Combustion-engine exhaust gases[1]
All figures are approximate
Petrol Diesel
Compound% of total Compound % of total
N2 71 N2 67
CO2 14 CO2 13
H2O 12 H2O 11
CO 1 - 2 O2 10
Trace elements < 0.5 ~ 0.3
NOx < 0.25 NOx < 0.15
CxHy < 0.25 CO < 0.045
SO2 possible traces PM < 0.045
CxHy < 0.03
SO2 < 0.03