This group was authorized in 2019 to consider the performance of tyres after initial use. The broad concern is to ensure that somewhat worn tyres continue to comply with the requirements for new tyre approvals (i.e., no serious degradation in performance after initial use and before such wear as would require tyre replacement).
| Wet grip on worn tyres: Status of tyre-selection deliberations |
| Reference Number: WT-65-02 |
| Meeting Sessions: 65th WT session (7 Jan 2025) |
| Document date: 07 Jan 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Participants list from the 65th Worn Tyres informal group session |
| Reference Number: WT-65-04 |
| Meeting Sessions: 65th WT session (7 Jan 2025) |
| Document date: 08 Jan 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 65th (January 2025) session |
| Reference Number: WT-65-03 |
| Meeting Sessions: 65th WT session (7 Jan 2025) |
| Document date: 08 Jan 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 66th (February 2025) session |
| Reference Number: WT-66-01 |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 05 Feb 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Comments on the proposed revisions to the terms of reference |
| Reference Number: WT-66-02 |
| Submitted by: Japan |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 06 Feb 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet grip on worn tyres: Comments on document WT-66-02 |
| Reference Number: WT-66-03 |
| Submitted by: ETRTO |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 12 Feb 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet grip on worn tyres anonymised listing for precision improvement testing |
| Reference Number: WT-66-05 |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 10 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 66th (February 2025) session |
| Reference Number: WT-66-06 |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 10 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Participants list: 66th (February) Wet Grip on Worn Tyres informal group session |
| Reference Number: WT-66-07 |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 10 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn Tyres working group anonymised tyre testing list |
| Reference Number: WT-66-04 |
| Meeting Sessions: 66th WT session (13 Feb 2025) |
| Document date: 26 Feb 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 67th (March 2025) session |
| Reference Number: WT-67-01 |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 21 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet braking of worn tires: Real-world assessment of regulatory requirements |
| Reference Number: WT-67-02 |
| Submitted by: JRC |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 25 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet grip on worn tyres: Template for Stage 1 test campaign data reporting |
| Reference Number: WT-67-03 |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 31 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet grip on worn tyres: Anonymised status of tyre deliveries |
| Reference Number: WT-67-04 |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 31 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Participants list from the 67th Worn Tyres working group session |
| Reference Number: WT-67-06 |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 31 Mar 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| VESevo: Viscoelasticity Evaluation System-Evolved |
| Reference Number: WT-68-03 |
| Submitted by: VESevo |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 21 May 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| JRC findings of non-compliance of tyres |
| Reference Number: WT-68-02 |
| Submitted by: JRC |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 21 May 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 67th (March 2025) session |
| Reference Number: WT-67-05/Rev.1 |
| Meeting Sessions: 67th WT session (27 Mar 2025) |
| Document date: 22 May 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Status of tyre deliveries (anonymised) |
| Reference Number: WT-68-04/Rev.2 |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 22 May 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 68th (May 2025) session |
| Reference Number: WT-68-01/Rev.2 |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 22 May 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 68th (May 2025) session |
| Reference Number: WT-68-05 |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 27 Jun 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn tyres: Participants list from the 68th informal group session |
| Reference Number: WT-68-06 |
| Meeting Sessions: 68th WT session (22 May 2025) |
| Document date: 27 Jun 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 69th (August 2025) session |
| Reference Number: WT-69-01 |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 19 Aug 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Assessment on removing C2-C3 provisions from wet grip worn tyre provisions |
| Reference Number: WT-69-02 |
| Submitted by: ETRTO |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 25 Aug 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn tyres: deliveries and testing status |
| Reference Number: WT-69-04 |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 25 Aug 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Proposal to amend the informal group terms of reference |
| Reference Number: WT-69-03 |
| Submitted by: JASIC |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 25 Aug 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 69th (August 2025) session |
| Reference Number: WT-69-05 |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 25 Sep 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn tyres: Participants list from the 69th informal group session |
| Reference Number: WT-69-06 |
| Meeting Sessions: 69th WT session (26 Aug 2025) |
| Document date: 25 Sep 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 70th (October 2025) session |
| Reference Number: WT-70-01 |
| Meeting Sessions: 70th WT session (14 Oct 2025) |
| Document date: 27 Sep 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn tyres: Status of tyre deliveries and testing |
| Reference Number: WT-70-02 |
| Meeting Sessions: 70th WT session (14 Oct 2025) |
| Document date: 14 Oct 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 70th (October 2025) session |
| Reference Number: WT-70-03 |
| Meeting Sessions: 70th WT session (14 Oct 2025) |
| Document date: 10 Nov 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Worn Tyres informal group: Participants list from the 70th session |
| Reference Number: WT-70-04 |
| Meeting Sessions: 70th WT session (14 Oct 2025) |
| Document date: 10 Nov 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Agenda for the 71st (November 2025) session |
| Reference Number: WT-71-01 |
| Meeting Sessions: 71st WT session (25 Nov 2025) |
| Document date: 18 Nov 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet grip on worn tyres: Status of tyre deliveries and validation testing |
| Reference Number: WT-71-02 |
| Meeting Sessions: 71st WT session (25 Nov 2025) |
| Document date: 25 Nov 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Minutes of the 71st (November 2025) session |
| Reference Number: WT-71-03 |
| Meeting Sessions: 71st WT session (25 Nov 2025) |
| Document date: 25 Nov 25 |
| Relevant to: UN Regulation No. 117 | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance |
| Click here to view the full document file |
| Wet Grip on Worn Tyres: Participants list from the 71st session |
| Reference Number: WT-71-04 |
| Meeting Sessions: 71st WT session (25 Nov 2025) |
| Document date: 25 Nov 25 |
| Click here to view the full document file |