28. The expert of OICA reported on a study with the aim to determine the inter-dependency between the rolling sound, rolling resistance and the main safety performances by carrying out tests according to regulatory or standard procedures (GRBP-70-25). The expert from OICA pointed out, that given the budget constraints, the study had focused on C1 tyres. The study results indicated a conflict between the rolling sound and safety performances, like wet grip, dry grip and lateral aquaplaning. According to the expert, a low level of rolling sound could not be proven as feasible without compromising other parameters essential for vehicle safety and CO2 emission reduction. He added that a full study report would soon be available. Various experts thanked OICA for the study and indicated they would further consider its results. The Chair invited experts to transmit their comments to OICA, if any.

29. The Chair presented a revised document on priorities of the future work (GRBP-70-10). The expert from EC reported on their ongoing study on requirements and test procedures for the tyre pressure monitoring system (TPMS) for vehicle categories M2, M3, N2, N3, O3 and O4 (GRBP-70-14) which might result in preparing amendment proposals to UN Regulation No. 141 on TPMS. GRBP decided to come back to the list of priorities, once the outcome of the study would be known.