Revision 3 | Amendment 2 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2016/45. This document incorporates the following change:

Proposal to clarify that conditioning of a silencing system is necessary only in cases where exhaust gases come into contact with silencer fibrous materials.

Revision 3 | Amendment 3 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2017/2. This document incorporates the following change:

Proposal to clarify the text and align the provisions of UN R9 with other vehicle sound regulations, especially UN R41, pursuant to research conducted by the European Commission.

Revision 3 | Amendment 4 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2019/6. This document incorporates the following change:

Proposal to introduce ASEP requirements for L₄ and L₅ category vehicles with PMR > 50 W/kg. The proposal aligns ASEP for high powered L₄ and L₅ vehicles, used for passenger transport, with UN Regulation No 41.04 due to comparable sound emissions levels of L₄ and L₅ vehicles with the ones of L₃ vehicles and the possibility of applying similar measurement methods for sound emissions for those vehicle categories. This proposal is supported by the Commission study on enhanced sound requirements for mopeds, quads and replacement silencers of L-category vehicles which resulted in amendments to UN Regulation Nos 9, 63 and 92 (ref. document WP.29/2017/2).

Revision 4 | Amendment 1 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2020/2. This document incorporates the following change:

Proposal to introduce mandatory additional sound emission provisions (ASEP) tests and to correct inconsistencies in the ASEP exemption conditions for vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios.

Revision 3 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2013/2. This document incorporates the following changes:

Text adopted by the Working Party on Noise (GRB) at its fifty-sixth session as a consolidated version of the Regulation and aligning the test methods with those introduced into Regulation No. 41.

Revision 3 | Amendment 1 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2015/59. This document incorporates the following change:

Proposal to update the reference to the latest version of the ISO 10844 and to introduce transitional provisions for the shift of the test track requirements from ISO 10844: 1994 to ISO 10844: 2014.