Some corrections and clarifications concerning power definition, calibration, temperature correction and Reference sound assessment

In introducing ASEP in Annex 7 in 2016, the scope was limited to vehicles with internal combustion engines (ICE) based on the experience of variabilities in the exhaust silencing systems. Electric driven vehicles have been exempted from ASEP. For electric driven vehicles the new UN Regulation No. 138, dealing with the reduced audibility of these vehicles, was worked out until 2017. At that moment no one expected sound enhancement systems beyond the scope and aim of UN R138.

This proposal is an approach to address the concern that electric vehicles might be equipped with sound enhancement systems beyond the scope and aim of UN R138. This proposal does not require any changes to UN R138.01. This proposal is given as a supplement to enable the quickest entry into force, providing all manufacturers clear direction on the design of sound enhancement systems.

Gives the background to proposal for the Application of Noise Limits to EVs fitted with Exterior Sound Enhancement Systems (ESES) to UN R51

The text reproduced below was prepared by the experts from OICA in order to address the original intent of the Task Force on Quiet Road Transport Vehicles (TF QRTV). This proposes to expand the speed range of ASEP forBEVs down to speeds > 0 km/h.

Proposal to clarify the original intent of the Task Force on Quiet Road Transport Vehicles (TF QRTV) conclusion

Proposal replaces document GRBP/2025/20

By this proposal all types of electric vehicles (xEVs) are included in the provisions of ASEP (Annex 7) in UN Regulation No. 51. If applicable, input of the dedicated subgroup of IWG RD-ASEP has been incorporated.

Proposal to make a correction to the procedure of free rolling tyre noise testing described in Annex 8.

Supplement 7 introduced an inconsistency in R51.03 Annex 8. As currently
written, it requires free-rolling tyre noise testing to be conducted in
accordance with both ISO 362-3:2016 and Annex 3, Appendix 3

Consolidation in Supplement 11 includes: clarification of Verification/Adjustment and editorial corrections with transitional provisions (GRBP/2025/20 with GRBP-82-07); correction of Tyre Road Sound Measurement for Indoor-Testing (GRBP-82-22); introduction of ASEP in Annex 7 for BEVs and HEVs (GRBP/2026/4 with GRBP-83-xx); update of ISO standards in Annex 3 and Annex 8 (GRBP/2026/5 with GRBP-83-xx); and reference for Power Definition regarding new UN R177 (GRBP/2026/13). The consolidated version of Supplement 11 is to be submitted to the 199th WP.29 in June.

Proposal to supersede document GRBP/2026/4 intended to introduce a “default mode”, to specify requirements to be applied to the emission of Enhanced Exterior Sound (EES), with corresponding transitional provisions, and to draw a limit curve to introduce electric vehicles and hybrid electric vehicles that can be propelled without an internal combustion engine operating in the scope of ASEP (Annex 7).

Proposal to amend UN Regulation No. 142 to clarify that a maximum speed warning label specifying the lowest value of the maximum speed capability of fitted snow tyres displayed inside the vehicle in a prominent position readily and permanently visible to the driver can be via a permanent physical label or an electronic display, and in case of an electronic display the warning can be shown permanently or when the respective speed limit is approached, reached or exceeded, and to provide that the speed warning label shall not be required for vehicles of categories X and Y equipped with an ADS.

Proposal to amend para. 6.2.1.1. to permit testing of vehicle sound either indoors or outdoors with equivalent results, add new Annex 11 specifying indoor testing provisions, amend Annex 1 to insert para. 8.5. and 8.5.1. requiring documentation of test method selected, amend Annex 3 para. 1. to specify sound level meter requirements for indoor testing per IEC 651 and IEC 61672-3, amend Annex 3 para. 1.1.1. to provide calibration procedures for indoor testing per IEC 942:1988, amend Annex 3 para. 1.3. to exempt wind speed monitoring for indoor facilities, amend Annex 3 para. 2.1. and add para. 2.1.4. to specify outdoor and indoor test site requirements per ISO 362-3:2022 and ISO 26101, add para. 2.1.5. specifying indoor ambient conditions, add para. 2.2.7. addressing test mass for indoor dynamometer testing, amend Annex 3 para. 3. to specify outdoor and indoor test procedures per ISO 362-3:2022 Variant A, amend Annex 3 para. 3.1.1. to clarify outdoor testing microphone placement, add para. 3.1.1.4. defining virtual lines and simulated vehicle speeds for indoor testing, and renumber former paras. 3.1.1.4. and 3.1.1.5. as 3.1.1.5. and 3.1.1.6.

Rationale for Figure Part B.5 of GRBP-84-36-Rev.1

Proposal to replace references to UN GTR 21 by its type-approval equivalent UN R177, provide transitional provisions pursuant to amendments introduced in Supplements 10 and 11, and clarify calibration provisions and procedure for system check (cf: ISO 362).

Proposal to cover all types of electric vehicles (xEVs) in the provisions of ASEP (Annex 7) in UN Regulation No. 51.

Proposal to replace references to GTR 21 by references to UN R177.

Proposal to address electric vehicle enhanced sound issues in the short term until the new 04 series of amendments enters into force.