The gas emitted from car exhaust is primarily carbon dioxide (CO2), along with nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons, and particulate matter. CO2 is produced from the combustion of fossil fuels, such as gasoline or diesel, in the engine. Other harmful emissions like NOx contribute to air pollution and can cause respiratory problems and environmental issues like acid rain. Modern vehicles are equipped with catalytic converters to reduce harmful emissions, promoting cleaner air. Regulations aim to limit these pollutants, encouraging the development of more environmentally friendly technologies, such as electric and hybrid vehicles.