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The market share of Gasoline Direct Injection (GDI) vehicles has been increasing, promoted by its positive contribution to the overall fleet fuel economy improvement. It has however been reported that this type of engine is emitting more ultrafine particles than the Euro 6c Particle Number (PN) limit of 6·1011 particles/km that will be introduced in Europe as of September 2017 in parallel with the Real Driving Emission (RDE) procedure. The emissions performance of a Euro 6b GDI passenger car was measured, first in the OEM build without a Gasoline Particulate Filter (GPF) and then as a demonstrator with a coated GPF in the underfloor position. Regulated emissions were measured on the European regulatory test cycles NEDC and WLTC and in real-world conditions with Portable Emissions Measurement Systems (PEMS) according to the published European RDE procedure (Commission Regulation (EU) 2016/427 and 2016/646).

AECC, the Association for Emissions Control by Catalyst, conducted a test program to compare the newly developed World-harmonized Light vehicles Test Cycle (WLTC) with the current European regulatory New European Drive Cycle (NEDC) and the cold-start Common Artemis Driving Cycle (CADC). Vehicle engines and aftertreatment technologies were selected to cover a wide range of future systems. Six European commercially available passenger cars were chosen: three Euro 5 Gasoline Direct Injection cars, two Euro 6 Diesel cars and a Euro 5 non-plug-in gasoline hybrid car. The hybrid car was tested with three different battery state of charge: nominal, minimum charge, and maximum charge. Investigations on the test temperature were also conducted by comparing emissions at 25°C and at −7°C. Regulated gaseous emissions (HC, CO, NOx) and particulate mass and particles number were measured, together with additional pollutants such as CH4, NO2 and ammonia.

The Euro VI Step E emission standard for heavy-duty vehicles (HDVs) is the first step to introduce cold-start emissions analysis as part of the on-road In-Service Conformity (ISC) requirements. The intention is to reflect the engine cold-start requirements foreseen in the World Harmonized Transient Cycle (WHTC) type approval cycle. In addition, a limit is introduced for solid particle number (PN) to be measured with Portable Emissions Measurement Systems (PEMS). The new regulatory step continues using the Moving Averaging Window (MAW) data post-processing prescribed by the Euro VI regulation, with additions to consider the cold-start emissions. In order to have a full understanding of the vehicle emissions performance during their daily operation, this study presents emissions data analysis of 25 Euro VI A-C and 3 Euro VI D vehicles. The aim is to screen for potential remaining high emission events during the day-to-day operation.

The gap between diesel vehicle emissions in laboratory tests compared to those in use has been addressed by the introduction of the Real Driving Emissions (RDE) requirements. Modern diesel technology now demonstrates low emissions on the road over a wide range of driving conditions. This paper further demonstrates that consistent low nitrogen oxide (NOx) and particle number (PN) emissions can be achieved over a wide range of driving conditions beyond Euro 6d RDE requirements, with emission control technologies combined in an integrated approach. An LNT (Lean NOx Trap) is combined with a dual-dosing SCR (Selective Catalytic Reduction) system. Low-load NOx control is achieved by the LNT in combination with a close-coupled SCR coated on the Diesel Particulate Filter (SDPF). High load conditions, on the other hand, are covered by the underfloor SCR system with a second AdBlue® injector.

Heavy-duty vehicles represent a significant portion of road transport and they need to operate in a clean and efficient manner. Their emission control systems need to be enhanced to sustain the high conversion efficiencies seen during motorway conditions inother operating conditions. The European Commission is developing legislative proposals for Euro 7 emissions regulations for light- and heavy-duty vehicles. The new Euro 7regulation will likely focus on ensuring the emissions from heavy-duty vehicles are minimized over extensive on-road operating conditions and specifically on operating conditions such as urban driving and cold-start operation. These challenges are increased by the need to ensure low secondary emissions like NH3 and N2O, as well as a low impact on CO2 emissions. The paper outlines the low pollutant emissions achieved by a heavy-duty Diesel demonstrator vehicle.

The electrified internal combustion engine can contribute to further improving air quality and reducing impact on climate change. A previous publication looked into ultra-low initial cold-start emissions with the implementation of a state-of-the-art emission control system on a gasoline vehicle with market E10 gasoline. This paper reports additional investigations on different drop-in sustainable renewable fuels, including e-fuels. The gasoline demonstrator vehicle is equipped with a 48V mild-hybrid powertrain with a 1.5 L direct injection engine. The innovative emission control system consists of an electrically pre-heated catalyst (EHC) and first three-way catalyst (TWC) in close-coupled position, in combination with an underfloor catalysed gasoline particulate filter (cGPF), second TWC and ammonia slip catalyst (ASC). Pollutant emission tests are conducted on a challenging chassis dyno test for cold-start emissions at 23 °C and -10 °C.