21. Recalling the discussion at the previous session of GRPE, the Chairman of the informal group on Worldwide harmonized Motorcycle emission Test Cycle (WMTC) introduced ECE/TRANS/WP.29/GRPE/2010/10 proposing to introduce limit values into gtr No. 2. He reported that the discussions on the proposal were still ongoing on the following three issues:
(i) final set of limit values,
(ii) reference fuel and
(iii) durability requirements.
He announced his intention to hold a further meeting in Brussels on 13-14 September 2010 to resolve the remaining open issues. He expected to submit the final proposal to GRPE for consideration at its next session.
22. The expert from IMMA raised concerns (GRPE-60-04) and suggested improving the text of ECE/TRANS/WP.2/GRPE/2010/10. The expert from Japan proposed to amend the provisions in part 1 (preamble) regarding reference fuel (GRPE-60-14). The expert from the United States of America presented GRPE-60-07 proposing a number of improvements and clarifications to ECE/TRANS/WP.29/GRPE/2010/10. The experts from India and Canada supported these comments. GRPE agreed to refer these informal documents to the WMTC informal group for a detailed consideration.
23. The GRPE Chairman expressed his intention to inform WP.29 and AC.3 in June 2010 about the status and he recommended having a final review of ECE/TRANS/WP.29/GRPE/2010/10 at the next session of GRPE in January 2011.
Mr Stein presented the Euromot informal document (GRPE-60-05) on NRMM retrofit, submitted to GRPE. Euromot proposed using Anlage XXVII as a basis but with the addition of elements from California and Switzerland.
The proposal includes degreening for 25 to 125 hours followed by baseline testing of the engine with and without aftertreatment, 1000 hours durability (in field or in the test cell with a specific durability schedule, not just repeated emissions cycles as proposed by Baarbe) and then re-testing with the original engine. Emissions during regeneration (based on gtr.11) would be taken into account. Stein commented that the chairman in his paper had suggested that emissions during regeneration should meet the limit, which is not in line with Euro standards where, as a weighted average, they must meet the limits. Emissions testing would be 3 hot start tests.
The proposal calls for NO2 to be limited to 20% of NOx. AECC pointed out that this would require deNOx capability if the engine-out NO2 emissions were >20%. The proposal is quite different from current Californian requirements, which is for an increase in the proportion of NO2 from engine-out.
AECC considers that if there are to be limits on NO2, they should be as absolute limits rather than percentages of total NOx. Euromot agreed to reconsider this.
Euromot is proposing an emissions classification scheme with 4 different classes for % PM reduction and 4 separate classes for % NOx reduction. It was commented that there could also be g/kWh requirements equivalent to Euro stages.
Euromot notes that NRMM regulations do not include PN and hence this should not be included in the NRMM retrofit requirements. The chairman commented that PN was introduced because of the difficulty of discrimination between low PM figures. Switzerland commented that they had introduced PN requirements because of this. Euromot repeated that PN should not be included in retrofit as there is no PN standard for NRMM. It there were to be such a requirement it should, in any case, be based on PMP, not the Swiss requirements.
AECC noted that safety and noise are machine requirements, not engine issues and that it would enormously expand the scope of the work to include these aspects as suggested by Euromot.
Sweden expressed the opinion that safety and noise must be covered, because the objective of retrofitting is to improve the machine, not just the engine. The chairman commented that it would be impossible to evaluate the safety aspects as this would be machine dependant but noise might be more readily handled though. Germany said that safety issues should be covered in fitting/instruction manuals etc.
Euromot said there are no requirements for off-cycle emissions included in their proposal as there are no current requirements on this for NRMM.
Germany supported the Euromot proposal and said that it would enable a common approach for HD and NRMM.
Sweden queried whether there would be any link between the Euro stage of the engine to be tested and the application. Could a system be tested, for instance, on an NRMM Stage I engine and then be applied to a Stage III engine. Euromot said that this would not be allowed, although depending on test results some extensions might be possible.
The Netherlands commented that from experience with gas retrofit, there should also be requirements on the amount and type of installation information to be provided. Germany agreed that the retrofit supplier needs to provide clear guidance for the installers. The chairman agreed that this would need careful consideration, but he felt that solutions are available.