The IWG RD-ASEP Informal Group is developing a mandatory test procedure for UN R51 to assess vehicle noise emission compliance under conditions other than Annex 3, ensuring no defeat device schemes exist. The Editing Task Force created a consolidated R51.04 draft incorporating Supplements up to Supplement 11, with mandatory random RD-ASEP testing for approval and revised control ranges. R51.04 RD-ASEP expands vehicle speed range to 1-100 km/h, adds vehicle performance criteria, implements random test points, and requires testing for approval. Working document submission is expected September 2027, with expected adoption February 2028.
Proposal to amend UN R51 in the 04 series of amendments based on GRBP-84-07, adding definitions and specifications for Real Driving Additional Sound Emission Provisions applying to vehicles of categories M1 and N1, modifying sound measurement methods and test procedures including indoor testing provisions, establishing a sound expectation model for RD-ASEP compliance evaluation, introducing provisions for vehicles equipped with an Automated Driving System, and updating Annexes 3 through 10 and associated appendices with revised test conditions, gear selection flowcharts, temperature and test-track corrections, tyre rolling sound measurement procedures, compressed air noise assessment, and conformity of production checks. No Contracting Party shall refuse to grant type-approvals under the 04 series of amendments from its entry into force until [TBD date], after which approvals under the preceding 03 series may no longer be accepted.
Proposal to amend para. 1.1. to clarify that retreaded pneumatic tyres of Classes C1, C2 and C3 are subject to snow performance requirements and C2 and C3 tyres to traction tyre classification, and insert new para. 1.2. to establish that Contracting Parties shall issue or accept approvals to snow performance of retreaded tyres of Classes C1, C2 and C3 and/or the classification as traction tyres for retreaded tyres of Classes C2 and C3.
Proposal for Supplement 3 to the original version of UN Regulation No. 172 to amend para. 1.1. to clarify that this Regulation applies to retreaded pneumatic tyres of Classes C1, C2 and C3 with regard to their snow performance and for C2 and C3 tyres with regards to their classification as traction tyre, and insert new para. 1.2. to state that Contracting Parties shall issue or accept approvals to snow performance of retreaded tyres of classes C1, C2 and C3 and/or the classification as traction tyres for retreaded tyres of classes C2 and C3.
Proposal to amend Annex 7, paragraph 3.1, to add provisions allowing discard of test runs when additional operating conditions lead to riding conditions not expected to occur in real traffic such as front wheel lift up, apparent wheel spin, chain slap, or engine lugging, and amend paragraph 3.2.2 to specify that if unusual riding conditions occur during testing, the test shall be performed in the next higher gear and maximum vehicle speed shall be reached at line BB’ instead, thereby ensuring consistency with the 05 and 06 series of UN Regulation No. 41.
The IWG for Wet Grip on Worn Tyres reports progress on evaluating methods for preparing tyres of Class C1 to be tested in worn state at type-approval, defining test conditions and methods, establishing type-approval thresholds for wet grip performance, and addressing requirements for classes C2 and C3. Test Campaign Stage 1 assesses test procedure precision per GRBP-80-11, with normal and 3PMSF tyres completely tested at 13 test centres. Outliers analysis and KPI target confirmation are ongoing. Stage 2, if needed, is planned for 2026-2027.
Draft agenda of the 76th session of the Informal Working Group WGWT scheduled for August 28th, 2026 on-line. The agenda includes welcome and opening remarks, adoption of the agenda, adoption of the minutes of the 75th session of 16 June 2026, review of work plan 2025-2026 for C1 tyres, review of IWG WGWT status report for GRBP 84th session of September 2026, and next meetings.
Spain’s signature of the 1997 Agreement has not been ratified or otherwise made definitively binding.