On-road Vehicles: Emission Trends
This chart shows that carbon monoxide emissions in motor vehicles would have been about 8 times higher than actual emissions in 2000 without the regulations and technological advances implemented after 1970. Emissions in 2020 are estimated to be 41 times higher if we had no controls!
View a detailed breakdown for passenger cars, light trucks (minivans, pickup trucks, and SUVs), and heavy trucks (buses and large trucks)