Proposal for an amendment to complement the content of working document GRVA/2018/5. The proposal includes amendments to:

1. The Standard Reference Test Tyre (SRTT) denominations
2. Remove the discrimination between the two Class C3 tyres
3. Clarify that there are no C3 tyres in the scope of this UN Regulation “not marked with speed symbol”
4. Align Annex 6 with the most recent amendments made to standard ISO 28580
5. Define “standard deviation” as appropriate in the text
6. Clarify that, in the cases of C2 and C3 tyres, the “Reference (test) pressure” and the value “Pr” correspond to the indication of the inflation pressure which is always marked on the sidewall
7. Use “repeatable” instead of references to “reproducibility”
8. Update test report forms
9. Include the date on which the new proposed supplement of UN Regulation No. 117 will apply
10. Improve the description of the evaluation of the rolling sound emission test
Correct the figure in Annex 2, Appendix 2, and
11. Update cross references pursuant to paragraph renumbering.

Proposal to amend GTR including:

• Amendment to the scope
• Addition of new definitions (Section 2)
• Harmonization of the Load Range concept in relationship to Inflation Pressure (Section 2)
• Alignment of the provisions with the most recent developments in UN Regulations Nos. 30 and 54 (Sections 3.3 and 3.5, Annexes 3 and 6)
• Harmonization with FMVSS 139 requirements relative to UN Regulation No. 54 “PSI” index (Sections 3.7 and 3.8)
• Addition of new harmonized provisions for physical dimensions of LT/C tyres (new Section 3.5.2; old Sections 3.20 & 3.21 deleted)
• Addition of new harmonized provisions for high speed test for LT/C tyres (new Section 3.6.2.2, old Section 3.16 modified with endurance test only and renumbered 3.9, old Section 3.19 deleted)