GAR | WT-76-03

WT-76-03

Wet Grip on Worn Tyres: Draft status report

Source(s)

Date

27 Aug 2026

Status

Subject

UN R117 Tire Noise, Wet Adhesion, and Rolling Resistance

Meeting(s)

WT | Session 76 | 28 Aug

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.

Downloads

UNECE server

Related documents

Excerpts from session reports

GRBP | Session 80 | 17-20 Sep 2024

26. The expert of IWG WGWT proposed improving the precision of the test method for C1 tyres (ECE/TRANS/WP.29/GRBP/2024/23, GRBP-80-11 and GRBP-80-30). GRBP adopted the proposal, as amended by GRBP-80-11 and requested the secretariat to submit them for consideration and vote at the June 2025 sessions of WP.29 and AC.1 as draft Supplement 3 to the 04 series of amendments to UN Regulation No. 117. Should GRBP adopt another draft amendment to the same series of amendments at its session in February 2025, it would be combined with the above proposal.

GRBP | Session 81 | 18-21 Feb 2025

17. The expert from ETRTO tabled editorial corrections to the 02 and 04 series of amendments to UN Regulation No. 117 (ECE/TRANS/WP.29/GRBP/2025/12 and ECE/TRANS/WP.29/GRBP/2025/13). GRBP adopted these proposals, as amended GRBP-81-08-Rev.1 and GRBP-81-09-Rev.1., and requested the secretariat to submit them for consideration and vote at the June 2025 sessions of WP.29 and AC.1 as respectively draft Supplement 17 to the 02 series of amendments and draft Supplement 3 to the 04 series of amendments to UN Regulation No. 117. For the latter, GRBP agreed to combine it with the amendment proposal to the same series of amendments that was adopted at the previous session (ECE/TRANS/WP.29/GRBP/2024/23 as amended by GRBP-80-11).