Due to the high output of diesel engines, they are widely used in public transport, commercial, engineering and military vehicles. The biggest users of diesel engines are buses, trucks, semi trailers and military vehicles. The pollutants emitted are mainly particulates and the Nitrated Polycyclic Aromatic Hydrocarbons (PAHs) associated with such emissions can cause cancer to lungs and throats and it is a major threat to human health. There are more than four hundred and eighty thousand (480,000) diesel vehicles in the country and the only means to monitor and test the exhaust emission of smoke from these vehicles are the Dynamometer Testing Centers. All the counties and cities in the country will be completing the installation of such dynamometer testing centers from 2004. There are now twenty three dynamometer testing lines around Taiwan with a capacity of testing eighty thousand (80,000) vehicles per year. It will take about six years to completely test all the four hundred and eighty thousand vehicles in the country. It is therefore impossible to rely on the existing testing centers to control the emission problem with regular tests. It would have to supplement the fixed and regular testing with irregular and random tests. Owners use fine tuning of vehicles as a means to pass such smoke tests and this is currently a universal problem and hence ways to control and further cut off means of cheating is an urgent issue if the air quality of the country is to be upheld.

Diesel Vehicle,Dynamometer