The ultimate goal of vehicle emissions control devices and programs are to improve ambient air quality, hence analysis of programs and technology effectiveness should focus as much as possible on real-world emissions reduction. Some of the significant implications of this work are the need for vehicle exhaust emissions guidelines in developing countries, as well as enlightening drivers on the use of catalytic converters in their vehicles. In this book, a mathematical formula was developed for quantifying vehicle emissions as well as set up illustrations and results of laboratory analysis with a clear description of the use of the gas chromatography. In addition, investigations were carried out on the effect of such emissions on human health and the difference in vehicle emissions measurement in developed and developing countries. Several factors such as emission control technology, age of vehicle, mileage covered, amongst others, contributed to the wide disparity between vehicles tested.