ABSTRACT
Air pollution is a serious problem in all over the world. Diesel engines seem to have a large influence on air pollution because they are used for heavy-duty trucks and emit a higher level of pollutants than petrol engines do, however diesel fuel has slightly higher energy content than petrol per unit volume. Off-road vehicles, trucks, buses and other types of heavyduty vehicle are powered almost exclusively by diesel engines. Diesel engines make a significant contribution to air pollution (Lindgren and Hansson, 2002).
