A NEW METHOD TO DETERMINE EXHAUST EMISSION FACTORS FOR HEAVY-DUTY VEHICLES

In contrast to the evaluation of exhaust gas and fuel consumption fact ors for passenger cars, heavy duty trucks and buses have not been test ed on a chassis dynamometer. For reasons of practicability and costs, exhaust gas emissions and fuel consumption of 34 different diesel engi nes have been measured on dynamic engine test benches. Using these eng ines, the fleet of heavy duty trucks and buses in the Federal Rebublic of Germany for the reference years 1986 and 1990 can be represented. From the engines' emission data sets, and data concerning the drive tr ain and the driving resistance of representative vehicles, the exhaust emission behaviour of more than 300 different types of trucks and bus es could be simulated on the basis of a newly developed method. It is therefore possible to calculate exhaust emission and fuel consumption factors for all categories of the entire fleet of heavy duty vehicles taking into account the road category, gradient, load factor and traff ic flow conditions. This new method allows the determination of exhaus t emission and fuel consumption factors for a broad range of different scales, from the emission simulation for a single vehicle up to globa l emission assessments.