13. The secretary of the WLTP informal subgroup on the Development of the Harmonized driving Cycle (DHC) introduced GRPE-66-34, containing the report on the progress made since January 2013. Having stated that almost all open issues were successfully closed, he reported that DHC successfully developed the harmonized test cycles, including the downscale procedure (even if the downscale calculation formula requires finalization after correcting minor issues), the mode construction, and the gear shift prescription (notwithstanding continued work for its improvement). A draft final report on the development of the Worldwide harmonized Light vehicles Test Cycle (WLTC) is already available and will be included in the Technical Report.

14. Responding to a question by the expert from Italy, the expert from the EC clarified work for regional weighting factors is ongoing in the European Union. He specified that Contracting Parties do not need to apply regional weighting factors for the harmonized cycle, even if there is a possibility to apply regional weighting factors if this is justified by regional driving characteristics. Having mentioned that the application of regional weighting factors can be further discussed, he added that this is not envisaged at the moment and he agreed with the GRPE recommendation to clarify this issue also in Part A of the UN GTR text.

15. The Chair of the informal subgroup on the Development of the Test Procedure (DTP) reported on the work status of the subgroup (GRPE-66-36). He stated that there are a number of remaining open issues that need to be addressed. According to the mandate documents (ECE/TRANS/WP.29/AC.3/26 and Add.1) three phases are included in the WLTP terms of reference: phase I, concerning the development of the UN GTR (test cycle and test procedure); phase II, concerning on-board diagnostics (OBD) and additional tests (e.g. on pollutants other than CO, NOX, hydrocarbons and particulate matter); and phase III, about reference fuels and performance requirements. Phase I can be further divided in two stages, with the aim to continue work on still open issues and to improve and correct the text of the GTR based on validation and experience. The issues that are foreseen to be solved in phase I, stage 1, include: (i) Rechargeable electric energy storage system Charge Balance (RCB) correction; (ii) the warm-up procedure for the road load and dynamometer setting; (iii) the speed trace violation, concerning deviations from the test cycle beyond the prescribed tolerances; (iv) the definition of the predominant mode for vehicles with multimode gearboxes; and (v) the temperature correction for regional representative conditions for the CO2 emission determination. Other issues could be finalized in phase I, stage 1, or eventually (in a fall back solution) postponed to stage 2: (i) the table of running resistances, concerning default values to be used in the dynamometer settings if the road load cannot be determined; (ii) the ambient temperature for coast-down (the latest discussions were settling on 5 to 40°C ± 5°C); and (iii) utility factors on electric vehicles. If an agreement is not reached in phase 1, stage 1, the issues will need to be defined regionally. Concluding his intervention of the status of the DTP subgroup, the DTP Chair reported that, even if the coast down and wheel torque methods are agreed, the wind tunnel and the comparison of road load determination methods are likely to be addressed in phase I, stage 2.

16. Reporting on the development of the WLTP regulatory text, the DTP Chair explained that a draft UN GTR was uploaded to the UNECE website prior to the GRPE session (GRPE-66-02). He recalled that there are a number of major open drafting points and outlined the schedule of forthcoming meetings and milestones for the completion of the drafting work. He specified that: (i) the analysis of results emerging from the GRPE discussion will be completed before end of June 2013; (ii) a meeting for the solution of outstanding issues is foreseen for the end of June 2013 in Brussels; (iii) the draft UN GTR will be circulated to WLTP members in early July 2013; (iv) a drafting group meeting will take place between 19 July 2013 and the last week of July 2013; (v) the finalisation of the draft of the UN GTR will be completed before the submission deadline for the working documents of the November 2013 session of GRPE. WP.29 is then expected to consider the text in March 2014. On the content of the regulatory text, he confirmed that the UN GTR will include an explanatory section (part A). A technical report on the UN GTR will be available as an informal document for the November 2013 session of GRPE.

17. The DTP Chair and the expert from the EC agreed that part A will be drafted by the EC, while the technical report will be delivered by an expert contracted in the framework of the DTP activities. Both these documents will be circulated to Contracting Parties for their inputs. The expert from the EC mentioned that the text of part A will be finalized by the end of July 2013. Given the involvement of OICA for the WLTP development, the expert from OICA informed GRPE about his availability and interest to contribute the preparation of the text of part A and the technical report.

18. Having recalled the mandate documents (ECE/TRANS/WP.29/AC.3/26 and Add.1) and the information on the status of the DTP work, the GRPE Chair concluded indicating that the adoption of the UN GTR will conclude the first stage of phase I, while the second stage will result in an amendment of the UN GTR.

19. GRPE agreed that the work plan shall include the adoption of the UN GTR in the extraordinary GRPE session of November 2013. The start of the work on the first UN GTR amendment shall take place right after the UN GTR adoption and after the approval, by AC3, of a request by the co-sponsors for a mandate to develop it under the WLTP informal working group. GRPE stressed the need to define, in part A of the regulatory text, which parts of the work will be tackled in stage 2 of phase I, and agreed that: (i) part A shall be distributed at the end of July 2013 and included in the working document submitted in August 2013; and (ii) the technical report shall be submitted, as an informal document, in November 2013. In case of adoption by GRPE, both these documents can then be considered as working documents by WP.29 in March 2014.