all of the workable measures taken so far to
controlling the combustion generated emissions from 4-stroke Spark Ignition Vehicular Engines ever
since the promulgation of emission control legislation/standards and their subsequent enforcement in
the late 1960s.