Search Results

Non-plugin hybrids represent a technology with the capability to significantly reduce fuel consumption (FC), without any changes to refuelling infrastructure. The EU market share for this vehicle type in the passenger car segment was 3% in 2018 and this powertrain type remains of interest as an option to meet the European Union (EU) fleet average CO2 limits. EU legislative procedures require emissions limits to be met during the chassis dynamometer test and in the on-road real driving emissions (RDE) test, while official CO2/FC figures are quantified via the laboratory chassis dynamometer test only. This study employed both legislative test procedures and compared the results. Laboratory (chassis) dynamometer testing was conducted using the Worldwide Harmonised Light Vehicles Test Procedure (WLTP). On-road testing was carried out in accordance with RDE requirements, measuring the concentration of regulated gaseous emissions and the number of solid particles (PN).

This paper discusses the legislative situation regarding type approval of plug-in hybrid vehicles (also known as off-vehicle charging hybrid-electric vehicles, OVC-HEV) in the range of exhaust emissions and fuel consumption. A range of tests were conducted on two Euro 6d-complaint OVC-HEVs to quantify emissions. Procedures were based on EU legislative requirements. For laboratory (chassis dyno) testing, two different test cycles and three different ambient temperatures were used for testing. Furthermore, in some cases additional measurements were performed, including measurement of emissions of particulate matter and continuous analysis of regulated and unregulated pollutants in undiluted exhaust. Consumption of electrical energy was also monitored. On-road testing was conducted on the test vehicle tested on the chassis dyno in the tests mentioned above, as well as on a second OVC-HEV test vehicle.

For over a decade, the EU has required in-service conformity testing of heavy-duty road vehicles. This paper briefly discusses the practical aspects of the test requirements, how they have evolved and how they compare to other precedents, such as the heavy-duty engine dynamometer-based type approval testing procedure, as well as broadly equivalent EU requirements for light duty vehicles. Emissions requirements for heavy-duty vehicles are work-specific, but based on standard test results a range of other parameters can be calculated to yield distance-specific, tonnage-distance specific, CO2-specific and (gravimetric) fuel-specific results. At present, CO2 and fuel consumption are not subject to any limits per se during on-road testing (and this is the case for both heavy and light duty vehicles); nevertheless, the aforementioned parameters must be measured and such results can be of interest for a variety of reasons.

This paper discusses the importance of the inclusion of emissions from the cold start event during legislative on-road tests on passenger cars (RDE - real driving emissions tests conducted under real-world driving conditions, as defined by EU legislation). Results from a recently-registered gasoline-powered vehicle are presented, with the main focus on the comparison of exhaust emission results: excluding/including the cold start during the initial phase of the RDE test. Cold start is the most challenging aspect of emissions control for vehicles with spark ignition engines and the inclusion of the cold start event in RDE test procedure has wide-ranging implications both for the testing process and compliance with RDE legislation via optimisation of aftertreatment systems and the engine calibration. In addition to some theoretical arguments, the results of an RDE-compliant test performed using the aforementioned procedures are presented.

The investigations into the emissions from light-duty vehicles have been carried out on a chassis dynamometer (NEDC test in Europe and FTP75 test in the US). Such tests do not entirely reflect the real road conditions and that is why we should analyze the correlation of the laboratory versus on-road test results. The paper presents the on-road test results obtained in an urban and extra urban cycles. For these measurements a portable SEMTECH DS analyzer by SENSORS has been used. The device is an analyzer enabling an on-line measurement of the emission gases concentration in a real driving cycle under real road conditions. The road tests were performed on road portions of several kilometers each. The obtained results were compared with the results obtained for the same vehicle during the NEDC test on a chassis dynamometer. The comparative analysis was performed including the urban and extra-urban cycles.