title: Experimental Assessment of NOx Emissions from 73 Euro 6 Diesel Passenger Cars.
abstract: Controlling nitrogen oxides (NOx) emissions from diesel passenger cars during real-world driving is one of the major technical challenges facing diesel auto manufacturers. Three main technologies are available for this purpose: exhaust gas recirculation (EGR), lean-burn NOx traps (LNT), and selective catalytic reduction (SCR). Seventy-three Euro 6 diesel passenger cars (8 EGR only, 40 LNT, and 25 SCR) were tested on a chassis dynamometer over both the European type-approval cycle (NEDC, cold engine start) and the more realistic Worldwide harmonized light-duty test cycle (WLTC version 2.0, hot start) between 2012 and 2015. Most vehicles met the legislative limit of 0.08 g/km of NOx over NEDC (average emission factors by technology: EGR-only 0.07 g/km, LNT 0.04 g/km, and SCR 0.05 g/km), but the average emission factors rose dramatically over WLTC (EGR-only 0.17 g/km, LNT 0.21 g/km, and SCR 0.13 g/km). Five LNT-equipped vehicles exhibited very poor performance over the WLTC, emitting 7-15 times the regulated limit. These results illustrate how diesel NOx emissions are not properly controlled under the current, NEDC-based homologation framework. The upcoming real-driving emissions (RDE) regulation, which mandates an additional on-road emissions test for EU type approvals, could be a step in the right direction to address this problem.
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.|International Council on Clean Transportation Europe , Berlin 10178, Germany.|Higher Institute for Environmental Engineering and Management (ISIGE), MINES ParisTech , Fontainebleau 77305, France.
authors.forename: Liuhanzi
authors.initials: L
authors.lastname: Yang
authors.affiliation: International Council on Clean Transportation Europe , Berlin 10178, Germany.
authors.forename: Vicente
authors.initials: V
authors.lastname: Franco
authors.affiliation: International Council on Clean Transportation Europe , Berlin 10178, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Mock
authors.affiliation: Allgemeiner Deutscher Automobil-Club, Technik Zentrum , Landsberg am Lech 86899, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Kolke
authors.affiliation: Department of Mechanical Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.|State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wu
authors.affiliation: International Council on Clean Transportation , Washington, District of Columbia 20005, United States.
authors.forename: John
authors.initials: J
authors.lastname: German
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001334:Automobile Driving / Q000331:legislation & jurisprudence; D001336:Automobiles; D005742:Gasoline; D009589:Nitrogen Oxides / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D005742:Gasoline; D009589:Nitrogen Oxides; D001335:Vehicle Emissions