21. GRBP was briefed on the activities of the Informal Working Group on Wet Grip Performance for Tyres in a Worn State (IWG WGWT) (GRBP-79-46).

22. The expert of ETRTO tabled proposals for a new Supplement to the 04 series of amendments with the aim to introduce editorial corrections and the new C3 reference test tyres (ECE/TRANS/WP.29/GRBP/2024/4, ECE/TRANS/WP.29/GRBP/2024/6, GRBP-79-21). The experts from France and Japan commented on the proposals (GRBP-79-50 and GRBP-79-07). GRBP adopted the proposals in ECE/TRANS/WP.29/GRBP/2024/4 as amended by GRBP-79-50 and in ECE/TRANS/WP.29/GRBP/2024/6 as amended by GRBP-79-21, and requested the secretariat to submit them for consideration and vote at the June 2024 sessions of WP.29 and AC.1 as part of draft Supplement 2 to the 04 series of amendments to UN Regulation No. 117.

23. The expert of ETRTO submitted proposals for a new Supplement to the 03 series of amendments with the aim to introduce editorial corrections, a temperature correction to decrease measurement uncertainties and the new C3 reference test tyres (ECE/TRANS/WP.29/GRBP/2024/9, ECE/TRANS/WP.29/GRBP/2024/12, GRBP-79-22). The experts from France and Japan commented on the proposals (GRBP-79-49 and GRBP-79-08). GRBP adopted the proposals in ECE/TRANS/WP.29/GRBP/2024/9 as amended by GRBP-79-22 and in ECE/TRANS/WP.29/GRBP/2024/12 as amended by GRBP-79-49 and requested the secretariat to submit them for consideration and vote at the June 2024 sessions of WP.29 and AC.1 as draft Supplement 2 to the 03 series of amendments to UN Regulation No. 117.

24. Similarly, the expert of ETRTO submitted proposals for a new Supplement to the 02 series of amendments which introduced editorial corrections, a temperature correction to decrease measurement uncertainties and the new C3 reference test tyres (ECE/TRANS/WP.29/GRBP/2024/5, ECE/TRANS/WP.29/GRBP/2024/7, GRBP-79-23). The expert from Japan commented on the proposals (GRBP-79-09). GRBP adopted the proposals in ECE/TRANS/WP.29/GRBP/2024/5 and in ECE/TRANS/WP.29/GRBP/2024/7 as amended by GRBP-79-23 and requested the secretariat to submit them for consideration and vote at the June 2024 sessions of WP.29 and AC.1 as draft Supplement 16 to the 02 series of amendments to UN Regulation No. 117.

25. During consideration of the above amendment proposals to various series of amendments to UN Regulation No. 117, GRBP took note of supporting material by Japan (GRBP-79-10) and by ETRTO (GRBP-79-36), as well as a summary table of all submitted documents (GRBP-79-35-Rev.2).

26. The expert from AAPC presented draft amendments that allowed, under certain conditions and weight limits, the use of LT-marked tyres with a rolling resistance greater than the current limits in UN Regulation No. 117 (ECE/TRANS/WP.29/GRBP/2024/17). The experts from Japan and the United Kingdom indicated that the proposed amendments would lead to relaxation of the current requirements. The expert from France pointed out that he would need more time to study the consequences of the proposal. GRBP agreed to continue consideration of this matter at the next session.