Quote (hurt_knee @ Sep 12 2011 02:04am)
Carbon Monoxide Carbon monoxide (CO) is a colorless, odorless, poisonous gas, a product of incomplete burning of hydrocarbon-based fuels. Carbon monoxide consists of a single carbon atom and a single oxygen atom linked together (CO), the product of incomplete combustion of fuel. Most CO is produced when air-to-fuel ratios are too low in the engine during vehicle starting, when cars are not tuned properly, and at higher altitudes, where thin air reduces the amount of oxygen available for combustion. Two-thirds of the carbon monoxide emissions come from transportation sources, with the largest contribution coming from cars. In urban areas, the passenger vehicle contribution to carbon monoxide pollution can exceed 90%. Read more about Carbon Monoxide
doesn't say anywhere that its the Main Gas from Car exhaust, One key fact is that it comes from Incomplete Combustion which is only a small percentage of the exhaust Hench the 3% i gave before.
Main gas expelled is still Carbon Dioxide, the next dangerous are the Nitrogen Oxides which are like 300 times worse than CO2 but only a small percentage of it is created