Wet Grip on Worn Tyres (WT)
Reports to GRBP

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).

2026 2025 2024 2023 2022 2021 2020 2019
Meetings (77) Documents Regulations ← Back
Documents 2020
9 Jan 2020 Draft agenda for the 7th Worn Tyres working group session WT-07-01
16 Jan 2020 Worn Tyres: Matrix for conducting testing of tyres WT-07-02
20 Jan 2020 Participants list from the 7th Worn Tyres working group session WT-07-04
20 Jan 2020 Minutes of the 7th Worn Tyres working group session WT-07-03
24 Jan 2020 Draft status report of the Working Group on Worn Tyres WT-08-02
24 Jan 2020 Draft agenda for the 8th Worn Tyres working group session WT-08-01
4 Feb 2020 Attendance list from the 8th Worn Tyres Working Group session WT-08-09
4 Feb 2020 Minutes of the 8th Worn Tyres Working Group session WT-08-08
4 Feb 2020 IWG for Wet Grip of Worn Tyres: Status report to 71st GRBP (January 2020) WT-08-07
4 Feb 2020 Worn tyre wet-grip performance: Ongoing tests status WT-08-06
4 Feb 2020 Worn tyres: Proposals on Trailer Method test campaign WT-08-05
4 Feb 2020 Worn tyres working group testing and validation matrix WT-08-04
4 Feb 2020 Proposal on winter tyres buff profile WT-08-03
13 Feb 2020 Japan comments on report of the 8th Worn Tyres working group session WT-09-01
13 Feb 2020 Worn Tyres working group and EU timetables WT-09-02
6 Mar 2020 Agenda for the 8th Worn Tyres working group session WT-09-03/Rev.2
6 Mar 2020 Reference Tyre and Wet Grip Index calculation: Trailer Method test campaign WT-09-08
9 Mar 2020 Worn tyre test engagement letter (template) WT-09-14
9 Mar 2020 China customs clearance for non-CCC tyres WT-09-13
9 Mar 2020 Attendance list from the 9th Worn Tyres working group session WT-09-12
9 Mar 2020 Worn tyres round-robin guidelines for testing centers-example WT-09-10
9 Mar 2020 Worn tyre testing raw data template WT-09-07/Rev.1
9 Mar 2020 Buffing report template for worn-tyre round robin testing WT-09-06/Rev.1
9 Mar 2020 Logistical matrix for worn-tyre test procedure validations WT-09-05/Rev.2
9 Mar 2020 Contacts for worn tyre validation test centres WT-09-04/Rev.2
9 Mar 2020 Worn tyres validation testing logistical principles WT-09-09
13 Mar 2020 Draft minutes of the 9th Work Tyres Working Group session WT-09-11
9 Apr 2020 Worn tyres: Example of individual test report WT-10-02
9 Apr 2020 Worn tyres: Example of aggregated test report WT-10-03
23 Apr 2020 Draft agenda for the 10th Worn Tyres Working Group session WT-10-01/Rev.1
27 Apr 2020 Worn tyres test program: Impact of COVID-19 for tyre logistics in Japan WT-10-05
28 Apr 2020 UN R117: Worn tyres and roughness measurement WT-10-04
13 May 2020 Worn Tyres: Impact of COVID-19 on tyre industry and the informal group work plan WT-10-06
13 May 2020 Status of worn tyres work plan as of 27 April WT-10-07
13 May 2020 UN R117: Worn tyre buffing method WT-10-08
13 May 2020 Minutes of the 10th Worn Tyre Working Group session WT-10-09
13 May 2020 Attendance list from the 10th Worn Tyres Working Group session WT-10-10
25 May 2020 Draft agenda for the 11th Worn Tyres working group session WT-11-01/Rev.1
25 May 2020 Worn tyres: Tread depth measurement locations SRTT 16’’ WT-11-02
25 May 2020 Life Test Study on New tyres versus Worn tyres WT-11-03
