On-Road Emissions of Euro 6d-TEMP Vehicles: Consequences of the Entry into Force of the RDE Regulation in Europe

Abstract

Human health and the environment are heavily impacted by air pollution. Air quality standards for Nitrogen dioxide (NO2) and particulate matter (PM) are commonly exceeded in Europe, particularly in urban areas with high density of traffic. Road transport contributed to 39% of NOx emissions, and 11% of PM emissions in the European Union (EU) in 2017. Measurements with Portable Emissions Measurement Systems (PEMS) showed that most Euro 5 and Euro 6b diesel vehicles emitted significantly more NOx on the road than their permissible limit in the laboratory type-approval test. In that context, EU Real Driving Emissions (EU-RDE) regulation aims at securing low on-road emissions of light duty vehicles under normal conditions of use. This paper assesses the tailpipe emissions performance of Euro 6d-TEMP gasoline and diesel passenger cars, type-approved after the entry into force of the RDE regulation in September 2017. Vehicles were tested by the Joint Research Centre (JRC), the in-house research center of the European Commission, on RDE-compliant and non-compliant tests with an AVL-MOVE PEMS. Gaseous emissions (NO, NO2, NOx, CO, CO2) and particle number (PN) emissions are discussed for the complete test and the respective urban, rural, and motorway sections, with emphasis on cold-start emissions. The relationship between emissions and driving dynamics is also presented. Our results indicate that in order to meet the emission limits under the wide range of RDE driving conditions, vehicle manufacturers have been forced to implement performant after-treatment systems for NOx and PN, namely Selective catalytic reduction (SCR) catalysts and particle filters. It can be expected that the progressive fleet renewal from pre-RDE to post-RDE vehicles in Europe will help mitigate urban pollution and decrease the frequency of exceedances of the air quality standards.