Version as subsequently revised by the full ASEP II informal group.

Combined draft text proposals prepared by the ASEP II Drafting Group.

Proposal to align UN R51 with ISO 5130:2019 and thereby set requirements for the microphone position as a function of the exhaust outlet configuration.

Presentation on the status of the 2019 update to ISO 16254 (Acoustics – Measurement of sound emitted by road vehicles of category M and N at standstill and low speed operation – Engineering method). ISO 16254 specifies an engineering method for measuring the sound emitted by M and N category road vehicles at standstill and low speed operating conditions.

Proposal for amendments to the draft Supplement 6 to the 03 series of amendments submitting clarifications to the text from the ASEP II informal group.

ASEP II informal group draft amendments to the annex on “Measuring method to evaluate compliance with the Real Driving Additional Sound Emission Provisions (RD-ASEP)” based upon original China proposal.

ASEP II informal group amendments to paragraphs 1, 2, 6.2.3., 6.2.4.

Open issues for discussion, including “starting tests” questions and the number of RD-ASEP tests to be conducted between 10 and 100 km/h.

Proposal to clarify that the gear ratio i+1 by definition has an acceleration (not an “engine speed”) lower than gear ratio i.

Proposal from the ASEP II informal group for clarifications to the Regulation.

Presentation on the research paper “Experimental approach for evaluating uncertainties associated to stationary vehicle noise according to ISO 5725”.

Proposal to correct a reference in Supplement 3 to the 03 series of amendments, to introduce transitional provisions in line with the transitional provisions in Supplement 3, and to reintroduce a sentence deleted by mistake in Supplement 4 to the 03 series of amendments to UN Regulation No. 51.

Terms of Reference as approved by the Working Party on Noise (GRB) during its 68th (October 2018) session (Annex III to the GRB session report).

Proposal to address comments on the adopted Supplement 4:

1. align the flowchart in the appendix to Annex 3, Figure 3c with the amendment to paragraph 3.1.2.1.4.1 (c) of Supplement 3 to the 03 series
2. amend Appendix to Annex 3, Table 1 to limit to pure electric vehicles the options to either use mechanical or electronic devices to control the gear shift or take measures to avoid accelerations greater than 2.0 m/s² (GRB/2018/2 and GRB-67-17)
3. under Annex 7, paragraph 5.2., align the principle of testing between automatic and manual transmission having more than 5 gears.

Proposal to address non-negligible differences in sound performance in cases where COP tests are carried out under conditions that differ from those used for the granting of the type approval. The proposal introduces conditions, procedures, and corrections to be applied to L_urban to account for the difference in test conditions.

Proposal to address comments on the adopted Supplement 4:

1. align the flowchart in the appendix to Annex 3, Figure 3c with the amendment to paragraph 3.1.2.1.4.1 (c) of Supplement 3 to the 03 series
2. amend Appendix to Annex 3, Table 1 to limit to pure electric vehicles the options to either use mechanical or electronic devices to control the gear shift or take measures to avoid accelerations greater than 2.0 m/s² (GRB/2018/2 and GRB-67-17)
3. under Annex 7, paragraph 5.2., align the principle of testing between automatic and manual transmission having more than 5 gears.