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

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.

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

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)

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.

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.

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.

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

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.

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).

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.

Proposal to permit the use of state-of-the-art test tracks per the latest standard ISO 10844:2021.

Proposal to strengthen provisions against test defeating and to facilitate Conformity of Production testing.

Proposal to clarify the gear selection procedure pursuant to the amendment to allow deviation from the reference acceleration a_wot,ref requirement for Conformity of Production tests.