OICA presentation of ACEA PM-3 programme

1. ORGANISATION INTERNATIONALE DES CONSTRUCTEURS D’AUTOMOBILES INTERNATIONAL ORGANIZATION OF MOTOR VEHICLE MANUFACTURERS OICA presentation ofACEA PM-3 programme Preliminary results PMP: 1st June 2004 Caroline Hosier, Pilot, ACEA Task-Force Particulates (TF-PM) Ford Motor Company

2. Background • The ACEA 1st and 2nd Particulate programmes concentrated on particulate measurement of mass, size, number and characterised particulate emissions from diesel, gasoline, diesel with trap and direct injection petrol engines. • The ACEA 3rd particulate programme, known as PM-3 was designed to contribute to the PMP process for light duty vehicles.

3. Background • PM-3 focused on the gravimetric measurement method. • PM-3 was initiated and funded by ACEA, using vehicles loaned from Fiat, PSA and VW. The 4th vehicle was loaned to the programme by Toyota. Further testing has been performed on an in-service Citroen. • All testing was conducted at an independent laboratory, AVL-MTC in Sweden.

4. Objectives • Examine potential enhancements to the existing particulate gravimetric measurement method. • Increase measurement filter loading. • Reduce Variability. • Investigate the potential of alternative dynamic mass-based particulate measurement methods.

5. Main Test Programme outline • 5 test sets using 4 particulate probes in parallel • Filters weighed on both 1.0 ug and 0.1ug balances. • 4 vehicles - 3 * diesel, 1 * gasoline • Gasoline fuel EN228 S<10 ppm • Diesel Fuel - Swedish class 1, S<10 ppm

6. Probe/filter set-up

7. Tunnel End-plate with mounted Probes Probes (Gasoline) mounted in tunnel.

8. New filter holder (as specified in US HD2007) New filter holder with thermostatically controlled heating jacket Note: very short length of unheated sample line emerging from tunnel

9. Results 1 - heated filter holder • Heating the sampling line and US HD 2007 filter holder to 47°C± 5°C does not appear to make any significant difference to the mean or the variability. • These results were supported by subsequent confirmation testing using a Citroen diesel vehicle with particulate filter. • OICA therefore raises the need for a heated filter and sample line as an open question for PMP.

10. Results 2 - flow rate • Increasing the flow rate (to increase filter loading) did not improve variability • This was not an expected result. ACEA is in discussions with AVL-MTC regarding further systematic testing of various flow rates.

11. Results 3 - teflo filters • Teflo filters • Require improved handling practices as they are very susceptible to damage. • Do not easily fit the filter cassettes. • Adoption likely in US HD 2007. • Further investigation into the use of teflo filters is required for UN-ECE / European applications.

12. Results 4 - microbalance • Preliminary analysis of results from the 1.0 ug and the 0.1ug balance show that using the 0.1ug balance increases the variability of the results. • At very low PM yield, the 0.1ug balance took over 20 minutes to stabilise in some cases. • Charge neutralisation on the filter prior to weighing is very important. The 0.1ug balance is more sensitive to this than the 1ug balance which may explain the results above.

13. Results 5 - filter cassette • When heavily loaded, cassette accumulates PM on the walls of the cassette itself. • Difficult to retain all the PM from such a sample for weighing. • The cassette has to be cleaned before being reused to relieve it from residual PM. • Cassette itself causes some handling difficulties. • Redesign of cassette may be required.

14. Results 6 - weighing room • Analysis at AVL-MTC shows that a increase in Relative Humidity of 8% gives a 23ug increase in filter mass. (This supports the Mettler results of 24ug increase per 8% RH increase). • As this is in the same order of magnitude as the filter loading from a DPF equipped vehicle, short term control of the weighing room environmental conditions is therefore essential.

15. Results 7 - gaseous emissions • Regulated gaseous emissions were measured on every test according to 70/220/EEC as last amended. • All vehicles fulfilled Euro IV emission requirements, including particulate standards. • All vehicles remained stable throughout the test programme.

16. Conclusions 1 • The PM mass measurement method can be adapted to be suitable for measurement of low PM emissions. • Use of a high efficiency filter (TX40) is recommended. Further work on the teflo filter is required. • Heating of the filter holder/sample lines is not necessary. • The filter cassette causes some handling difficulties and may introduce errors.

17. Conclusions 2 • Therefore, OICA supports continuing use of the existing filter holder. • Increasing flow rate does not improve variability. ACEA plans further testing. • The 1.0 ug balance performs better in a working environment than the 0.1ug balance. • Strict control of the weighing room environmental conditions is necessary on a short term basis - supports use of the reference filter.

18. Next Steps • AVL-MTC will run further testing according to a new test scheduled proposed by ACEA which will provide further detailed investigation into the effect of flow rates, filter holders etc, using the TX-40. • The test vehicle will be a diesel passenger car equipped with a particulate filter.

19. Further work • This project concentrated on the PM gravimetric method for light duty vehicles, however, only passenger cars were actually studied. • The revised test procedure/protocol for an enhanced gravimetric test must also be validated using light commercial vehicles (vans) as there are potential issues regarding flow rates and temperature profile at the filter face.