2 Jun 2020 Minutes of the 11th Worn Tyres working group session WT-11-07
2 Jun 2020 Worn tyres: UTAC aggregated test report WT-11-05
2 Jun 2020 Status of the Worn Tyres informal group work plan WT-11-04
2 Jun 2020 Participants list from the 11th Worn Tyres working group session WT-11-06
16 Jun 2020 Worn tyres working group testing and validation matrix WT-08-04/Rev.2
16 Jun 2020 List of contact test centers WT-09-04/Rev.3
22 Jun 2020 Worn tyres: Buffing procedures preliminary experience WT-12-03
22 Jun 2020 Status of the Worn Tyres Working Group work plan as of 18 June WT-12-02
22 Jun 2020 Worn tyres: ETRTO response on question from IDIADA regarding tread depth measurement in shoulder zone WT-12-04
22 Jun 2020 IDIADA worn tyres aggregated testing report WT-12-06
22 Jun 2020 Draft agenda for the 12th Worn Tyres working group session WT-12-01/Rev.1
23 Jun 2020 Participants list from the 12th Worn Tyres Working Group session WT-12-05
23 Jun 2020 Minutes of the 12th Worn Tyres Working Group session WT-12-07
23 Jun 2020 Worn tyres: IDIADA aggregated testing data with task force comments WT-12-06/Rev.1
25 Jun 2020 Life Test Study on New Tyres vs Worn Tyres: France WT-12-08
5 Jul 2020 Worn tyres: Aggregate testing reports WT-13-02
6 Jul 2020 Agenda for the 13th Worn Tyres working group session WT-13-01
24 Jul 2020 Status of the Worn Tyres working group work plan WT-13-03
24 Jul 2020 Worn Tyres working group draft status report to GRBP WT-13-04
24 Jul 2020 Participants list from the 13th Worn Tyres working group session WT-13-05
24 Jul 2020 Minutes of the 13th Worn Tyres working group session WT-13-06
29 Aug 2020 Draft agenda for the 14th Worn Tyres working group session WT-14-01
10 Sep 2020 Worn tyres: Aggregated testing report WT-14-02
10 Sep 2020 Worn tyres: Test data collection tables WT-14-03
23 Sep 2020 Attendance list of the 14th Worn Tyres working group session WT-14-06
23 Sep 2020 Minutes of the 14th Worn Tyres working group session WT-14-05
23 Sep 2020 Work plan of the Worn Tyres working group WT-14-04
18 Oct 2020 Worn tyres informal group data collection template WT-15-03
19 Oct 2020 Agenda for the 15th Worn Tyres informal group session WT-15-01
20 Oct 2020 Worn tyres working group testing and validation matrix WT-08-04/Rev.1
21 Oct 2020 Worn tyres: Guidelines for testing phase of the informal group work plan WT-15-05/Rev.2
23 Oct 2020 Attendance list from the 15th Worn Tyres informal group session WT-15-07
23 Oct 2020 Draft report of the 15th Worn Tyres working group session WT-15-06
23 Oct 2020 Worn tyres data collection template (final version) WT-15-08
23 Oct 2020 Worn tyres: Proposal for data sharing process WT-15-04/Rev.1
23 Oct 2020 Status of the Worn Tyres informal group work plan WT-15-02/Rev.1
16 Nov 2020 Worn tyres working group testing and validation matrix WT-08-04/Rev.3
16 Nov 2020 SRTT 16" tread depth wear evolution measurements WT-16-03
19 Nov 2020 Draft agenda for the 16th Worn Tyres working group session WT-16-01/Rev.1
23 Nov 2020 Draft minutes of the 16th Worn Tyres working group session WT-16-06
23 Nov 2020 Attendance list from the 16th Worn Tyres working group session WT-16-05
23 Nov 2020 Status of the Worn Tyres working group work plan WT-16-02
23 Nov 2020 Worn tyres: Proposals for sharing of the buffing reports WT-16-04