Petrol engines release gaseous oxides of

Petrol engines release gaseous oxides of nitrogen, formed when high combustion temperatures fuse atmospheric nitrogen with oxygen.

Sulphur oxides come mainly from sulphur-rich fuels like coal and diesel, not clean petrol.

Phosphorus oxides are not a normal product of petrol engine combustion.

Carbon does leave as carbon oxides, but the oxide highlighted here for petrol engines is that of nitrogen.

These nitrogen oxides help create photochemical smog and acid rain.

Catalytic converters are fitted to cut such nitrogen oxide emissions.