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.

UN R51 specifies that conditioning of a silencing system is necessary only in cases where exhaust gases come into contact with silencer fibrous materials. This proposal would apply the same concept in L category noise regulations.

Proposal to clarify the test procedure by explicitly excluding first gear where possible from the ASEP control range.

Overview of discussions for the future development of vehicle noise regulations prepared by the GRB secretariat.

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.