The Worn Tyres Post-Processing task force completed data collection for 3PMSF and Normal tyres, each with 57 samples representing 100% of target. Ongoing activities include outliers analysis of the 3PMSF and Normal cluster and post processing of the data conclusions.

Proposal to amend Annex 3 and Annex 7 regarding ASEP calculations and temperature corrections:

• Add reference to nMAX and kp factor for ASEP anchor point calculation in Annex 3, Appendix 1 Table 1,
• Clarify temperature correction equations and coefficients K1 and K2 by defining them uniquely in para. 3.2.3. and adding missing index j references in Annex 3, Appendix 2 paras. 3.2.3., 3.2.4., 3.3.3. and 3.3.4.,
• Delete from Annex 7 para. 5.2. a sentence regarding gear ratios for ASEP Lref that was wrongly introduced in Supplement 10 (GRBP-79-33/Rev.1).

IWG RD-ASEP created a mandatory test assessing compliance with paragraph 6.2.3 of Regulation 51.03 (later 51.04) to assure vehicle noise emission at speed, load, or acceleration conditions other than Annex 3 condition is linked to vehicle physics, with no noise emission test detection or defeat device schemes. R51.04 draft incorporates R51.03 Supplements up to Supplement 11, revises manipulation and defeat device provisions, establishes mandatory random RD-ASEP testing for approval with expanded vehicle speed range of 1-100 km/h and vehicle performance criteria, and includes expectation model technical basis in Annex 7.

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.

Minutes of the 75th session of the Informal Working Group WGWT held 16 June 2026 on-line. The agenda was adopted. Previous meeting minutes from the 73rd session (31 March 2026) and 74th session (19 May 2026) were adopted. WTPP secretary updated on testing activities status per document WT-75-2. ETRTO stated the agreed number of tests was a statistical minimum and IWG WGWT conclusions to GRBP must be based on complete test results. IWG WGWT agreed to await WTPP conclusions on outliers before deciding whether to keep the current number of tests or make additional tests. The co-chair stated a status report must be prepared for GRBP 84th session (September 2026) and suggested an IWG WGWT meeting days before GRBP. Next IWG WGWT meeting scheduled for 28 August 9:00–10:00 CET.