The 76th session of the Informal Working Group on Wet Grip of Worn Tyres convened on 28 August 2026 remotely. The agenda was adopted and previous meeting minutes from the 75th session were adopted. The WTPP secretary updated the IWG WGWT on testing activities status; the Co-chair noted the Gantt should reflect additional postprocessing time extending to September 2026. The Co-chair presented the status report for GRBP 84th session, with an ETRTO expert proposing clarification of the word outlier. A revised status report will be sent to GRBP secretariat. Next meetings are scheduled for 11 August, 14 September, and 28 October 2026.

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.

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.

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.