UN R41 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2011/62. This document incorporates the following changes:

Adopted proposal integrated into UN R41: Revision 2 on 14 August 2012.

Revision 2 | Amendment 1 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2014/2. This document incorporates the following change:

Proposal approved by the GRB to update UN R41 with the latest amendment of ISO 5130:2012, to correct the typing error of the decibel unit dB(A) (corrected from db(A)) and delete the unnecessary unit, and to revise the current list in Annex 4 as an itemized list for greater clarity.

Revision 2 | Amendment 10 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2021/3. This document incorporates the following change:

Proposal to clarify UN R41 and introduce provisions to improve testing to be more representative of real-world operation by expanding the scope of test and to align the Regulation with ISO 10844:2014, replacing provisions from ISO 10844:1998 (and proposing a clearer image for Figure 1).

Revision 2 | Amendment 11 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2021/77. This document incorporates the following change:

Proposal to correct some references, which need to be updated as a consequence of document WP.29/2020/70, adopted at the June 2020 WP.29 session, notably

1. Paragraph 5.4.1 renumbered as paragraph 5.5.1.
2. Paragraphs 5.4. and 5.5. respectively renumbered as paragraphs 5.5. and 5.6.

Revision 2 | Amendment 2 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2015/2. This document incorporates the following change:

Proposal as approved by GRB to clarify certain terms and symbols used in Annex 7 (ASEP) of the regulation.

Revision 2 | Amendment 3 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2015/61. This document incorporates the following change:

Proposal to introduce a calculated engine speed (in addition to measured engine speed) for MT vehicles and for continuously variable transmission (CVT)/automatic transmission (AT) with locked gear mechanism into UN Regulation No. 41 for the tests in Annex 3 and Annex 7 (Additional sound emission provisions – ASEP)

Revision 2 | Amendment 4 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2016/3. This document incorporates the following change:

In response to concerns that approval agencies may not grant manufacturers the additional 1dB for L(wot) on conformity of production tests as changes had been made to Annex 6 of R41-04, GRB issued an interpretation recorded in the report of its 56th session. The proposal formalizes the interpretation as an explicit provision of the regulation.

Revision 2 | Amendment 5 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2016/46. This document incorporates the following change:

Proposal to clarify the test procedure by explicitly excluding first gear where possible from the ASEP control range and to clarify that conditioning of a silencing system is necessary only in cases where exhaust gases come into contact with silencer fibrous materials.

Revision 2 | Amendment 6 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2018/6. This document incorporates the following change:

Proposal to delete a description of the L₄ vehicle category (motorcycles with a side car) from Annex 3 to Regulation No. 41. These vehicles fall under the scope of UN R9, having been removed from the scope of UN R41 as of the 04 series of amendments.

Revision 2 | Amendment 7 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2019/3. This document incorporates the following change:

Proposal to require additional sound emission provisions (ASEP) testing under UN R41.

Revision 2 | Amendment 8 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2020/70. This document incorporates the following change:

Proposal to introduce provisions for stationary noise measurements on a single-sided dual exhaust system, minimize proliferation of approval numbers from models with differences in vehicle exhaust and silencing systems, and correct an omission regarding the compensating resevoir fill time thereby aligning UN R41 with the other noise UN Regulations Nos. 9, 51 and 63.

Revision 2 | Amendment 9 has been prepared purely as documentation tool. The authentic and legally binding text is WP.29/2021/4. This document incorporates the following change:

Proposal to align the 04 series of amendments with ISO 10844:2014, replacing provisions from ISO 10844:1998 (and proposing a clearer image for Figure 1).