15. The expert from the Netherlands provided an overview of their research projects on tyres and proposed a two-stage tightening of the tyre limits for the rolling resistance coefficient, wet grip index and rolling sound emissions (GRB-66-01 and Add.1, GRB-66-03). He also highlighted the importance of keeping the correct tyre pressure for fuel efficiency and pointed out shortcomings of the EU system for labelling tyres.

16. The expert from ETRTO was of the view that the selections of tyres in the Dutch studies was not representative enough for the European market and volunteered to submit to the next GRB session a more comprehensive analysis. The expert from OICA supported the ETRTO view and proposal. He further introduced the results of a recent study of C1 summer tyres (GRB-66-22) according to which no tyre was performing equally well in rolling sound and handling. The expert from Germany acknowledged the progress achieved in rolling sound and pointed out the need to find a compromise for the three tyre parameters in question. He also agreed that the tyre labelling system would need to be improved.

17. The Chair was of the view that amending the limit values in Regulation No. 117 would first require a general agreement of all stakeholders, including the Working Party on Brakes and Running Gear (GRRF). Finally, GRB decided to continue the discussion at the next session.

12. The expert from the Netherlands presented a study (GRB-62-09 and Add.1) on noise emission from the Original Equipment Manufacturer (OEM) tyres of a specific size which were found to be around 1 dB(A) lower than the one from replacement tyres of the same size. The expert, thus, proposed to further reduce the limit values for OEM tyres in the 02 series of amendments to Regulation No. 117 (GRB-62-11 and Add.1).

13. The expert from Switzerland expressed his support for the general direction of the Dutch proposal. The experts from Germany and EC were of the view that, at this stage, it would be premature to tighten the tyre noise limits of Regulation No. 117. The expert from France called for a holistic approach to this issue. The experts from ETRTO and OICA expressed doubts about the representativeness of the tyre sample used in the Dutch study. The expert from ETRTO also delivered comments on the proposal for amendments to Regulation No. 117 (GRB-62-17). Finally, GRB invited all experts to further study the Dutch proposal and decided to revert to this issue at the next session.

18. The expert from the Netherlands recalled the two studies presented at the previous session of GRB and introduced further arguments for tightening tyre noise limits in Regulation No. 117, together with the text of draft amendments (GRB-61-03 and Add.1). The expert from ETRTO questioned if the pool of tyres selected for the Dutch studies had indeed been a representative sample (GRB-61-18). He further pointed out that, for the time being, the tyre industry was busy meeting the requirements of 02 series of amendments to Regulation No. 117 which had recently come into force, in November 2012. According to him, until the completion of this process by 2018-2020, it would be premature to consider further reducing of tyre noise limits. The experts from China, Norway and Switzerland agreed that the proposal by the Netherlands needed further study. The experts from France and Germany pointed out various problems with labelling of tyres. GRB invited experts to provide their comments on the Dutch proposal and decided to revert to this issue at the next session on the basis of a new informal document containing the draft amendment proposals tabled by the expert from the Netherlands in GRB-61-03.

14. The expert from the Netherlands presented the outcome of a study (GRB-60-08 and Add.1) of the shifts in tyre sound emission levels in his country between 2007 and 2013, i.e. before and after the revision of tyre noise limits in 2009 (EC/661/2009 and UN Regulation No. 117). The study addressed the most common C1, C2 and C3 tyres in terms of size and manufacturer. The reductions in tyre sound levels between 2007 and 2013 were found to be respectively 1.5, 1.4 and 1.1 dB(A) for C1, C2 and C3 tyres.

15. The expert from the Netherlands informed GRB about the results of two studies (GRB-60-03, GRB-60-13, GRB-60-14) commissioned by the Dutch Ministry of Infrastructure and Environment with a view to assessing cost savings that could be achieved in the Netherlands and EU by a switch from currently used tyres to high-performance tyres with A-labels on each parameter of the EU tyre label: energy efficiency, wet grip and noise (so called ‘triple-A’ tyres). According to the studies, moving towards ‘triple-A’ tyres could bring considerable potential benefits for the society in terms of energy, safety and noise reduction, which were estimated to be around 1 billion Euros in the Netherlands and 34 billion Euros in EU per year. In addition, individual consumers could also benefits from substantial fuel cost savings.

16. As a first reaction, the experts from ETRTO and OICA pointed out the rather theoretical character of some assumptions used for these studies, as well as the fact that ‘triple-A’ tyres were not yet available on the market. The expert from the Netherlands added that a common objective of these studies, together with the one mentioned in paragraph 22 above, was to shift the society to better tyres, either by introducing stricter limits or by raising the awareness of tyre labels. Finally, GRB agreed to include this issue in the agenda of its next session and invited experts to submit their comments for discussion.