combustion efficiency

Often emissions test for CO+CO2 as a measure of combustion efficiency. An ideal burning of a hydrocarbon would only release water vapor and carbon dioxide. Unfortunately engines are far from ideal, and the real chemistry of combustion is very complicated as a result. The pollutants in exhaust are what we call the byproducts of combustion. Bad fuel air ratios that cause noxious emissions are caused by the engine operating outside of its ideal rpm range. Engines have only one speed at which they produce the best ratio of power output to low emissions. Thus STAR smog check station is ready for cooperation and assistance. Unfortunately to work with transmissions for variable vehicle speed and power output variation, engines must operate over a wide range of speeds from idle to redline. Incomplete combustion also causes particulate matter and VOC/ HC to form. These dust/ soot/ vapors are extremely toxic: they are the parts that give some of the color and most of the nasty smell to v…