Emissions testing with PEMS versus random laboratory driving cycles - Preliminary results Pierre Bonnel Martin Weiss Joint Research Centre (JRC) IES - Institute for Environment and Sustainability Ispra – Italy http://ies.jrc.ec.europa.eu/ http://www.jrc.ec.europa.eu/

JRC emissions testing Euro 5 diesel vehicle (4 cylinders; 55 kW; 49.8 kW/t; start-stop; DPF; 108 g CO2/km) PEMS emissions testing on three routes (rural-motorway; rural-urban; rural-uphill/downhill) Laboratory emissions testing based on NEDC, Artemis, two fixed driving cycles and one random driving cycle

PEMS emissions testing NOx CO

PEMS emissions testing Averaging window NOx emissions: exceedance of the Euro 5 emissions limit (0.18 g/km) by all windows

PEMS emissions testing Accuracy of PEMS is comparable to laboratory equipment (tailpipe emission measurements) - PEMS uncertainty NOx ± 4% of reading; CO2 ± 3% of reading - different calibration gases

Lab emissions testing (i) speed trace urban driving in Rome (low-medium severity) (ii) speed trace urban driving in Rome + 600 s of the Artemis urban cycles + 2x128 s of the US06 cycle (medium-high severity) (iii) free cycle based in defined idling periods and constant speed points (1,200s; 15 km; 46 km/h)

Lab emissions testing Cycles (i) and (ii): - easily implemented; standard gear-shifting procedure - prescribed speed trace - good drivability despite severe acceleration (>0.8 m/s2)

Lab emissions testing Cycles (i) and (ii): - easily implemented; standard gear-shifting procedure - prescribed speed trace - good drivability despite severe acceleration (>0.8 m/s2)

Lab emissions testing Cycle (iii): Free cycle

Lab emissions testing Speed trace free-cycle

Lab emissions testing Speed trace free-cycle

Lab emissions testing Speed trace free-cycle

Lab emissions testing Emissions random cycles

Conclusions Test procedures: - PEMS accuracy comparable to laboratory equipment - Fixed speed traces easily implemented; quick cycle design; gear shift prescriptions taken from the NEDC - Drivability (acceleration ~ 0.8 m/s2) has not been an issue - Free-cycle: more challenging with respect to implementation and execution - Free-cycle: variability of speed traces is limited (variability is difficult to achieve; drivers are used to follow prescribed speed traces)

Thank you!

Overall CO2 emissions Overview: CO2 emissions

Conclusions Emissions: - on-road NOx emissions substantially exceed Euro 5 emissions limit - CO2 emissions slightly elevated; average tested emissions vary between 110-157 g CO2/km