Real Driving Emissions from Four Euro 6 Diesel Passenger Cars

Report no. 5/20: In Europe, the development and implementation of new regulatory test procedures including the chassis dynamometer (CD) based World Harmonised Light Duty Test Procedure (WLTP) and the road-based Real Driving Emissions (RDE) procedure, has been driven by the close scrutiny that real driving emissions and fuel consumption from passenger cars have come under in recent times. This is due to a divergence between stated certification performance and measured on-road performance, and has been most pointed in the case of NOx (oxides of nitrogen) emissions from diesel cars.

The RDE test is more relevant than CD test cycles, but currently certification RDE cycles will not necessarily include the most extreme low speed congested, low temperature or high speed highway conditions which are likely to be more challenging for NOx after-treatment systems. To build understanding of the emissions and fuel consumption performance of the latest available diesel passenger cars, Concawe has conducted a study of the performance of four vehicle types over a range of test cycles. The data generated provides insights into the emissions performance of Euro 6 diesel passenger cars, and their after-treatment systems, in extreme congested cold urban conditions including, and beyond, the most demanding likely to be encountered under regulatory RDE testing.