Insights for post-Euro 6 based on analysis of Euro 6d-TEMP PEMS data

Real-Driving Emissions (RDE) requirements were introduced in the European emission legislation to address the gap between lab and real-world emissions. The procedure focuses on on-road testing with a Portable Emissions Measurement System (PEMS) and defines a Not-to-Exceed limit for NOx and PN emissions. This paper analyses a database of publicly available PEMS data of mostly Euro 6d-TEMP vehicles. Emissions data of 7 gasoline and 13 diesel vehicles are investigated. Different routes are included per vehicle to explore the emissions over a range of driving conditions. A standard analysis approach is to look at the average emissions per kilometer over the total test, but it has to become difficult to derive trends as overall emissions have reduced significantly compared to the pre-RDE era. This investigation therefore looks at smaller trips within the RDE tests. The intention is to explore remaining emission events to derive insights for Euro 7. The results firstly confirm a significant reduction in real-world emissions with the introduction of RDE requirements, both for PN and NOx emissions. Secondly, the paper shows cold-start emissions are important for both gasoline and diesel vehicles. Once the emissions control technologies are at normal operation temperature, emissions are well controlled for most cases. Finally, it is shown that relatively high emission events are still happening and that this is not only limited during to the cold-start phase. As overall emission levels are indeed reducing, the relative contribution of the remaining emission events becomes significant. Effective legislation must ensure that the remaining emission peaks are properly controlled by designing the testing protocol to apply appropriate averaging of emissions over the emissions test, or part of it.

Jaar van publicatie:2021

Toegankelijkheid:Open