Will Euro 6 reduce the NO sub(x) emissions of new diesel cars? - Insights from on-road tests with Portable Emissions Measurement Systems (PEMS)

• Published in: Atmospheric environment (1994) Vol. 62; pp. 657 - 665
• Main Authors: Weiss, Martin, Bonnel, Pierre, Kuehlwein, Jorg, Provenza, Alessio, Lambrecht, Udo, Alessandrini, Stefano, Carriero, Massimo, Colombo, Rinaldo, ni, Fausto, Lanappe, Gaston, Le Lijour, Philippe, Manfredi, Urbano, Montigny, Francois, Sculati, Mirco
• Format: Journal Article
• Language: English
• Published: 01.12.2012
• Subjects: Automobiles; Automotive engineering; Cars; Diesel; Diesel fuels; Emission analysis; Emissions control
• ISSN: 1352-2310
• DOI: 10.1016/j.atmosenv.2012.08.056

The nitrogen dioxide (NO sub(2)) pollution in urban areas of Europe can be partially attributed to the increasing market penetration of diesel cars that show higher distance-specific nitrogen oxides (NO sub(x)) emissions than gasoline cars. The on-road NO sub(x) emissions of diesel cars, furthermore, appear to exceed substantially applicable emissions standards. This observation raises concerns that the introduction of more stringent Euro 6 emissions standards in 2014 may not adequately reduce the distance-specific on-road NO sub(x) emissions of new diesel cars. We address the existing concerns by analyzing the gaseous emissions of one novel Euro 6 diesel car and six Euro 4-5 diesel cars with Portable Emissions Measurement Systems (PEMS). We find that the average on-road NO sub(x) emissions of the Euro 6 car (0.21 plus or minus 0.09 g per kilometer [g km super(-1)]) are considerably lower than those of the Euro 4 cars (0.76 plus or minus 0.12 g km super(-1)) and the Euro 5 cars (0.71 plus or minus 0.30 g km super(-1)). The selective catalytic reduction (SCR) system of the Euro 6 diesel car is suitable to limit NO sub(x) emissions during real-world on-road driving. Still, all tested cars, including the Euro 6 diesel car, exceed their NO sub(x) emissions standards on the road by 260 plus or minus 130%. This finding suggests that the current type-approval procedure does not adequately capture the on-road NO sub(x) emissions of diesel cars. By introducing a complementary emissions test procedure that covers a wide range of normal operating conditions, the European legislative authorities can address this problem and ensure that Euro 6 will indeed deliver an adequate reduction in the NO sub(x) emissions of new diesel cars.