EMISSION MEASUREMENTS ON HEAVY DUTY VEHICLES DURING THE PERIOD 1980-1988

During the period 1980-1988, emission measurements have been carried out on heavy duty vehicles at the Automotive Emission Research Section of the National Environment Protection Board. Measurements have been performed for investigation of different fuels and exhaust gas treatments. In all cases reference tests were carried out using standard diesel fuel without control devices such as catalysts and particulate emission traps. Also tests have been performed to map the emissions from the Swedish heavy duty vehicles. All tests performed according to the 13 mode test cycle are reported. About 350 tests have been performed on 128 vehicles. The results are presented as mean values mostly in diagrams. Heavy buses, heavy trucks and medium sized trucks intended for distribution in cities are included in the type of vehicle studied. Changes in emissions and fuel consumption mostly have been a result of technical development and lower fuel consumption. Emissions of CO and HC has been considerably lowered during the model years studied (1970-1988) but for nitrogen oxide no change can be seen for medium size trucks; for the heavy duty trucks an increase is seen. For the buses however, a decrease in nitrogen oxide emissions can be seen, probably due to the demand from city traffic companies to have buses with low emissions.