Text as adopted by the Working Party on Brakes and Running Gear (GRRF) at its 75th session based upon a proposal by the European Commission, France and ETRTO to introduce wet grip provisions and testing procedures for tyres of categories C2 and C3.

Pursuant to discussions on setting uniform wet-grip requirements for C3 snow tires, Japan affirms that its national data supports a minimum wet-grip value of 0.65 (as proposed in document WP.29/2013/66: Proposal for Supplement 5 to the 02 series of amendments).

Proposal to maintain a wet grip index of 0.95 for class C2 normal tires and regular snow tires under the discussions to establish wet grip provisions and testing procedures for category C2 and C3 tires.

Proposal to maintain a wet grip index of 0.65 for class C3 normal tires and regular snow tires under the discussions to establish wet grip provisions and testing procedures for category C2 and C3 tires.

European Commission proposal for minimum wet grip limits on Class C3 tyres. The EC notes that the wet grip (G) index is intended as a precautionary measure that would set a minimum level already satisfied by products currently on the market. In anticipation of improvements in new tires, the EC proposes to add a notation “Wet grip index (G) ≥ 0.80 may be considered for new types of tyres 96 months after the entry into force date of Supplement 5 to the 02 series of amendments, based on robust field data and cost-effectiveness analysis.”

Report of the special meeting held in Paris on 21 November 2013 to discuss wet grip values for Class C2 and C3 tyres.

Proposal to elaborate on the concept of tyre deceleration (dω/dt) in the test procedures. The Russian Federation has developed a “Deceleration Calculator” for use in the UN R117 procedures. Following work by an ad hoc group (including NAMI, UTAC, and ETRTO) formed to review and validate this tool, Russia has prepared this new proposal, modifying the version (document GRB/2013/10) submitted at the last GRB session. The changes primarily concern the explanation of the tool rather than the basic mathematical equations.

Full report of the ad hoc group on the development of the method for determining tire rolling resistance using the variant dω/dt method.

Submission of the wet grip limit values for Class C3 tires as agreed to within the Working Party on Brakes and Running Gear (GRRF). These values were originally proposed in document WP.29/2013/66.

Report of the ad‐hoc working group organized in accordance with the recommendation of the 58th GRB session to consider testing and evaluation of the variant method using the dω/dt form proposed by Russia.

Proposal to elaborate on the concept of tyre deceleration (dω/dt) in the test procedures. The Russian Federation has developed a “Deceleration Calculator” for use in the UN R117 procedures. Following work by an ad hoc group (including NAMI, UTAC, and ETRTO) formed to review and validate this tool, Russia has prepared this new proposal, modifying the version (document GRB/2013/10) submitted at the last GRB session. The changes primarily concern the explanation of the tool rather than the basic mathematical equations.